2 2009-06-19 : Igor Pavlov : Public domain */
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10 SRes Xz_ReadHeader(CXzStreamFlags *p, ISeqInStream *inStream)
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12 Byte sig[XZ_STREAM_HEADER_SIZE];
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13 RINOK(SeqInStream_Read2(inStream, sig, XZ_STREAM_HEADER_SIZE, SZ_ERROR_NO_ARCHIVE));
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14 if (memcmp(sig, XZ_SIG, XZ_SIG_SIZE) != 0)
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15 return SZ_ERROR_NO_ARCHIVE;
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16 return Xz_ParseHeader(p, sig);
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19 #define READ_VARINT_AND_CHECK(buf, pos, size, res) \
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20 { unsigned s = Xz_ReadVarInt(buf + pos, size - pos, res); \
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21 if (s == 0) return SZ_ERROR_ARCHIVE; pos += s; }
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23 SRes XzBlock_ReadHeader(CXzBlock *p, ISeqInStream *inStream, Bool *isIndex, UInt32 *headerSizeRes)
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25 Byte header[XZ_BLOCK_HEADER_SIZE_MAX];
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26 unsigned headerSize;
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28 RINOK(SeqInStream_ReadByte(inStream, &header[0]));
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29 headerSize = ((unsigned)header[0] << 2) + 4;
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30 if (headerSize == 0)
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38 *headerSizeRes = headerSize;
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39 RINOK(SeqInStream_Read(inStream, header + 1, headerSize - 1));
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40 return XzBlock_Parse(p, header);
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43 #define ADD_SIZE_CHECH(size, val) \
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44 { UInt64 newSize = size + (val); if (newSize < size) return XZ_SIZE_OVERFLOW; size = newSize; }
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46 UInt64 Xz_GetUnpackSize(const CXzStream *p)
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50 for (i = 0; i < p->numBlocks; i++)
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51 ADD_SIZE_CHECH(size, p->blocks[i].unpackSize);
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55 UInt64 Xz_GetPackSize(const CXzStream *p)
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59 for (i = 0; i < p->numBlocks; i++)
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60 ADD_SIZE_CHECH(size, (p->blocks[i].totalSize + 3) & ~(UInt64)3);
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65 SRes XzBlock_ReadFooter(CXzBlock *p, CXzStreamFlags f, ISeqInStream *inStream)
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67 return SeqInStream_Read(inStream, p->check, XzFlags_GetCheckSize(f));
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71 static SRes Xz_ReadIndex2(CXzStream *p, const Byte *buf, size_t size, ISzAlloc *alloc)
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73 size_t i, numBlocks, crcStartPos, pos = 1;
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76 if (size < 5 || buf[0] != 0)
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77 return SZ_ERROR_ARCHIVE;
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80 crc = CrcCalc(buf, size);
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81 if (crc != GetUi32(buf + size))
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82 return SZ_ERROR_ARCHIVE;
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86 READ_VARINT_AND_CHECK(buf, pos, size, &numBlocks64);
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87 numBlocks = (size_t)numBlocks64;
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88 if (numBlocks != numBlocks64 || numBlocks * 2 > size)
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89 return SZ_ERROR_ARCHIVE;
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96 p->numBlocks = numBlocks;
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97 p->numBlocksAllocated = numBlocks;
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98 p->blocks = alloc->Alloc(alloc, sizeof(CXzBlockSizes) * numBlocks);
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100 return SZ_ERROR_MEM;
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101 for (i = 0; i < numBlocks; i++)
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103 CXzBlockSizes *block = &p->blocks[i];
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104 READ_VARINT_AND_CHECK(buf, pos, size, &block->totalSize);
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105 READ_VARINT_AND_CHECK(buf, pos, size, &block->unpackSize);
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106 if (block->totalSize == 0)
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107 return SZ_ERROR_ARCHIVE;
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110 while ((pos & 3) != 0)
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111 if (buf[pos++] != 0)
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112 return SZ_ERROR_ARCHIVE;
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113 return (pos == size) ? SZ_OK : SZ_ERROR_ARCHIVE;
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116 static SRes Xz_ReadIndex(CXzStream *p, ILookInStream *stream, UInt64 indexSize, ISzAlloc *alloc)
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121 if (indexSize > ((UInt32)1 << 31))
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122 return SZ_ERROR_UNSUPPORTED;
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123 size = (size_t)indexSize;
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124 if (size != indexSize)
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125 return SZ_ERROR_UNSUPPORTED;
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126 buf = alloc->Alloc(alloc, size);
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128 return SZ_ERROR_MEM;
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129 res = LookInStream_Read2(stream, buf, size, SZ_ERROR_UNSUPPORTED);
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131 res = Xz_ReadIndex2(p, buf, size, alloc);
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132 alloc->Free(alloc, buf);
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136 static SRes SeekFromCur(ILookInStream *inStream, Int64 *res)
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138 return inStream->Seek(inStream, res, SZ_SEEK_CUR);
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141 static SRes Xz_ReadBackward(CXzStream *p, ILookInStream *stream, Int64 *startOffset, ISzAlloc *alloc)
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144 Byte buf[XZ_STREAM_FOOTER_SIZE];
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146 if ((*startOffset & 3) != 0 || *startOffset < XZ_STREAM_FOOTER_SIZE)
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147 return SZ_ERROR_NO_ARCHIVE;
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148 *startOffset = -XZ_STREAM_FOOTER_SIZE;
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149 RINOK(SeekFromCur(stream, startOffset));
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151 RINOK(LookInStream_Read2(stream, buf, XZ_STREAM_FOOTER_SIZE, SZ_ERROR_NO_ARCHIVE));
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153 if (memcmp(buf + 10, XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) != 0)
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156 *startOffset += XZ_STREAM_FOOTER_SIZE;
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160 size_t processedSize;
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161 #define TEMP_BUF_SIZE (1 << 10)
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162 Byte tempBuf[TEMP_BUF_SIZE];
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163 if (*startOffset < XZ_STREAM_FOOTER_SIZE || i > (1 << 16))
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164 return SZ_ERROR_NO_ARCHIVE;
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165 processedSize = (*startOffset > TEMP_BUF_SIZE) ? TEMP_BUF_SIZE : (size_t)*startOffset;
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166 i += processedSize;
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167 *startOffset = -(Int64)processedSize;
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168 RINOK(SeekFromCur(stream, startOffset));
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169 RINOK(LookInStream_Read2(stream, tempBuf, processedSize, SZ_ERROR_NO_ARCHIVE));
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170 for (j = (int)processedSize; j >= 0; j--)
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171 if (tempBuf[j -1] != 0)
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176 return SZ_ERROR_NO_ARCHIVE;
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178 if (*startOffset < XZ_STREAM_FOOTER_SIZE)
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179 return SZ_ERROR_NO_ARCHIVE;
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180 *startOffset -= XZ_STREAM_FOOTER_SIZE;
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181 RINOK(stream->Seek(stream, startOffset, SZ_SEEK_SET));
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182 RINOK(LookInStream_Read2(stream, buf, XZ_STREAM_FOOTER_SIZE, SZ_ERROR_NO_ARCHIVE));
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183 if (memcmp(buf + 10, XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) != 0)
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184 return SZ_ERROR_NO_ARCHIVE;
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190 p->flags = (CXzStreamFlags)GetBe16(buf + 8);
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192 if (!XzFlags_IsSupported(p->flags))
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193 return SZ_ERROR_UNSUPPORTED;
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195 if (GetUi32(buf) != CrcCalc(buf + 4, 6))
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196 return SZ_ERROR_ARCHIVE;
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198 indexSize = ((UInt64)GetUi32(buf + 4) + 1) << 2;
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200 *startOffset = -(Int64)(indexSize + XZ_STREAM_FOOTER_SIZE);
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201 RINOK(SeekFromCur(stream, startOffset));
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203 RINOK(Xz_ReadIndex(p, stream, indexSize, alloc));
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206 UInt64 totalSize = Xz_GetPackSize(p);
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207 UInt64 sum = XZ_STREAM_HEADER_SIZE + totalSize + indexSize;
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208 if (totalSize == XZ_SIZE_OVERFLOW ||
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209 sum >= ((UInt64)1 << 63) ||
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210 totalSize >= ((UInt64)1 << 63))
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211 return SZ_ERROR_ARCHIVE;
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212 *startOffset = -(Int64)sum;
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213 RINOK(SeekFromCur(stream, startOffset));
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216 CXzStreamFlags headerFlags;
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217 CSecToRead secToRead;
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218 SecToRead_CreateVTable(&secToRead);
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219 secToRead.realStream = stream;
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221 RINOK(Xz_ReadHeader(&headerFlags, &secToRead.s));
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222 return (p->flags == headerFlags) ? SZ_OK : SZ_ERROR_ARCHIVE;
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227 /* ---------- Xz Streams ---------- */
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229 void Xzs_Construct(CXzs *p)
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231 p->num = p->numAllocated = 0;
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235 void Xzs_Free(CXzs *p, ISzAlloc *alloc)
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238 for (i = 0; i < p->num; i++)
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239 Xz_Free(&p->streams[i], alloc);
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240 alloc->Free(alloc, p->streams);
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241 p->num = p->numAllocated = 0;
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245 UInt64 Xzs_GetNumBlocks(const CXzs *p)
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249 for (i = 0; i < p->num; i++)
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250 num += p->streams[i].numBlocks;
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254 UInt64 Xzs_GetUnpackSize(const CXzs *p)
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258 for (i = 0; i < p->num; i++)
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259 ADD_SIZE_CHECH(size, Xz_GetUnpackSize(&p->streams[i]));
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264 UInt64 Xzs_GetPackSize(const CXzs *p)
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268 for (i = 0; i < p->num; i++)
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269 ADD_SIZE_CHECH(size, Xz_GetTotalSize(&p->streams[i]));
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274 SRes Xzs_ReadBackward(CXzs *p, ILookInStream *stream, Int64 *startOffset, ICompressProgress *progress, ISzAlloc *alloc)
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276 Int64 endOffset = 0;
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277 RINOK(stream->Seek(stream, &endOffset, SZ_SEEK_END));
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278 *startOffset = endOffset;
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284 res = Xz_ReadBackward(&st, stream, startOffset, alloc);
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285 st.startOffset = *startOffset;
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287 if (p->num == p->numAllocated)
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289 size_t newNum = p->num + p->num / 4 + 1;
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290 Byte *data = (Byte *)alloc->Alloc(alloc, newNum * sizeof(CXzStream));
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292 return SZ_ERROR_MEM;
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293 p->numAllocated = newNum;
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294 memcpy(data, p->streams, p->num * sizeof(CXzStream));
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295 alloc->Free(alloc, p->streams);
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296 p->streams = (CXzStream *)data;
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298 p->streams[p->num++] = st;
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299 if (*startOffset == 0)
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301 RINOK(stream->Seek(stream, startOffset, SZ_SEEK_SET));
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302 if (progress && progress->Progress(progress, endOffset - *startOffset, (UInt64)(Int64)-1) != SZ_OK)
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303 return SZ_ERROR_PROGRESS;
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