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| 1 // Copyright (c) 2009 The Chromium Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. |
| 4 |
| 5 #include "update_engine/gzip.h" |
| 6 #include <stdlib.h> |
| 7 #include <algorithm> |
| 8 #include <zlib.h> |
| 9 #include "chromeos/obsolete_logging.h" |
| 10 #include "update_engine/utils.h" |
| 11 |
| 12 using std::max; |
| 13 using std::string; |
| 14 using std::vector; |
| 15 |
| 16 namespace chromeos_update_engine { |
| 17 |
| 18 bool GzipDecompressData(const char* const in, const size_t in_size, |
| 19 char** out, size_t* out_size) { |
| 20 if (in_size == 0) { |
| 21 // malloc(0) may legally return NULL, so do malloc(1) |
| 22 *out = reinterpret_cast<char*>(malloc(1)); |
| 23 *out_size = 0; |
| 24 return true; |
| 25 } |
| 26 TEST_AND_RETURN_FALSE(out); |
| 27 TEST_AND_RETURN_FALSE(out_size); |
| 28 z_stream stream; |
| 29 memset(&stream, 0, sizeof(stream)); |
| 30 TEST_AND_RETURN_FALSE(inflateInit2(&stream, 16 + MAX_WBITS) == Z_OK); |
| 31 |
| 32 // guess that output will be roughly double the input size |
| 33 *out_size = in_size * 2; |
| 34 *out = reinterpret_cast<char*>(malloc(*out_size)); |
| 35 TEST_AND_RETURN_FALSE(*out); |
| 36 |
| 37 // TODO(adlr): ensure that this const_cast is safe. |
| 38 stream.next_in = const_cast<Bytef*>(reinterpret_cast<const Bytef*>(in)); |
| 39 stream.avail_in = in_size; |
| 40 stream.next_out = reinterpret_cast<Bytef*>(*out); |
| 41 stream.avail_out = *out_size; |
| 42 for (;;) { |
| 43 int rc = inflate(&stream, Z_FINISH); |
| 44 switch (rc) { |
| 45 case Z_STREAM_END: { |
| 46 *out_size = reinterpret_cast<char*>(stream.next_out) - (*out); |
| 47 TEST_AND_RETURN_FALSE(inflateEnd(&stream) == Z_OK); |
| 48 return true; |
| 49 } |
| 50 case Z_OK: // fall through |
| 51 case Z_BUF_ERROR: { |
| 52 // allocate more space |
| 53 ptrdiff_t out_length = |
| 54 reinterpret_cast<char*>(stream.next_out) - (*out); |
| 55 *out_size *= 2; |
| 56 char* new_out = reinterpret_cast<char*>(realloc(*out, *out_size)); |
| 57 if (!new_out) { |
| 58 free(*out); |
| 59 return false; |
| 60 } |
| 61 *out = new_out; |
| 62 stream.next_out = reinterpret_cast<Bytef*>((*out) + out_length); |
| 63 stream.avail_out = (*out_size) - out_length; |
| 64 break; |
| 65 } |
| 66 default: |
| 67 LOG(INFO) << "Unknown inflate() return value: " << rc; |
| 68 if (stream.msg) |
| 69 LOG(INFO) << " message: " << stream.msg; |
| 70 free(*out); |
| 71 return false; |
| 72 } |
| 73 } |
| 74 } |
| 75 |
| 76 bool GzipCompressData(const char* const in, const size_t in_size, |
| 77 char** out, size_t* out_size) { |
| 78 if (in_size == 0) { |
| 79 // malloc(0) may legally return NULL, so do malloc(1) |
| 80 *out = reinterpret_cast<char*>(malloc(1)); |
| 81 *out_size = 0; |
| 82 return true; |
| 83 } |
| 84 TEST_AND_RETURN_FALSE(out); |
| 85 TEST_AND_RETURN_FALSE(out_size); |
| 86 z_stream stream; |
| 87 memset(&stream, 0, sizeof(stream)); |
| 88 TEST_AND_RETURN_FALSE(deflateInit2(&stream, |
| 89 Z_BEST_COMPRESSION, |
| 90 Z_DEFLATED, |
| 91 16 + MAX_WBITS, |
| 92 9, // most memory used/best compression |
| 93 Z_DEFAULT_STRATEGY) == Z_OK); |
| 94 |
| 95 // guess that output will be roughly half the input size |
| 96 *out_size = max(1U, in_size / 2); |
| 97 *out = reinterpret_cast<char*>(malloc(*out_size)); |
| 98 TEST_AND_RETURN_FALSE(*out); |
| 99 |
| 100 // TODO(adlr): ensure that this const_cast is safe. |
| 101 stream.next_in = const_cast<Bytef*>(reinterpret_cast<const Bytef*>(in)); |
| 102 stream.avail_in = in_size; |
| 103 stream.next_out = reinterpret_cast<Bytef*>(*out); |
| 104 stream.avail_out = *out_size; |
| 105 for (;;) { |
| 106 int rc = deflate(&stream, Z_FINISH); |
| 107 switch (rc) { |
| 108 case Z_STREAM_END: { |
| 109 *out_size = reinterpret_cast<char*>(stream.next_out) - (*out); |
| 110 TEST_AND_RETURN_FALSE(deflateEnd(&stream) == Z_OK); |
| 111 return true; |
| 112 } |
| 113 case Z_OK: // fall through |
| 114 case Z_BUF_ERROR: { |
| 115 // allocate more space |
| 116 ptrdiff_t out_length = |
| 117 reinterpret_cast<char*>(stream.next_out) - (*out); |
| 118 *out_size *= 2; |
| 119 char* new_out = reinterpret_cast<char*>(realloc(*out, *out_size)); |
| 120 if (!new_out) { |
| 121 free(*out); |
| 122 return false; |
| 123 } |
| 124 *out = new_out; |
| 125 stream.next_out = reinterpret_cast<Bytef*>((*out) + out_length); |
| 126 stream.avail_out = (*out_size) - out_length; |
| 127 break; |
| 128 } |
| 129 default: |
| 130 LOG(INFO) << "Unknown defalate() return value: " << rc; |
| 131 if (stream.msg) |
| 132 LOG(INFO) << " message: " << stream.msg; |
| 133 free(*out); |
| 134 return false; |
| 135 } |
| 136 } |
| 137 } |
| 138 |
| 139 bool GzipDecompress(const std::vector<char>& in, std::vector<char>* out) { |
| 140 TEST_AND_RETURN_FALSE(out); |
| 141 char* out_buf; |
| 142 size_t out_size; |
| 143 TEST_AND_RETURN_FALSE(GzipDecompressData(&in[0], in.size(), |
| 144 &out_buf, &out_size)); |
| 145 out->insert(out->end(), out_buf, out_buf + out_size); |
| 146 free(out_buf); |
| 147 return true; |
| 148 } |
| 149 |
| 150 bool GzipCompress(const std::vector<char>& in, std::vector<char>* out) { |
| 151 TEST_AND_RETURN_FALSE(out); |
| 152 char* out_buf; |
| 153 size_t out_size; |
| 154 TEST_AND_RETURN_FALSE(GzipCompressData(&in[0], in.size(), |
| 155 &out_buf, &out_size)); |
| 156 out->insert(out->end(), out_buf, out_buf + out_size); |
| 157 free(out_buf); |
| 158 return true; |
| 159 } |
| 160 |
| 161 bool GzipCompressString(const std::string& str, |
| 162 std::vector<char>* out) { |
| 163 TEST_AND_RETURN_FALSE(out); |
| 164 char* out_buf; |
| 165 size_t out_size; |
| 166 TEST_AND_RETURN_FALSE(GzipCompressData(str.data(), str.size(), |
| 167 &out_buf, &out_size)); |
| 168 out->insert(out->end(), out_buf, out_buf + out_size); |
| 169 free(out_buf); |
| 170 return true; |
| 171 } |
| 172 |
| 173 bool GzipDecompressString(const std::string& str, |
| 174 std::vector<char>* out) { |
| 175 TEST_AND_RETURN_FALSE(out); |
| 176 char* out_buf; |
| 177 size_t out_size; |
| 178 TEST_AND_RETURN_FALSE(GzipDecompressData(str.data(), str.size(), |
| 179 &out_buf, &out_size)); |
| 180 out->insert(out->end(), out_buf, out_buf + out_size); |
| 181 free(out_buf); |
| 182 return true; |
| 183 } |
| 184 |
| 185 } // namespace chromeos_update_engine |
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