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4.58 beta

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This commit is contained in:
Igor Pavlov
2008-05-05 00:00:00 +00:00
committed by Kornel Lesiński
parent bd1fa36322
commit 3901bf0ab8
326 changed files with 10643 additions and 14913 deletions
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DOC/lzma.txt
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@@ -1,7 +1,7 @@
LZMA SDK 4.49
-------------
LZMA SDK 4.58 beta
------------------
LZMA SDK Copyright (C) 1999-2007 Igor Pavlov
LZMA SDK Copyright (C) 1999-2008 Igor Pavlov
LZMA SDK provides the documentation, samples, header files, libraries,
and tools you need to develop applications that use LZMA compression.
@@ -24,26 +24,21 @@ LZMA SDK is available under any of the following licenses:
1) GNU Lesser General Public License (GNU LGPL)
2) Common Public License (CPL)
3) Simplified license for unmodified code (read SPECIAL EXCEPTION)
4) Proprietary license
3) Common Development and Distribution License (CDDL) Version 1.0
4) Simplified license for unmodified code (read SPECIAL EXCEPTION)
It means that you can select one of these four options and follow rules of that license.
It means that you can select one of these options and follow rules of that license.
1,2) GNU LGPL and CPL licenses are pretty similar and both these
licenses are classified as
1,2,3) GNU LGPL, CPL and CDDL licenses are classified as
- "Free software licenses" at http://www.gnu.org/
- "OSI-approved" at http://www.opensource.org/
3) SPECIAL EXCEPTION
4) Simplified license for unmodified code (read SPECIAL EXCEPTION)
Igor Pavlov, as the author of this code, expressly permits you
to statically or dynamically link your code (or bind by name)
to the files from LZMA SDK without subjecting your linked
code to the terms of the CPL or GNU LGPL.
Any modifications or additions to files from LZMA SDK, however,
are subject to the GNU LGPL or CPL terms.
to the files from LZMA SDK.
SPECIAL EXCEPTION allows you to use LZMA SDK in applications with closed code,
while you keep LZMA SDK code unmodified.
@@ -56,27 +51,21 @@ Agreement you have for any previous version of LZMA SDK developed by Igor Pavlov
SPECIAL EXCEPTION #2 allows owners of proprietary licenses to use latest version
of LZMA SDK as update for previous versions.
Some files in LZMA SDK are placed in public domain.
Some of these "public domain" files:
C\Types.h,
C\LzmaLib.*
C\LzmaLibUtil.*
LzmaAlone.cpp,
LzmaAlone.cs,
LzmaAlone.java
SPECIAL EXCEPTION #3: Igor Pavlov, as the author of this code, expressly permits
you to use code of the following files:
BranchTypes.h, LzmaTypes.h, LzmaTest.c, LzmaStateTest.c, LzmaAlone.cpp,
LzmaAlone.cs, LzmaAlone.java
as public domain code.
So you can change them as you want and use "SPECIAL EXCEPTION"
for other unmodified files. For example, you can edit C\Types.h to solve some
compatibility problems with your compiler.
4) Proprietary license
LZMA SDK also can be available under a proprietary license which
can include:
1) Right to modify code without subjecting modified code to the
terms of the CPL or GNU LGPL
2) Technical support for code
To request such proprietary license or any additional consultations,
send email message from that page:
http://www.7-zip.org/support.html
-----
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
@@ -85,92 +74,82 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
You should have received a copy of the Common Public License
along with this library.
You should have received a copy of the Common Development and Distribution
License Version 1.0 along with this library.
LZMA SDK Contents
-----------------
LZMA SDK includes:
- C++ source code of LZMA compressing and decompressing
- ANSI-C compatible source code for LZMA decompressing
- C# source code for LZMA compressing and decompressing
- Java source code for LZMA compressing and decompressing
- ANSI-C/C++/C#/Java source code for LZMA compressing and decompressing
- Compiled file->file LZMA compressing/decompressing program for Windows system
ANSI-C LZMA decompression code was ported from original C++ sources to C.
Also it was simplified and optimized for code size.
But it is fully compatible with LZMA from 7-Zip.
UNIX/Linux version
------------------
To compile C++ version of file->file LZMA, go to directory
C/7zip/Compress/LZMA_Alone
and type "make" or "make clean all" to recompile all.
To compile C++ version of file->file LZMA encoding, go to directory
C++/7zip/Compress/LZMA_Alone
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, change string in makefile
LIB = -lm
to string
To compile with static libraries, you can use
LIB = -lm -static
Files
---------------------
C - C source code
CPP - CPP source code
CS - C# source code
Java - Java source code
lzma.txt - LZMA SDK description (this file)
lzma.txt - LZMA SDK description (this file)
7zFormat.txt - 7z Format description
7zC.txt - 7z ANSI-C Decoder description (this file)
7zC.txt - 7z ANSI-C Decoder description
methods.txt - Compression method IDs for .7z
LGPL.txt - GNU Lesser General Public License
CPL.html - Common Public License
lzma.exe - Compiled file->file LZMA encoder/decoder for Windows
history.txt - history of the LZMA SDK
lzma.exe - Compiled file->file LZMA encoder/decoder for Windows
history.txt - history of the LZMA SDK
LGPL.txt - GNU Lesser General Public License
CPL.html - Common Public License
CDDL.html - Common Development and Distribution License (CDDL)
Source code structure
---------------------
C - C files
Compress - files related to compression/decompression
Lz - files related to LZ (Lempel-Ziv) compression algorithm
Lzma - ANSI-C compatible LZMA decompressor
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.
LzmaDecode.h - interface for LZMA decoding on ANSI-C
LzmaDecode.c - LZMA decoding on ANSI-C (new fastest version)
LzmaDecodeSize.c - LZMA decoding on ANSI-C (old size-optimized version)
LzmaTest.c - test application that decodes LZMA encoded file
LzmaTypes.h - basic types for LZMA Decoder
LzmaStateDecode.h - interface for LZMA decoding (State version)
LzmaStateDecode.c - LZMA decoding on ANSI-C (State version)
LzmaStateTest.c - test application (State version)
Branch - Filters for x86, IA-64, ARM, ARM-Thumb, PowerPC and SPARC code
LzmaLib - LZMA Library (.DLL for Windows)
LzmaUtil - LZMA Utility (file->file LZMA encoder/decoder).
Archive - files related to archiving
7z_C - 7z ANSI-C Decoder
7z - 7z ANSI-C Decoder
CPP -- CPP files
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
LZ - files related to LZ (Lempel-Ziv) compression algorithm
Copy - Copy coder
RangeCoder - Range Coder (special code of compression/decompression)
LZMA - LZMA compression/decompression on C++
LZMA_Alone - file->file LZMA compression/decompression
Branch - Filters for x86, IA-64, ARM, ARM-Thumb, PowerPC and SPARC code
Archive - files related to archiving
@@ -192,7 +171,7 @@ CPP -- CPP files
CS - C# files
CS/ - C# files
7zip
Common - some common files for 7-Zip
Compress - files related to compression/decompression
@@ -201,46 +180,40 @@ CS - C# files
LzmaAlone - file->file LZMA compression/decompression
RangeCoder - Range Coder (special code of compression/decompression)
Java - Java files
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.
You can find ANSI-C LZMA decompressing code at folder
C/7zip/Compress/Lzma
7-Zip doesn't use that ANSI-C LZMA code and that code was developed
specially for this SDK. And files from C/7zip/Compress/Lzma do not need
files from other directories of SDK for compiling.
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 1 MB/s on 1 GHz CPU
- Estimated compressing speed: about 2 MB/s on 2 GHz CPU
- Estimated decompressing speed:
- 8-12 MB/s on 1 GHz Intel Pentium 3 or AMD Athlon
- 500-1000 KB/s on 100 MHz ARM, MIPS, PowerPC or other simple RISC
- Small memory requirements for decompressing (8-32 KB + DictionarySize)
- Small code size for decompressing: 2-8 KB (depending from
speed optimizations)
- 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 to speed of LZMA decompression:
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
Speed of LZMA decompressing mostly depends from CPU speed.
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.
@@ -260,11 +233,11 @@ Usage: LZMA <e|d> inputFile outputFile [<switches>...]
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 AMD Athlon 64 X2 CPU
results. Also Benchmark checks possible hardware errors (RAM
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. Also you
can change number of iterations. Example for 30 iterations:
(-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.
@@ -345,32 +318,29 @@ Compression ratio hints
Recommendations
---------------
To increase compression ratio for LZMA compressing it's desirable
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, ...).
Using Filters
-------------
You can increase compression ratio for some data types, using
Filters
-------
You can increase the compression ratio for some data types, using
special filters before compressing. For example, it's possible to
increase compression ratio on 5-10% for code for those CPU ISAs:
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/C++ source code of such filters in folder "7zip/Compress/Branch"
You can find C source code of such filters in C/Bra*.* files
You can check compression ratio gain of these filters with such
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=bc_arm -m1=lzma
With filter for big-endian ARM code (using additional Swap4 filter):
7z a a3.7z a.bin -m0=swap4 -m1=bc_arm -m2=lzma
7z a a2.7z a.bin -m0=arm -m1=lzma
It works in such manner:
Compressing = Filter_encoding + LZMA_encoding
@@ -383,8 +353,7 @@ 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. Source code of these CALL filters is pretty simple
(about 20 lines of C++), so you can convert it from C++ version yourself.
compressible.
For some ISAs (for example, for MIPS) it's impossible to get gain from such filter.
@@ -392,7 +361,7 @@ For some ISAs (for example, for MIPS) it's impossible to get gain from such filt
LZMA compressed file format
---------------------------
Offset Size Description
0 1 Special LZMA properties for compressed data
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
@@ -401,263 +370,285 @@ Offset Size Description
ANSI-C LZMA Decoder
~~~~~~~~~~~~~~~~~~~
To compile ANSI-C LZMA Decoder you can use one of the following files sets:
1) LzmaDecode.h + LzmaDecode.c + LzmaTest.c (fastest version)
2) LzmaDecode.h + LzmaDecodeSize.c + LzmaTest.c (old size-optimized version)
3) LzmaStateDecode.h + LzmaStateDecode.c + LzmaStateTest.c (zlib-like interface)
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
-------------------------------------
LZMA decoder doesn't allocate memory itself, so you must
allocate memory and send it to LZMA.
Stack usage of LZMA decoding function for local variables is not
larger than 200 bytes.
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 5 interfaces:
LZMA Decoder (ANSI-C version) now supports 2 interfaces:
1) Single-call Decompressing
2) Single-call Decompressing with input stream callback
3) Multi-call Decompressing with output buffer
4) Multi-call Decompressing with input callback and output buffer
5) Multi-call State Decompressing (zlib-like interface)
2) Multi-call State Decompressing (zlib-like interface)
Variant-5 is similar to Variant-4, but Variant-5 doesn't use callback functions.
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 };
Decompressing steps
-------------------
1) read LZMA properties (5 bytes):
unsigned char properties[LZMA_PROPERTIES_SIZE];
2) read uncompressed size (8 bytes, little-endian)
3) Decode properties:
CLzmaDecoderState state; /* it's 24-140 bytes structure, if int is 32-bit */
if (LzmaDecodeProperties(&state.Properties, properties, LZMA_PROPERTIES_SIZE) != LZMA_RESULT_OK)
return PrintError(rs, "Incorrect stream properties");
4) Allocate memory block for internal Structures:
state.Probs = (CProb *)malloc(LzmaGetNumProbs(&state.Properties) * sizeof(CProb));
if (state.Probs == 0)
return PrintError(rs, kCantAllocateMessage);
LZMA decoder uses array of CProb variables as internal structure.
By default, CProb is unsigned_short. But you can define _LZMA_PROB32 to make
it unsigned_int. It can increase speed on some 32-bit CPUs, but memory
usage will be doubled in that case.
You can use p = p; operator to disable compiler warnings.
5) Main Decompressing
You must use one of the following interfaces:
5.1 Single-call Decompressing
-----------------------------
Single-call Decompressing
-------------------------
When to use: RAM->RAM decompressing
Compile files: LzmaDecode.h, LzmaDecode.c
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 (~16 KB for default settings)
- LZMA Internal Structures: state_size (16 KB for default settings)
Interface:
int res = LzmaDecode(&state,
inStream, compressedSize, &inProcessed,
outStream, outSize, &outProcessed);
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. */
5.2 Single-call Decompressing with input stream callback
--------------------------------------------------------
When to use: File->RAM or Flash->RAM decompressing.
Compile files: LzmaDecode.h, LzmaDecode.c
Compile defines: _LZMA_IN_CB
Memory Requirements:
- Buffer for input stream: any size (for example, 16 KB)
- Output buffer: uncompressed size
- LZMA Internal Structures (~16 KB for default settings)
Multi-call State Decompressing (zlib-like interface)
----------------------------------------------------
Interface:
typedef struct _CBuffer
{
ILzmaInCallback InCallback;
FILE *File;
unsigned char Buffer[kInBufferSize];
} CBuffer;
int LzmaReadCompressed(void *object, const unsigned char **buffer, SizeT *size)
{
CBuffer *bo = (CBuffer *)object;
*buffer = bo->Buffer;
*size = MyReadFile(bo->File, bo->Buffer, kInBufferSize);
return LZMA_RESULT_OK;
}
CBuffer g_InBuffer;
g_InBuffer.File = inFile;
g_InBuffer.InCallback.Read = LzmaReadCompressed;
int res = LzmaDecode(&state,
&g_InBuffer.InCallback,
outStream, outSize, &outProcessed);
5.3 Multi-call decompressing with output buffer
-----------------------------------------------
When to use: RAM->File decompressing
Compile files: LzmaDecode.h, LzmaDecode.c
Compile defines: _LZMA_OUT_READ
Memory Requirements:
- Input buffer: compressed size
- Buffer for output stream: any size (for example, 16 KB)
- LZMA Internal Structures (~16 KB for default settings)
- LZMA dictionary (dictionary size is encoded in stream properties)
Interface:
state.Dictionary = (unsigned char *)malloc(state.Properties.DictionarySize);
LzmaDecoderInit(&state);
do
{
LzmaDecode(&state,
inBuffer, inAvail, &inProcessed,
g_OutBuffer, outAvail, &outProcessed);
inAvail -= inProcessed;
inBuffer += inProcessed;
}
while you need more bytes
see LzmaTest.c for more details.
5.4 Multi-call decompressing with input callback and output buffer
------------------------------------------------------------------
When to use: File->File decompressing
Compile files: LzmaDecode.h, LzmaDecode.c
Compile defines: _LZMA_IN_CB, _LZMA_OUT_READ
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 (~16 KB for default settings)
- LZMA dictionary (dictionary size is encoded in stream properties)
Interface:
state.Dictionary = (unsigned char *)malloc(state.Properties.DictionarySize);
LzmaDecoderInit(&state);
do
{
LzmaDecode(&state,
&bo.InCallback,
g_OutBuffer, outAvail, &outProcessed);
}
while you need more bytes
see LzmaTest.c for more details:
5.5 Multi-call State Decompressing (zlib-like interface)
------------------------------------------------------------------
When to use: file->file decompressing
Compile files: LzmaStateDecode.h, LzmaStateDecode.c
Compile defines:
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 (~16 KB for default settings)
- LZMA dictionary (dictionary size is encoded in stream properties)
Interface:
- LZMA Internal Structures: state_size (16 KB for default settings)
- LZMA dictionary (dictionary size is encoded in LZMA properties header)
state.Dictionary = (unsigned char *)malloc(state.Properties.DictionarySize);
1) read LZMA properties (5 bytes) and uncompressed size (8 bytes, little-endian) to header:
unsigned char header[LZMA_PROPERTIES_SIZE + 8];
ReadFile(inFile, header, sizeof(header)
LzmaDecoderInit(&state);
do
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 (;;)
{
res = LzmaDecode(&state,
inBuffer, inAvail, &inProcessed,
g_OutBuffer, outAvail, &outProcessed,
finishDecoding);
inAvail -= inProcessed;
inBuffer += inProcessed;
...
int res = LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen,
const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode);
...
}
while you need more bytes
see LzmaStateTest.c for more details:
6) Free all allocated blocks
4) Free all allocated structures
LzmaDec_Free(&state, &g_Alloc);
For full code example, look at C/LzmaUtil/LzmaUtil.c code.
Note
----
LzmaDecodeSize.c is size-optimized version of LzmaDecode.c.
But compiled code of LzmaDecodeSize.c can be larger than
compiled code of LzmaDecode.c. So it's better to use
LzmaDecode.c in most cases.
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.
EXIT codes
-----------
Single-call Compression with callbacks
--------------------------------------
LZMA decoder can return one of the following codes:
Check C/LzmaUtil/LzmaUtil.c as example,
#define LZMA_RESULT_OK 0
#define LZMA_RESULT_DATA_ERROR 1
When to use: file->file decompressing
If you use callback function for input data and you return some
error code, LZMA Decoder also returns that code.
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.
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)
LZMA Defines
------------
_LZMA_IN_CB - Use callback for input data
_LZMA_SIZE_OPT - Enable some optimizations in LZMA Decoder to get smaller executable code.
_LZMA_OUT_READ - Use read function for output data
_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_LOC_OPT - Enable local speed optimizations inside code.
_LZMA_LOC_OPT is only for LzmaDecodeSize.c (size-optimized version).
_LZMA_LOC_OPT doesn't affect LzmaDecode.c (speed-optimized version)
and LzmaStateDecode.c
_LZMA_PROB32 - It can increase speed on some 32-bit CPUs,
but memory usage 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_SYSTEM_SIZE_T - Define it if you want to use system's size_t.
You can use it to enable 64-bit sizes supporting
_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.
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.
By default, LZMA Encoder contains all Match Finders.
But for compressing it's enough to have just one of them.
So for reducing size of compressing code you can define:
#define COMPRESS_MF_BT
#define COMPRESS_MF_BT4
and it will use only bt4 match finder.
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.
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