3537 lines
117 KiB
Lua
3537 lines
117 KiB
Lua
--[[--
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LibDeflate 1.0.2-release <br>
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Pure Lua compressor and decompressor with high compression ratio using
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DEFLATE/zlib format.
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@file LibDeflate.lua
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@author Haoqian He (Github: SafeteeWoW; World of Warcraft: Safetyy-Illidan(US))
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@copyright LibDeflate <2018-2020> Haoqian He
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@license zlib License
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This library is implemented according to the following specifications. <br>
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Report a bug if LibDeflate is not fully compliant with those specs. <br>
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Both compressors and decompressors have been implemented in the library.<br>
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1. RFC1950: DEFLATE Compressed Data Format Specification version 1.3 <br>
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https://tools.ietf.org/html/rfc1951 <br>
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2. RFC1951: ZLIB Compressed Data Format Specification version 3.3 <br>
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https://tools.ietf.org/html/rfc1950 <br>
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This library requires Lua 5.1/5.2/5.3/5.4 interpreter or LuaJIT v2.0+. <br>
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This library does not have any dependencies. <br>
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Note at the time of this release, Lua 5.4 final is not released yet. <br>
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For Lua 5.4, This library is tested with its rc6 version. <br>
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<br>
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This file "LibDeflate.lua" is the only source file of
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the library. <br>
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Submit suggestions or report bugs to
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https://github.com/safeteeWow/LibDeflate/issues
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]]
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--[[
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zlib License
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(C) 2018-2020 Haoqian He
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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Credits and Disclaimer:
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The following projects are used to the help to test the correctness
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of this program. The code of this program (LibDeflate.lua) does not
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use their code directly, but uses their ideas and algorithms. Their original
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licenses shall be comply when used.
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1. zlib, by Jean-loup Gailly (compression) and Mark Adler (decompression).
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http://www.zlib.net/
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Licensed under zlib License. http://www.zlib.net/zlib_license.html
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For the compression algorithm.
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2. puff, by Mark Adler. https://github.com/madler/zlib/tree/master/contrib/puff
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Licensed under zlib License. http://www.zlib.net/zlib_license.html
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For the decompression algorithm.
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3. LibCompress, by jjsheets and Galmok of European Stormrage (Horde)
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https://www.wowace.com/projects/libcompress
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Licensed under GPLv2.
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https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
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For the code to create customized codec.
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4. WeakAuras2,
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https://github.com/WeakAuras/WeakAuras2
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Licensed under GPLv2.
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For the 6bit encoding and decoding.
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]]
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--[[
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Curseforge auto-packaging replacements:
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Project Date: 2020-06-26T15:11:26Z
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Project Hash: c19f978f053ebd22950eb6f1df4445677a4b0160
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Project Version: 1.0.2-release
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--]]
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local LibDeflate
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do
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-- Semantic version. all lowercase.
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-- Suffix can be alpha1, alpha2, beta1, beta2, rc1, rc2, etc.
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-- NOTE: Two version numbers needs to modify.
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-- 1. On the top of LibDeflate.lua
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-- 2. _VERSION
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-- 3. _MINOR
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-- version to store the official version of LibDeflate
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local _VERSION = "1.0.2-release"
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-- When MAJOR is changed, I should name it as LibDeflate2
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local _MAJOR = "LibDeflate"
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-- Update this whenever a new version, for LibStub version registration.
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-- 0 : v0.x
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-- 1 : v1.0.0
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-- 2 : v1.0.1
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-- 3 : v1.0.2
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local _MINOR = 3
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local _COPYRIGHT =
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"LibDeflate ".._VERSION
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.." Copyright (C) 2018-2020 Haoqian He."
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.." Licensed under the zlib License"
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-- Register in the World of Warcraft library "LibStub" if detected.
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if LibStub then
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local lib, minor = LibStub:GetLibrary(_MAJOR, true)
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if lib and minor and minor >= _MINOR then -- No need to update.
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return lib
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else -- Update or first time register
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LibDeflate = LibStub:NewLibrary(_MAJOR, _MINOR)
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-- NOTE: It is important that new version has implemented
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-- all exported APIs and tables in the old version,
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-- so the old library is fully garbage collected,
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-- and we 100% ensure the backward compatibility.
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end
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else -- "LibStub" is not detected.
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LibDeflate = {}
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end
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LibDeflate._VERSION = _VERSION
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LibDeflate._MAJOR = _MAJOR
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LibDeflate._MINOR = _MINOR
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LibDeflate._COPYRIGHT = _COPYRIGHT
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end
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-- localize Lua api for faster access.
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local assert = assert
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local error = error
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local pairs = pairs
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local string_byte = string.byte
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local string_char = string.char
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local string_find = string.find
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local string_gsub = string.gsub
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local string_sub = string.sub
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local table_concat = table.concat
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local table_sort = table.sort
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local tostring = tostring
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local type = type
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-- Converts i to 2^i, (0<=i<=32)
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-- This is used to implement bit left shift and bit right shift.
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-- "x >> y" in C: "(x-x%_pow2[y])/_pow2[y]" in Lua
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-- "x << y" in C: "x*_pow2[y]" in Lua
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local _pow2 = {}
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-- Converts any byte to a character, (0<=byte<=255)
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local _byte_to_char = {}
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-- _reverseBitsTbl[len][val] stores the bit reverse of
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-- the number with bit length "len" and value "val"
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-- For example, decimal number 6 with bits length 5 is binary 00110
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-- It's reverse is binary 01100,
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-- which is decimal 12 and 12 == _reverseBitsTbl[5][6]
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-- 1<=len<=9, 0<=val<=2^len-1
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-- The reason for 1<=len<=9 is that the max of min bitlen of huffman code
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-- of a huffman alphabet is 9?
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local _reverse_bits_tbl = {}
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-- Convert a LZ77 length (3<=len<=258) to
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-- a deflate literal/LZ77_length code (257<=code<=285)
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local _length_to_deflate_code = {}
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-- convert a LZ77 length (3<=len<=258) to
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-- a deflate literal/LZ77_length code extra bits.
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local _length_to_deflate_extra_bits = {}
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-- Convert a LZ77 length (3<=len<=258) to
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-- a deflate literal/LZ77_length code extra bit length.
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local _length_to_deflate_extra_bitlen = {}
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-- Convert a small LZ77 distance (1<=dist<=256) to a deflate code.
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local _dist256_to_deflate_code = {}
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-- Convert a small LZ77 distance (1<=dist<=256) to
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-- a deflate distance code extra bits.
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local _dist256_to_deflate_extra_bits = {}
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-- Convert a small LZ77 distance (1<=dist<=256) to
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-- a deflate distance code extra bit length.
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local _dist256_to_deflate_extra_bitlen = {}
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-- Convert a literal/LZ77_length deflate code to LZ77 base length
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-- The key of the table is (code - 256), 257<=code<=285
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local _literal_deflate_code_to_base_len = {
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3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
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35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258,
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}
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-- Convert a literal/LZ77_length deflate code to base LZ77 length extra bits
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-- The key of the table is (code - 256), 257<=code<=285
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local _literal_deflate_code_to_extra_bitlen = {
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0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
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3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0,
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}
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-- Convert a distance deflate code to base LZ77 distance. (0<=code<=29)
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local _dist_deflate_code_to_base_dist = {
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[0] = 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
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257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
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8193, 12289, 16385, 24577,
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}
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-- Convert a distance deflate code to LZ77 bits length. (0<=code<=29)
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local _dist_deflate_code_to_extra_bitlen = {
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[0] = 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
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7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13,
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}
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-- The code order of the first huffman header in the dynamic deflate block.
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-- See the page 12 of RFC1951
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local _rle_codes_huffman_bitlen_order = {16, 17, 18,
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0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15,
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}
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-- The following tables are used by fixed deflate block.
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-- The value of these tables are assigned at the bottom of the source.
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-- The huffman code of the literal/LZ77_length deflate codes,
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-- in fixed deflate block.
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local _fix_block_literal_huffman_code
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-- Convert huffman code of the literal/LZ77_length to deflate codes,
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-- in fixed deflate block.
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local _fix_block_literal_huffman_to_deflate_code
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-- The bit length of the huffman code of literal/LZ77_length deflate codes,
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-- in fixed deflate block.
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local _fix_block_literal_huffman_bitlen
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-- The count of each bit length of the literal/LZ77_length deflate codes,
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-- in fixed deflate block.
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local _fix_block_literal_huffman_bitlen_count
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-- The huffman code of the distance deflate codes,
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-- in fixed deflate block.
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local _fix_block_dist_huffman_code
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-- Convert huffman code of the distance to deflate codes,
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-- in fixed deflate block.
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local _fix_block_dist_huffman_to_deflate_code
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-- The bit length of the huffman code of the distance deflate codes,
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-- in fixed deflate block.
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local _fix_block_dist_huffman_bitlen
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-- The count of each bit length of the huffman code of
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-- the distance deflate codes,
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-- in fixed deflate block.
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local _fix_block_dist_huffman_bitlen_count
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for i = 0, 255 do
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_byte_to_char[i] = string_char(i)
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end
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do
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local pow = 1
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for i = 0, 32 do
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_pow2[i] = pow
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pow = pow * 2
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end
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end
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for i = 1, 9 do
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_reverse_bits_tbl[i] = {}
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for j=0, _pow2[i+1]-1 do
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local reverse = 0
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local value = j
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for _ = 1, i do
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-- The following line is equivalent to "res | (code %2)" in C.
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reverse = reverse - reverse%2
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+ (((reverse%2==1) or (value % 2) == 1) and 1 or 0)
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value = (value-value%2)/2
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reverse = reverse * 2
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end
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_reverse_bits_tbl[i][j] = (reverse-reverse%2)/2
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end
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end
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-- The source code is written according to the pattern in the numbers
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-- in RFC1951 Page10.
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do
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local a = 18
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local b = 16
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local c = 265
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local bitlen = 1
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for len = 3, 258 do
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if len <= 10 then
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_length_to_deflate_code[len] = len + 254
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_length_to_deflate_extra_bitlen[len] = 0
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elseif len == 258 then
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_length_to_deflate_code[len] = 285
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_length_to_deflate_extra_bitlen[len] = 0
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else
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if len > a then
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a = a + b
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b = b * 2
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c = c + 4
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bitlen = bitlen + 1
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end
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local t = len-a-1+b/2
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_length_to_deflate_code[len] = (t-(t%(b/8)))/(b/8) + c
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_length_to_deflate_extra_bitlen[len] = bitlen
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_length_to_deflate_extra_bits[len] = t % (b/8)
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end
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end
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end
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-- The source code is written according to the pattern in the numbers
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-- in RFC1951 Page11.
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do
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_dist256_to_deflate_code[1] = 0
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_dist256_to_deflate_code[2] = 1
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_dist256_to_deflate_extra_bitlen[1] = 0
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_dist256_to_deflate_extra_bitlen[2] = 0
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local a = 3
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local b = 4
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local code = 2
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local bitlen = 0
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for dist = 3, 256 do
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if dist > b then
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a = a * 2
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b = b * 2
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code = code + 2
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bitlen = bitlen + 1
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end
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_dist256_to_deflate_code[dist] = (dist <= a) and code or (code+1)
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_dist256_to_deflate_extra_bitlen[dist] = (bitlen < 0) and 0 or bitlen
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if b >= 8 then
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_dist256_to_deflate_extra_bits[dist] = (dist-b/2-1) % (b/4)
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end
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end
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end
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--- Calculate the Adler-32 checksum of the string. <br>
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-- See RFC1950 Page 9 https://tools.ietf.org/html/rfc1950 for the
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-- definition of Adler-32 checksum.
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-- @param str [string] the input string to calcuate its Adler-32 checksum.
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-- @return [integer] The Adler-32 checksum, which is greater or equal to 0,
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-- and less than 2^32 (4294967296).
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function LibDeflate:Adler32(str)
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-- This function is loop unrolled by better performance.
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--
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-- Here is the minimum code:
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--
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-- local a = 1
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-- local b = 0
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-- for i=1, #str do
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-- local s = string.byte(str, i, i)
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-- a = (a+s)%65521
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-- b = (b+a)%65521
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-- end
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-- return b*65536+a
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if type(str) ~= "string" then
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error(("Usage: LibDeflate:Adler32(str):"
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.." 'str' - string expected got '%s'."):format(type(str)), 2)
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end
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local strlen = #str
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local i = 1
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local a = 1
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local b = 0
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while i <= strlen - 15 do
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local x1, x2, x3, x4, x5, x6, x7, x8,
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x9, x10, x11, x12, x13, x14, x15, x16 = string_byte(str, i, i+15)
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b = (b+16*a+16*x1+15*x2+14*x3+13*x4+12*x5+11*x6+10*x7+9*x8+8*x9
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+7*x10+6*x11+5*x12+4*x13+3*x14+2*x15+x16)%65521
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a = (a+x1+x2+x3+x4+x5+x6+x7+x8+x9+x10+x11+x12+x13+x14+x15+x16)%65521
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i = i + 16
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end
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while (i <= strlen) do
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local x = string_byte(str, i, i)
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a = (a + x) % 65521
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b = (b + a) % 65521
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i = i + 1
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end
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return (b*65536+a) % 4294967296
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end
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-- Compare adler32 checksum.
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-- adler32 should be compared with a mod to avoid sign problem
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-- 4072834167 (unsigned) is the same adler32 as -222133129
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local function IsEqualAdler32(actual, expected)
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return (actual % 4294967296) == (expected % 4294967296)
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end
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--- Create a preset dictionary.
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--
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-- This function is not fast, and the memory consumption of the produced
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-- dictionary is about 50 times of the input string. Therefore, it is suggestted
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-- to run this function only once in your program.
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--
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-- It is very important to know that if you do use a preset dictionary,
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-- compressors and decompressors MUST USE THE SAME dictionary. That is,
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-- dictionary must be created using the same string. If you update your program
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-- with a new dictionary, people with the old version won't be able to transmit
|
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-- data with people with the new version. Therefore, changing the dictionary
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-- must be very careful.
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--
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-- The parameters "strlen" and "adler32" add a layer of verification to ensure
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-- the parameter "str" is not modified unintentionally during the program
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-- development.
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--
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-- @usage local dict_str = "1234567890"
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--
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-- -- print(dict_str:len(), LibDeflate:Adler32(dict_str))
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-- -- Hardcode the print result below to verify it to avoid acciently
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-- -- modification of 'str' during the program development.
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-- -- string length: 10, Adler-32: 187433486,
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-- -- Don't calculate string length and its Adler-32 at run-time.
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--
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-- local dict = LibDeflate:CreateDictionary(dict_str, 10, 187433486)
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--
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-- @param str [string] The string used as the preset dictionary. <br>
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-- You should put stuffs that frequently appears in the dictionary
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-- string and preferablely put more frequently appeared stuffs toward the end
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-- of the string. <br>
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-- Empty string and string longer than 32768 bytes are not allowed.
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-- @param strlen [integer] The length of 'str'. Please pass in this parameter
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|
-- as a hardcoded constant, in order to verify the content of 'str'. The value
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|
-- of this parameter should be known before your program runs.
|
|
-- @param adler32 [integer] The Adler-32 checksum of 'str'. Please pass in this
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|
-- parameter as a hardcoded constant, in order to verify the content of 'str'.
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-- The value of this parameter should be known before your program runs.
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-- @return [table] The dictionary used for preset dictionary compression and
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-- decompression.
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-- @raise error if 'strlen' does not match the length of 'str',
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-- or if 'adler32' does not match the Adler-32 checksum of 'str'.
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function LibDeflate:CreateDictionary(str, strlen, adler32)
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if type(str) ~= "string" then
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error(("Usage: LibDeflate:CreateDictionary(str, strlen, adler32):"
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.." 'str' - string expected got '%s'."):format(type(str)), 2)
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end
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if type(strlen) ~= "number" then
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error(("Usage: LibDeflate:CreateDictionary(str, strlen, adler32):"
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.." 'strlen' - number expected got '%s'."):format(
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type(strlen)), 2)
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end
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|
if type(adler32) ~= "number" then
|
|
error(("Usage: LibDeflate:CreateDictionary(str, strlen, adler32):"
|
|
.." 'adler32' - number expected got '%s'."):format(
|
|
type(adler32)), 2)
|
|
end
|
|
if strlen ~= #str then
|
|
error(("Usage: LibDeflate:CreateDictionary(str, strlen, adler32):"
|
|
.." 'strlen' does not match the actual length of 'str'."
|
|
.." 'strlen': %u, '#str': %u ."
|
|
.." Please check if 'str' is modified unintentionally.")
|
|
:format(strlen, #str))
|
|
end
|
|
if strlen == 0 then
|
|
error(("Usage: LibDeflate:CreateDictionary(str, strlen, adler32):"
|
|
.." 'str' - Empty string is not allowed."), 2)
|
|
end
|
|
if strlen > 32768 then
|
|
error(("Usage: LibDeflate:CreateDictionary(str, strlen, adler32):"
|
|
.." 'str' - string longer than 32768 bytes is not allowed."
|
|
.." Got %d bytes."):format(strlen), 2)
|
|
end
|
|
local actual_adler32 = self:Adler32(str)
|
|
if not IsEqualAdler32(adler32, actual_adler32) then
|
|
error(("Usage: LibDeflate:CreateDictionary(str, strlen, adler32):"
|
|
.." 'adler32' does not match the actual adler32 of 'str'."
|
|
.." 'adler32': %u, 'Adler32(str)': %u ."
|
|
.." Please check if 'str' is modified unintentionally.")
|
|
:format(adler32, actual_adler32))
|
|
end
|
|
|
|
local dictionary = {}
|
|
dictionary.adler32 = adler32
|
|
dictionary.hash_tables = {}
|
|
dictionary.string_table = {}
|
|
dictionary.strlen = strlen
|
|
local string_table = dictionary.string_table
|
|
local hash_tables = dictionary.hash_tables
|
|
string_table[1] = string_byte(str, 1, 1)
|
|
string_table[2] = string_byte(str, 2, 2)
|
|
if strlen >= 3 then
|
|
local i = 1
|
|
local hash = string_table[1]*256+string_table[2]
|
|
while i <= strlen - 2 - 3 do
|
|
local x1, x2, x3, x4 = string_byte(str, i+2, i+5)
|
|
string_table[i+2] = x1
|
|
string_table[i+3] = x2
|
|
string_table[i+4] = x3
|
|
string_table[i+5] = x4
|
|
hash = (hash*256+x1)%16777216
|
|
local t = hash_tables[hash]
|
|
if not t then t = {}; hash_tables[hash] = t end
|
|
t[#t+1] = i-strlen
|
|
i = i + 1
|
|
hash = (hash*256+x2)%16777216
|
|
t = hash_tables[hash]
|
|
if not t then t = {}; hash_tables[hash] = t end
|
|
t[#t+1] = i-strlen
|
|
i = i + 1
|
|
hash = (hash*256+x3)%16777216
|
|
t = hash_tables[hash]
|
|
if not t then t = {}; hash_tables[hash] = t end
|
|
t[#t+1] = i-strlen
|
|
i = i + 1
|
|
hash = (hash*256+x4)%16777216
|
|
t = hash_tables[hash]
|
|
if not t then t = {}; hash_tables[hash] = t end
|
|
t[#t+1] = i-strlen
|
|
i = i + 1
|
|
end
|
|
while i <= strlen - 2 do
|
|
local x = string_byte(str, i+2)
|
|
string_table[i+2] = x
|
|
hash = (hash*256+x)%16777216
|
|
local t = hash_tables[hash]
|
|
if not t then t = {}; hash_tables[hash] = t end
|
|
t[#t+1] = i-strlen
|
|
i = i + 1
|
|
end
|
|
end
|
|
return dictionary
|
|
end
|
|
|
|
-- Check if the dictionary is valid.
|
|
-- @param dictionary The preset dictionary for compression and decompression.
|
|
-- @return true if valid, false if not valid.
|
|
-- @return if not valid, the error message.
|
|
local function IsValidDictionary(dictionary)
|
|
if type(dictionary) ~= "table" then
|
|
return false, ("'dictionary' - table expected got '%s'.")
|
|
:format(type(dictionary))
|
|
end
|
|
if type(dictionary.adler32) ~= "number"
|
|
or type(dictionary.string_table) ~= "table"
|
|
or type(dictionary.strlen) ~= "number"
|
|
or dictionary.strlen <= 0
|
|
or dictionary.strlen > 32768
|
|
or dictionary.strlen ~= #dictionary.string_table
|
|
or type(dictionary.hash_tables) ~= "table"
|
|
then
|
|
return false, ("'dictionary' - corrupted dictionary.")
|
|
:format(type(dictionary))
|
|
end
|
|
return true, ""
|
|
end
|
|
|
|
--[[
|
|
key of the configuration table is the compression level,
|
|
and its value stores the compression setting.
|
|
These numbers come from zlib source code.
|
|
|
|
Higher compression level usually means better compression.
|
|
(Because LibDeflate uses a simplified version of zlib algorithm,
|
|
there is no guarantee that higher compression level does not create
|
|
bigger file than lower level, but I can say it's 99% likely)
|
|
|
|
Be careful with the high compression level. This is a pure lua
|
|
implementation compressor/decompressor, which is significant slower than
|
|
a C/C++ equivalant compressor/decompressor. Very high compression level
|
|
costs significant more CPU time, and usually compression size won't be
|
|
significant smaller when you increase compression level by 1, when the
|
|
level is already very high. Benchmark yourself if you can afford it.
|
|
|
|
See also https://github.com/madler/zlib/blob/master/doc/algorithm.txt,
|
|
https://github.com/madler/zlib/blob/master/deflate.c for more information.
|
|
|
|
The meaning of each field:
|
|
@field 1 use_lazy_evaluation:
|
|
true/false. Whether the program uses lazy evaluation.
|
|
See what is "lazy evaluation" in the link above.
|
|
lazy_evaluation improves ratio, but relatively slow.
|
|
@field 2 good_prev_length:
|
|
Only effective if lazy is set, Only use 1/4 of max_chain,
|
|
if prev length of lazy match is above this.
|
|
@field 3 max_insert_length/max_lazy_match:
|
|
If not using lazy evaluation,
|
|
insert new strings in the hash table only if the match length is not
|
|
greater than this length.
|
|
If using lazy evaluation, only continue lazy evaluation,
|
|
if previous match length is strictly smaller than this value.
|
|
@field 4 nice_length:
|
|
Number. Don't continue to go down the hash chain,
|
|
if match length is above this.
|
|
@field 5 max_chain:
|
|
Number. The maximum number of hash chains we look.
|
|
--]]
|
|
local _compression_level_configs = {
|
|
[0] = {false, nil, 0, 0, 0}, -- level 0, no compression
|
|
[1] = {false, nil, 4, 8, 4}, -- level 1, similar to zlib level 1
|
|
[2] = {false, nil, 5, 18, 8}, -- level 2, similar to zlib level 2
|
|
[3] = {false, nil, 6, 32, 32}, -- level 3, similar to zlib level 3
|
|
[4] = {true, 4, 4, 16, 16}, -- level 4, similar to zlib level 4
|
|
[5] = {true, 8, 16, 32, 32}, -- level 5, similar to zlib level 5
|
|
[6] = {true, 8, 16, 128, 128}, -- level 6, similar to zlib level 6
|
|
[7] = {true, 8, 32, 128, 256}, -- (SLOW) level 7, similar to zlib level 7
|
|
[8] = {true, 32, 128, 258, 1024} , --(SLOW) level 8,similar to zlib level 8
|
|
[9] = {true, 32, 258, 258, 4096},
|
|
-- (VERY SLOW) level 9, similar to zlib level 9
|
|
}
|
|
|
|
-- Check if the compression/decompression arguments is valid
|
|
-- @param str The input string.
|
|
-- @param check_dictionary if true, check if dictionary is valid.
|
|
-- @param dictionary The preset dictionary for compression and decompression.
|
|
-- @param check_configs if true, check if config is valid.
|
|
-- @param configs The compression configuration table
|
|
-- @return true if valid, false if not valid.
|
|
-- @return if not valid, the error message.
|
|
local function IsValidArguments(str,
|
|
check_dictionary, dictionary,
|
|
check_configs, configs)
|
|
|
|
if type(str) ~= "string" then
|
|
return false,
|
|
("'str' - string expected got '%s'."):format(type(str))
|
|
end
|
|
if check_dictionary then
|
|
local dict_valid, dict_err = IsValidDictionary(dictionary)
|
|
if not dict_valid then
|
|
return false, dict_err
|
|
end
|
|
end
|
|
if check_configs then
|
|
local type_configs = type(configs)
|
|
if type_configs ~= "nil" and type_configs ~= "table" then
|
|
return false,
|
|
("'configs' - nil or table expected got '%s'.")
|
|
:format(type(configs))
|
|
end
|
|
if type_configs == "table" then
|
|
for k, v in pairs(configs) do
|
|
if k ~= "level" and k ~= "strategy" then
|
|
return false,
|
|
("'configs' - unsupported table key in the configs: '%s'.")
|
|
:format(k)
|
|
elseif k == "level" and not _compression_level_configs[v] then
|
|
return false,
|
|
("'configs' - unsupported 'level': %s."):format(tostring(v))
|
|
elseif k == "strategy" and v ~= "fixed" and v ~= "huffman_only"
|
|
and v ~= "dynamic" then
|
|
-- random_block_type is for testing purpose
|
|
return false, ("'configs' - unsupported 'strategy': '%s'.")
|
|
:format(tostring(v))
|
|
end
|
|
end
|
|
end
|
|
end
|
|
return true, ""
|
|
end
|
|
|
|
|
|
|
|
--[[ --------------------------------------------------------------------------
|
|
Compress code
|
|
--]] --------------------------------------------------------------------------
|
|
|
|
-- partial flush to save memory
|
|
local _FLUSH_MODE_MEMORY_CLEANUP = 0
|
|
-- full flush with partial bytes
|
|
local _FLUSH_MODE_OUTPUT = 1
|
|
-- write bytes to get to byte boundary
|
|
local _FLUSH_MODE_BYTE_BOUNDARY = 2
|
|
-- no flush, just get num of bits written so far
|
|
local _FLUSH_MODE_NO_FLUSH = 3
|
|
|
|
--[[
|
|
Create an empty writer to easily write stuffs as the unit of bits.
|
|
Return values:
|
|
1. WriteBits(code, bitlen):
|
|
2. WriteString(str):
|
|
3. Flush(mode):
|
|
--]]
|
|
local function CreateWriter()
|
|
local buffer_size = 0
|
|
local cache = 0
|
|
local cache_bitlen = 0
|
|
local total_bitlen = 0
|
|
local buffer = {}
|
|
-- When buffer is big enough, flush into result_buffer to save memory.
|
|
local result_buffer = {}
|
|
|
|
-- Write bits with value "value" and bit length of "bitlen" into writer.
|
|
-- @param value: The value being written
|
|
-- @param bitlen: The bit length of "value"
|
|
-- @return nil
|
|
local function WriteBits(value, bitlen)
|
|
cache = cache + value * _pow2[cache_bitlen]
|
|
cache_bitlen = cache_bitlen + bitlen
|
|
total_bitlen = total_bitlen + bitlen
|
|
-- Only bulk to buffer every 4 bytes. This is quicker.
|
|
if cache_bitlen >= 32 then
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] =
|
|
_byte_to_char[cache % 256]
|
|
.._byte_to_char[((cache-cache%256)/256 % 256)]
|
|
.._byte_to_char[((cache-cache%65536)/65536 % 256)]
|
|
.._byte_to_char[((cache-cache%16777216)/16777216 % 256)]
|
|
local rshift_mask = _pow2[32 - cache_bitlen + bitlen]
|
|
cache = (value - value%rshift_mask)/rshift_mask
|
|
cache_bitlen = cache_bitlen - 32
|
|
end
|
|
end
|
|
|
|
-- Write the entire string into the writer.
|
|
-- @param str The string being written
|
|
-- @return nil
|
|
local function WriteString(str)
|
|
for _ = 1, cache_bitlen, 8 do
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] = string_char(cache % 256)
|
|
cache = (cache-cache%256)/256
|
|
end
|
|
cache_bitlen = 0
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] = str
|
|
total_bitlen = total_bitlen + #str*8
|
|
end
|
|
|
|
-- Flush current stuffs in the writer and return it.
|
|
-- This operation will free most of the memory.
|
|
-- @param mode See the descrtion of the constant and the source code.
|
|
-- @return The total number of bits stored in the writer right now.
|
|
-- for byte boundary mode, it includes the padding bits.
|
|
-- for output mode, it does not include padding bits.
|
|
-- @return Return the outputs if mode is output.
|
|
local function FlushWriter(mode)
|
|
if mode == _FLUSH_MODE_NO_FLUSH then
|
|
return total_bitlen
|
|
end
|
|
|
|
if mode == _FLUSH_MODE_OUTPUT
|
|
or mode == _FLUSH_MODE_BYTE_BOUNDARY then
|
|
-- Full flush, also output cache.
|
|
-- Need to pad some bits if cache_bitlen is not multiple of 8.
|
|
local padding_bitlen = (8 - cache_bitlen % 8) % 8
|
|
|
|
if cache_bitlen > 0 then
|
|
-- padding with all 1 bits, mainly because "\000" is not
|
|
-- good to be tranmitted. I do this so "\000" is a little bit
|
|
-- less frequent.
|
|
cache = cache - _pow2[cache_bitlen]
|
|
+ _pow2[cache_bitlen+padding_bitlen]
|
|
for _ = 1, cache_bitlen, 8 do
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] = _byte_to_char[cache % 256]
|
|
cache = (cache-cache%256)/256
|
|
end
|
|
|
|
cache = 0
|
|
cache_bitlen = 0
|
|
end
|
|
if mode == _FLUSH_MODE_BYTE_BOUNDARY then
|
|
total_bitlen = total_bitlen + padding_bitlen
|
|
return total_bitlen
|
|
end
|
|
end
|
|
|
|
local flushed = table_concat(buffer)
|
|
buffer = {}
|
|
buffer_size = 0
|
|
result_buffer[#result_buffer+1] = flushed
|
|
|
|
if mode == _FLUSH_MODE_MEMORY_CLEANUP then
|
|
return total_bitlen
|
|
else
|
|
return total_bitlen, table_concat(result_buffer)
|
|
end
|
|
end
|
|
|
|
return WriteBits, WriteString, FlushWriter
|
|
end
|
|
|
|
-- Push an element into a max heap
|
|
-- @param heap A max heap whose max element is at index 1.
|
|
-- @param e The element to be pushed. Assume element "e" is a table
|
|
-- and comparison is done via its first entry e[1]
|
|
-- @param heap_size current number of elements in the heap.
|
|
-- NOTE: There may be some garbage stored in
|
|
-- heap[heap_size+1], heap[heap_size+2], etc..
|
|
-- @return nil
|
|
local function MinHeapPush(heap, e, heap_size)
|
|
heap_size = heap_size + 1
|
|
heap[heap_size] = e
|
|
local value = e[1]
|
|
local pos = heap_size
|
|
local parent_pos = (pos-pos%2)/2
|
|
|
|
while (parent_pos >= 1 and heap[parent_pos][1] > value) do
|
|
local t = heap[parent_pos]
|
|
heap[parent_pos] = e
|
|
heap[pos] = t
|
|
pos = parent_pos
|
|
parent_pos = (parent_pos-parent_pos%2)/2
|
|
end
|
|
end
|
|
|
|
-- Pop an element from a max heap
|
|
-- @param heap A max heap whose max element is at index 1.
|
|
-- @param heap_size current number of elements in the heap.
|
|
-- @return the poped element
|
|
-- Note: This function does not change table size of "heap" to save CPU time.
|
|
local function MinHeapPop(heap, heap_size)
|
|
local top = heap[1]
|
|
local e = heap[heap_size]
|
|
local value = e[1]
|
|
heap[1] = e
|
|
heap[heap_size] = top
|
|
heap_size = heap_size - 1
|
|
|
|
local pos = 1
|
|
local left_child_pos = pos * 2
|
|
local right_child_pos = left_child_pos + 1
|
|
|
|
while (left_child_pos <= heap_size) do
|
|
local left_child = heap[left_child_pos]
|
|
if (right_child_pos <= heap_size
|
|
and heap[right_child_pos][1] < left_child[1]) then
|
|
local right_child = heap[right_child_pos]
|
|
if right_child[1] < value then
|
|
heap[right_child_pos] = e
|
|
heap[pos] = right_child
|
|
pos = right_child_pos
|
|
left_child_pos = pos * 2
|
|
right_child_pos = left_child_pos + 1
|
|
else
|
|
break
|
|
end
|
|
else
|
|
if left_child[1] < value then
|
|
heap[left_child_pos] = e
|
|
heap[pos] = left_child
|
|
pos = left_child_pos
|
|
left_child_pos = pos * 2
|
|
right_child_pos = left_child_pos + 1
|
|
else
|
|
break
|
|
end
|
|
end
|
|
end
|
|
|
|
return top
|
|
end
|
|
|
|
-- Deflate defines a special huffman tree, which is unique once the bit length
|
|
-- of huffman code of all symbols are known.
|
|
-- @param bitlen_count Number of symbols with a specific bitlen
|
|
-- @param symbol_bitlen The bit length of a symbol
|
|
-- @param max_symbol The max symbol among all symbols,
|
|
-- which is (number of symbols - 1)
|
|
-- @param max_bitlen The max huffman bit length among all symbols.
|
|
-- @return The huffman code of all symbols.
|
|
local function GetHuffmanCodeFromBitlen(bitlen_counts, symbol_bitlens
|
|
, max_symbol, max_bitlen)
|
|
local huffman_code = 0
|
|
local next_codes = {}
|
|
local symbol_huffman_codes = {}
|
|
for bitlen = 1, max_bitlen do
|
|
huffman_code = (huffman_code+(bitlen_counts[bitlen-1] or 0))*2
|
|
next_codes[bitlen] = huffman_code
|
|
end
|
|
for symbol = 0, max_symbol do
|
|
local bitlen = symbol_bitlens[symbol]
|
|
if bitlen then
|
|
huffman_code = next_codes[bitlen]
|
|
next_codes[bitlen] = huffman_code + 1
|
|
|
|
-- Reverse the bits of huffman code,
|
|
-- because most signifant bits of huffman code
|
|
-- is stored first into the compressed data.
|
|
-- @see RFC1951 Page5 Section 3.1.1
|
|
if bitlen <= 9 then -- Have cached reverse for small bitlen.
|
|
symbol_huffman_codes[symbol] =
|
|
_reverse_bits_tbl[bitlen][huffman_code]
|
|
else
|
|
local reverse = 0
|
|
for _ = 1, bitlen do
|
|
reverse = reverse - reverse%2
|
|
+ (((reverse%2==1)
|
|
or (huffman_code % 2) == 1) and 1 or 0)
|
|
huffman_code = (huffman_code-huffman_code%2)/2
|
|
reverse = reverse*2
|
|
end
|
|
symbol_huffman_codes[symbol] = (reverse-reverse%2)/2
|
|
end
|
|
end
|
|
end
|
|
return symbol_huffman_codes
|
|
end
|
|
|
|
-- A helper function to sort heap elements
|
|
-- a[1], b[1] is the huffman frequency
|
|
-- a[2], b[2] is the symbol value.
|
|
local function SortByFirstThenSecond(a, b)
|
|
return a[1] < b[1] or
|
|
(a[1] == b[1] and a[2] < b[2])
|
|
end
|
|
|
|
-- Calculate the huffman bit length and huffman code.
|
|
-- @param symbol_count: A table whose table key is the symbol, and table value
|
|
-- is the symbol frenquency (nil means 0 frequency).
|
|
-- @param max_bitlen: See description of return value.
|
|
-- @param max_symbol: The maximum symbol
|
|
-- @return a table whose key is the symbol, and the value is the huffman bit
|
|
-- bit length. We guarantee that all bit length <= max_bitlen.
|
|
-- For 0<=symbol<=max_symbol, table value could be nil if the frequency
|
|
-- of the symbol is 0 or nil.
|
|
-- @return a table whose key is the symbol, and the value is the huffman code.
|
|
-- @return a number indicating the maximum symbol whose bitlen is not 0.
|
|
local function GetHuffmanBitlenAndCode(symbol_counts, max_bitlen, max_symbol)
|
|
local heap_size
|
|
local max_non_zero_bitlen_symbol = -1
|
|
local leafs = {}
|
|
local heap = {}
|
|
local symbol_bitlens = {}
|
|
local symbol_codes = {}
|
|
local bitlen_counts = {}
|
|
|
|
--[[
|
|
tree[1]: weight, temporarily used as parent and bitLengths
|
|
tree[2]: symbol
|
|
tree[3]: left child
|
|
tree[4]: right child
|
|
--]]
|
|
local number_unique_symbols = 0
|
|
for symbol, count in pairs(symbol_counts) do
|
|
number_unique_symbols = number_unique_symbols + 1
|
|
leafs[number_unique_symbols] = {count, symbol}
|
|
end
|
|
|
|
if (number_unique_symbols == 0) then
|
|
-- no code.
|
|
return {}, {}, -1
|
|
elseif (number_unique_symbols == 1) then
|
|
-- Only one code. In this case, its huffman code
|
|
-- needs to be assigned as 0, and bit length is 1.
|
|
-- This is the only case that the return result
|
|
-- represents an imcomplete huffman tree.
|
|
local symbol = leafs[1][2]
|
|
symbol_bitlens[symbol] = 1
|
|
symbol_codes[symbol] = 0
|
|
return symbol_bitlens, symbol_codes, symbol
|
|
else
|
|
table_sort(leafs, SortByFirstThenSecond)
|
|
heap_size = number_unique_symbols
|
|
for i = 1, heap_size do
|
|
heap[i] = leafs[i]
|
|
end
|
|
|
|
while (heap_size > 1) do
|
|
-- Note: pop does not change table size of heap
|
|
local leftChild = MinHeapPop(heap, heap_size)
|
|
heap_size = heap_size - 1
|
|
local rightChild = MinHeapPop(heap, heap_size)
|
|
heap_size = heap_size - 1
|
|
local newNode =
|
|
{leftChild[1]+rightChild[1], -1, leftChild, rightChild}
|
|
MinHeapPush(heap, newNode, heap_size)
|
|
heap_size = heap_size + 1
|
|
end
|
|
|
|
-- Number of leafs whose bit length is greater than max_len.
|
|
local number_bitlen_overflow = 0
|
|
|
|
-- Calculate bit length of all nodes
|
|
local fifo = {heap[1], 0, 0, 0} -- preallocate some spaces.
|
|
local fifo_size = 1
|
|
local index = 1
|
|
heap[1][1] = 0
|
|
while (index <= fifo_size) do -- Breath first search
|
|
local e = fifo[index]
|
|
local bitlen = e[1]
|
|
local symbol = e[2]
|
|
local left_child = e[3]
|
|
local right_child = e[4]
|
|
if left_child then
|
|
fifo_size = fifo_size + 1
|
|
fifo[fifo_size] = left_child
|
|
left_child[1] = bitlen + 1
|
|
end
|
|
if right_child then
|
|
fifo_size = fifo_size + 1
|
|
fifo[fifo_size] = right_child
|
|
right_child[1] = bitlen + 1
|
|
end
|
|
index = index + 1
|
|
|
|
if (bitlen > max_bitlen) then
|
|
number_bitlen_overflow = number_bitlen_overflow + 1
|
|
bitlen = max_bitlen
|
|
end
|
|
if symbol >= 0 then
|
|
symbol_bitlens[symbol] = bitlen
|
|
max_non_zero_bitlen_symbol =
|
|
(symbol > max_non_zero_bitlen_symbol)
|
|
and symbol or max_non_zero_bitlen_symbol
|
|
bitlen_counts[bitlen] = (bitlen_counts[bitlen] or 0) + 1
|
|
end
|
|
end
|
|
|
|
-- Resolve bit length overflow
|
|
-- @see ZLib/trees.c:gen_bitlen(s, desc), for reference
|
|
if (number_bitlen_overflow > 0) then
|
|
repeat
|
|
local bitlen = max_bitlen - 1
|
|
while ((bitlen_counts[bitlen] or 0) == 0) do
|
|
bitlen = bitlen - 1
|
|
end
|
|
-- move one leaf down the tree
|
|
bitlen_counts[bitlen] = bitlen_counts[bitlen] - 1
|
|
-- move one overflow item as its brother
|
|
bitlen_counts[bitlen+1] = (bitlen_counts[bitlen+1] or 0) + 2
|
|
bitlen_counts[max_bitlen] = bitlen_counts[max_bitlen] - 1
|
|
number_bitlen_overflow = number_bitlen_overflow - 2
|
|
until (number_bitlen_overflow <= 0)
|
|
|
|
index = 1
|
|
for bitlen = max_bitlen, 1, -1 do
|
|
local n = bitlen_counts[bitlen] or 0
|
|
while (n > 0) do
|
|
local symbol = leafs[index][2]
|
|
symbol_bitlens[symbol] = bitlen
|
|
n = n - 1
|
|
index = index + 1
|
|
end
|
|
end
|
|
end
|
|
|
|
symbol_codes = GetHuffmanCodeFromBitlen(bitlen_counts, symbol_bitlens,
|
|
max_symbol, max_bitlen)
|
|
return symbol_bitlens, symbol_codes, max_non_zero_bitlen_symbol
|
|
end
|
|
end
|
|
|
|
-- Calculate the first huffman header in the dynamic huffman block
|
|
-- @see RFC1951 Page 12
|
|
-- @param lcode_bitlen: The huffman bit length of literal/LZ77_length.
|
|
-- @param max_non_zero_bitlen_lcode: The maximum literal/LZ77_length symbol
|
|
-- whose huffman bit length is not zero.
|
|
-- @param dcode_bitlen: The huffman bit length of LZ77 distance.
|
|
-- @param max_non_zero_bitlen_dcode: The maximum LZ77 distance symbol
|
|
-- whose huffman bit length is not zero.
|
|
-- @return The run length encoded codes.
|
|
-- @return The extra bits. One entry for each rle code that needs extra bits.
|
|
-- (code == 16 or 17 or 18).
|
|
-- @return The count of appearance of each rle codes.
|
|
local function RunLengthEncodeHuffmanBitlen(
|
|
lcode_bitlens,
|
|
max_non_zero_bitlen_lcode,
|
|
dcode_bitlens,
|
|
max_non_zero_bitlen_dcode)
|
|
local rle_code_tblsize = 0
|
|
local rle_codes = {}
|
|
local rle_code_counts = {}
|
|
local rle_extra_bits_tblsize = 0
|
|
local rle_extra_bits = {}
|
|
local prev = nil
|
|
local count = 0
|
|
|
|
-- If there is no distance code, assume one distance code of bit length 0.
|
|
-- RFC1951: One distance code of zero bits means that
|
|
-- there are no distance codes used at all (the data is all literals).
|
|
max_non_zero_bitlen_dcode = (max_non_zero_bitlen_dcode < 0)
|
|
and 0 or max_non_zero_bitlen_dcode
|
|
local max_code = max_non_zero_bitlen_lcode+max_non_zero_bitlen_dcode+1
|
|
|
|
for code = 0, max_code+1 do
|
|
local len = (code <= max_non_zero_bitlen_lcode)
|
|
and (lcode_bitlens[code] or 0)
|
|
or ((code <= max_code)
|
|
and (dcode_bitlens[code-max_non_zero_bitlen_lcode-1] or 0) or nil)
|
|
if len == prev then
|
|
count = count + 1
|
|
if len ~= 0 and count == 6 then
|
|
rle_code_tblsize = rle_code_tblsize + 1
|
|
rle_codes[rle_code_tblsize] = 16
|
|
rle_extra_bits_tblsize = rle_extra_bits_tblsize + 1
|
|
rle_extra_bits[rle_extra_bits_tblsize] = 3
|
|
rle_code_counts[16] = (rle_code_counts[16] or 0) + 1
|
|
count = 0
|
|
elseif len == 0 and count == 138 then
|
|
rle_code_tblsize = rle_code_tblsize + 1
|
|
rle_codes[rle_code_tblsize] = 18
|
|
rle_extra_bits_tblsize = rle_extra_bits_tblsize + 1
|
|
rle_extra_bits[rle_extra_bits_tblsize] = 127
|
|
rle_code_counts[18] = (rle_code_counts[18] or 0) + 1
|
|
count = 0
|
|
end
|
|
else
|
|
if count == 1 then
|
|
rle_code_tblsize = rle_code_tblsize + 1
|
|
rle_codes[rle_code_tblsize] = prev
|
|
rle_code_counts[prev] = (rle_code_counts[prev] or 0) + 1
|
|
elseif count == 2 then
|
|
rle_code_tblsize = rle_code_tblsize + 1
|
|
rle_codes[rle_code_tblsize] = prev
|
|
rle_code_tblsize = rle_code_tblsize + 1
|
|
rle_codes[rle_code_tblsize] = prev
|
|
rle_code_counts[prev] = (rle_code_counts[prev] or 0) + 2
|
|
elseif count >= 3 then
|
|
rle_code_tblsize = rle_code_tblsize + 1
|
|
local rleCode = (prev ~= 0) and 16 or (count <= 10 and 17 or 18)
|
|
rle_codes[rle_code_tblsize] = rleCode
|
|
rle_code_counts[rleCode] = (rle_code_counts[rleCode] or 0) + 1
|
|
rle_extra_bits_tblsize = rle_extra_bits_tblsize + 1
|
|
rle_extra_bits[rle_extra_bits_tblsize] =
|
|
(count <= 10) and (count - 3) or (count - 11)
|
|
end
|
|
|
|
prev = len
|
|
if len and len ~= 0 then
|
|
rle_code_tblsize = rle_code_tblsize + 1
|
|
rle_codes[rle_code_tblsize] = len
|
|
rle_code_counts[len] = (rle_code_counts[len] or 0) + 1
|
|
count = 0
|
|
else
|
|
count = 1
|
|
end
|
|
end
|
|
end
|
|
|
|
return rle_codes, rle_extra_bits, rle_code_counts
|
|
end
|
|
|
|
-- Load the string into a table, in order to speed up LZ77.
|
|
-- Loop unrolled 16 times to speed this function up.
|
|
-- @param str The string to be loaded.
|
|
-- @param t The load destination
|
|
-- @param start str[index] will be the first character to be loaded.
|
|
-- @param end str[index] will be the last character to be loaded
|
|
-- @param offset str[index] will be loaded into t[index-offset]
|
|
-- @return t
|
|
local function LoadStringToTable(str, t, start, stop, offset)
|
|
local i = start - offset
|
|
while i <= stop - 15 - offset do
|
|
t[i], t[i+1], t[i+2], t[i+3], t[i+4], t[i+5], t[i+6], t[i+7], t[i+8],
|
|
t[i+9], t[i+10], t[i+11], t[i+12], t[i+13], t[i+14], t[i+15] =
|
|
string_byte(str, i + offset, i + 15 + offset)
|
|
i = i + 16
|
|
end
|
|
while (i <= stop - offset) do
|
|
t[i] = string_byte(str, i + offset, i + offset)
|
|
i = i + 1
|
|
end
|
|
return t
|
|
end
|
|
|
|
-- Do LZ77 process. This function uses the majority of the CPU time.
|
|
-- @see zlib/deflate.c:deflate_fast(), zlib/deflate.c:deflate_slow()
|
|
-- @see https://github.com/madler/zlib/blob/master/doc/algorithm.txt
|
|
-- This function uses the algorithms used above. You should read the
|
|
-- algorithm.txt above to understand what is the hash function and the
|
|
-- lazy evaluation.
|
|
--
|
|
-- The special optimization used here is hash functions used here.
|
|
-- The hash function is just the multiplication of the three consective
|
|
-- characters. So if the hash matches, it guarantees 3 characters are matched.
|
|
-- This optimization can be implemented because Lua table is a hash table.
|
|
--
|
|
-- @param level integer that describes compression level.
|
|
-- @param string_table table that stores the value of string to be compressed.
|
|
-- The index of this table starts from 1.
|
|
-- The caller needs to make sure all values needed by this function
|
|
-- are loaded.
|
|
-- Assume "str" is the origin input string into the compressor
|
|
-- str[block_start]..str[block_end+3] needs to be loaded into
|
|
-- string_table[block_start-offset]..string_table[block_end-offset]
|
|
-- If dictionary is presented, the last 258 bytes of the dictionary
|
|
-- needs to be loaded into sing_table[-257..0]
|
|
-- (See more in the description of offset.)
|
|
-- @param hash_tables. The table key is the hash value (0<=hash<=16777216=256^3)
|
|
-- The table value is an array0 that stores the indexes of the
|
|
-- input data string to be compressed, such that
|
|
-- hash == str[index]*str[index+1]*str[index+2]
|
|
-- Indexes are ordered in this array.
|
|
-- @param block_start The indexes of the input data string to be compressed.
|
|
-- that starts the LZ77 block.
|
|
-- @param block_end The indexes of the input data string to be compressed.
|
|
-- that stores the LZ77 block.
|
|
-- @param offset str[index] is stored in string_table[index-offset],
|
|
-- This offset is mainly an optimization to limit the index
|
|
-- of string_table, so lua can access this table quicker.
|
|
-- @param dictionary See LibDeflate:CreateDictionary
|
|
-- @return literal/LZ77_length deflate codes.
|
|
-- @return the extra bits of literal/LZ77_length deflate codes.
|
|
-- @return the count of each literal/LZ77 deflate code.
|
|
-- @return LZ77 distance deflate codes.
|
|
-- @return the extra bits of LZ77 distance deflate codes.
|
|
-- @return the count of each LZ77 distance deflate code.
|
|
local function GetBlockLZ77Result(level, string_table, hash_tables, block_start,
|
|
block_end, offset, dictionary)
|
|
local config = _compression_level_configs[level]
|
|
local config_use_lazy
|
|
, config_good_prev_length
|
|
, config_max_lazy_match
|
|
, config_nice_length
|
|
, config_max_hash_chain =
|
|
config[1], config[2], config[3], config[4], config[5]
|
|
|
|
local config_max_insert_length = (not config_use_lazy)
|
|
and config_max_lazy_match or 2147483646
|
|
local config_good_hash_chain =
|
|
(config_max_hash_chain-config_max_hash_chain%4/4)
|
|
|
|
local hash
|
|
|
|
local dict_hash_tables
|
|
local dict_string_table
|
|
local dict_string_len = 0
|
|
|
|
if dictionary then
|
|
dict_hash_tables = dictionary.hash_tables
|
|
dict_string_table = dictionary.string_table
|
|
dict_string_len = dictionary.strlen
|
|
assert(block_start == 1)
|
|
if block_end >= block_start and dict_string_len >= 2 then
|
|
hash = dict_string_table[dict_string_len-1]*65536
|
|
+ dict_string_table[dict_string_len]*256 + string_table[1]
|
|
local t = hash_tables[hash]
|
|
if not t then t = {}; hash_tables[hash] = t end
|
|
t[#t+1] = -1
|
|
end
|
|
if block_end >= block_start+1 and dict_string_len >= 1 then
|
|
hash = dict_string_table[dict_string_len]*65536
|
|
+ string_table[1]*256 + string_table[2]
|
|
local t = hash_tables[hash]
|
|
if not t then t = {}; hash_tables[hash] = t end
|
|
t[#t+1] = 0
|
|
end
|
|
end
|
|
|
|
local dict_string_len_plus3 = dict_string_len + 3
|
|
|
|
hash = (string_table[block_start-offset] or 0)*256
|
|
+ (string_table[block_start+1-offset] or 0)
|
|
|
|
local lcodes = {}
|
|
local lcode_tblsize = 0
|
|
local lcodes_counts = {}
|
|
local dcodes = {}
|
|
local dcodes_tblsize = 0
|
|
local dcodes_counts = {}
|
|
|
|
local lextra_bits = {}
|
|
local lextra_bits_tblsize = 0
|
|
local dextra_bits = {}
|
|
local dextra_bits_tblsize = 0
|
|
|
|
local match_available = false
|
|
local prev_len
|
|
local prev_dist
|
|
local cur_len = 0
|
|
local cur_dist = 0
|
|
|
|
local index = block_start
|
|
local index_end = block_end + (config_use_lazy and 1 or 0)
|
|
|
|
-- the zlib source code writes separate code for lazy evaluation and
|
|
-- not lazy evaluation, which is easier to understand.
|
|
-- I put them together, so it is a bit harder to understand.
|
|
-- because I think this is easier for me to maintain it.
|
|
while (index <= index_end) do
|
|
local string_table_index = index - offset
|
|
local offset_minus_three = offset - 3
|
|
prev_len = cur_len
|
|
prev_dist = cur_dist
|
|
cur_len = 0
|
|
|
|
hash = (hash*256+(string_table[string_table_index+2] or 0))%16777216
|
|
|
|
local chain_index
|
|
local cur_chain
|
|
local hash_chain = hash_tables[hash]
|
|
local chain_old_size
|
|
if not hash_chain then
|
|
chain_old_size = 0
|
|
hash_chain = {}
|
|
hash_tables[hash] = hash_chain
|
|
if dict_hash_tables then
|
|
cur_chain = dict_hash_tables[hash]
|
|
chain_index = cur_chain and #cur_chain or 0
|
|
else
|
|
chain_index = 0
|
|
end
|
|
else
|
|
chain_old_size = #hash_chain
|
|
cur_chain = hash_chain
|
|
chain_index = chain_old_size
|
|
end
|
|
|
|
if index <= block_end then
|
|
hash_chain[chain_old_size+1] = index
|
|
end
|
|
|
|
if (chain_index > 0 and index + 2 <= block_end
|
|
and (not config_use_lazy or prev_len < config_max_lazy_match)) then
|
|
|
|
local depth =
|
|
(config_use_lazy and prev_len >= config_good_prev_length)
|
|
and config_good_hash_chain or config_max_hash_chain
|
|
|
|
local max_len_minus_one = block_end - index
|
|
max_len_minus_one = (max_len_minus_one >= 257) and 257 or max_len_minus_one
|
|
max_len_minus_one = max_len_minus_one + string_table_index
|
|
local string_table_index_plus_three = string_table_index + 3
|
|
|
|
while chain_index >= 1 and depth > 0 do
|
|
local prev = cur_chain[chain_index]
|
|
|
|
if index - prev > 32768 then
|
|
break
|
|
end
|
|
if prev < index then
|
|
local sj = string_table_index_plus_three
|
|
|
|
if prev >= -257 then
|
|
local pj = prev - offset_minus_three
|
|
while (sj <= max_len_minus_one
|
|
and string_table[pj]
|
|
== string_table[sj]) do
|
|
sj = sj + 1
|
|
pj = pj + 1
|
|
end
|
|
else
|
|
local pj = dict_string_len_plus3 + prev
|
|
while (sj <= max_len_minus_one
|
|
and dict_string_table[pj]
|
|
== string_table[sj]) do
|
|
sj = sj + 1
|
|
pj = pj + 1
|
|
end
|
|
end
|
|
local j = sj - string_table_index
|
|
if j > cur_len then
|
|
cur_len = j
|
|
cur_dist = index - prev
|
|
end
|
|
if cur_len >= config_nice_length then
|
|
break
|
|
end
|
|
end
|
|
|
|
chain_index = chain_index - 1
|
|
depth = depth - 1
|
|
if chain_index == 0 and prev > 0 and dict_hash_tables then
|
|
cur_chain = dict_hash_tables[hash]
|
|
chain_index = cur_chain and #cur_chain or 0
|
|
end
|
|
end
|
|
end
|
|
|
|
if not config_use_lazy then
|
|
prev_len, prev_dist = cur_len, cur_dist
|
|
end
|
|
if ((not config_use_lazy or match_available)
|
|
and (prev_len > 3 or (prev_len == 3 and prev_dist < 4096))
|
|
and cur_len <= prev_len )then
|
|
local code = _length_to_deflate_code[prev_len]
|
|
local length_extra_bits_bitlen =
|
|
_length_to_deflate_extra_bitlen[prev_len]
|
|
local dist_code, dist_extra_bits_bitlen, dist_extra_bits
|
|
if prev_dist <= 256 then -- have cached code for small distance.
|
|
dist_code = _dist256_to_deflate_code[prev_dist]
|
|
dist_extra_bits = _dist256_to_deflate_extra_bits[prev_dist]
|
|
dist_extra_bits_bitlen =
|
|
_dist256_to_deflate_extra_bitlen[prev_dist]
|
|
else
|
|
dist_code = 16
|
|
dist_extra_bits_bitlen = 7
|
|
local a = 384
|
|
local b = 512
|
|
|
|
while true do
|
|
if prev_dist <= a then
|
|
dist_extra_bits = (prev_dist-(b/2)-1) % (b/4)
|
|
break
|
|
elseif prev_dist <= b then
|
|
dist_extra_bits = (prev_dist-(b/2)-1) % (b/4)
|
|
dist_code = dist_code + 1
|
|
break
|
|
else
|
|
dist_code = dist_code + 2
|
|
dist_extra_bits_bitlen = dist_extra_bits_bitlen + 1
|
|
a = a*2
|
|
b = b*2
|
|
end
|
|
end
|
|
end
|
|
lcode_tblsize = lcode_tblsize + 1
|
|
lcodes[lcode_tblsize] = code
|
|
lcodes_counts[code] = (lcodes_counts[code] or 0) + 1
|
|
|
|
dcodes_tblsize = dcodes_tblsize + 1
|
|
dcodes[dcodes_tblsize] = dist_code
|
|
dcodes_counts[dist_code] = (dcodes_counts[dist_code] or 0) + 1
|
|
|
|
if length_extra_bits_bitlen > 0 then
|
|
local lenExtraBits = _length_to_deflate_extra_bits[prev_len]
|
|
lextra_bits_tblsize = lextra_bits_tblsize + 1
|
|
lextra_bits[lextra_bits_tblsize] = lenExtraBits
|
|
end
|
|
if dist_extra_bits_bitlen > 0 then
|
|
dextra_bits_tblsize = dextra_bits_tblsize + 1
|
|
dextra_bits[dextra_bits_tblsize] = dist_extra_bits
|
|
end
|
|
|
|
for i=index+1, index+prev_len-(config_use_lazy and 2 or 1) do
|
|
hash = (hash*256+(string_table[i-offset+2] or 0))%16777216
|
|
if prev_len <= config_max_insert_length then
|
|
hash_chain = hash_tables[hash]
|
|
if not hash_chain then
|
|
hash_chain = {}
|
|
hash_tables[hash] = hash_chain
|
|
end
|
|
hash_chain[#hash_chain+1] = i
|
|
end
|
|
end
|
|
index = index + prev_len - (config_use_lazy and 1 or 0)
|
|
match_available = false
|
|
elseif (not config_use_lazy) or match_available then
|
|
local code = string_table[config_use_lazy
|
|
and (string_table_index-1) or string_table_index]
|
|
lcode_tblsize = lcode_tblsize + 1
|
|
lcodes[lcode_tblsize] = code
|
|
lcodes_counts[code] = (lcodes_counts[code] or 0) + 1
|
|
index = index + 1
|
|
else
|
|
match_available = true
|
|
index = index + 1
|
|
end
|
|
end
|
|
|
|
-- Write "end of block" symbol
|
|
lcode_tblsize = lcode_tblsize + 1
|
|
lcodes[lcode_tblsize] = 256
|
|
lcodes_counts[256] = (lcodes_counts[256] or 0) + 1
|
|
|
|
return lcodes, lextra_bits, lcodes_counts, dcodes, dextra_bits
|
|
, dcodes_counts
|
|
end
|
|
|
|
-- Get the header data of dynamic block.
|
|
-- @param lcodes_count The count of each literal/LZ77_length codes.
|
|
-- @param dcodes_count The count of each Lz77 distance codes.
|
|
-- @return a lots of stuffs.
|
|
-- @see RFC1951 Page 12
|
|
local function GetBlockDynamicHuffmanHeader(lcodes_counts, dcodes_counts)
|
|
local lcodes_huffman_bitlens, lcodes_huffman_codes
|
|
, max_non_zero_bitlen_lcode =
|
|
GetHuffmanBitlenAndCode(lcodes_counts, 15, 285)
|
|
local dcodes_huffman_bitlens, dcodes_huffman_codes
|
|
, max_non_zero_bitlen_dcode =
|
|
GetHuffmanBitlenAndCode(dcodes_counts, 15, 29)
|
|
|
|
local rle_deflate_codes, rle_extra_bits, rle_codes_counts =
|
|
RunLengthEncodeHuffmanBitlen(lcodes_huffman_bitlens
|
|
,max_non_zero_bitlen_lcode, dcodes_huffman_bitlens
|
|
, max_non_zero_bitlen_dcode)
|
|
|
|
local rle_codes_huffman_bitlens, rle_codes_huffman_codes =
|
|
GetHuffmanBitlenAndCode(rle_codes_counts, 7, 18)
|
|
|
|
local HCLEN = 0
|
|
for i = 1, 19 do
|
|
local symbol = _rle_codes_huffman_bitlen_order[i]
|
|
local length = rle_codes_huffman_bitlens[symbol] or 0
|
|
if length ~= 0 then
|
|
HCLEN = i
|
|
end
|
|
end
|
|
|
|
HCLEN = HCLEN - 4
|
|
local HLIT = max_non_zero_bitlen_lcode + 1 - 257
|
|
local HDIST = max_non_zero_bitlen_dcode + 1 - 1
|
|
if HDIST < 0 then HDIST = 0 end
|
|
|
|
return HLIT, HDIST, HCLEN, rle_codes_huffman_bitlens
|
|
, rle_codes_huffman_codes, rle_deflate_codes, rle_extra_bits
|
|
, lcodes_huffman_bitlens, lcodes_huffman_codes
|
|
, dcodes_huffman_bitlens, dcodes_huffman_codes
|
|
end
|
|
|
|
-- Get the size of dynamic block without writing any bits into the writer.
|
|
-- @param ... Read the source code of GetBlockDynamicHuffmanHeader()
|
|
-- @return the bit length of the dynamic block
|
|
local function GetDynamicHuffmanBlockSize(lcodes, dcodes, HCLEN
|
|
, rle_codes_huffman_bitlens, rle_deflate_codes
|
|
, lcodes_huffman_bitlens, dcodes_huffman_bitlens)
|
|
|
|
local block_bitlen = 17 -- 1+2+5+5+4
|
|
block_bitlen = block_bitlen + (HCLEN+4)*3
|
|
|
|
for i = 1, #rle_deflate_codes do
|
|
local code = rle_deflate_codes[i]
|
|
block_bitlen = block_bitlen + rle_codes_huffman_bitlens[code]
|
|
if code >= 16 then
|
|
block_bitlen = block_bitlen +
|
|
((code == 16) and 2 or (code == 17 and 3 or 7))
|
|
end
|
|
end
|
|
|
|
local length_code_count = 0
|
|
for i = 1, #lcodes do
|
|
local code = lcodes[i]
|
|
local huffman_bitlen = lcodes_huffman_bitlens[code]
|
|
block_bitlen = block_bitlen + huffman_bitlen
|
|
if code > 256 then -- Length code
|
|
length_code_count = length_code_count + 1
|
|
if code > 264 and code < 285 then -- Length code with extra bits
|
|
local extra_bits_bitlen =
|
|
_literal_deflate_code_to_extra_bitlen[code-256]
|
|
block_bitlen = block_bitlen + extra_bits_bitlen
|
|
end
|
|
local dist_code = dcodes[length_code_count]
|
|
local dist_huffman_bitlen = dcodes_huffman_bitlens[dist_code]
|
|
block_bitlen = block_bitlen + dist_huffman_bitlen
|
|
|
|
if dist_code > 3 then -- dist code with extra bits
|
|
local dist_extra_bits_bitlen = (dist_code-dist_code%2)/2 - 1
|
|
block_bitlen = block_bitlen + dist_extra_bits_bitlen
|
|
end
|
|
end
|
|
end
|
|
return block_bitlen
|
|
end
|
|
|
|
-- Write dynamic block.
|
|
-- @param ... Read the source code of GetBlockDynamicHuffmanHeader()
|
|
local function CompressDynamicHuffmanBlock(WriteBits, is_last_block
|
|
, lcodes, lextra_bits, dcodes, dextra_bits, HLIT, HDIST, HCLEN
|
|
, rle_codes_huffman_bitlens, rle_codes_huffman_codes
|
|
, rle_deflate_codes, rle_extra_bits
|
|
, lcodes_huffman_bitlens, lcodes_huffman_codes
|
|
, dcodes_huffman_bitlens, dcodes_huffman_codes)
|
|
|
|
WriteBits(is_last_block and 1 or 0, 1) -- Last block identifier
|
|
WriteBits(2, 2) -- Dynamic Huffman block identifier
|
|
|
|
WriteBits(HLIT, 5)
|
|
WriteBits(HDIST, 5)
|
|
WriteBits(HCLEN, 4)
|
|
|
|
for i = 1, HCLEN+4 do
|
|
local symbol = _rle_codes_huffman_bitlen_order[i]
|
|
local length = rle_codes_huffman_bitlens[symbol] or 0
|
|
WriteBits(length, 3)
|
|
end
|
|
|
|
local rleExtraBitsIndex = 1
|
|
for i=1, #rle_deflate_codes do
|
|
local code = rle_deflate_codes[i]
|
|
WriteBits(rle_codes_huffman_codes[code]
|
|
, rle_codes_huffman_bitlens[code])
|
|
if code >= 16 then
|
|
local extraBits = rle_extra_bits[rleExtraBitsIndex]
|
|
WriteBits(extraBits, (code == 16) and 2 or (code == 17 and 3 or 7))
|
|
rleExtraBitsIndex = rleExtraBitsIndex + 1
|
|
end
|
|
end
|
|
|
|
local length_code_count = 0
|
|
local length_code_with_extra_count = 0
|
|
local dist_code_with_extra_count = 0
|
|
|
|
for i=1, #lcodes do
|
|
local deflate_codee = lcodes[i]
|
|
local huffman_code = lcodes_huffman_codes[deflate_codee]
|
|
local huffman_bitlen = lcodes_huffman_bitlens[deflate_codee]
|
|
WriteBits(huffman_code, huffman_bitlen)
|
|
if deflate_codee > 256 then -- Length code
|
|
length_code_count = length_code_count + 1
|
|
if deflate_codee > 264 and deflate_codee < 285 then
|
|
-- Length code with extra bits
|
|
length_code_with_extra_count = length_code_with_extra_count + 1
|
|
local extra_bits = lextra_bits[length_code_with_extra_count]
|
|
local extra_bits_bitlen =
|
|
_literal_deflate_code_to_extra_bitlen[deflate_codee-256]
|
|
WriteBits(extra_bits, extra_bits_bitlen)
|
|
end
|
|
-- Write distance code
|
|
local dist_deflate_code = dcodes[length_code_count]
|
|
local dist_huffman_code = dcodes_huffman_codes[dist_deflate_code]
|
|
local dist_huffman_bitlen =
|
|
dcodes_huffman_bitlens[dist_deflate_code]
|
|
WriteBits(dist_huffman_code, dist_huffman_bitlen)
|
|
|
|
if dist_deflate_code > 3 then -- dist code with extra bits
|
|
dist_code_with_extra_count = dist_code_with_extra_count + 1
|
|
local dist_extra_bits = dextra_bits[dist_code_with_extra_count]
|
|
local dist_extra_bits_bitlen =
|
|
(dist_deflate_code-dist_deflate_code%2)/2 - 1
|
|
WriteBits(dist_extra_bits, dist_extra_bits_bitlen)
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
-- Get the size of fixed block without writing any bits into the writer.
|
|
-- @param lcodes literal/LZ77_length deflate codes
|
|
-- @param decodes LZ77 distance deflate codes
|
|
-- @return the bit length of the fixed block
|
|
local function GetFixedHuffmanBlockSize(lcodes, dcodes)
|
|
local block_bitlen = 3
|
|
local length_code_count = 0
|
|
for i=1, #lcodes do
|
|
local code = lcodes[i]
|
|
local huffman_bitlen = _fix_block_literal_huffman_bitlen[code]
|
|
block_bitlen = block_bitlen + huffman_bitlen
|
|
if code > 256 then -- Length code
|
|
length_code_count = length_code_count + 1
|
|
if code > 264 and code < 285 then -- Length code with extra bits
|
|
local extra_bits_bitlen =
|
|
_literal_deflate_code_to_extra_bitlen[code-256]
|
|
block_bitlen = block_bitlen + extra_bits_bitlen
|
|
end
|
|
local dist_code = dcodes[length_code_count]
|
|
block_bitlen = block_bitlen + 5
|
|
|
|
if dist_code > 3 then -- dist code with extra bits
|
|
local dist_extra_bits_bitlen =
|
|
(dist_code-dist_code%2)/2 - 1
|
|
block_bitlen = block_bitlen + dist_extra_bits_bitlen
|
|
end
|
|
end
|
|
end
|
|
return block_bitlen
|
|
end
|
|
|
|
-- Write fixed block.
|
|
-- @param lcodes literal/LZ77_length deflate codes
|
|
-- @param decodes LZ77 distance deflate codes
|
|
local function CompressFixedHuffmanBlock(WriteBits, is_last_block,
|
|
lcodes, lextra_bits, dcodes, dextra_bits)
|
|
WriteBits(is_last_block and 1 or 0, 1) -- Last block identifier
|
|
WriteBits(1, 2) -- Fixed Huffman block identifier
|
|
local length_code_count = 0
|
|
local length_code_with_extra_count = 0
|
|
local dist_code_with_extra_count = 0
|
|
for i=1, #lcodes do
|
|
local deflate_code = lcodes[i]
|
|
local huffman_code = _fix_block_literal_huffman_code[deflate_code]
|
|
local huffman_bitlen = _fix_block_literal_huffman_bitlen[deflate_code]
|
|
WriteBits(huffman_code, huffman_bitlen)
|
|
if deflate_code > 256 then -- Length code
|
|
length_code_count = length_code_count + 1
|
|
if deflate_code > 264 and deflate_code < 285 then
|
|
-- Length code with extra bits
|
|
length_code_with_extra_count = length_code_with_extra_count + 1
|
|
local extra_bits = lextra_bits[length_code_with_extra_count]
|
|
local extra_bits_bitlen =
|
|
_literal_deflate_code_to_extra_bitlen[deflate_code-256]
|
|
WriteBits(extra_bits, extra_bits_bitlen)
|
|
end
|
|
-- Write distance code
|
|
local dist_code = dcodes[length_code_count]
|
|
local dist_huffman_code = _fix_block_dist_huffman_code[dist_code]
|
|
WriteBits(dist_huffman_code, 5)
|
|
|
|
if dist_code > 3 then -- dist code with extra bits
|
|
dist_code_with_extra_count = dist_code_with_extra_count + 1
|
|
local dist_extra_bits = dextra_bits[dist_code_with_extra_count]
|
|
local dist_extra_bits_bitlen = (dist_code-dist_code%2)/2 - 1
|
|
WriteBits(dist_extra_bits, dist_extra_bits_bitlen)
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
-- Get the size of store block without writing any bits into the writer.
|
|
-- @param block_start The start index of the origin input string
|
|
-- @param block_end The end index of the origin input string
|
|
-- @param Total bit lens had been written into the compressed result before,
|
|
-- because store block needs to shift to byte boundary.
|
|
-- @return the bit length of the fixed block
|
|
local function GetStoreBlockSize(block_start, block_end, total_bitlen)
|
|
assert(block_end-block_start+1 <= 65535)
|
|
local block_bitlen = 3
|
|
total_bitlen = total_bitlen + 3
|
|
local padding_bitlen = (8-total_bitlen%8)%8
|
|
block_bitlen = block_bitlen + padding_bitlen
|
|
block_bitlen = block_bitlen + 32
|
|
block_bitlen = block_bitlen + (block_end - block_start + 1) * 8
|
|
return block_bitlen
|
|
end
|
|
|
|
-- Write the store block.
|
|
-- @param ... lots of stuffs
|
|
-- @return nil
|
|
local function CompressStoreBlock(WriteBits, WriteString, is_last_block, str
|
|
, block_start, block_end, total_bitlen)
|
|
assert(block_end-block_start+1 <= 65535)
|
|
WriteBits(is_last_block and 1 or 0, 1) -- Last block identifer.
|
|
WriteBits(0, 2) -- Store block identifier.
|
|
total_bitlen = total_bitlen + 3
|
|
local padding_bitlen = (8-total_bitlen%8)%8
|
|
if padding_bitlen > 0 then
|
|
WriteBits(_pow2[padding_bitlen]-1, padding_bitlen)
|
|
end
|
|
local size = block_end - block_start + 1
|
|
WriteBits(size, 16)
|
|
|
|
-- Write size's one's complement
|
|
local comp = (255 - size % 256) + (255 - (size-size%256)/256)*256
|
|
WriteBits(comp, 16)
|
|
|
|
WriteString(str:sub(block_start, block_end))
|
|
end
|
|
|
|
-- Do the deflate
|
|
-- Currently using a simple way to determine the block size
|
|
-- (This is why the compression ratio is little bit worse than zlib when
|
|
-- the input size is very large
|
|
-- The first block is 64KB, the following block is 32KB.
|
|
-- After each block, there is a memory cleanup operation.
|
|
-- This is not a fast operation, but it is needed to save memory usage, so
|
|
-- the memory usage does not grow unboundly. If the data size is less than
|
|
-- 64KB, then memory cleanup won't happen.
|
|
-- This function determines whether to use store/fixed/dynamic blocks by
|
|
-- calculating the block size of each block type and chooses the smallest one.
|
|
local function Deflate(configs, WriteBits, WriteString, FlushWriter, str
|
|
, dictionary)
|
|
local string_table = {}
|
|
local hash_tables = {}
|
|
local is_last_block = nil
|
|
local block_start
|
|
local block_end
|
|
local bitlen_written
|
|
local total_bitlen = FlushWriter(_FLUSH_MODE_NO_FLUSH)
|
|
local strlen = #str
|
|
local offset
|
|
|
|
local level
|
|
local strategy
|
|
if configs then
|
|
if configs.level then
|
|
level = configs.level
|
|
end
|
|
if configs.strategy then
|
|
strategy = configs.strategy
|
|
end
|
|
end
|
|
|
|
if not level then
|
|
if strlen < 2048 then
|
|
level = 7
|
|
elseif strlen > 65536 then
|
|
level = 3
|
|
else
|
|
level = 5
|
|
end
|
|
end
|
|
|
|
while not is_last_block do
|
|
if not block_start then
|
|
block_start = 1
|
|
block_end = 64*1024 - 1
|
|
offset = 0
|
|
else
|
|
block_start = block_end + 1
|
|
block_end = block_end + 32*1024
|
|
offset = block_start - 32*1024 - 1
|
|
end
|
|
|
|
if block_end >= strlen then
|
|
block_end = strlen
|
|
is_last_block = true
|
|
else
|
|
is_last_block = false
|
|
end
|
|
|
|
local lcodes, lextra_bits, lcodes_counts, dcodes, dextra_bits
|
|
, dcodes_counts
|
|
|
|
local HLIT, HDIST, HCLEN, rle_codes_huffman_bitlens
|
|
, rle_codes_huffman_codes, rle_deflate_codes
|
|
, rle_extra_bits, lcodes_huffman_bitlens, lcodes_huffman_codes
|
|
, dcodes_huffman_bitlens, dcodes_huffman_codes
|
|
|
|
local dynamic_block_bitlen
|
|
local fixed_block_bitlen
|
|
local store_block_bitlen
|
|
|
|
if level ~= 0 then
|
|
|
|
-- GetBlockLZ77 needs block_start to block_end+3 to be loaded.
|
|
LoadStringToTable(str, string_table, block_start, block_end + 3
|
|
, offset)
|
|
if block_start == 1 and dictionary then
|
|
local dict_string_table = dictionary.string_table
|
|
local dict_strlen = dictionary.strlen
|
|
for i=0, (-dict_strlen+1)<-257
|
|
and -257 or (-dict_strlen+1), -1 do
|
|
string_table[i] = dict_string_table[dict_strlen+i]
|
|
end
|
|
end
|
|
|
|
if strategy == "huffman_only" then
|
|
lcodes = {}
|
|
LoadStringToTable(str, lcodes, block_start, block_end
|
|
, block_start-1)
|
|
lextra_bits = {}
|
|
lcodes_counts = {}
|
|
lcodes[block_end - block_start+2] = 256 -- end of block
|
|
for i=1, block_end - block_start+2 do
|
|
local code = lcodes[i]
|
|
lcodes_counts[code] = (lcodes_counts[code] or 0) + 1
|
|
end
|
|
dcodes = {}
|
|
dextra_bits = {}
|
|
dcodes_counts = {}
|
|
else
|
|
lcodes, lextra_bits, lcodes_counts, dcodes, dextra_bits
|
|
, dcodes_counts = GetBlockLZ77Result(level, string_table
|
|
, hash_tables, block_start, block_end, offset, dictionary
|
|
)
|
|
end
|
|
|
|
HLIT, HDIST, HCLEN, rle_codes_huffman_bitlens
|
|
, rle_codes_huffman_codes, rle_deflate_codes
|
|
, rle_extra_bits, lcodes_huffman_bitlens, lcodes_huffman_codes
|
|
, dcodes_huffman_bitlens, dcodes_huffman_codes =
|
|
GetBlockDynamicHuffmanHeader(lcodes_counts, dcodes_counts)
|
|
dynamic_block_bitlen = GetDynamicHuffmanBlockSize(
|
|
lcodes, dcodes, HCLEN, rle_codes_huffman_bitlens
|
|
, rle_deflate_codes, lcodes_huffman_bitlens
|
|
, dcodes_huffman_bitlens)
|
|
fixed_block_bitlen = GetFixedHuffmanBlockSize(lcodes, dcodes)
|
|
end
|
|
|
|
store_block_bitlen = GetStoreBlockSize(block_start, block_end
|
|
, total_bitlen)
|
|
|
|
local min_bitlen = store_block_bitlen
|
|
min_bitlen = (fixed_block_bitlen and fixed_block_bitlen < min_bitlen)
|
|
and fixed_block_bitlen or min_bitlen
|
|
min_bitlen = (dynamic_block_bitlen
|
|
and dynamic_block_bitlen < min_bitlen)
|
|
and dynamic_block_bitlen or min_bitlen
|
|
|
|
if level == 0 or (strategy ~= "fixed" and strategy ~= "dynamic" and
|
|
store_block_bitlen == min_bitlen) then
|
|
CompressStoreBlock(WriteBits, WriteString, is_last_block
|
|
, str, block_start, block_end, total_bitlen)
|
|
total_bitlen = total_bitlen + store_block_bitlen
|
|
elseif strategy ~= "dynamic" and (
|
|
strategy == "fixed" or fixed_block_bitlen == min_bitlen) then
|
|
CompressFixedHuffmanBlock(WriteBits, is_last_block,
|
|
lcodes, lextra_bits, dcodes, dextra_bits)
|
|
total_bitlen = total_bitlen + fixed_block_bitlen
|
|
elseif strategy == "dynamic" or dynamic_block_bitlen == min_bitlen then
|
|
CompressDynamicHuffmanBlock(WriteBits, is_last_block, lcodes
|
|
, lextra_bits, dcodes, dextra_bits, HLIT, HDIST, HCLEN
|
|
, rle_codes_huffman_bitlens, rle_codes_huffman_codes
|
|
, rle_deflate_codes, rle_extra_bits
|
|
, lcodes_huffman_bitlens, lcodes_huffman_codes
|
|
, dcodes_huffman_bitlens, dcodes_huffman_codes)
|
|
total_bitlen = total_bitlen + dynamic_block_bitlen
|
|
end
|
|
|
|
if is_last_block then
|
|
bitlen_written = FlushWriter(_FLUSH_MODE_NO_FLUSH)
|
|
else
|
|
bitlen_written = FlushWriter(_FLUSH_MODE_MEMORY_CLEANUP)
|
|
end
|
|
|
|
assert(bitlen_written == total_bitlen)
|
|
|
|
-- Memory clean up, so memory consumption does not always grow linearly
|
|
-- , even if input string is > 64K.
|
|
-- Not a very efficient operation, but this operation won't happen
|
|
-- when the input data size is less than 64K.
|
|
if not is_last_block then
|
|
local j
|
|
if dictionary and block_start == 1 then
|
|
j = 0
|
|
while (string_table[j]) do
|
|
string_table[j] = nil
|
|
j = j - 1
|
|
end
|
|
end
|
|
dictionary = nil
|
|
j = 1
|
|
for i = block_end-32767, block_end do
|
|
string_table[j] = string_table[i-offset]
|
|
j = j + 1
|
|
end
|
|
|
|
for k, t in pairs(hash_tables) do
|
|
local tSize = #t
|
|
if tSize > 0 and block_end+1 - t[1] > 32768 then
|
|
if tSize == 1 then
|
|
hash_tables[k] = nil
|
|
else
|
|
local new = {}
|
|
local newSize = 0
|
|
for i = 2, tSize do
|
|
j = t[i]
|
|
if block_end+1 - j <= 32768 then
|
|
newSize = newSize + 1
|
|
new[newSize] = j
|
|
end
|
|
end
|
|
hash_tables[k] = new
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
--- The description to compression configuration table. <br>
|
|
-- Any field can be nil to use its default. <br>
|
|
-- Table with keys other than those below is an invalid table.
|
|
-- @class table
|
|
-- @name compression_configs
|
|
-- @field level The compression level ranged from 0 to 9. 0 is no compression.
|
|
-- 9 is the slowest but best compression. Use nil for default level.
|
|
-- @field strategy The compression strategy. "fixed" to only use fixed deflate
|
|
-- compression block. "dynamic" to only use dynamic block. "huffman_only" to
|
|
-- do no LZ77 compression. Only do huffman compression.
|
|
|
|
|
|
-- @see LibDeflate:CompressDeflate(str, configs)
|
|
-- @see LibDeflate:CompressDeflateWithDict(str, dictionary, configs)
|
|
local function CompressDeflateInternal(str, dictionary, configs)
|
|
local WriteBits, WriteString, FlushWriter = CreateWriter()
|
|
Deflate(configs, WriteBits, WriteString, FlushWriter, str, dictionary)
|
|
local total_bitlen, result = FlushWriter(_FLUSH_MODE_OUTPUT)
|
|
local padding_bitlen = (8-total_bitlen%8)%8
|
|
return result, padding_bitlen
|
|
end
|
|
|
|
-- @see LibDeflate:CompressZlib
|
|
-- @see LibDeflate:CompressZlibWithDict
|
|
local function CompressZlibInternal(str, dictionary, configs)
|
|
local WriteBits, WriteString, FlushWriter = CreateWriter()
|
|
|
|
local CM = 8 -- Compression method
|
|
local CINFO = 7 --Window Size = 32K
|
|
local CMF = CINFO*16+CM
|
|
WriteBits(CMF, 8)
|
|
|
|
local FDIST = dictionary and 1 or 0
|
|
local FLEVEL = 2 -- Default compression
|
|
local FLG = FLEVEL*64+FDIST*32
|
|
local FCHECK = (31-(CMF*256+FLG)%31)
|
|
-- The FCHECK value must be such that CMF and FLG,
|
|
-- when viewed as a 16-bit unsigned integer stored
|
|
-- in MSB order (CMF*256 + FLG), is a multiple of 31.
|
|
FLG = FLG + FCHECK
|
|
WriteBits(FLG, 8)
|
|
|
|
if FDIST == 1 then
|
|
local adler32 = dictionary.adler32
|
|
local byte0 = adler32 % 256
|
|
adler32 = (adler32 - byte0) / 256
|
|
local byte1 = adler32 % 256
|
|
adler32 = (adler32 - byte1) / 256
|
|
local byte2 = adler32 % 256
|
|
adler32 = (adler32 - byte2) / 256
|
|
local byte3 = adler32 % 256
|
|
WriteBits(byte3, 8)
|
|
WriteBits(byte2, 8)
|
|
WriteBits(byte1, 8)
|
|
WriteBits(byte0, 8)
|
|
end
|
|
|
|
Deflate(configs, WriteBits, WriteString, FlushWriter, str, dictionary)
|
|
FlushWriter(_FLUSH_MODE_BYTE_BOUNDARY)
|
|
|
|
local adler32 = LibDeflate:Adler32(str)
|
|
|
|
-- Most significant byte first
|
|
local byte3 = adler32%256
|
|
adler32 = (adler32 - byte3) / 256
|
|
local byte2 = adler32%256
|
|
adler32 = (adler32 - byte2) / 256
|
|
local byte1 = adler32%256
|
|
adler32 = (adler32 - byte1) / 256
|
|
local byte0 = adler32%256
|
|
|
|
WriteBits(byte0, 8)
|
|
WriteBits(byte1, 8)
|
|
WriteBits(byte2, 8)
|
|
WriteBits(byte3, 8)
|
|
local total_bitlen, result = FlushWriter(_FLUSH_MODE_OUTPUT)
|
|
local padding_bitlen = (8-total_bitlen%8)%8
|
|
return result, padding_bitlen
|
|
end
|
|
|
|
--- Compress using the raw deflate format.
|
|
-- @param str [string] The data to be compressed.
|
|
-- @param configs [table/nil] The configuration table to control the compression
|
|
-- . If nil, use the default configuration.
|
|
-- @return [string] The compressed data.
|
|
-- @return [integer] The number of bits padded at the end of output.
|
|
-- 0 <= bits < 8 <br>
|
|
-- This means the most significant "bits" of the last byte of the returned
|
|
-- compressed data are padding bits and they don't affect decompression.
|
|
-- You don't need to use this value unless you want to do some postprocessing
|
|
-- to the compressed data.
|
|
-- @see compression_configs
|
|
-- @see LibDeflate:DecompressDeflate
|
|
function LibDeflate:CompressDeflate(str, configs)
|
|
local arg_valid, arg_err = IsValidArguments(str, false, nil, true, configs)
|
|
if not arg_valid then
|
|
error(("Usage: LibDeflate:CompressDeflate(str, configs): "
|
|
..arg_err), 2)
|
|
end
|
|
return CompressDeflateInternal(str, nil, configs)
|
|
end
|
|
|
|
--- Compress using the raw deflate format with a preset dictionary.
|
|
-- @param str [string] The data to be compressed.
|
|
-- @param dictionary [table] The preset dictionary produced by
|
|
-- LibDeflate:CreateDictionary
|
|
-- @param configs [table/nil] The configuration table to control the compression
|
|
-- . If nil, use the default configuration.
|
|
-- @return [string] The compressed data.
|
|
-- @return [integer] The number of bits padded at the end of output.
|
|
-- 0 <= bits < 8 <br>
|
|
-- This means the most significant "bits" of the last byte of the returned
|
|
-- compressed data are padding bits and they don't affect decompression.
|
|
-- You don't need to use this value unless you want to do some postprocessing
|
|
-- to the compressed data.
|
|
-- @see compression_configs
|
|
-- @see LibDeflate:CreateDictionary
|
|
-- @see LibDeflate:DecompressDeflateWithDict
|
|
function LibDeflate:CompressDeflateWithDict(str, dictionary, configs)
|
|
local arg_valid, arg_err = IsValidArguments(str, true, dictionary
|
|
, true, configs)
|
|
if not arg_valid then
|
|
error(("Usage: LibDeflate:CompressDeflateWithDict"
|
|
.."(str, dictionary, configs): "
|
|
..arg_err), 2)
|
|
end
|
|
return CompressDeflateInternal(str, dictionary, configs)
|
|
end
|
|
|
|
--- Compress using the zlib format.
|
|
-- @param str [string] the data to be compressed.
|
|
-- @param configs [table/nil] The configuration table to control the compression
|
|
-- . If nil, use the default configuration.
|
|
-- @return [string] The compressed data.
|
|
-- @return [integer] The number of bits padded at the end of output.
|
|
-- Should always be 0.
|
|
-- Zlib formatted compressed data never has padding bits at the end.
|
|
-- @see compression_configs
|
|
-- @see LibDeflate:DecompressZlib
|
|
function LibDeflate:CompressZlib(str, configs)
|
|
local arg_valid, arg_err = IsValidArguments(str, false, nil, true, configs)
|
|
if not arg_valid then
|
|
error(("Usage: LibDeflate:CompressZlib(str, configs): "
|
|
..arg_err), 2)
|
|
end
|
|
return CompressZlibInternal(str, nil, configs)
|
|
end
|
|
|
|
--- Compress using the zlib format with a preset dictionary.
|
|
-- @param str [string] the data to be compressed.
|
|
-- @param dictionary [table] A preset dictionary produced
|
|
-- by LibDeflate:CreateDictionary()
|
|
-- @param configs [table/nil] The configuration table to control the compression
|
|
-- . If nil, use the default configuration.
|
|
-- @return [string] The compressed data.
|
|
-- @return [integer] The number of bits padded at the end of output.
|
|
-- Should always be 0.
|
|
-- Zlib formatted compressed data never has padding bits at the end.
|
|
-- @see compression_configs
|
|
-- @see LibDeflate:CreateDictionary
|
|
-- @see LibDeflate:DecompressZlibWithDict
|
|
function LibDeflate:CompressZlibWithDict(str, dictionary, configs)
|
|
local arg_valid, arg_err = IsValidArguments(str, true, dictionary
|
|
, true, configs)
|
|
if not arg_valid then
|
|
error(("Usage: LibDeflate:CompressZlibWithDict"
|
|
.."(str, dictionary, configs): "
|
|
..arg_err), 2)
|
|
end
|
|
return CompressZlibInternal(str, dictionary, configs)
|
|
end
|
|
|
|
--[[ --------------------------------------------------------------------------
|
|
Decompress code
|
|
--]] --------------------------------------------------------------------------
|
|
|
|
--[[
|
|
Create a reader to easily reader stuffs as the unit of bits.
|
|
Return values:
|
|
1. ReadBits(bitlen)
|
|
2. ReadBytes(bytelen, buffer, buffer_size)
|
|
3. Decode(huffman_bitlen_count, huffman_symbol, min_bitlen)
|
|
4. ReaderBitlenLeft()
|
|
5. SkipToByteBoundary()
|
|
--]]
|
|
local function CreateReader(input_string)
|
|
local input = input_string
|
|
local input_strlen = #input_string
|
|
local input_next_byte_pos = 1
|
|
local cache_bitlen = 0
|
|
local cache = 0
|
|
|
|
-- Read some bits.
|
|
-- To improve speed, this function does not
|
|
-- check if the input has been exhausted.
|
|
-- Use ReaderBitlenLeft() < 0 to check it.
|
|
-- @param bitlen the number of bits to read
|
|
-- @return the data is read.
|
|
local function ReadBits(bitlen)
|
|
local rshift_mask = _pow2[bitlen]
|
|
local code
|
|
if bitlen <= cache_bitlen then
|
|
code = cache % rshift_mask
|
|
cache = (cache - code) / rshift_mask
|
|
cache_bitlen = cache_bitlen - bitlen
|
|
else -- Whether input has been exhausted is not checked.
|
|
local lshift_mask = _pow2[cache_bitlen]
|
|
local byte1, byte2, byte3, byte4 = string_byte(input
|
|
, input_next_byte_pos, input_next_byte_pos+3)
|
|
-- This requires lua number to be at least double ()
|
|
cache = cache + ((byte1 or 0)+(byte2 or 0)*256
|
|
+ (byte3 or 0)*65536+(byte4 or 0)*16777216)*lshift_mask
|
|
input_next_byte_pos = input_next_byte_pos + 4
|
|
cache_bitlen = cache_bitlen + 32 - bitlen
|
|
code = cache % rshift_mask
|
|
cache = (cache - code) / rshift_mask
|
|
end
|
|
return code
|
|
end
|
|
|
|
-- Read some bytes from the reader.
|
|
-- Assume reader is on the byte boundary.
|
|
-- @param bytelen The number of bytes to be read.
|
|
-- @param buffer The byte read will be stored into this buffer.
|
|
-- @param buffer_size The buffer will be modified starting from
|
|
-- buffer[buffer_size+1], ending at buffer[buffer_size+bytelen-1]
|
|
-- @return the new buffer_size
|
|
local function ReadBytes(bytelen, buffer, buffer_size)
|
|
assert(cache_bitlen % 8 == 0)
|
|
|
|
local byte_from_cache = (cache_bitlen/8 < bytelen)
|
|
and (cache_bitlen/8) or bytelen
|
|
for _=1, byte_from_cache do
|
|
local byte = cache % 256
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] = string_char(byte)
|
|
cache = (cache - byte) / 256
|
|
end
|
|
cache_bitlen = cache_bitlen - byte_from_cache*8
|
|
bytelen = bytelen - byte_from_cache
|
|
if (input_strlen - input_next_byte_pos - bytelen + 1) * 8
|
|
+ cache_bitlen < 0 then
|
|
return -1 -- out of input
|
|
end
|
|
for i=input_next_byte_pos, input_next_byte_pos+bytelen-1 do
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] = string_sub(input, i, i)
|
|
end
|
|
|
|
input_next_byte_pos = input_next_byte_pos + bytelen
|
|
return buffer_size
|
|
end
|
|
|
|
-- Decode huffman code
|
|
-- To improve speed, this function does not check
|
|
-- if the input has been exhausted.
|
|
-- Use ReaderBitlenLeft() < 0 to check it.
|
|
-- Credits for Mark Adler. This code is from puff:Decode()
|
|
-- @see puff:Decode(...)
|
|
-- @param huffman_bitlen_count
|
|
-- @param huffman_symbol
|
|
-- @param min_bitlen The minimum huffman bit length of all symbols
|
|
-- @return The decoded deflate code.
|
|
-- Negative value is returned if decoding fails.
|
|
local function Decode(huffman_bitlen_counts, huffman_symbols, min_bitlen)
|
|
local code = 0
|
|
local first = 0
|
|
local index = 0
|
|
local count
|
|
if min_bitlen > 0 then
|
|
if cache_bitlen < 15 and input then
|
|
local lshift_mask = _pow2[cache_bitlen]
|
|
local byte1, byte2, byte3, byte4 =
|
|
string_byte(input, input_next_byte_pos
|
|
, input_next_byte_pos+3)
|
|
-- This requires lua number to be at least double ()
|
|
cache = cache + ((byte1 or 0)+(byte2 or 0)*256
|
|
+(byte3 or 0)*65536+(byte4 or 0)*16777216)*lshift_mask
|
|
input_next_byte_pos = input_next_byte_pos + 4
|
|
cache_bitlen = cache_bitlen + 32
|
|
end
|
|
|
|
local rshift_mask = _pow2[min_bitlen]
|
|
cache_bitlen = cache_bitlen - min_bitlen
|
|
code = cache % rshift_mask
|
|
cache = (cache - code) / rshift_mask
|
|
-- Reverse the bits
|
|
code = _reverse_bits_tbl[min_bitlen][code]
|
|
|
|
count = huffman_bitlen_counts[min_bitlen]
|
|
if code < count then
|
|
return huffman_symbols[code]
|
|
end
|
|
index = count
|
|
first = count * 2
|
|
code = code * 2
|
|
end
|
|
|
|
for bitlen = min_bitlen+1, 15 do
|
|
local bit
|
|
bit = cache % 2
|
|
cache = (cache - bit) / 2
|
|
cache_bitlen = cache_bitlen - 1
|
|
|
|
code = (bit==1) and (code + 1 - code % 2) or code
|
|
count = huffman_bitlen_counts[bitlen] or 0
|
|
local diff = code - first
|
|
if diff < count then
|
|
return huffman_symbols[index + diff]
|
|
end
|
|
index = index + count
|
|
first = first + count
|
|
first = first * 2
|
|
code = code * 2
|
|
end
|
|
-- invalid literal/length or distance code
|
|
-- in fixed or dynamic block (run out of code)
|
|
return -10
|
|
end
|
|
|
|
local function ReaderBitlenLeft()
|
|
return (input_strlen - input_next_byte_pos + 1) * 8 + cache_bitlen
|
|
end
|
|
|
|
local function SkipToByteBoundary()
|
|
local skipped_bitlen = cache_bitlen%8
|
|
local rshift_mask = _pow2[skipped_bitlen]
|
|
cache_bitlen = cache_bitlen - skipped_bitlen
|
|
cache = (cache - cache % rshift_mask) / rshift_mask
|
|
end
|
|
|
|
return ReadBits, ReadBytes, Decode, ReaderBitlenLeft, SkipToByteBoundary
|
|
end
|
|
|
|
-- Create a deflate state, so I can pass in less arguments to functions.
|
|
-- @param str the whole string to be decompressed.
|
|
-- @param dictionary The preset dictionary. nil if not provided.
|
|
-- This dictionary should be produced by LibDeflate:CreateDictionary(str)
|
|
-- @return The decomrpess state.
|
|
local function CreateDecompressState(str, dictionary)
|
|
local ReadBits, ReadBytes, Decode, ReaderBitlenLeft
|
|
, SkipToByteBoundary = CreateReader(str)
|
|
local state =
|
|
{
|
|
ReadBits = ReadBits,
|
|
ReadBytes = ReadBytes,
|
|
Decode = Decode,
|
|
ReaderBitlenLeft = ReaderBitlenLeft,
|
|
SkipToByteBoundary = SkipToByteBoundary,
|
|
buffer_size = 0,
|
|
buffer = {},
|
|
result_buffer = {},
|
|
dictionary = dictionary,
|
|
}
|
|
return state
|
|
end
|
|
|
|
-- Get the stuffs needed to decode huffman codes
|
|
-- @see puff.c:construct(...)
|
|
-- @param huffman_bitlen The huffman bit length of the huffman codes.
|
|
-- @param max_symbol The maximum symbol
|
|
-- @param max_bitlen The min huffman bit length of all codes
|
|
-- @return zero or positive for success, negative for failure.
|
|
-- @return The count of each huffman bit length.
|
|
-- @return A table to convert huffman codes to deflate codes.
|
|
-- @return The minimum huffman bit length.
|
|
local function GetHuffmanForDecode(huffman_bitlens, max_symbol, max_bitlen)
|
|
local huffman_bitlen_counts = {}
|
|
local min_bitlen = max_bitlen
|
|
for symbol = 0, max_symbol do
|
|
local bitlen = huffman_bitlens[symbol] or 0
|
|
min_bitlen = (bitlen > 0 and bitlen < min_bitlen)
|
|
and bitlen or min_bitlen
|
|
huffman_bitlen_counts[bitlen] = (huffman_bitlen_counts[bitlen] or 0)+1
|
|
end
|
|
|
|
if huffman_bitlen_counts[0] == max_symbol+1 then -- No Codes
|
|
return 0, huffman_bitlen_counts, {}, 0 -- Complete, but decode will fail
|
|
end
|
|
|
|
local left = 1
|
|
for len = 1, max_bitlen do
|
|
left = left * 2
|
|
left = left - (huffman_bitlen_counts[len] or 0)
|
|
if left < 0 then
|
|
return left -- Over-subscribed, return negative
|
|
end
|
|
end
|
|
|
|
-- Generate offsets info symbol table for each length for sorting
|
|
local offsets = {}
|
|
offsets[1] = 0
|
|
for len = 1, max_bitlen-1 do
|
|
offsets[len + 1] = offsets[len] + (huffman_bitlen_counts[len] or 0)
|
|
end
|
|
|
|
local huffman_symbols = {}
|
|
for symbol = 0, max_symbol do
|
|
local bitlen = huffman_bitlens[symbol] or 0
|
|
if bitlen ~= 0 then
|
|
local offset = offsets[bitlen]
|
|
huffman_symbols[offset] = symbol
|
|
offsets[bitlen] = offsets[bitlen] + 1
|
|
end
|
|
end
|
|
|
|
-- Return zero for complete set, positive for incomplete set.
|
|
return left, huffman_bitlen_counts, huffman_symbols, min_bitlen
|
|
end
|
|
|
|
-- Decode a fixed or dynamic huffman blocks, excluding last block identifier
|
|
-- and block type identifer.
|
|
-- @see puff.c:codes()
|
|
-- @param state decompression state that will be modified by this function.
|
|
-- @see CreateDecompressState
|
|
-- @param ... Read the source code
|
|
-- @return 0 on success, other value on failure.
|
|
local function DecodeUntilEndOfBlock(state, lcodes_huffman_bitlens
|
|
, lcodes_huffman_symbols, lcodes_huffman_min_bitlen
|
|
, dcodes_huffman_bitlens, dcodes_huffman_symbols
|
|
, dcodes_huffman_min_bitlen)
|
|
local buffer, buffer_size, ReadBits, Decode, ReaderBitlenLeft
|
|
, result_buffer =
|
|
state.buffer, state.buffer_size, state.ReadBits, state.Decode
|
|
, state.ReaderBitlenLeft, state.result_buffer
|
|
local dictionary = state.dictionary
|
|
local dict_string_table
|
|
local dict_strlen
|
|
|
|
local buffer_end = 1
|
|
if dictionary and not buffer[0] then
|
|
-- If there is a dictionary, copy the last 258 bytes into
|
|
-- the string_table to make the copy in the main loop quicker.
|
|
-- This is done only once per decompression.
|
|
dict_string_table = dictionary.string_table
|
|
dict_strlen = dictionary.strlen
|
|
buffer_end = -dict_strlen + 1
|
|
for i=0, (-dict_strlen+1)<-257 and -257 or (-dict_strlen+1), -1 do
|
|
buffer[i] = _byte_to_char[dict_string_table[dict_strlen+i]]
|
|
end
|
|
end
|
|
|
|
repeat
|
|
local symbol = Decode(lcodes_huffman_bitlens
|
|
, lcodes_huffman_symbols, lcodes_huffman_min_bitlen)
|
|
if symbol < 0 or symbol > 285 then
|
|
-- invalid literal/length or distance code in fixed or dynamic block
|
|
return -10
|
|
elseif symbol < 256 then -- Literal
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] = _byte_to_char[symbol]
|
|
elseif symbol > 256 then -- Length code
|
|
symbol = symbol - 256
|
|
local bitlen = _literal_deflate_code_to_base_len[symbol]
|
|
bitlen = (symbol >= 8)
|
|
and (bitlen
|
|
+ ReadBits(_literal_deflate_code_to_extra_bitlen[symbol]))
|
|
or bitlen
|
|
symbol = Decode(dcodes_huffman_bitlens, dcodes_huffman_symbols
|
|
, dcodes_huffman_min_bitlen)
|
|
if symbol < 0 or symbol > 29 then
|
|
-- invalid literal/length or distance code in fixed or dynamic block
|
|
return -10
|
|
end
|
|
local dist = _dist_deflate_code_to_base_dist[symbol]
|
|
dist = (dist > 4) and (dist
|
|
+ ReadBits(_dist_deflate_code_to_extra_bitlen[symbol])) or dist
|
|
|
|
local char_buffer_index = buffer_size-dist+1
|
|
if char_buffer_index < buffer_end then
|
|
-- distance is too far back in fixed or dynamic block
|
|
return -11
|
|
end
|
|
if char_buffer_index >= -257 then
|
|
for _=1, bitlen do
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] = buffer[char_buffer_index]
|
|
char_buffer_index = char_buffer_index + 1
|
|
end
|
|
else
|
|
char_buffer_index = dict_strlen + char_buffer_index
|
|
for _=1, bitlen do
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] =
|
|
_byte_to_char[dict_string_table[char_buffer_index]]
|
|
char_buffer_index = char_buffer_index + 1
|
|
end
|
|
end
|
|
end
|
|
|
|
if ReaderBitlenLeft() < 0 then
|
|
return 2 -- available inflate data did not terminate
|
|
end
|
|
|
|
if buffer_size >= 65536 then
|
|
result_buffer[#result_buffer+1] =
|
|
table_concat(buffer, "", 1, 32768)
|
|
for i=32769, buffer_size do
|
|
buffer[i-32768] = buffer[i]
|
|
end
|
|
buffer_size = buffer_size - 32768
|
|
buffer[buffer_size+1] = nil
|
|
-- NOTE: buffer[32769..end] and buffer[-257..0] are not cleared.
|
|
-- This is why "buffer_size" variable is needed.
|
|
end
|
|
until symbol == 256
|
|
|
|
state.buffer_size = buffer_size
|
|
|
|
return 0
|
|
end
|
|
|
|
-- Decompress a store block
|
|
-- @param state decompression state that will be modified by this function.
|
|
-- @return 0 if succeeds, other value if fails.
|
|
local function DecompressStoreBlock(state)
|
|
local buffer, buffer_size, ReadBits, ReadBytes, ReaderBitlenLeft
|
|
, SkipToByteBoundary, result_buffer =
|
|
state.buffer, state.buffer_size, state.ReadBits, state.ReadBytes
|
|
, state.ReaderBitlenLeft, state.SkipToByteBoundary, state.result_buffer
|
|
|
|
SkipToByteBoundary()
|
|
local bytelen = ReadBits(16)
|
|
if ReaderBitlenLeft() < 0 then
|
|
return 2 -- available inflate data did not terminate
|
|
end
|
|
local bytelenComp = ReadBits(16)
|
|
if ReaderBitlenLeft() < 0 then
|
|
return 2 -- available inflate data did not terminate
|
|
end
|
|
|
|
if bytelen % 256 + bytelenComp % 256 ~= 255 then
|
|
return -2 -- Not one's complement
|
|
end
|
|
if (bytelen-bytelen % 256)/256
|
|
+ (bytelenComp-bytelenComp % 256)/256 ~= 255 then
|
|
return -2 -- Not one's complement
|
|
end
|
|
|
|
-- Note that ReadBytes will skip to the next byte boundary first.
|
|
buffer_size = ReadBytes(bytelen, buffer, buffer_size)
|
|
if buffer_size < 0 then
|
|
return 2 -- available inflate data did not terminate
|
|
end
|
|
|
|
-- memory clean up when there are enough bytes in the buffer.
|
|
if buffer_size >= 65536 then
|
|
result_buffer[#result_buffer+1] = table_concat(buffer, "", 1, 32768)
|
|
for i=32769, buffer_size do
|
|
buffer[i-32768] = buffer[i]
|
|
end
|
|
buffer_size = buffer_size - 32768
|
|
buffer[buffer_size+1] = nil
|
|
end
|
|
state.buffer_size = buffer_size
|
|
return 0
|
|
end
|
|
|
|
-- Decompress a fixed block
|
|
-- @param state decompression state that will be modified by this function.
|
|
-- @return 0 if succeeds other value if fails.
|
|
local function DecompressFixBlock(state)
|
|
return DecodeUntilEndOfBlock(state
|
|
, _fix_block_literal_huffman_bitlen_count
|
|
, _fix_block_literal_huffman_to_deflate_code, 7
|
|
, _fix_block_dist_huffman_bitlen_count
|
|
, _fix_block_dist_huffman_to_deflate_code, 5)
|
|
end
|
|
|
|
-- Decompress a dynamic block
|
|
-- @param state decompression state that will be modified by this function.
|
|
-- @return 0 if success, other value if fails.
|
|
local function DecompressDynamicBlock(state)
|
|
local ReadBits, Decode = state.ReadBits, state.Decode
|
|
local nlen = ReadBits(5) + 257
|
|
local ndist = ReadBits(5) + 1
|
|
local ncode = ReadBits(4) + 4
|
|
if nlen > 286 or ndist > 30 then
|
|
-- dynamic block code description: too many length or distance codes
|
|
return -3
|
|
end
|
|
|
|
local rle_codes_huffman_bitlens = {}
|
|
|
|
for i = 1, ncode do
|
|
rle_codes_huffman_bitlens[_rle_codes_huffman_bitlen_order[i]] =
|
|
ReadBits(3)
|
|
end
|
|
|
|
local rle_codes_err, rle_codes_huffman_bitlen_counts,
|
|
rle_codes_huffman_symbols, rle_codes_huffman_min_bitlen =
|
|
GetHuffmanForDecode(rle_codes_huffman_bitlens, 18, 7)
|
|
if rle_codes_err ~= 0 then -- Require complete code set here
|
|
-- dynamic block code description: code lengths codes incomplete
|
|
return -4
|
|
end
|
|
|
|
local lcodes_huffman_bitlens = {}
|
|
local dcodes_huffman_bitlens = {}
|
|
-- Read length/literal and distance code length tables
|
|
local index = 0
|
|
while index < nlen + ndist do
|
|
local symbol -- Decoded value
|
|
local bitlen -- Last length to repeat
|
|
|
|
symbol = Decode(rle_codes_huffman_bitlen_counts
|
|
, rle_codes_huffman_symbols, rle_codes_huffman_min_bitlen)
|
|
|
|
if symbol < 0 then
|
|
return symbol -- Invalid symbol
|
|
elseif symbol < 16 then
|
|
if index < nlen then
|
|
lcodes_huffman_bitlens[index] = symbol
|
|
else
|
|
dcodes_huffman_bitlens[index-nlen] = symbol
|
|
end
|
|
index = index + 1
|
|
else
|
|
bitlen = 0
|
|
if symbol == 16 then
|
|
if index == 0 then
|
|
-- dynamic block code description: repeat lengths
|
|
-- with no first length
|
|
return -5
|
|
end
|
|
if index-1 < nlen then
|
|
bitlen = lcodes_huffman_bitlens[index-1]
|
|
else
|
|
bitlen = dcodes_huffman_bitlens[index-nlen-1]
|
|
end
|
|
symbol = 3 + ReadBits(2)
|
|
elseif symbol == 17 then -- Repeat zero 3..10 times
|
|
symbol = 3 + ReadBits(3)
|
|
else -- == 18, repeat zero 11.138 times
|
|
symbol = 11 + ReadBits(7)
|
|
end
|
|
if index + symbol > nlen + ndist then
|
|
-- dynamic block code description:
|
|
-- repeat more than specified lengths
|
|
return -6
|
|
end
|
|
while symbol > 0 do -- Repeat last or zero symbol times
|
|
symbol = symbol - 1
|
|
if index < nlen then
|
|
lcodes_huffman_bitlens[index] = bitlen
|
|
else
|
|
dcodes_huffman_bitlens[index-nlen] = bitlen
|
|
end
|
|
index = index + 1
|
|
end
|
|
end
|
|
end
|
|
|
|
if (lcodes_huffman_bitlens[256] or 0) == 0 then
|
|
-- dynamic block code description: missing end-of-block code
|
|
return -9
|
|
end
|
|
|
|
local lcodes_err, lcodes_huffman_bitlen_counts
|
|
, lcodes_huffman_symbols, lcodes_huffman_min_bitlen =
|
|
GetHuffmanForDecode(lcodes_huffman_bitlens, nlen-1, 15)
|
|
--dynamic block code description: invalid literal/length code lengths,
|
|
-- Incomplete code ok only for single length 1 code
|
|
if (lcodes_err ~=0 and (lcodes_err < 0
|
|
or nlen ~= (lcodes_huffman_bitlen_counts[0] or 0)
|
|
+(lcodes_huffman_bitlen_counts[1] or 0))) then
|
|
return -7
|
|
end
|
|
|
|
local dcodes_err, dcodes_huffman_bitlen_counts
|
|
, dcodes_huffman_symbols, dcodes_huffman_min_bitlen =
|
|
GetHuffmanForDecode(dcodes_huffman_bitlens, ndist-1, 15)
|
|
-- dynamic block code description: invalid distance code lengths,
|
|
-- Incomplete code ok only for single length 1 code
|
|
if (dcodes_err ~=0 and (dcodes_err < 0
|
|
or ndist ~= (dcodes_huffman_bitlen_counts[0] or 0)
|
|
+ (dcodes_huffman_bitlen_counts[1] or 0))) then
|
|
return -8
|
|
end
|
|
|
|
-- Build buffman table for literal/length codes
|
|
return DecodeUntilEndOfBlock(state, lcodes_huffman_bitlen_counts
|
|
, lcodes_huffman_symbols, lcodes_huffman_min_bitlen
|
|
, dcodes_huffman_bitlen_counts, dcodes_huffman_symbols
|
|
, dcodes_huffman_min_bitlen)
|
|
end
|
|
|
|
-- Decompress a deflate stream
|
|
-- @param state: a decompression state
|
|
-- @return the decompressed string if succeeds. nil if fails.
|
|
local function Inflate(state)
|
|
local ReadBits = state.ReadBits
|
|
|
|
local is_last_block
|
|
while not is_last_block do
|
|
is_last_block = (ReadBits(1) == 1)
|
|
local block_type = ReadBits(2)
|
|
local status
|
|
if block_type == 0 then
|
|
status = DecompressStoreBlock(state)
|
|
elseif block_type == 1 then
|
|
status = DecompressFixBlock(state)
|
|
elseif block_type == 2 then
|
|
status = DecompressDynamicBlock(state)
|
|
else
|
|
return nil, -1 -- invalid block type (type == 3)
|
|
end
|
|
if status ~= 0 then
|
|
return nil, status
|
|
end
|
|
end
|
|
|
|
state.result_buffer[#state.result_buffer+1] =
|
|
table_concat(state.buffer, "", 1, state.buffer_size)
|
|
local result = table_concat(state.result_buffer)
|
|
return result
|
|
end
|
|
|
|
-- @see LibDeflate:DecompressDeflate(str)
|
|
-- @see LibDeflate:DecompressDeflateWithDict(str, dictionary)
|
|
local function DecompressDeflateInternal(str, dictionary)
|
|
local state = CreateDecompressState(str, dictionary)
|
|
local result, status = Inflate(state)
|
|
if not result then
|
|
return nil, status
|
|
end
|
|
|
|
local bitlen_left = state.ReaderBitlenLeft()
|
|
local bytelen_left = (bitlen_left - bitlen_left % 8) / 8
|
|
return result, bytelen_left
|
|
end
|
|
|
|
-- @see LibDeflate:DecompressZlib(str)
|
|
-- @see LibDeflate:DecompressZlibWithDict(str)
|
|
local function DecompressZlibInternal(str, dictionary)
|
|
local state = CreateDecompressState(str, dictionary)
|
|
local ReadBits = state.ReadBits
|
|
|
|
local CMF = ReadBits(8)
|
|
if state.ReaderBitlenLeft() < 0 then
|
|
return nil, 2 -- available inflate data did not terminate
|
|
end
|
|
local CM = CMF % 16
|
|
local CINFO = (CMF - CM) / 16
|
|
if CM ~= 8 then
|
|
return nil, -12 -- invalid compression method
|
|
end
|
|
if CINFO > 7 then
|
|
return nil, -13 -- invalid window size
|
|
end
|
|
|
|
local FLG = ReadBits(8)
|
|
if state.ReaderBitlenLeft() < 0 then
|
|
return nil, 2 -- available inflate data did not terminate
|
|
end
|
|
if (CMF*256+FLG)%31 ~= 0 then
|
|
return nil, -14 -- invalid header checksum
|
|
end
|
|
|
|
local FDIST = ((FLG-FLG%32)/32 % 2)
|
|
local FLEVEL = ((FLG-FLG%64)/64 % 4) -- luacheck: ignore FLEVEL
|
|
|
|
if FDIST == 1 then
|
|
if not dictionary then
|
|
return nil, -16 -- need dictonary, but dictionary is not provided.
|
|
end
|
|
local byte3 = ReadBits(8)
|
|
local byte2 = ReadBits(8)
|
|
local byte1 = ReadBits(8)
|
|
local byte0 = ReadBits(8)
|
|
local actual_adler32 = byte3*16777216+byte2*65536+byte1*256+byte0
|
|
if state.ReaderBitlenLeft() < 0 then
|
|
return nil, 2 -- available inflate data did not terminate
|
|
end
|
|
if not IsEqualAdler32(actual_adler32, dictionary.adler32) then
|
|
return nil, -17 -- dictionary adler32 does not match
|
|
end
|
|
end
|
|
local result, status = Inflate(state)
|
|
if not result then
|
|
return nil, status
|
|
end
|
|
state.SkipToByteBoundary()
|
|
|
|
local adler_byte0 = ReadBits(8)
|
|
local adler_byte1 = ReadBits(8)
|
|
local adler_byte2 = ReadBits(8)
|
|
local adler_byte3 = ReadBits(8)
|
|
if state.ReaderBitlenLeft() < 0 then
|
|
return nil, 2 -- available inflate data did not terminate
|
|
end
|
|
|
|
local adler32_expected = adler_byte0*16777216
|
|
+ adler_byte1*65536 + adler_byte2*256 + adler_byte3
|
|
local adler32_actual = LibDeflate:Adler32(result)
|
|
if not IsEqualAdler32(adler32_expected, adler32_actual) then
|
|
return nil, -15 -- Adler32 checksum does not match
|
|
end
|
|
|
|
local bitlen_left = state.ReaderBitlenLeft()
|
|
local bytelen_left = (bitlen_left - bitlen_left % 8) / 8
|
|
return result, bytelen_left
|
|
end
|
|
|
|
--- Decompress a raw deflate compressed data.
|
|
-- @param str [string] The data to be decompressed.
|
|
-- @return [string/nil] If the decompression succeeds, return the decompressed
|
|
-- data. If the decompression fails, return nil. You should check if this return
|
|
-- value is non-nil to know if the decompression succeeds.
|
|
-- @return [integer] If the decompression succeeds, return the number of
|
|
-- unprocessed bytes in the input compressed data. This return value is a
|
|
-- positive integer if the input data is a valid compressed data appended by an
|
|
-- arbitary non-empty string. This return value is 0 if the input data does not
|
|
-- contain any extra bytes.<br>
|
|
-- If the decompression fails (The first return value of this function is nil),
|
|
-- this return value is undefined.
|
|
-- @see LibDeflate:CompressDeflate
|
|
function LibDeflate:DecompressDeflate(str)
|
|
local arg_valid, arg_err = IsValidArguments(str)
|
|
if not arg_valid then
|
|
error(("Usage: LibDeflate:DecompressDeflate(str): "
|
|
..arg_err), 2)
|
|
end
|
|
return DecompressDeflateInternal(str)
|
|
end
|
|
|
|
--- Decompress a raw deflate compressed data with a preset dictionary.
|
|
-- @param str [string] The data to be decompressed.
|
|
-- @param dictionary [table] The preset dictionary used by
|
|
-- LibDeflate:CompressDeflateWithDict when the compressed data is produced.
|
|
-- Decompression and compression must use the same dictionary.
|
|
-- Otherwise wrong decompressed data could be produced without generating any
|
|
-- error.
|
|
-- @return [string/nil] If the decompression succeeds, return the decompressed
|
|
-- data. If the decompression fails, return nil. You should check if this return
|
|
-- value is non-nil to know if the decompression succeeds.
|
|
-- @return [integer] If the decompression succeeds, return the number of
|
|
-- unprocessed bytes in the input compressed data. This return value is a
|
|
-- positive integer if the input data is a valid compressed data appended by an
|
|
-- arbitary non-empty string. This return value is 0 if the input data does not
|
|
-- contain any extra bytes.<br>
|
|
-- If the decompression fails (The first return value of this function is nil),
|
|
-- this return value is undefined.
|
|
-- @see LibDeflate:CompressDeflateWithDict
|
|
function LibDeflate:DecompressDeflateWithDict(str, dictionary)
|
|
local arg_valid, arg_err = IsValidArguments(str, true, dictionary)
|
|
if not arg_valid then
|
|
error(("Usage: LibDeflate:DecompressDeflateWithDict(str, dictionary): "
|
|
..arg_err), 2)
|
|
end
|
|
return DecompressDeflateInternal(str, dictionary)
|
|
end
|
|
|
|
--- Decompress a zlib compressed data.
|
|
-- @param str [string] The data to be decompressed
|
|
-- @return [string/nil] If the decompression succeeds, return the decompressed
|
|
-- data. If the decompression fails, return nil. You should check if this return
|
|
-- value is non-nil to know if the decompression succeeds.
|
|
-- @return [integer] If the decompression succeeds, return the number of
|
|
-- unprocessed bytes in the input compressed data. This return value is a
|
|
-- positive integer if the input data is a valid compressed data appended by an
|
|
-- arbitary non-empty string. This return value is 0 if the input data does not
|
|
-- contain any extra bytes.<br>
|
|
-- If the decompression fails (The first return value of this function is nil),
|
|
-- this return value is undefined.
|
|
-- @see LibDeflate:CompressZlib
|
|
function LibDeflate:DecompressZlib(str)
|
|
local arg_valid, arg_err = IsValidArguments(str)
|
|
if not arg_valid then
|
|
error(("Usage: LibDeflate:DecompressZlib(str): "
|
|
..arg_err), 2)
|
|
end
|
|
return DecompressZlibInternal(str)
|
|
end
|
|
|
|
--- Decompress a zlib compressed data with a preset dictionary.
|
|
-- @param str [string] The data to be decompressed
|
|
-- @param dictionary [table] The preset dictionary used by
|
|
-- LibDeflate:CompressDeflateWithDict when the compressed data is produced.
|
|
-- Decompression and compression must use the same dictionary.
|
|
-- Otherwise wrong decompressed data could be produced without generating any
|
|
-- error.
|
|
-- @return [string/nil] If the decompression succeeds, return the decompressed
|
|
-- data. If the decompression fails, return nil. You should check if this return
|
|
-- value is non-nil to know if the decompression succeeds.
|
|
-- @return [integer] If the decompression succeeds, return the number of
|
|
-- unprocessed bytes in the input compressed data. This return value is a
|
|
-- positive integer if the input data is a valid compressed data appended by an
|
|
-- arbitary non-empty string. This return value is 0 if the input data does not
|
|
-- contain any extra bytes.<br>
|
|
-- If the decompression fails (The first return value of this function is nil),
|
|
-- this return value is undefined.
|
|
-- @see LibDeflate:CompressZlibWithDict
|
|
function LibDeflate:DecompressZlibWithDict(str, dictionary)
|
|
local arg_valid, arg_err = IsValidArguments(str, true, dictionary)
|
|
if not arg_valid then
|
|
error(("Usage: LibDeflate:DecompressZlibWithDict(str, dictionary): "
|
|
..arg_err), 2)
|
|
end
|
|
return DecompressZlibInternal(str, dictionary)
|
|
end
|
|
|
|
-- Calculate the huffman code of fixed block
|
|
do
|
|
_fix_block_literal_huffman_bitlen = {}
|
|
for sym=0, 143 do
|
|
_fix_block_literal_huffman_bitlen[sym] = 8
|
|
end
|
|
for sym=144, 255 do
|
|
_fix_block_literal_huffman_bitlen[sym] = 9
|
|
end
|
|
for sym=256, 279 do
|
|
_fix_block_literal_huffman_bitlen[sym] = 7
|
|
end
|
|
for sym=280, 287 do
|
|
_fix_block_literal_huffman_bitlen[sym] = 8
|
|
end
|
|
|
|
_fix_block_dist_huffman_bitlen = {}
|
|
for dist=0, 31 do
|
|
_fix_block_dist_huffman_bitlen[dist] = 5
|
|
end
|
|
local status
|
|
status, _fix_block_literal_huffman_bitlen_count
|
|
, _fix_block_literal_huffman_to_deflate_code =
|
|
GetHuffmanForDecode(_fix_block_literal_huffman_bitlen, 287, 9)
|
|
assert(status == 0)
|
|
status, _fix_block_dist_huffman_bitlen_count,
|
|
_fix_block_dist_huffman_to_deflate_code =
|
|
GetHuffmanForDecode(_fix_block_dist_huffman_bitlen, 31, 5)
|
|
assert(status == 0)
|
|
|
|
_fix_block_literal_huffman_code =
|
|
GetHuffmanCodeFromBitlen(_fix_block_literal_huffman_bitlen_count
|
|
, _fix_block_literal_huffman_bitlen, 287, 9)
|
|
_fix_block_dist_huffman_code =
|
|
GetHuffmanCodeFromBitlen(_fix_block_dist_huffman_bitlen_count
|
|
, _fix_block_dist_huffman_bitlen, 31, 5)
|
|
end
|
|
|
|
-- Encoding algorithms
|
|
-- Prefix encoding algorithm
|
|
-- implemented by Galmok of European Stormrage (Horde), galmok@gmail.com
|
|
-- From LibCompress <https://www.wowace.com/projects/libcompress>,
|
|
-- which is licensed under GPLv2
|
|
-- The code has been modified by the author of LibDeflate.
|
|
------------------------------------------------------------------------------
|
|
|
|
-- to be able to match any requested byte value, the search
|
|
-- string must be preprocessed characters to escape with %:
|
|
-- ( ) . % + - * ? [ ] ^ $
|
|
-- "illegal" byte values:
|
|
-- 0 is replaces %z
|
|
local _gsub_escape_table = {
|
|
["\000"] = "%z", ["("] = "%(", [")"] = "%)", ["."] = "%.",
|
|
["%"] = "%%", ["+"] = "%+", ["-"] = "%-", ["*"] = "%*",
|
|
["?"] = "%?", ["["] = "%[", ["]"] = "%]", ["^"] = "%^",
|
|
["$"] = "%$",
|
|
}
|
|
|
|
local function escape_for_gsub(str)
|
|
return str:gsub("([%z%(%)%.%%%+%-%*%?%[%]%^%$])", _gsub_escape_table)
|
|
end
|
|
|
|
--- Create a custom codec with encoder and decoder. <br>
|
|
-- This codec is used to convert an input string to make it not contain
|
|
-- some specific bytes.
|
|
-- This created codec and the parameters of this function do NOT take
|
|
-- localization into account. One byte (0-255) in the string is exactly one
|
|
-- character (0-255).
|
|
-- Credits to LibCompress.
|
|
-- @param reserved_chars [string] The created encoder will ensure encoded
|
|
-- data does not contain any single character in reserved_chars. This parameter
|
|
-- should be non-empty.
|
|
-- @param escape_chars [string] The escape character(s) used in the created
|
|
-- codec. The codec converts any character included in reserved\_chars /
|
|
-- escape\_chars / map\_chars to (one escape char + one character not in
|
|
-- reserved\_chars / escape\_chars / map\_chars).
|
|
-- You usually only need to provide a length-1 string for this parameter.
|
|
-- Length-2 string is only needed when
|
|
-- reserved\_chars + escape\_chars + map\_chars is longer than 127.
|
|
-- This parameter should be non-empty.
|
|
-- @param map_chars [string] The created encoder will map every
|
|
-- reserved\_chars:sub(i, i) (1 <= i <= #map\_chars) to map\_chars:sub(i, i).
|
|
-- This parameter CAN be empty string.
|
|
-- @return [table/nil] If the codec cannot be created, return nil.<br>
|
|
-- If the codec can be created according to the given
|
|
-- parameters, return the codec, which is a encode/decode table.
|
|
-- The table contains two functions: <br>
|
|
-- t:Encode(str) returns the encoded string. <br>
|
|
-- t:Decode(str) returns the decoded string if succeeds. nil if fails.
|
|
-- @return [nil/string] If the codec is successfully created, return nil.
|
|
-- If not, return a string that describes the reason why the codec cannot be
|
|
-- created.
|
|
-- @usage
|
|
-- -- Create an encoder/decoder that maps all "\000" to "\003",
|
|
-- -- and escape "\001" (and "\002" and "\003") properly
|
|
-- local codec = LibDeflate:CreateCodec("\000\001", "\002", "\003")
|
|
--
|
|
-- local encoded = codec:Encode(SOME_STRING)
|
|
-- -- "encoded" does not contain "\000" or "\001"
|
|
-- local decoded = codec:Decode(encoded)
|
|
-- -- assert(decoded == SOME_STRING)
|
|
function LibDeflate:CreateCodec(reserved_chars, escape_chars
|
|
, map_chars)
|
|
-- select a default escape character
|
|
if type(reserved_chars) ~= "string"
|
|
or type(escape_chars) ~= "string"
|
|
or type(map_chars) ~= "string" then
|
|
error(
|
|
"Usage: LibDeflate:CreateCodec(reserved_chars,"
|
|
.." escape_chars, map_chars):"
|
|
.." All arguments must be string.", 2)
|
|
end
|
|
|
|
if escape_chars == "" then
|
|
return nil, "No escape characters supplied."
|
|
end
|
|
if #reserved_chars < #map_chars then
|
|
return nil, "The number of reserved characters must be"
|
|
.." at least as many as the number of mapped chars."
|
|
end
|
|
if reserved_chars == "" then
|
|
return nil, "No characters to encode."
|
|
end
|
|
|
|
local encode_bytes = reserved_chars..escape_chars..map_chars
|
|
-- build list of bytes not available as a suffix to a prefix byte
|
|
local taken = {}
|
|
for i = 1, #encode_bytes do
|
|
local byte = string_byte(encode_bytes, i, i)
|
|
if taken[byte] then -- Modified by LibDeflate:
|
|
return nil, "There must be no duplicate characters in the"
|
|
.." concatenation of reserved_chars, escape_chars and"
|
|
.." map_chars."
|
|
end
|
|
taken[byte] = true
|
|
end
|
|
|
|
-- Modified by LibDeflate:
|
|
-- Store the patterns and replacement in tables for later use.
|
|
-- This function is modified that loadstring() lua api is no longer used.
|
|
local decode_patterns = {}
|
|
local decode_repls = {}
|
|
|
|
-- the encoding can be a single gsub
|
|
-- , but the decoding can require multiple gsubs
|
|
local encode_search = {}
|
|
local encode_translate = {}
|
|
|
|
-- map single byte to single byte
|
|
if #map_chars > 0 then
|
|
local decode_search = {}
|
|
local decode_translate = {}
|
|
for i = 1, #map_chars do
|
|
local from = string_sub(reserved_chars, i, i)
|
|
local to = string_sub(map_chars, i, i)
|
|
encode_translate[from] = to
|
|
encode_search[#encode_search+1] = from
|
|
decode_translate[to] = from
|
|
decode_search[#decode_search+1] = to
|
|
end
|
|
decode_patterns[#decode_patterns+1] =
|
|
"([".. escape_for_gsub(table_concat(decode_search)).."])"
|
|
decode_repls[#decode_repls+1] = decode_translate
|
|
end
|
|
|
|
local escape_char_index = 1
|
|
local escape_char = string_sub(escape_chars
|
|
, escape_char_index, escape_char_index)
|
|
-- map single byte to double-byte
|
|
local r = 0 -- suffix char value to the escapeChar
|
|
|
|
local decode_search = {}
|
|
local decode_translate = {}
|
|
for i = 1, #encode_bytes do
|
|
local c = string_sub(encode_bytes, i, i)
|
|
if not encode_translate[c] then
|
|
-- this loop will update escapeChar and r
|
|
while r >= 256 or taken[r] do
|
|
-- Bug in LibCompress r81
|
|
-- while r < 256 and taken[r] do
|
|
r = r + 1
|
|
if r > 255 then -- switch to next escapeChar
|
|
decode_patterns[#decode_patterns+1] =
|
|
escape_for_gsub(escape_char)
|
|
.."(["
|
|
.. escape_for_gsub(table_concat(decode_search)).."])"
|
|
decode_repls[#decode_repls+1] = decode_translate
|
|
|
|
escape_char_index = escape_char_index + 1
|
|
escape_char = string_sub(escape_chars, escape_char_index
|
|
, escape_char_index)
|
|
r = 0
|
|
decode_search = {}
|
|
decode_translate = {}
|
|
|
|
-- Fixes Another bug in LibCompress r82.
|
|
-- LibCompress checks this error condition
|
|
-- right after "if r > 255 then"
|
|
-- This is why error case should also be tested.
|
|
if not escape_char or escape_char == "" then
|
|
-- actually I don't need to check
|
|
-- "not ecape_char", but what if Lua changes
|
|
-- the behavior of string.sub() in the future?
|
|
-- we are out of escape chars and we need more!
|
|
return nil, "Out of escape characters."
|
|
end
|
|
end
|
|
end
|
|
|
|
local char_r = _byte_to_char[r]
|
|
encode_translate[c] = escape_char..char_r
|
|
encode_search[#encode_search+1] = c
|
|
decode_translate[char_r] = c
|
|
decode_search[#decode_search+1] = char_r
|
|
r = r + 1
|
|
end
|
|
if i == #encode_bytes then
|
|
decode_patterns[#decode_patterns+1] =
|
|
escape_for_gsub(escape_char).."(["
|
|
.. escape_for_gsub(table_concat(decode_search)).."])"
|
|
decode_repls[#decode_repls+1] = decode_translate
|
|
end
|
|
end
|
|
|
|
local codec = {}
|
|
|
|
local encode_pattern = "(["
|
|
.. escape_for_gsub(table_concat(encode_search)).."])"
|
|
local encode_repl = encode_translate
|
|
|
|
function codec:Encode(str)
|
|
if type(str) ~= "string" then
|
|
error(("Usage: codec:Encode(str):"
|
|
.." 'str' - string expected got '%s'."):format(type(str)), 2)
|
|
end
|
|
return string_gsub(str, encode_pattern, encode_repl)
|
|
end
|
|
|
|
local decode_tblsize = #decode_patterns
|
|
local decode_fail_pattern = "(["
|
|
.. escape_for_gsub(reserved_chars).."])"
|
|
|
|
function codec:Decode(str)
|
|
if type(str) ~= "string" then
|
|
error(("Usage: codec:Decode(str):"
|
|
.." 'str' - string expected got '%s'."):format(type(str)), 2)
|
|
end
|
|
if string_find(str, decode_fail_pattern) then
|
|
return nil
|
|
end
|
|
for i = 1, decode_tblsize do
|
|
str = string_gsub(str, decode_patterns[i], decode_repls[i])
|
|
end
|
|
return str
|
|
end
|
|
|
|
return codec
|
|
end
|
|
|
|
local _addon_channel_codec
|
|
|
|
local function GenerateWoWAddonChannelCodec()
|
|
return LibDeflate:CreateCodec("\000", "\001", "")
|
|
end
|
|
|
|
--- Encode the string to make it ready to be transmitted in World of
|
|
-- Warcraft addon channel. <br>
|
|
-- The encoded string is guaranteed to contain no NULL ("\000") character.
|
|
-- @param str [string] The string to be encoded.
|
|
-- @return The encoded string.
|
|
-- @see LibDeflate:DecodeForWoWAddonChannel
|
|
function LibDeflate:EncodeForWoWAddonChannel(str)
|
|
if type(str) ~= "string" then
|
|
error(("Usage: LibDeflate:EncodeForWoWAddonChannel(str):"
|
|
.." 'str' - string expected got '%s'."):format(type(str)), 2)
|
|
end
|
|
if not _addon_channel_codec then
|
|
_addon_channel_codec = GenerateWoWAddonChannelCodec()
|
|
end
|
|
return _addon_channel_codec:Encode(str)
|
|
end
|
|
|
|
--- Decode the string produced by LibDeflate:EncodeForWoWAddonChannel
|
|
-- @param str [string] The string to be decoded.
|
|
-- @return [string/nil] The decoded string if succeeds. nil if fails.
|
|
-- @see LibDeflate:EncodeForWoWAddonChannel
|
|
function LibDeflate:DecodeForWoWAddonChannel(str)
|
|
if type(str) ~= "string" then
|
|
error(("Usage: LibDeflate:DecodeForWoWAddonChannel(str):"
|
|
.." 'str' - string expected got '%s'."):format(type(str)), 2)
|
|
end
|
|
if not _addon_channel_codec then
|
|
_addon_channel_codec = GenerateWoWAddonChannelCodec()
|
|
end
|
|
return _addon_channel_codec:Decode(str)
|
|
end
|
|
|
|
-- For World of Warcraft Chat Channel Encoding
|
|
-- implemented by Galmok of European Stormrage (Horde), galmok@gmail.com
|
|
-- From LibCompress <https://www.wowace.com/projects/libcompress>,
|
|
-- which is licensed under GPLv2
|
|
-- The code has been modified by the author of LibDeflate.
|
|
-- Following byte values are not allowed:
|
|
-- \000, s, S, \010, \013, \124, %
|
|
-- Because SendChatMessage will error
|
|
-- if an UTF8 multibyte character is incomplete,
|
|
-- all character values above 127 have to be encoded to avoid this.
|
|
-- This costs quite a bit of bandwidth (about 13-14%)
|
|
-- Also, because drunken status is unknown for the received
|
|
-- , strings used with SendChatMessage should be terminated with
|
|
-- an identifying byte value, after which the server MAY add "...hic!"
|
|
-- or as much as it can fit(!).
|
|
-- Pass the identifying byte as a reserved character to this function
|
|
-- to ensure the encoding doesn't contain that value.
|
|
-- or use this: local message, match = arg1:gsub("^(.*)\029.-$", "%1")
|
|
-- arg1 is message from channel, \029 is the string terminator
|
|
-- , but may be used in the encoded datastream as well. :-)
|
|
-- This encoding will expand data anywhere from:
|
|
-- 0% (average with pure ascii text)
|
|
-- 53.5% (average with random data valued zero to 255)
|
|
-- 100% (only encoding data that encodes to two bytes)
|
|
local function GenerateWoWChatChannelCodec()
|
|
local r = {}
|
|
for i = 128, 255 do
|
|
r[#r+1] = _byte_to_char[i]
|
|
end
|
|
|
|
local reserved_chars = "sS\000\010\013\124%"..table_concat(r)
|
|
return LibDeflate:CreateCodec(reserved_chars
|
|
, "\029\031", "\015\020")
|
|
end
|
|
|
|
local _chat_channel_codec
|
|
|
|
--- Encode the string to make it ready to be transmitted in World of
|
|
-- Warcraft chat channel. <br>
|
|
-- See also https://wow.gamepedia.com/ValidChatMessageCharacters
|
|
-- @param str [string] The string to be encoded.
|
|
-- @return [string] The encoded string.
|
|
-- @see LibDeflate:DecodeForWoWChatChannel
|
|
function LibDeflate:EncodeForWoWChatChannel(str)
|
|
if type(str) ~= "string" then
|
|
error(("Usage: LibDeflate:EncodeForWoWChatChannel(str):"
|
|
.." 'str' - string expected got '%s'."):format(type(str)), 2)
|
|
end
|
|
if not _chat_channel_codec then
|
|
_chat_channel_codec = GenerateWoWChatChannelCodec()
|
|
end
|
|
return _chat_channel_codec:Encode(str)
|
|
end
|
|
|
|
--- Decode the string produced by LibDeflate:EncodeForWoWChatChannel.
|
|
-- @param str [string] The string to be decoded.
|
|
-- @return [string/nil] The decoded string if succeeds. nil if fails.
|
|
-- @see LibDeflate:EncodeForWoWChatChannel
|
|
function LibDeflate:DecodeForWoWChatChannel(str)
|
|
if type(str) ~= "string" then
|
|
error(("Usage: LibDeflate:DecodeForWoWChatChannel(str):"
|
|
.." 'str' - string expected got '%s'."):format(type(str)), 2)
|
|
end
|
|
if not _chat_channel_codec then
|
|
_chat_channel_codec = GenerateWoWChatChannelCodec()
|
|
end
|
|
return _chat_channel_codec:Decode(str)
|
|
end
|
|
|
|
-- Credits to WeakAuras <https://github.com/WeakAuras/WeakAuras2>,
|
|
-- and Galmok (galmok@gmail.com) for the 6 bit encoding algorithm.
|
|
-- The result of encoding will be 25% larger than the
|
|
-- origin string, but every single byte of the encoding result will be
|
|
-- printable characters as the following.
|
|
local _byte_to_6bit_char = {
|
|
[0]="a", "b", "c", "d", "e", "f", "g", "h",
|
|
"i", "j", "k", "l", "m", "n", "o", "p",
|
|
"q", "r", "s", "t", "u", "v", "w", "x",
|
|
"y", "z", "A", "B", "C", "D", "E", "F",
|
|
"G", "H", "I", "J", "K", "L", "M", "N",
|
|
"O", "P", "Q", "R", "S", "T", "U", "V",
|
|
"W", "X", "Y", "Z", "0", "1", "2", "3",
|
|
"4", "5", "6", "7", "8", "9", "(", ")",
|
|
}
|
|
|
|
local _6bit_to_byte = {
|
|
[97]=0,[98]=1,[99]=2,[100]=3,[101]=4,[102]=5,[103]=6,[104]=7,
|
|
[105]=8,[106]=9,[107]=10,[108]=11,[109]=12,[110]=13,[111]=14,[112]=15,
|
|
[113]=16,[114]=17,[115]=18,[116]=19,[117]=20,[118]=21,[119]=22,[120]=23,
|
|
[121]=24,[122]=25,[65]=26,[66]=27,[67]=28,[68]=29,[69]=30,[70]=31,
|
|
[71]=32,[72]=33,[73]=34,[74]=35,[75]=36,[76]=37,[77]=38,[78]=39,
|
|
[79]=40,[80]=41,[81]=42,[82]=43,[83]=44,[84]=45,[85]=46,[86]=47,
|
|
[87]=48,[88]=49,[89]=50,[90]=51,[48]=52,[49]=53,[50]=54,[51]=55,
|
|
[52]=56,[53]=57,[54]=58,[55]=59,[56]=60,[57]=61,[40]=62,[41]=63,
|
|
}
|
|
|
|
--- Encode the string to make it printable. <br>
|
|
--
|
|
-- Credis to WeakAuras2, this function is equivalant to the implementation
|
|
-- it is using right now. <br>
|
|
-- The encoded string will be 25% larger than the origin string. However, every
|
|
-- single byte of the encoded string will be one of 64 printable ASCII
|
|
-- characters, which are can be easier copied, pasted and displayed.
|
|
-- (26 lowercase letters, 26 uppercase letters, 10 numbers digits,
|
|
-- left parenthese, or right parenthese)
|
|
-- @param str [string] The string to be encoded.
|
|
-- @return [string] The encoded string.
|
|
function LibDeflate:EncodeForPrint(str)
|
|
if type(str) ~= "string" then
|
|
error(("Usage: LibDeflate:EncodeForPrint(str):"
|
|
.." 'str' - string expected got '%s'."):format(type(str)), 2)
|
|
end
|
|
local strlen = #str
|
|
local strlenMinus2 = strlen - 2
|
|
local i = 1
|
|
local buffer = {}
|
|
local buffer_size = 0
|
|
while i <= strlenMinus2 do
|
|
local x1, x2, x3 = string_byte(str, i, i+2)
|
|
i = i + 3
|
|
local cache = x1+x2*256+x3*65536
|
|
local b1 = cache % 64
|
|
cache = (cache - b1) / 64
|
|
local b2 = cache % 64
|
|
cache = (cache - b2) / 64
|
|
local b3 = cache % 64
|
|
local b4 = (cache - b3) / 64
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] =
|
|
_byte_to_6bit_char[b1].._byte_to_6bit_char[b2]
|
|
.._byte_to_6bit_char[b3].._byte_to_6bit_char[b4]
|
|
end
|
|
|
|
local cache = 0
|
|
local cache_bitlen = 0
|
|
while i <= strlen do
|
|
local x = string_byte(str, i, i)
|
|
cache = cache + x * _pow2[cache_bitlen]
|
|
cache_bitlen = cache_bitlen + 8
|
|
i = i + 1
|
|
end
|
|
while cache_bitlen > 0 do
|
|
local bit6 = cache % 64
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] = _byte_to_6bit_char[bit6]
|
|
cache = (cache - bit6) / 64
|
|
cache_bitlen = cache_bitlen - 6
|
|
end
|
|
|
|
return table_concat(buffer)
|
|
end
|
|
|
|
--- Decode the printable string produced by LibDeflate:EncodeForPrint.
|
|
-- "str" will have its prefixed and trailing control characters or space
|
|
-- removed before it is decoded, so it is easier to use if "str" comes form
|
|
-- user copy and paste with some prefixed or trailing spaces.
|
|
-- Then decode fails if the string contains any characters cant be produced by
|
|
-- LibDeflate:EncodeForPrint. That means, decode fails if the string contains a
|
|
-- characters NOT one of 26 lowercase letters, 26 uppercase letters,
|
|
-- 10 numbers digits, left parenthese, or right parenthese.
|
|
-- @param str [string] The string to be decoded
|
|
-- @return [string/nil] The decoded string if succeeds. nil if fails.
|
|
function LibDeflate:DecodeForPrint(str)
|
|
if type(str) ~= "string" then
|
|
error(("Usage: LibDeflate:DecodeForPrint(str):"
|
|
.." 'str' - string expected got '%s'."):format(type(str)), 2)
|
|
end
|
|
str = str:gsub("^[%c ]+", "")
|
|
str = str:gsub("[%c ]+$", "")
|
|
|
|
local strlen = #str
|
|
if strlen == 1 then
|
|
return nil
|
|
end
|
|
local strlenMinus3 = strlen - 3
|
|
local i = 1
|
|
local buffer = {}
|
|
local buffer_size = 0
|
|
while i <= strlenMinus3 do
|
|
local x1, x2, x3, x4 = string_byte(str, i, i+3)
|
|
x1 = _6bit_to_byte[x1]
|
|
x2 = _6bit_to_byte[x2]
|
|
x3 = _6bit_to_byte[x3]
|
|
x4 = _6bit_to_byte[x4]
|
|
if not (x1 and x2 and x3 and x4) then
|
|
return nil
|
|
end
|
|
i = i + 4
|
|
local cache = x1+x2*64+x3*4096+x4*262144
|
|
local b1 = cache % 256
|
|
cache = (cache - b1) / 256
|
|
local b2 = cache % 256
|
|
local b3 = (cache - b2) / 256
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] =
|
|
_byte_to_char[b1].._byte_to_char[b2].._byte_to_char[b3]
|
|
end
|
|
|
|
local cache = 0
|
|
local cache_bitlen = 0
|
|
while i <= strlen do
|
|
local x = string_byte(str, i, i)
|
|
x = _6bit_to_byte[x]
|
|
if not x then
|
|
return nil
|
|
end
|
|
cache = cache + x * _pow2[cache_bitlen]
|
|
cache_bitlen = cache_bitlen + 6
|
|
i = i + 1
|
|
end
|
|
|
|
while cache_bitlen >= 8 do
|
|
local byte = cache % 256
|
|
buffer_size = buffer_size + 1
|
|
buffer[buffer_size] = _byte_to_char[byte]
|
|
cache = (cache - byte) / 256
|
|
cache_bitlen = cache_bitlen - 8
|
|
end
|
|
|
|
return table_concat(buffer)
|
|
end
|
|
|
|
local function InternalClearCache()
|
|
_chat_channel_codec = nil
|
|
_addon_channel_codec = nil
|
|
end
|
|
|
|
-- For test. Don't use the functions in this table for real application.
|
|
-- Stuffs in this table is subject to change.
|
|
LibDeflate.internals = {
|
|
LoadStringToTable = LoadStringToTable,
|
|
IsValidDictionary = IsValidDictionary,
|
|
IsEqualAdler32 = IsEqualAdler32,
|
|
_byte_to_6bit_char = _byte_to_6bit_char,
|
|
_6bit_to_byte = _6bit_to_byte,
|
|
InternalClearCache = InternalClearCache,
|
|
}
|
|
|
|
--[[-- Commandline options
|
|
@class table
|
|
@name CommandlineOptions
|
|
@usage lua LibDeflate.lua [OPTION] [INPUT] [OUTPUT]
|
|
\-0 store only. no compression.
|
|
\-1 fastest compression.
|
|
\-9 slowest and best compression.
|
|
\-d do decompression instead of compression.
|
|
\--dict <filename> specify the file that contains
|
|
the entire preset dictionary.
|
|
\-h give this help.
|
|
\--strategy <fixed/huffman_only/dynamic> specify a special compression strategy.
|
|
\-v print the version and copyright info.
|
|
\--zlib use zlib format instead of raw deflate.
|
|
]]
|
|
|
|
-- currently no plan to support stdin and stdout.
|
|
-- Because Lua in Windows does not set stdout with binary mode.
|
|
if io and os and debug and _G.arg then
|
|
local io = io
|
|
local os = os
|
|
local debug = debug
|
|
local arg = _G.arg
|
|
local debug_info = debug.getinfo(1)
|
|
if debug_info.source == arg[0]
|
|
or debug_info.short_src == arg[0] then
|
|
-- We are indeed runnning THIS file from the commandline.
|
|
local input
|
|
local output
|
|
local i = 1
|
|
local status
|
|
local is_zlib = false
|
|
local is_decompress = false
|
|
local level
|
|
local strategy
|
|
local dictionary
|
|
while (arg[i]) do
|
|
local a = arg[i]
|
|
if a == "-h" then
|
|
print(LibDeflate._COPYRIGHT
|
|
.."\nUsage: lua LibDeflate.lua [OPTION] [INPUT] [OUTPUT]\n"
|
|
.." -0 store only. no compression.\n"
|
|
.." -1 fastest compression.\n"
|
|
.." -9 slowest and best compression.\n"
|
|
.." -d do decompression instead of compression.\n"
|
|
.." --dict <filename> specify the file that contains"
|
|
.." the entire preset dictionary.\n"
|
|
.." -h give this help.\n"
|
|
.." --strategy <fixed/huffman_only/dynamic>"
|
|
.." specify a special compression strategy.\n"
|
|
.." -v print the version and copyright info.\n"
|
|
.." --zlib use zlib format instead of raw deflate.\n")
|
|
os.exit(0)
|
|
elseif a == "-v" then
|
|
print(LibDeflate._COPYRIGHT)
|
|
os.exit(0)
|
|
elseif a:find("^%-[0-9]$") then
|
|
level = tonumber(a:sub(2, 2))
|
|
elseif a == "-d" then
|
|
is_decompress = true
|
|
elseif a == "--dict" then
|
|
i = i + 1
|
|
local dict_filename = arg[i]
|
|
if not dict_filename then
|
|
io.stderr:write("You must speicify the dict filename")
|
|
os.exit(1)
|
|
end
|
|
local dict_file, dict_status = io.open(dict_filename, "rb")
|
|
if not dict_file then
|
|
io.stderr:write(
|
|
("LibDeflate: Cannot read the dictionary file '%s': %s")
|
|
:format(dict_filename, dict_status))
|
|
os.exit(1)
|
|
end
|
|
local dict_str = dict_file:read("*all")
|
|
dict_file:close()
|
|
-- In your lua program, you should pass in adler32 as a CONSTANT
|
|
-- , so it actually prevent you from modifying dictionary
|
|
-- unintentionally during the program development. I do this
|
|
-- here just because no convenient way to verify in commandline.
|
|
dictionary = LibDeflate:CreateDictionary(dict_str,
|
|
#dict_str, LibDeflate:Adler32(dict_str))
|
|
elseif a == "--strategy" then
|
|
-- Not sure if I should check error here
|
|
-- If I do, redudant code.
|
|
i = i + 1
|
|
strategy = arg[i]
|
|
elseif a == "--zlib" then
|
|
is_zlib = true
|
|
elseif a:find("^%-") then
|
|
io.stderr:write(("LibDeflate: Invalid argument: %s")
|
|
:format(a))
|
|
os.exit(1)
|
|
else
|
|
if not input then
|
|
input, status = io.open(a, "rb")
|
|
if not input then
|
|
io.stderr:write(
|
|
("LibDeflate: Cannot read the file '%s': %s")
|
|
:format(a, tostring(status)))
|
|
os.exit(1)
|
|
end
|
|
elseif not output then
|
|
output, status = io.open(a, "wb")
|
|
if not output then
|
|
io.stderr:write(
|
|
("LibDeflate: Cannot write the file '%s': %s")
|
|
:format(a, tostring(status)))
|
|
os.exit(1)
|
|
end
|
|
end
|
|
end
|
|
i = i + 1
|
|
end -- while (arg[i])
|
|
|
|
if not input or not output then
|
|
io.stderr:write("LibDeflate:"
|
|
.." You must specify both input and output files.")
|
|
os.exit(1)
|
|
end
|
|
|
|
local input_data = input:read("*all")
|
|
local configs = {
|
|
level = level,
|
|
strategy = strategy,
|
|
}
|
|
local output_data
|
|
if not is_decompress then
|
|
if not is_zlib then
|
|
if not dictionary then
|
|
output_data =
|
|
LibDeflate:CompressDeflate(input_data, configs)
|
|
else
|
|
output_data =
|
|
LibDeflate:CompressDeflateWithDict(input_data, dictionary
|
|
, configs)
|
|
end
|
|
else
|
|
if not dictionary then
|
|
output_data =
|
|
LibDeflate:CompressZlib(input_data, configs)
|
|
else
|
|
output_data =
|
|
LibDeflate:CompressZlibWithDict(input_data, dictionary
|
|
, configs)
|
|
end
|
|
end
|
|
else
|
|
if not is_zlib then
|
|
if not dictionary then
|
|
output_data = LibDeflate:DecompressDeflate(input_data)
|
|
else
|
|
output_data = LibDeflate:DecompressDeflateWithDict(
|
|
input_data, dictionary)
|
|
end
|
|
else
|
|
if not dictionary then
|
|
output_data = LibDeflate:DecompressZlib(input_data)
|
|
else
|
|
output_data = LibDeflate:DecompressZlibWithDict(
|
|
input_data, dictionary)
|
|
end
|
|
end
|
|
end
|
|
|
|
if not output_data then
|
|
io.stderr:write("LibDeflate: Decompress fails.")
|
|
os.exit(1)
|
|
end
|
|
|
|
output:write(output_data)
|
|
if input and input ~= io.stdin then
|
|
input:close()
|
|
end
|
|
if output and output ~= io.stdout then
|
|
output:close()
|
|
end
|
|
|
|
io.stderr:write(("Successfully writes %d bytes"):format(
|
|
output_data:len()))
|
|
os.exit(0)
|
|
end
|
|
end
|
|
|
|
return LibDeflate
|