| Index: third_party/lzma_sdk/lzma.txt
|
| ===================================================================
|
| --- third_party/lzma_sdk/lzma.txt (revision 0)
|
| +++ third_party/lzma_sdk/lzma.txt (revision 0)
|
| @@ -0,0 +1,598 @@
|
| +LZMA SDK 9.20
|
| +-------------
|
| +
|
| +LZMA SDK provides the documentation, samples, header files, libraries,
|
| +and tools you need to develop applications that use LZMA compression.
|
| +
|
| +LZMA is default and general compression method of 7z format
|
| +in 7-Zip compression program (www.7-zip.org). LZMA provides high
|
| +compression ratio and very fast decompression.
|
| +
|
| +LZMA is an improved version of famous LZ77 compression algorithm.
|
| +It was improved in way of maximum increasing of compression ratio,
|
| +keeping high decompression speed and low memory requirements for
|
| +decompressing.
|
| +
|
| +
|
| +
|
| +LICENSE
|
| +-------
|
| +
|
| +LZMA SDK is written and placed in the public domain by Igor Pavlov.
|
| +
|
| +Some code in LZMA SDK is based on public domain code from another developers:
|
| + 1) PPMd var.H (2001): Dmitry Shkarin
|
| + 2) SHA-256: Wei Dai (Crypto++ library)
|
| +
|
| +
|
| +LZMA SDK Contents
|
| +-----------------
|
| +
|
| +LZMA SDK includes:
|
| +
|
| + - ANSI-C/C++/C#/Java source code for LZMA compressing and decompressing
|
| + - Compiled file->file LZMA compressing/decompressing program for Windows system
|
| +
|
| +
|
| +UNIX/Linux version
|
| +------------------
|
| +To compile C++ version of file->file LZMA encoding, go to directory
|
| +CPP/7zip/Bundles/LzmaCon
|
| +and call make to recompile it:
|
| + make -f makefile.gcc clean all
|
| +
|
| +In some UNIX/Linux versions you must compile LZMA with static libraries.
|
| +To compile with static libraries, you can use
|
| +LIB = -lm -static
|
| +
|
| +
|
| +Files
|
| +---------------------
|
| +lzma.txt - LZMA SDK description (this file)
|
| +7zFormat.txt - 7z Format description
|
| +7zC.txt - 7z ANSI-C Decoder description
|
| +methods.txt - Compression method IDs for .7z
|
| +lzma.exe - Compiled file->file LZMA encoder/decoder for Windows
|
| +7zr.exe - 7-Zip with 7z/lzma/xz support.
|
| +history.txt - history of the LZMA SDK
|
| +
|
| +
|
| +Source code structure
|
| +---------------------
|
| +
|
| +C/ - C files
|
| + 7zCrc*.* - CRC code
|
| + Alloc.* - Memory allocation functions
|
| + Bra*.* - Filters for x86, IA-64, ARM, ARM-Thumb, PowerPC and SPARC code
|
| + LzFind.* - Match finder for LZ (LZMA) encoders
|
| + LzFindMt.* - Match finder for LZ (LZMA) encoders for multithreading encoding
|
| + LzHash.h - Additional file for LZ match finder
|
| + LzmaDec.* - LZMA decoding
|
| + LzmaEnc.* - LZMA encoding
|
| + LzmaLib.* - LZMA Library for DLL calling
|
| + Types.h - Basic types for another .c files
|
| + Threads.* - The code for multithreading.
|
| +
|
| + LzmaLib - LZMA Library (.DLL for Windows)
|
| +
|
| + LzmaUtil - LZMA Utility (file->file LZMA encoder/decoder).
|
| +
|
| + Archive - files related to archiving
|
| + 7z - 7z ANSI-C Decoder
|
| +
|
| +CPP/ -- CPP files
|
| +
|
| + Common - common files for C++ projects
|
| + Windows - common files for Windows related code
|
| +
|
| + 7zip - files related to 7-Zip Project
|
| +
|
| + Common - common files for 7-Zip
|
| +
|
| + Compress - files related to compression/decompression
|
| +
|
| + Archive - files related to archiving
|
| +
|
| + Common - common files for archive handling
|
| + 7z - 7z C++ Encoder/Decoder
|
| +
|
| + Bundles - Modules that are bundles of other modules
|
| +
|
| + Alone7z - 7zr.exe: Standalone version of 7z.exe that supports only 7z/LZMA/BCJ/BCJ2
|
| + LzmaCon - lzma.exe: LZMA compression/decompression
|
| + Format7zR - 7zr.dll: Reduced version of 7za.dll: extracting/compressing to 7z/LZMA/BCJ/BCJ2
|
| + Format7zExtractR - 7zxr.dll: Reduced version of 7zxa.dll: extracting from 7z/LZMA/BCJ/BCJ2.
|
| +
|
| + UI - User Interface files
|
| +
|
| + Client7z - Test application for 7za.dll, 7zr.dll, 7zxr.dll
|
| + Common - Common UI files
|
| + Console - Code for console archiver
|
| +
|
| +
|
| +
|
| +CS/ - C# files
|
| + 7zip
|
| + Common - some common files for 7-Zip
|
| + Compress - files related to compression/decompression
|
| + LZ - files related to LZ (Lempel-Ziv) compression algorithm
|
| + LZMA - LZMA compression/decompression
|
| + LzmaAlone - file->file LZMA compression/decompression
|
| + RangeCoder - Range Coder (special code of compression/decompression)
|
| +
|
| +Java/ - Java files
|
| + SevenZip
|
| + Compression - files related to compression/decompression
|
| + LZ - files related to LZ (Lempel-Ziv) compression algorithm
|
| + LZMA - LZMA compression/decompression
|
| + RangeCoder - Range Coder (special code of compression/decompression)
|
| +
|
| +
|
| +C/C++ source code of LZMA SDK is part of 7-Zip project.
|
| +7-Zip source code can be downloaded from 7-Zip's SourceForge page:
|
| +
|
| + http://sourceforge.net/projects/sevenzip/
|
| +
|
| +
|
| +
|
| +LZMA features
|
| +-------------
|
| + - Variable dictionary size (up to 1 GB)
|
| + - Estimated compressing speed: about 2 MB/s on 2 GHz CPU
|
| + - Estimated decompressing speed:
|
| + - 20-30 MB/s on 2 GHz Core 2 or AMD Athlon 64
|
| + - 1-2 MB/s on 200 MHz ARM, MIPS, PowerPC or other simple RISC
|
| + - Small memory requirements for decompressing (16 KB + DictionarySize)
|
| + - Small code size for decompressing: 5-8 KB
|
| +
|
| +LZMA decoder uses only integer operations and can be
|
| +implemented in any modern 32-bit CPU (or on 16-bit CPU with some conditions).
|
| +
|
| +Some critical operations that affect the speed of LZMA decompression:
|
| + 1) 32*16 bit integer multiply
|
| + 2) Misspredicted branches (penalty mostly depends from pipeline length)
|
| + 3) 32-bit shift and arithmetic operations
|
| +
|
| +The speed of LZMA decompressing mostly depends from CPU speed.
|
| +Memory speed has no big meaning. But if your CPU has small data cache,
|
| +overall weight of memory speed will slightly increase.
|
| +
|
| +
|
| +How To Use
|
| +----------
|
| +
|
| +Using LZMA encoder/decoder executable
|
| +--------------------------------------
|
| +
|
| +Usage: LZMA <e|d> inputFile outputFile [<switches>...]
|
| +
|
| + e: encode file
|
| +
|
| + d: decode file
|
| +
|
| + b: Benchmark. There are two tests: compressing and decompressing
|
| + with LZMA method. Benchmark shows rating in MIPS (million
|
| + instructions per second). Rating value is calculated from
|
| + measured speed and it is normalized with Intel's Core 2 results.
|
| + Also Benchmark checks possible hardware errors (RAM
|
| + errors in most cases). Benchmark uses these settings:
|
| + (-a1, -d21, -fb32, -mfbt4). You can change only -d parameter.
|
| + Also you can change the number of iterations. Example for 30 iterations:
|
| + LZMA b 30
|
| + Default number of iterations is 10.
|
| +
|
| +<Switches>
|
| +
|
| +
|
| + -a{N}: set compression mode 0 = fast, 1 = normal
|
| + default: 1 (normal)
|
| +
|
| + d{N}: Sets Dictionary size - [0, 30], default: 23 (8MB)
|
| + The maximum value for dictionary size is 1 GB = 2^30 bytes.
|
| + Dictionary size is calculated as DictionarySize = 2^N bytes.
|
| + For decompressing file compressed by LZMA method with dictionary
|
| + size D = 2^N you need about D bytes of memory (RAM).
|
| +
|
| + -fb{N}: set number of fast bytes - [5, 273], default: 128
|
| + Usually big number gives a little bit better compression ratio
|
| + and slower compression process.
|
| +
|
| + -lc{N}: set number of literal context bits - [0, 8], default: 3
|
| + Sometimes lc=4 gives gain for big files.
|
| +
|
| + -lp{N}: set number of literal pos bits - [0, 4], default: 0
|
| + lp switch is intended for periodical data when period is
|
| + equal 2^N. For example, for 32-bit (4 bytes)
|
| + periodical data you can use lp=2. Often it's better to set lc0,
|
| + if you change lp switch.
|
| +
|
| + -pb{N}: set number of pos bits - [0, 4], default: 2
|
| + pb switch is intended for periodical data
|
| + when period is equal 2^N.
|
| +
|
| + -mf{MF_ID}: set Match Finder. Default: bt4.
|
| + Algorithms from hc* group doesn't provide good compression
|
| + ratio, but they often works pretty fast in combination with
|
| + fast mode (-a0).
|
| +
|
| + Memory requirements depend from dictionary size
|
| + (parameter "d" in table below).
|
| +
|
| + MF_ID Memory Description
|
| +
|
| + bt2 d * 9.5 + 4MB Binary Tree with 2 bytes hashing.
|
| + bt3 d * 11.5 + 4MB Binary Tree with 3 bytes hashing.
|
| + bt4 d * 11.5 + 4MB Binary Tree with 4 bytes hashing.
|
| + hc4 d * 7.5 + 4MB Hash Chain with 4 bytes hashing.
|
| +
|
| + -eos: write End Of Stream marker. By default LZMA doesn't write
|
| + eos marker, since LZMA decoder knows uncompressed size
|
| + stored in .lzma file header.
|
| +
|
| + -si: Read data from stdin (it will write End Of Stream marker).
|
| + -so: Write data to stdout
|
| +
|
| +
|
| +Examples:
|
| +
|
| +1) LZMA e file.bin file.lzma -d16 -lc0
|
| +
|
| +compresses file.bin to file.lzma with 64 KB dictionary (2^16=64K)
|
| +and 0 literal context bits. -lc0 allows to reduce memory requirements
|
| +for decompression.
|
| +
|
| +
|
| +2) LZMA e file.bin file.lzma -lc0 -lp2
|
| +
|
| +compresses file.bin to file.lzma with settings suitable
|
| +for 32-bit periodical data (for example, ARM or MIPS code).
|
| +
|
| +3) LZMA d file.lzma file.bin
|
| +
|
| +decompresses file.lzma to file.bin.
|
| +
|
| +
|
| +Compression ratio hints
|
| +-----------------------
|
| +
|
| +Recommendations
|
| +---------------
|
| +
|
| +To increase the compression ratio for LZMA compressing it's desirable
|
| +to have aligned data (if it's possible) and also it's desirable to locate
|
| +data in such order, where code is grouped in one place and data is
|
| +grouped in other place (it's better than such mixing: code, data, code,
|
| +data, ...).
|
| +
|
| +
|
| +Filters
|
| +-------
|
| +You can increase the compression ratio for some data types, using
|
| +special filters before compressing. For example, it's possible to
|
| +increase the compression ratio on 5-10% for code for those CPU ISAs:
|
| +x86, IA-64, ARM, ARM-Thumb, PowerPC, SPARC.
|
| +
|
| +You can find C source code of such filters in C/Bra*.* files
|
| +
|
| +You can check the compression ratio gain of these filters with such
|
| +7-Zip commands (example for ARM code):
|
| +No filter:
|
| + 7z a a1.7z a.bin -m0=lzma
|
| +
|
| +With filter for little-endian ARM code:
|
| + 7z a a2.7z a.bin -m0=arm -m1=lzma
|
| +
|
| +It works in such manner:
|
| +Compressing = Filter_encoding + LZMA_encoding
|
| +Decompressing = LZMA_decoding + Filter_decoding
|
| +
|
| +Compressing and decompressing speed of such filters is very high,
|
| +so it will not increase decompressing time too much.
|
| +Moreover, it reduces decompression time for LZMA_decoding,
|
| +since compression ratio with filtering is higher.
|
| +
|
| +These filters convert CALL (calling procedure) instructions
|
| +from relative offsets to absolute addresses, so such data becomes more
|
| +compressible.
|
| +
|
| +For some ISAs (for example, for MIPS) it's impossible to get gain from such filter.
|
| +
|
| +
|
| +LZMA compressed file format
|
| +---------------------------
|
| +Offset Size Description
|
| + 0 1 Special LZMA properties (lc,lp, pb in encoded form)
|
| + 1 4 Dictionary size (little endian)
|
| + 5 8 Uncompressed size (little endian). -1 means unknown size
|
| + 13 Compressed data
|
| +
|
| +
|
| +ANSI-C LZMA Decoder
|
| +~~~~~~~~~~~~~~~~~~~
|
| +
|
| +Please note that interfaces for ANSI-C code were changed in LZMA SDK 4.58.
|
| +If you want to use old interfaces you can download previous version of LZMA SDK
|
| +from sourceforge.net site.
|
| +
|
| +To use ANSI-C LZMA Decoder you need the following files:
|
| +1) LzmaDec.h + LzmaDec.c + Types.h
|
| +LzmaUtil/LzmaUtil.c is example application that uses these files.
|
| +
|
| +
|
| +Memory requirements for LZMA decoding
|
| +-------------------------------------
|
| +
|
| +Stack usage of LZMA decoding function for local variables is not
|
| +larger than 200-400 bytes.
|
| +
|
| +LZMA Decoder uses dictionary buffer and internal state structure.
|
| +Internal state structure consumes
|
| + state_size = (4 + (1.5 << (lc + lp))) KB
|
| +by default (lc=3, lp=0), state_size = 16 KB.
|
| +
|
| +
|
| +How To decompress data
|
| +----------------------
|
| +
|
| +LZMA Decoder (ANSI-C version) now supports 2 interfaces:
|
| +1) Single-call Decompressing
|
| +2) Multi-call State Decompressing (zlib-like interface)
|
| +
|
| +You must use external allocator:
|
| +Example:
|
| +void *SzAlloc(void *p, size_t size) { p = p; return malloc(size); }
|
| +void SzFree(void *p, void *address) { p = p; free(address); }
|
| +ISzAlloc alloc = { SzAlloc, SzFree };
|
| +
|
| +You can use p = p; operator to disable compiler warnings.
|
| +
|
| +
|
| +Single-call Decompressing
|
| +-------------------------
|
| +When to use: RAM->RAM decompressing
|
| +Compile files: LzmaDec.h + LzmaDec.c + Types.h
|
| +Compile defines: no defines
|
| +Memory Requirements:
|
| + - Input buffer: compressed size
|
| + - Output buffer: uncompressed size
|
| + - LZMA Internal Structures: state_size (16 KB for default settings)
|
| +
|
| +Interface:
|
| + int LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
|
| + const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
|
| + ELzmaStatus *status, ISzAlloc *alloc);
|
| + In:
|
| + dest - output data
|
| + destLen - output data size
|
| + src - input data
|
| + srcLen - input data size
|
| + propData - LZMA properties (5 bytes)
|
| + propSize - size of propData buffer (5 bytes)
|
| + finishMode - It has meaning only if the decoding reaches output limit (*destLen).
|
| + LZMA_FINISH_ANY - Decode just destLen bytes.
|
| + LZMA_FINISH_END - Stream must be finished after (*destLen).
|
| + You can use LZMA_FINISH_END, when you know that
|
| + current output buffer covers last bytes of stream.
|
| + alloc - Memory allocator.
|
| +
|
| + Out:
|
| + destLen - processed output size
|
| + srcLen - processed input size
|
| +
|
| + Output:
|
| + SZ_OK
|
| + status:
|
| + LZMA_STATUS_FINISHED_WITH_MARK
|
| + LZMA_STATUS_NOT_FINISHED
|
| + LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK
|
| + SZ_ERROR_DATA - Data error
|
| + SZ_ERROR_MEM - Memory allocation error
|
| + SZ_ERROR_UNSUPPORTED - Unsupported properties
|
| + SZ_ERROR_INPUT_EOF - It needs more bytes in input buffer (src).
|
| +
|
| + If LZMA decoder sees end_marker before reaching output limit, it returns OK result,
|
| + and output value of destLen will be less than output buffer size limit.
|
| +
|
| + You can use multiple checks to test data integrity after full decompression:
|
| + 1) Check Result and "status" variable.
|
| + 2) Check that output(destLen) = uncompressedSize, if you know real uncompressedSize.
|
| + 3) Check that output(srcLen) = compressedSize, if you know real compressedSize.
|
| + You must use correct finish mode in that case. */
|
| +
|
| +
|
| +Multi-call State Decompressing (zlib-like interface)
|
| +----------------------------------------------------
|
| +
|
| +When to use: file->file decompressing
|
| +Compile files: LzmaDec.h + LzmaDec.c + Types.h
|
| +
|
| +Memory Requirements:
|
| + - Buffer for input stream: any size (for example, 16 KB)
|
| + - Buffer for output stream: any size (for example, 16 KB)
|
| + - LZMA Internal Structures: state_size (16 KB for default settings)
|
| + - LZMA dictionary (dictionary size is encoded in LZMA properties header)
|
| +
|
| +1) read LZMA properties (5 bytes) and uncompressed size (8 bytes, little-endian) to header:
|
| + unsigned char header[LZMA_PROPS_SIZE + 8];
|
| + ReadFile(inFile, header, sizeof(header)
|
| +
|
| +2) Allocate CLzmaDec structures (state + dictionary) using LZMA properties
|
| +
|
| + CLzmaDec state;
|
| + LzmaDec_Constr(&state);
|
| + res = LzmaDec_Allocate(&state, header, LZMA_PROPS_SIZE, &g_Alloc);
|
| + if (res != SZ_OK)
|
| + return res;
|
| +
|
| +3) Init LzmaDec structure before any new LZMA stream. And call LzmaDec_DecodeToBuf in loop
|
| +
|
| + LzmaDec_Init(&state);
|
| + for (;;)
|
| + {
|
| + ...
|
| + int res = LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen,
|
| + const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode);
|
| + ...
|
| + }
|
| +
|
| +
|
| +4) Free all allocated structures
|
| + LzmaDec_Free(&state, &g_Alloc);
|
| +
|
| +For full code example, look at C/LzmaUtil/LzmaUtil.c code.
|
| +
|
| +
|
| +How To compress data
|
| +--------------------
|
| +
|
| +Compile files: LzmaEnc.h + LzmaEnc.c + Types.h +
|
| +LzFind.c + LzFind.h + LzFindMt.c + LzFindMt.h + LzHash.h
|
| +
|
| +Memory Requirements:
|
| + - (dictSize * 11.5 + 6 MB) + state_size
|
| +
|
| +Lzma Encoder can use two memory allocators:
|
| +1) alloc - for small arrays.
|
| +2) allocBig - for big arrays.
|
| +
|
| +For example, you can use Large RAM Pages (2 MB) in allocBig allocator for
|
| +better compression speed. Note that Windows has bad implementation for
|
| +Large RAM Pages.
|
| +It's OK to use same allocator for alloc and allocBig.
|
| +
|
| +
|
| +Single-call Compression with callbacks
|
| +--------------------------------------
|
| +
|
| +Check C/LzmaUtil/LzmaUtil.c as example,
|
| +
|
| +When to use: file->file decompressing
|
| +
|
| +1) you must implement callback structures for interfaces:
|
| +ISeqInStream
|
| +ISeqOutStream
|
| +ICompressProgress
|
| +ISzAlloc
|
| +
|
| +static void *SzAlloc(void *p, size_t size) { p = p; return MyAlloc(size); }
|
| +static void SzFree(void *p, void *address) { p = p; MyFree(address); }
|
| +static ISzAlloc g_Alloc = { SzAlloc, SzFree };
|
| +
|
| + CFileSeqInStream inStream;
|
| + CFileSeqOutStream outStream;
|
| +
|
| + inStream.funcTable.Read = MyRead;
|
| + inStream.file = inFile;
|
| + outStream.funcTable.Write = MyWrite;
|
| + outStream.file = outFile;
|
| +
|
| +
|
| +2) Create CLzmaEncHandle object;
|
| +
|
| + CLzmaEncHandle enc;
|
| +
|
| + enc = LzmaEnc_Create(&g_Alloc);
|
| + if (enc == 0)
|
| + return SZ_ERROR_MEM;
|
| +
|
| +
|
| +3) initialize CLzmaEncProps properties;
|
| +
|
| + LzmaEncProps_Init(&props);
|
| +
|
| + Then you can change some properties in that structure.
|
| +
|
| +4) Send LZMA properties to LZMA Encoder
|
| +
|
| + res = LzmaEnc_SetProps(enc, &props);
|
| +
|
| +5) Write encoded properties to header
|
| +
|
| + Byte header[LZMA_PROPS_SIZE + 8];
|
| + size_t headerSize = LZMA_PROPS_SIZE;
|
| + UInt64 fileSize;
|
| + int i;
|
| +
|
| + res = LzmaEnc_WriteProperties(enc, header, &headerSize);
|
| + fileSize = MyGetFileLength(inFile);
|
| + for (i = 0; i < 8; i++)
|
| + header[headerSize++] = (Byte)(fileSize >> (8 * i));
|
| + MyWriteFileAndCheck(outFile, header, headerSize)
|
| +
|
| +6) Call encoding function:
|
| + res = LzmaEnc_Encode(enc, &outStream.funcTable, &inStream.funcTable,
|
| + NULL, &g_Alloc, &g_Alloc);
|
| +
|
| +7) Destroy LZMA Encoder Object
|
| + LzmaEnc_Destroy(enc, &g_Alloc, &g_Alloc);
|
| +
|
| +
|
| +If callback function return some error code, LzmaEnc_Encode also returns that code
|
| +or it can return the code like SZ_ERROR_READ, SZ_ERROR_WRITE or SZ_ERROR_PROGRESS.
|
| +
|
| +
|
| +Single-call RAM->RAM Compression
|
| +--------------------------------
|
| +
|
| +Single-call RAM->RAM Compression is similar to Compression with callbacks,
|
| +but you provide pointers to buffers instead of pointers to stream callbacks:
|
| +
|
| +HRes LzmaEncode(Byte *dest, SizeT *destLen, const Byte *src, SizeT srcLen,
|
| + CLzmaEncProps *props, Byte *propsEncoded, SizeT *propsSize, int writeEndMark,
|
| + ICompressProgress *progress, ISzAlloc *alloc, ISzAlloc *allocBig);
|
| +
|
| +Return code:
|
| + SZ_OK - OK
|
| + SZ_ERROR_MEM - Memory allocation error
|
| + SZ_ERROR_PARAM - Incorrect paramater
|
| + SZ_ERROR_OUTPUT_EOF - output buffer overflow
|
| + SZ_ERROR_THREAD - errors in multithreading functions (only for Mt version)
|
| +
|
| +
|
| +
|
| +Defines
|
| +-------
|
| +
|
| +_LZMA_SIZE_OPT - Enable some optimizations in LZMA Decoder to get smaller executable code.
|
| +
|
| +_LZMA_PROB32 - It can increase the speed on some 32-bit CPUs, but memory usage for
|
| + some structures will be doubled in that case.
|
| +
|
| +_LZMA_UINT32_IS_ULONG - Define it if int is 16-bit on your compiler and long is 32-bit.
|
| +
|
| +_LZMA_NO_SYSTEM_SIZE_T - Define it if you don't want to use size_t type.
|
| +
|
| +
|
| +_7ZIP_PPMD_SUPPPORT - Define it if you don't want to support PPMD method in AMSI-C .7z decoder.
|
| +
|
| +
|
| +C++ LZMA Encoder/Decoder
|
| +~~~~~~~~~~~~~~~~~~~~~~~~
|
| +C++ LZMA code use COM-like interfaces. So if you want to use it,
|
| +you can study basics of COM/OLE.
|
| +C++ LZMA code is just wrapper over ANSI-C code.
|
| +
|
| +
|
| +C++ Notes
|
| +~~~~~~~~~~~~~~~~~~~~~~~~
|
| +If you use some C++ code folders in 7-Zip (for example, C++ code for .7z handling),
|
| +you must check that you correctly work with "new" operator.
|
| +7-Zip can be compiled with MSVC 6.0 that doesn't throw "exception" from "new" operator.
|
| +So 7-Zip uses "CPP\Common\NewHandler.cpp" that redefines "new" operator:
|
| +operator new(size_t size)
|
| +{
|
| + void *p = ::malloc(size);
|
| + if (p == 0)
|
| + throw CNewException();
|
| + return p;
|
| +}
|
| +If you use MSCV that throws exception for "new" operator, you can compile without
|
| +"NewHandler.cpp". So standard exception will be used. Actually some code of
|
| +7-Zip catches any exception in internal code and converts it to HRESULT code.
|
| +So you don't need to catch CNewException, if you call COM interfaces of 7-Zip.
|
| +
|
| +---
|
| +
|
| +http://www.7-zip.org
|
| +http://www.7-zip.org/sdk.html
|
| +http://www.7-zip.org/support.html
|
|
|
| Property changes on: third_party\lzma_sdk\lzma.txt
|
| ___________________________________________________________________
|
| Added: svn:executable
|
| + *
|
|
|
|
|