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diff --git a/app/lzo/doc/LZO.TXT b/app/lzo/doc/LZO.TXT deleted file mode 100644 index 7426ab2b..00000000 --- a/app/lzo/doc/LZO.TXT +++ /dev/null @@ -1,292 +0,0 @@ - - ============================================================================ - LZO -- a real-time data compression library - ============================================================================ - - Author : Markus Franz Xaver Johannes Oberhumer - <markus@oberhumer.com> - http://www.oberhumer.com/opensource/lzo/ - Version : 2.06 - Date : 12 Aug 2011 - - - Abstract - -------- - LZO is a portable lossless data compression library written in ANSI C. - It offers pretty fast compression and very fast decompression. - Decompression requires no memory. - - In addition there are slower compression levels achieving a quite - competitive compression ratio while still decompressing at - this very high speed. - - The LZO algorithms and implementations are copyrighted OpenSource - distributed under the GNU General Public License. - - - Introduction - ------------ - LZO is a data compression library which is suitable for data - de-/compression in real-time. This means it favours speed - over compression ratio. - - The acronym LZO is standing for Lempel-Ziv-Oberhumer. - - LZO is written in ANSI C. Both the source code and the compressed - data format are designed to be portable across platforms. - - LZO implements a number of algorithms with the following features: - - - Decompression is simple and *very* fast. - - Requires no memory for decompression. - - Compression is pretty fast. - - Requires 64 KiB of memory for compression. - - Allows you to dial up extra compression at a speed cost in the - compressor. The speed of the decompressor is not reduced. - - Includes compression levels for generating pre-compressed - data which achieve a quite competitive compression ratio. - - There is also a compression level which needs only 8 KiB for compression. - - Algorithm is thread safe. - - Algorithm is lossless. - - LZO supports overlapping compression and in-place decompression. - - - Design criteria - --------------- - LZO was designed with speed in mind. Decompressor speed has been - favoured over compressor speed. Real-time decompression should be - possible for virtually any application. The implementation of the - LZO1X decompressor in optimized i386 assembler code runs about at - the third of the speed of a memcpy() - and even faster for many files. - - In fact I first wrote the decompressor of each algorithm thereby - defining the compressed data format, verified it with manually - created test data and at last added the compressor. - - - Performance - ----------- - To keep you interested, here is an overview of the average results - when compressing the Calgary Corpus test suite with a blocksize - of 256 KiB, originally done on an ancient Intel Pentium 133. - - The naming convention of the various algorithms goes LZOxx-N, where N is - the compression level. Range 1-9 indicates the fast standard levels using - 64 KiB memory for compression. Level 99 offers better compression at the - cost of more memory (256 KiB), and is still reasonably fast. - Level 999 achieves nearly optimal compression - but it is slow - and uses much memory, and is mainly intended for generating - pre-compressed data. - - The C version of LZO1X-1 is about 4-5 times faster than the fastest - zlib compression level, and it also outperforms other algorithms - like LZRW1-A and LZV in both compression ratio and compression speed - and decompression speed. - - +------------------------------------------------------------------------+ - | Algorithm Length CxB ComLen %Remn Bits Com K/s Dec K/s | - | --------- ------ --- ------ ----- ---- ------- ------- | - | | - | memcpy() 224401 1 224401 100.0 8.00 60956.83 59124.58 | - | | - | LZO1-1 224401 1 117362 53.1 4.25 4665.24 13341.98 | - | LZO1-99 224401 1 101560 46.7 3.73 1373.29 13823.40 | - | | - | LZO1A-1 224401 1 115174 51.7 4.14 4937.83 14410.35 | - | LZO1A-99 224401 1 99958 45.5 3.64 1362.72 14734.17 | - | | - | LZO1B-1 224401 1 109590 49.6 3.97 4565.53 15438.34 | - | LZO1B-2 224401 1 106235 48.4 3.88 4297.33 15492.79 | - | LZO1B-3 224401 1 104395 47.8 3.83 4018.21 15373.52 | - | LZO1B-4 224401 1 104828 47.4 3.79 3024.48 15100.11 | - | LZO1B-5 224401 1 102724 46.7 3.73 2827.82 15427.62 | - | LZO1B-6 224401 1 101210 46.0 3.68 2615.96 15325.68 | - | LZO1B-7 224401 1 101388 46.0 3.68 2430.89 15361.47 | - | LZO1B-8 224401 1 99453 45.2 3.62 2183.87 15402.77 | - | LZO1B-9 224401 1 99118 45.0 3.60 1677.06 15069.60 | - | LZO1B-99 224401 1 95399 43.6 3.48 1286.87 15656.11 | - | LZO1B-999 224401 1 83934 39.1 3.13 232.40 16445.05 | - | | - | LZO1C-1 224401 1 111735 50.4 4.03 4883.08 15570.91 | - | LZO1C-2 224401 1 108652 49.3 3.94 4424.24 15733.14 | - | LZO1C-3 224401 1 106810 48.7 3.89 4127.65 15645.69 | - | LZO1C-4 224401 1 105717 47.7 3.82 3007.92 15346.44 | - | LZO1C-5 224401 1 103605 47.0 3.76 2829.15 15153.88 | - | LZO1C-6 224401 1 102585 46.5 3.72 2631.37 15257.58 | - | LZO1C-7 224401 1 101937 46.2 3.70 2378.57 15492.49 | - | LZO1C-8 224401 1 100779 45.6 3.65 2171.93 15386.07 | - | LZO1C-9 224401 1 100255 45.4 3.63 1691.44 15194.68 | - | LZO1C-99 224401 1 97252 44.1 3.53 1462.88 15341.37 | - | LZO1C-999 224401 1 87740 40.2 3.21 306.44 16411.94 | - | | - | LZO1F-1 224401 1 113412 50.8 4.07 4755.97 16074.12 | - | LZO1F-999 224401 1 89599 40.3 3.23 280.68 16553.90 | - | | - | LZO1X-1(11) 224401 1 118810 52.6 4.21 4544.42 15879.04 | - | LZO1X-1(12) 224401 1 113675 50.6 4.05 4411.15 15721.59 | - | LZO1X-1 224401 1 109323 49.4 3.95 4991.76 15584.89 | - | LZO1X-1(15) 224401 1 108500 49.1 3.93 5077.50 15744.56 | - | LZO1X-999 224401 1 82854 38.0 3.04 135.77 16548.48 | - | | - | LZO1Y-1 224401 1 110820 49.8 3.98 4952.52 15638.82 | - | LZO1Y-999 224401 1 83614 38.2 3.05 135.07 16385.40 | - | | - | LZO1Z-999 224401 1 83034 38.0 3.04 133.31 10553.74 | - | | - | LZO2A-999 224401 1 87880 40.0 3.20 301.21 8115.75 | - +------------------------------------------------------------------------+ - - Notes: - - CxB is the number of blocks - - K/s is the speed measured in 1000 uncompressed bytes per second - - the assembler decompressors are even faster - - - Short documentation - ------------------- - LZO is a block compression algorithm - it compresses and decompresses - a block of data. Block size must be the same for compression - and decompression. - - LZO compresses a block of data into matches (a sliding dictionary) - and runs of non-matching literals. LZO takes care about long matches - and long literal runs so that it produces good results on highly - redundant data and deals acceptably with non-compressible data. - - When dealing with incompressible data, LZO expands the input - block by a maximum of 64 bytes per 1024 bytes input. - - I have verified LZO using such tools as valgrind and other memory checkers. - And in addition to compressing gigabytes of files when tuning some parameters - I have also consulted various 'lint' programs to spot potential portability - problems. LZO is free of any known bugs. - - - The algorithms - -------------- - There are too many algorithms implemented. But I want to support - unlimited backward compatibility, so I will not reduce the LZO - distribution in the future. - - As the many object files are mostly independent of each other, the - size overhead for an executable statically linked with the LZO library - is usually pretty low (just a few KiB) because the linker will only add - the modules that you are actually using. - - I first published LZO1 and LZO1A in the Internet newsgroups - comp.compression and comp.compression.research in March 1996. - They are mainly included for compatibility reasons. The LZO2A - decompressor is too slow, and there is no fast compressor anyway. - - My experiments have shown that LZO1B is good with a large blocksize - or with very redundant data, LZO1F is good with a small blocksize or - with binary data and that LZO1X is often the best choice of all. - LZO1Y and LZO1Z are almost identical to LZO1X - they can achieve a - better compression ratio on some files. - Beware, your mileage may vary. - - - Usage of the library - -------------------- - Despite of its size, the basic usage of LZO is really very simple. - - Let's assume you want to compress some data with LZO1X-1: - A) compression - * include <lzo/lzo1x.h> - call lzo_init() - compress your data with lzo1x_1_compress() - * link your application with the LZO library - B) decompression - * include <lzo/lzo1x.h> - call lzo_init() - decompress your data with lzo1x_decompress() - * link your application with the LZO library - - The program examples/simple.c shows a fully working example. - See also LZO.FAQ for more information. - - - Building LZO - ------------ - As LZO uses Autoconf+Automake+Libtool the building process under - UNIX systems should be very unproblematic. Shared libraries are - supported on many architectures as well. - For detailed instructions see the file INSTALL. - - Please note that due to the design of the ELF executable format - the performance of a shared library on i386 systems (e.g. Linux) - is a little bit slower, so you may want to link your applications - with the static version (liblzo2.a) anyway. - - For building under DOS, Win16, Win32, OS/2 and other systems - take a look at the file B/00readme.txt. - - In case of troubles (like decompression data errors) try recompiling - everything without optimizations - LZO may break the optimizer - of your compiler. See the file BUGS. - - LZO is written in ANSI C. In particular this means: - - your compiler must understand prototypes - - your compiler must understand prototypes in function pointers - - your compiler must correctly promote integrals ("value-preserving") - - your preprocessor must implement #elif, #error and stringizing - - you must have a conforming and correct <limits.h> header - - you must have <stddef.h>, <string.h> and other ANSI C headers - - you should have size_t and ptrdiff_t - - - Portability - ----------- - I have built and tested LZO successfully on a variety of platforms - including DOS (16 + 32 bit), Windows 3.x (16-bit), Win32, Win64, - Linux, *BSD, HP-UX and many more. - - LZO is also reported to work under AIX, ConvexOS, IRIX, MacOS, PalmOS (Pilot), - PSX (Sony Playstation), Solaris, SunOS, TOS (Atari ST) and VxWorks. - Furthermore it is said that its performance on a Cray is superior - to all other machines... - - And I think it would be much fun to translate the decompressors - to Z-80 or 6502 assembly. - - - The future - ---------- - Here is what I'm planning for the next months. No promises, though... - - - interfaces to .NET and Mono - - interfaces to Perl, Java, Python, Delphi, Visual Basic, ... - - improve documentation and API reference - - - Some comments about the source code - ----------------------------------- - Be warned: the main source code in the 'src' directory is a - real pain to understand as I've experimented with hundreds of slightly - different versions. It contains many #if and some gotos, and - is *completely optimized for speed* and not for readability. - Code sharing of the different algorithms is implemented by stressing - the preprocessor - this can be really confusing. Lots of marcos and - assertions don't make things better. - - Nevertheless LZO compiles very quietly on a variety of - compilers with the highest warning levels turned on, even - in C++ mode. - - - Copyright - --------- - LZO is Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, - 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 - Markus Franz Xaver Oberhumer <markus@oberhumer.com>. - - LZO is distributed under the terms of the GNU General Public License (GPL). - See the file COPYING. - - Special licenses for commercial and other applications which - are not willing to accept the GNU General Public License - are available by contacting the author. - - - |