The Tor Browser / file comparison
comparison: js/src/vm/Compression.cpp
js/src/vm/Compression.cpp
- branch
- TOR_BUG_3246
- changeset 5
- 4ab42b5ab56c
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| -1:000000000000 | 0:3bfbc50a2a5b |
|---|---|
| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- | |
| 2 * vim: set ts=8 sts=4 et sw=4 tw=99: | |
| 3 * This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 #include "vm/Compression.h" | |
| 8 | |
| 9 #include "js/Utility.h" | |
| 10 | |
| 11 using namespace js; | |
| 12 | |
| 13 #if USE_ZLIB | |
| 14 static void * | |
| 15 zlib_alloc(void *cx, uInt items, uInt size) | |
| 16 { | |
| 17 return js_calloc(items, size); | |
| 18 } | |
| 19 | |
| 20 static void | |
| 21 zlib_free(void *cx, void *addr) | |
| 22 { | |
| 23 js_free(addr); | |
| 24 } | |
| 25 | |
| 26 Compressor::Compressor(const unsigned char *inp, size_t inplen) | |
| 27 : inp(inp), | |
| 28 inplen(inplen), | |
| 29 outbytes(0), | |
| 30 initialized(false) | |
| 31 { | |
| 32 JS_ASSERT(inplen > 0); | |
| 33 zs.opaque = nullptr; | |
| 34 zs.next_in = (Bytef *)inp; | |
| 35 zs.avail_in = 0; | |
| 36 zs.next_out = nullptr; | |
| 37 zs.avail_out = 0; | |
| 38 zs.zalloc = zlib_alloc; | |
| 39 zs.zfree = zlib_free; | |
| 40 } | |
| 41 | |
| 42 | |
| 43 Compressor::~Compressor() | |
| 44 { | |
| 45 if (initialized) { | |
| 46 int ret = deflateEnd(&zs); | |
| 47 if (ret != Z_OK) { | |
| 48 // If we finished early, we can get a Z_DATA_ERROR. | |
| 49 JS_ASSERT(ret == Z_DATA_ERROR); | |
| 50 JS_ASSERT(uInt(zs.next_in - inp) < inplen || !zs.avail_out); | |
| 51 } | |
| 52 } | |
| 53 } | |
| 54 | |
| 55 bool | |
| 56 Compressor::init() | |
| 57 { | |
| 58 if (inplen >= UINT32_MAX) | |
| 59 return false; | |
| 60 // zlib is slow and we'd rather be done compression sooner | |
| 61 // even if it means decompression is slower which penalizes | |
| 62 // Function.toString() | |
| 63 int ret = deflateInit(&zs, Z_BEST_SPEED); | |
| 64 if (ret != Z_OK) { | |
| 65 JS_ASSERT(ret == Z_MEM_ERROR); | |
| 66 return false; | |
| 67 } | |
| 68 initialized = true; | |
| 69 return true; | |
| 70 } | |
| 71 | |
| 72 void | |
| 73 Compressor::setOutput(unsigned char *out, size_t outlen) | |
| 74 { | |
| 75 JS_ASSERT(outlen > outbytes); | |
| 76 zs.next_out = out + outbytes; | |
| 77 zs.avail_out = outlen - outbytes; | |
| 78 } | |
| 79 | |
| 80 Compressor::Status | |
| 81 Compressor::compressMore() | |
| 82 { | |
| 83 JS_ASSERT(zs.next_out); | |
| 84 uInt left = inplen - (zs.next_in - inp); | |
| 85 bool done = left <= CHUNKSIZE; | |
| 86 if (done) | |
| 87 zs.avail_in = left; | |
| 88 else if (zs.avail_in == 0) | |
| 89 zs.avail_in = CHUNKSIZE; | |
| 90 Bytef *oldout = zs.next_out; | |
| 91 int ret = deflate(&zs, done ? Z_FINISH : Z_NO_FLUSH); | |
| 92 outbytes += zs.next_out - oldout; | |
| 93 if (ret == Z_MEM_ERROR) { | |
| 94 zs.avail_out = 0; | |
| 95 return OOM; | |
| 96 } | |
| 97 if (ret == Z_BUF_ERROR || (done && ret == Z_OK)) { | |
| 98 JS_ASSERT(zs.avail_out == 0); | |
| 99 return MOREOUTPUT; | |
| 100 } | |
| 101 JS_ASSERT_IF(!done, ret == Z_OK); | |
| 102 JS_ASSERT_IF(done, ret == Z_STREAM_END); | |
| 103 return done ? DONE : CONTINUE; | |
| 104 } | |
| 105 | |
| 106 bool | |
| 107 js::DecompressString(const unsigned char *inp, size_t inplen, unsigned char *out, size_t outlen) | |
| 108 { | |
| 109 JS_ASSERT(inplen <= UINT32_MAX); | |
| 110 z_stream zs; | |
| 111 zs.zalloc = zlib_alloc; | |
| 112 zs.zfree = zlib_free; | |
| 113 zs.opaque = nullptr; | |
| 114 zs.next_in = (Bytef *)inp; | |
| 115 zs.avail_in = inplen; | |
| 116 zs.next_out = out; | |
| 117 JS_ASSERT(outlen); | |
| 118 zs.avail_out = outlen; | |
| 119 int ret = inflateInit(&zs); | |
| 120 if (ret != Z_OK) { | |
| 121 JS_ASSERT(ret == Z_MEM_ERROR); | |
| 122 return false; | |
| 123 } | |
| 124 ret = inflate(&zs, Z_FINISH); | |
| 125 JS_ASSERT(ret == Z_STREAM_END); | |
| 126 ret = inflateEnd(&zs); | |
| 127 JS_ASSERT(ret == Z_OK); | |
| 128 return true; | |
| 129 } | |
| 130 #endif /* USE_ZLIB */ | |
| 131 |
