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author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
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committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /gfx/graphite2/src/Decompressor.cpp | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
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Add m-esr52 at 52.6.0
Diffstat (limited to 'gfx/graphite2/src/Decompressor.cpp')
-rw-r--r-- | gfx/graphite2/src/Decompressor.cpp | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/gfx/graphite2/src/Decompressor.cpp b/gfx/graphite2/src/Decompressor.cpp new file mode 100644 index 000000000..4b8b1b495 --- /dev/null +++ b/gfx/graphite2/src/Decompressor.cpp @@ -0,0 +1,115 @@ +/* GRAPHITE2 LICENSING + + Copyright 2015, SIL International + All rights reserved. + + This library is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation; either version 2.1 of License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should also have received a copy of the GNU Lesser General Public + License along with this library in the file named "LICENSE". + If not, write to the Free Software Foundation, 51 Franklin Street, + Suite 500, Boston, MA 02110-1335, USA or visit their web page on the + internet at http://www.fsf.org/licenses/lgpl.html. + +Alternatively, the contents of this file may be used under the terms of the +Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public +License, as published by the Free Software Foundation, either version 2 +of the License or (at your option) any later version. +*/ +#include <cassert> + +#include "inc/Decompressor.h" +#include "inc/Compression.h" + +using namespace lz4; + +namespace { + +inline +u32 read_literal(u8 const * &s, u8 const * const e, u32 l) { + if (l == 15 && s != e) + { + u8 b = 0; + do { l += b = *s++; } while(b==0xff && s != e); + } + return l; +} + +bool read_sequence(u8 const * &src, u8 const * const end, u8 const * &literal, u32 & literal_len, u32 & match_len, u32 & match_dist) +{ + u8 const token = *src++; + + literal_len = read_literal(src, end, token >> 4); + literal = src; + src += literal_len; + + if (src > end - 2 || src < literal) + return false; + + match_dist = *src++; + match_dist |= *src++ << 8; + match_len = read_literal(src, end, token & 0xf); + + return src <= end-5; +} + +} + +int lz4::decompress(void const *in, size_t in_size, void *out, size_t out_size) +{ + if (out_size <= in_size || in_size < sizeof(unsigned long)+1) + return -1; + + u8 const * src = static_cast<u8 const *>(in), + * literal = 0, + * const src_end = src + in_size; + + u8 * dst = static_cast<u8*>(out), + * const dst_end = dst + out_size; + + u32 literal_len = 0, + match_len = 0, + match_dist = 0; + + while (read_sequence(src, src_end, literal, literal_len, match_len, match_dist)) + { + if (literal_len != 0) + { + // Copy in literal. At this point the last full sequence must be at + // least MINMATCH + 5 from the end of the output buffer. + if (align(literal_len) > unsigned(dst_end - dst - (MINMATCH+5)) || dst_end - dst < MINMATCH + 5) + return -1; + dst = overrun_copy(dst, literal, literal_len); + } + + // Copy, possibly repeating, match from earlier in the + // decoded output. + u8 const * const pcpy = dst - match_dist; + if (pcpy < static_cast<u8*>(out) + || pcpy >= dst + || match_len > unsigned(dst_end - dst - (MINMATCH+5)) + || dst_end - dst < MINMATCH + 5) + return -1; + if (dst > pcpy+sizeof(unsigned long) + && dst + align(match_len + MINMATCH) <= dst_end) + dst = overrun_copy(dst, pcpy, match_len + MINMATCH); + else + dst = safe_copy(dst, pcpy, match_len + MINMATCH); + } + + if (literal_len > src_end - literal + || literal_len > dst_end - dst) + return -1; + dst = fast_copy(dst, literal, literal_len); + + return dst - (u8*)out; +} + |