This commit was generated by cvs2svn to compensate for changes in r26952,
which included commits to RCS files with non-trunk default branches. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@26953 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Václav Slavík
@@ -1,5 +1,246 @@
|
||||
|
||||
ChangeLog file for zlib
|
||||
ChangeLog file for zlib
|
||||
|
||||
Changes in 1.2.1 (17 November 2003)
|
||||
- Remove a tab in contrib/gzappend/gzappend.c
|
||||
- Update some interfaces in contrib for new zlib functions
|
||||
- Update zlib version number in some contrib entries
|
||||
- Add Windows CE definition for ptrdiff_t in zutil.h [Mai, Truta]
|
||||
- Support shared libraries on Hurd and KFreeBSD [Brown]
|
||||
- Fix error in NO_DIVIDE option of adler32.c
|
||||
|
||||
Changes in 1.2.0.8 (4 November 2003)
|
||||
- Update version in contrib/delphi/ZLib.pas and contrib/pascal/zlibpas.pas
|
||||
- Add experimental NO_DIVIDE #define in adler32.c
|
||||
- Possibly faster on some processors (let me know if it is)
|
||||
- Correct Z_BLOCK to not return on first inflate call if no wrap
|
||||
- Fix strm->data_type on inflate() return to correctly indicate EOB
|
||||
- Add deflatePrime() function for appending in the middle of a byte
|
||||
- Add contrib/gzappend for an example of appending to a stream
|
||||
- Update win32/DLL_FAQ.txt [Truta]
|
||||
- Delete Turbo C comment in README [Truta]
|
||||
- Improve some indentation in zconf.h [Truta]
|
||||
- Fix infinite loop on bad input in configure script [Church]
|
||||
- Fix gzeof() for concatenated gzip files [Johnson]
|
||||
- Add example to contrib/visual-basic.txt [Michael B.]
|
||||
- Add -p to mkdir's in Makefile.in [vda]
|
||||
- Fix configure to properly detect presence or lack of printf functions
|
||||
- Add AS400 support [Monnerat]
|
||||
- Add a little Cygwin support [Wilson]
|
||||
|
||||
Changes in 1.2.0.7 (21 September 2003)
|
||||
- Correct some debug formats in contrib/infback9
|
||||
- Cast a type in a debug statement in trees.c
|
||||
- Change search and replace delimiter in configure from % to # [Beebe]
|
||||
- Update contrib/untgz to 0.2 with various fixes [Truta]
|
||||
- Add build support for Amiga [Nikl]
|
||||
- Remove some directories in old that have been updated to 1.2
|
||||
- Add dylib building for Mac OS X in configure and Makefile.in
|
||||
- Remove old distribution stuff from Makefile
|
||||
- Update README to point to DLL_FAQ.txt, and add comment on Mac OS X
|
||||
- Update links in README
|
||||
|
||||
Changes in 1.2.0.6 (13 September 2003)
|
||||
- Minor FAQ updates
|
||||
- Update contrib/minizip to 1.00 [Vollant]
|
||||
- Remove test of gz functions in example.c when GZ_COMPRESS defined [Truta]
|
||||
- Update POSTINC comment for 68060 [Nikl]
|
||||
- Add contrib/infback9 with deflate64 decoding (unsupported)
|
||||
- For MVS define NO_vsnprintf and undefine FAR [van Burik]
|
||||
- Add pragma for fdopen on MVS [van Burik]
|
||||
|
||||
Changes in 1.2.0.5 (8 September 2003)
|
||||
- Add OF to inflateBackEnd() declaration in zlib.h
|
||||
- Remember start when using gzdopen in the middle of a file
|
||||
- Use internal off_t counters in gz* functions to properly handle seeks
|
||||
- Perform more rigorous check for distance-too-far in inffast.c
|
||||
- Add Z_BLOCK flush option to return from inflate at block boundary
|
||||
- Set strm->data_type on return from inflate
|
||||
- Indicate bits unused, if at block boundary, and if in last block
|
||||
- Replace size_t with ptrdiff_t in crc32.c, and check for correct size
|
||||
- Add condition so old NO_DEFLATE define still works for compatibility
|
||||
- FAQ update regarding the Windows DLL [Truta]
|
||||
- INDEX update: add qnx entry, remove aix entry [Truta]
|
||||
- Install zlib.3 into mandir [Wilson]
|
||||
- Move contrib/zlib_dll_FAQ.txt to win32/DLL_FAQ.txt; update [Truta]
|
||||
- Adapt the zlib interface to the new DLL convention guidelines [Truta]
|
||||
- Introduce ZLIB_WINAPI macro to allow the export of functions using
|
||||
the WINAPI calling convention, for Visual Basic [Vollant, Truta]
|
||||
- Update msdos and win32 scripts and makefiles [Truta]
|
||||
- Export symbols by name, not by ordinal, in win32/zlib.def [Truta]
|
||||
- Add contrib/ada [Anisimkov]
|
||||
- Move asm files from contrib/vstudio/vc70_32 to contrib/asm386 [Truta]
|
||||
- Rename contrib/asm386 to contrib/masmx86 [Truta, Vollant]
|
||||
- Add contrib/masm686 [Truta]
|
||||
- Fix offsets in contrib/inflate86 and contrib/masmx86/inffas32.asm
|
||||
[Truta, Vollant]
|
||||
- Update contrib/delphi; rename to contrib/pascal; add example [Truta]
|
||||
- Remove contrib/delphi2; add a new contrib/delphi [Truta]
|
||||
- Avoid inclusion of the nonstandard <memory.h> in contrib/iostream,
|
||||
and fix some method prototypes [Truta]
|
||||
- Fix the ZCR_SEED2 constant to avoid warnings in contrib/minizip
|
||||
[Truta]
|
||||
- Avoid the use of backslash (\) in contrib/minizip [Vollant]
|
||||
- Fix file time handling in contrib/untgz; update makefiles [Truta]
|
||||
- Update contrib/vstudio/vc70_32 to comply with the new DLL guidelines
|
||||
[Vollant]
|
||||
- Remove contrib/vstudio/vc15_16 [Vollant]
|
||||
- Rename contrib/vstudio/vc70_32 to contrib/vstudio/vc7 [Truta]
|
||||
- Update README.contrib [Truta]
|
||||
- Invert the assignment order of match_head and s->prev[...] in
|
||||
INSERT_STRING [Truta]
|
||||
- Compare TOO_FAR with 32767 instead of 32768, to avoid 16-bit warnings
|
||||
[Truta]
|
||||
- Compare function pointers with 0, not with NULL or Z_NULL [Truta]
|
||||
- Fix prototype of syncsearch in inflate.c [Truta]
|
||||
- Introduce ASMINF macro to be enabled when using an ASM implementation
|
||||
of inflate_fast [Truta]
|
||||
- Change NO_DEFLATE to NO_GZCOMPRESS [Truta]
|
||||
- Modify test_gzio in example.c to take a single file name as a
|
||||
parameter [Truta]
|
||||
- Exit the example.c program if gzopen fails [Truta]
|
||||
- Add type casts around strlen in example.c [Truta]
|
||||
- Remove casting to sizeof in minigzip.c; give a proper type
|
||||
to the variable compared with SUFFIX_LEN [Truta]
|
||||
- Update definitions of STDC and STDC99 in zconf.h [Truta]
|
||||
- Synchronize zconf.h with the new Windows DLL interface [Truta]
|
||||
- Use SYS16BIT instead of __32BIT__ to distinguish between
|
||||
16- and 32-bit platforms [Truta]
|
||||
- Use far memory allocators in small 16-bit memory models for
|
||||
Turbo C [Truta]
|
||||
- Add info about the use of ASMV, ASMINF and ZLIB_WINAPI in
|
||||
zlibCompileFlags [Truta]
|
||||
- Cygwin has vsnprintf [Wilson]
|
||||
- In Windows16, OS_CODE is 0, as in MSDOS [Truta]
|
||||
- In Cygwin, OS_CODE is 3 (Unix), not 11 (Windows32) [Wilson]
|
||||
|
||||
Changes in 1.2.0.4 (10 August 2003)
|
||||
- Minor FAQ updates
|
||||
- Be more strict when checking inflateInit2's windowBits parameter
|
||||
- Change NO_GUNZIP compile option to NO_GZIP to cover deflate as well
|
||||
- Add gzip wrapper option to deflateInit2 using windowBits
|
||||
- Add updated QNX rule in configure and qnx directory [Bonnefoy]
|
||||
- Make inflate distance-too-far checks more rigorous
|
||||
- Clean up FAR usage in inflate
|
||||
- Add casting to sizeof() in gzio.c and minigzip.c
|
||||
|
||||
Changes in 1.2.0.3 (19 July 2003)
|
||||
- Fix silly error in gzungetc() implementation [Vollant]
|
||||
- Update contrib/minizip and contrib/vstudio [Vollant]
|
||||
- Fix printf format in example.c
|
||||
- Correct cdecl support in zconf.in.h [Anisimkov]
|
||||
- Minor FAQ updates
|
||||
|
||||
Changes in 1.2.0.2 (13 July 2003)
|
||||
- Add ZLIB_VERNUM in zlib.h for numerical preprocessor comparisons
|
||||
- Attempt to avoid warnings in crc32.c for pointer-int conversion
|
||||
- Add AIX to configure, remove aix directory [Bakker]
|
||||
- Add some casts to minigzip.c
|
||||
- Improve checking after insecure sprintf() or vsprintf() calls
|
||||
- Remove #elif's from crc32.c
|
||||
- Change leave label to inf_leave in inflate.c and infback.c to avoid
|
||||
library conflicts
|
||||
- Remove inflate gzip decoding by default--only enable gzip decoding by
|
||||
special request for stricter backward compatibility
|
||||
- Add zlibCompileFlags() function to return compilation information
|
||||
- More typecasting in deflate.c to avoid warnings
|
||||
- Remove leading underscore from _Capital #defines [Truta]
|
||||
- Fix configure to link shared library when testing
|
||||
- Add some Windows CE target adjustments [Mai]
|
||||
- Remove #define ZLIB_DLL in zconf.h [Vollant]
|
||||
- Add zlib.3 [Rodgers]
|
||||
- Update RFC URL in deflate.c and algorithm.txt [Mai]
|
||||
- Add zlib_dll_FAQ.txt to contrib [Truta]
|
||||
- Add UL to some constants [Truta]
|
||||
- Update minizip and vstudio [Vollant]
|
||||
- Remove vestigial NEED_DUMMY_RETURN from zconf.in.h
|
||||
- Expand use of NO_DUMMY_DECL to avoid all dummy structures
|
||||
- Added iostream3 to contrib [Schwardt]
|
||||
- Replace rewind() with fseek() for WinCE [Truta]
|
||||
- Improve setting of zlib format compression level flags
|
||||
- Report 0 for huffman and rle strategies and for level == 0 or 1
|
||||
- Report 2 only for level == 6
|
||||
- Only deal with 64K limit when necessary at compile time [Truta]
|
||||
- Allow TOO_FAR check to be turned off at compile time [Truta]
|
||||
- Add gzclearerr() function [Souza]
|
||||
- Add gzungetc() function
|
||||
|
||||
Changes in 1.2.0.1 (17 March 2003)
|
||||
- Add Z_RLE strategy for run-length encoding [Truta]
|
||||
- When Z_RLE requested, restrict matches to distance one
|
||||
- Update zlib.h, minigzip.c, gzopen(), gzdopen() for Z_RLE
|
||||
- Correct FASTEST compilation to allow level == 0
|
||||
- Clean up what gets compiled for FASTEST
|
||||
- Incorporate changes to zconf.in.h [Vollant]
|
||||
- Refine detection of Turbo C need for dummy returns
|
||||
- Refine ZLIB_DLL compilation
|
||||
- Include additional header file on VMS for off_t typedef
|
||||
- Try to use _vsnprintf where it supplants vsprintf [Vollant]
|
||||
- Add some casts in inffast.c
|
||||
- Enchance comments in zlib.h on what happens if gzprintf() tries to
|
||||
write more than 4095 bytes before compression
|
||||
- Remove unused state from inflateBackEnd()
|
||||
- Remove exit(0) from minigzip.c, example.c
|
||||
- Get rid of all those darn tabs
|
||||
- Add "check" target to Makefile.in that does the same thing as "test"
|
||||
- Add "mostlyclean" and "maintainer-clean" targets to Makefile.in
|
||||
- Update contrib/inflate86 [Anderson]
|
||||
- Update contrib/testzlib, contrib/vstudio, contrib/minizip [Vollant]
|
||||
- Add msdos and win32 directories with makefiles [Truta]
|
||||
- More additions and improvements to the FAQ
|
||||
|
||||
Changes in 1.2.0 (9 March 2003)
|
||||
- New and improved inflate code
|
||||
- About 20% faster
|
||||
- Does not allocate 32K window unless and until needed
|
||||
- Automatically detects and decompresses gzip streams
|
||||
- Raw inflate no longer needs an extra dummy byte at end
|
||||
- Added inflateBack functions using a callback interface--even faster
|
||||
than inflate, useful for file utilities (gzip, zip)
|
||||
- Added inflateCopy() function to record state for random access on
|
||||
externally generated deflate streams (e.g. in gzip files)
|
||||
- More readable code (I hope)
|
||||
- New and improved crc32()
|
||||
- About 50% faster, thanks to suggestions from Rodney Brown
|
||||
- Add deflateBound() and compressBound() functions
|
||||
- Fix memory leak in deflateInit2()
|
||||
- Permit setting dictionary for raw deflate (for parallel deflate)
|
||||
- Fix const declaration for gzwrite()
|
||||
- Check for some malloc() failures in gzio.c
|
||||
- Fix bug in gzopen() on single-byte file 0x1f
|
||||
- Fix bug in gzread() on concatenated file with 0x1f at end of buffer
|
||||
and next buffer doesn't start with 0x8b
|
||||
- Fix uncompress() to return Z_DATA_ERROR on truncated input
|
||||
- Free memory at end of example.c
|
||||
- Remove MAX #define in trees.c (conflicted with some libraries)
|
||||
- Fix static const's in deflate.c, gzio.c, and zutil.[ch]
|
||||
- Declare malloc() and free() in gzio.c if STDC not defined
|
||||
- Use malloc() instead of calloc() in zutil.c if int big enough
|
||||
- Define STDC for AIX
|
||||
- Add aix/ with approach for compiling shared library on AIX
|
||||
- Add HP-UX support for shared libraries in configure
|
||||
- Add OpenUNIX support for shared libraries in configure
|
||||
- Use $cc instead of gcc to build shared library
|
||||
- Make prefix directory if needed when installing
|
||||
- Correct Macintosh avoidance of typedef Byte in zconf.h
|
||||
- Correct Turbo C memory allocation when under Linux
|
||||
- Use libz.a instead of -lz in Makefile (assure use of compiled library)
|
||||
- Update configure to check for snprintf or vsnprintf functions and their
|
||||
return value, warn during make if using an insecure function
|
||||
- Fix configure problem with compile-time knowledge of HAVE_UNISTD_H that
|
||||
is lost when library is used--resolution is to build new zconf.h
|
||||
- Documentation improvements (in zlib.h):
|
||||
- Document raw deflate and inflate
|
||||
- Update RFCs URL
|
||||
- Point out that zlib and gzip formats are different
|
||||
- Note that Z_BUF_ERROR is not fatal
|
||||
- Document string limit for gzprintf() and possible buffer overflow
|
||||
- Note requirement on avail_out when flushing
|
||||
- Note permitted values of flush parameter of inflate()
|
||||
- Add some FAQs (and even answers) to the FAQ
|
||||
- Add contrib/inflate86/ for x86 faster inflate
|
||||
- Add contrib/blast/ for PKWare Data Compression Library decompression
|
||||
- Add contrib/puff/ simple inflate for deflate format description
|
||||
|
||||
Changes in 1.1.4 (11 March 2002)
|
||||
- ZFREE was repeated on same allocation on some error conditions.
|
||||
@@ -10,7 +251,7 @@ Changes in 1.1.4 (11 March 2002)
|
||||
less than 32K.
|
||||
- force windowBits > 8 to avoid a bug in the encoder for a window size
|
||||
of 256 bytes. (A complete fix will be available in 1.1.5).
|
||||
|
||||
|
||||
Changes in 1.1.3 (9 July 1998)
|
||||
- fix "an inflate input buffer bug that shows up on rare but persistent
|
||||
occasions" (Mark)
|
||||
@@ -184,13 +425,13 @@ Changes in 1.0.6 (19 Jan 1998)
|
||||
- added Makefile.nt (thanks to Stephen Williams)
|
||||
- added the unsupported "contrib" directory:
|
||||
contrib/asm386/ by Gilles Vollant <info@winimage.com>
|
||||
386 asm code replacing longest_match().
|
||||
386 asm code replacing longest_match().
|
||||
contrib/iostream/ by Kevin Ruland <kevin@rodin.wustl.edu>
|
||||
A C++ I/O streams interface to the zlib gz* functions
|
||||
contrib/iostream2/ by Tyge L<>vset <Tyge.Lovset@cmr.no>
|
||||
Another C++ I/O streams interface
|
||||
Another C++ I/O streams interface
|
||||
contrib/untgz/ by "Pedro A. Aranda Guti\irrez" <paag@tid.es>
|
||||
A very simple tar.gz file extractor using zlib
|
||||
A very simple tar.gz file extractor using zlib
|
||||
contrib/visual-basic.txt by Carlos Rios <c_rios@sonda.cl>
|
||||
How to use compress(), uncompress() and the gz* functions from VB.
|
||||
- pass params -f (filtered data), -h (huffman only), -1 to -9 (compression
|
||||
@@ -217,7 +458,7 @@ Changes in 1.0.6 (19 Jan 1998)
|
||||
- add NEED_DUMMY_RETURN for Borland
|
||||
- use variable z_verbose for tracing in debug mode (L. Peter Deutsch).
|
||||
- allow compilation with CC
|
||||
- defined STDC for OS/2 (David Charlap)
|
||||
- defined STDC for OS/2 (David Charlap)
|
||||
- limit external names to 8 chars for MVS (Thomas Lund)
|
||||
- in minigzip.c, use static buffers only for 16-bit systems
|
||||
- fix suffix check for "minigzip -d foo.gz"
|
||||
@@ -242,7 +483,7 @@ Changes in 1.0.5 (3 Jan 98)
|
||||
- Eliminate memory leaks on error conditions in inflate
|
||||
- Removed some vestigial code in inflate
|
||||
- Update web address in README
|
||||
|
||||
|
||||
Changes in 1.0.4 (24 Jul 96)
|
||||
- In very rare conditions, deflate(s, Z_FINISH) could fail to produce an EOF
|
||||
bit, so the decompressor could decompress all the correct data but went
|
||||
|
||||
@@ -1,86 +1,48 @@
|
||||
ChangeLog history of changes
|
||||
INDEX this file
|
||||
FAQ Frequently Asked Questions about zlib
|
||||
Make_vms.com script for Vax/VMS
|
||||
Makefile makefile for Unix (generated by configure)
|
||||
Makefile.in makefile for Unix (template for configure)
|
||||
Makefile.riscos makefile for RISCOS
|
||||
README guess what
|
||||
algorithm.txt description of the (de)compression algorithm
|
||||
configure configure script for Unix
|
||||
descrip.mms makefile for Vax/VMS
|
||||
zlib.3 mini man page for zlib (volunteers to write full
|
||||
man pages from zlib.h welcome. write to jloup@gzip.org)
|
||||
ChangeLog history of changes
|
||||
FAQ Frequently Asked Questions about zlib
|
||||
INDEX this file
|
||||
Makefile makefile for Unix (generated by configure)
|
||||
Makefile.in makefile for Unix (template for configure)
|
||||
README guess what
|
||||
algorithm.txt description of the (de)compression algorithm
|
||||
configure configure script for Unix
|
||||
zconf.in.h template for zconf.h (used by configure)
|
||||
|
||||
amiga/Makefile.sas makefile for Amiga SAS/C
|
||||
amiga/Makefile.pup makefile for Amiga powerUP SAS/C PPC
|
||||
msdos/ makefiles for MSDOS
|
||||
old/ makefiles for various architectures and zlib documentation
|
||||
files that have not yet been updated for zlib 1.2.x
|
||||
qnx/ makefiles for QNX
|
||||
win32/ makefiles for Windows
|
||||
|
||||
msdos/Makefile.w32 makefile for Microsoft Visual C++ 32-bit
|
||||
msdos/Makefile.b32 makefile for Borland C++ 32-bit
|
||||
msdos/Makefile.bor makefile for Borland C/C++ 16-bit
|
||||
msdos/Makefile.dj2 makefile for DJGPP 2.x
|
||||
msdos/Makefile.emx makefile for EMX 0.9c (32-bit DOS/OS2)
|
||||
msdos/Makefile.msc makefile for Microsoft C 16-bit
|
||||
msdos/Makefile.tc makefile for Turbo C
|
||||
msdos/Makefile.wat makefile for Watcom C
|
||||
msdos/zlib.def definition file for Windows DLL
|
||||
msdos/zlib.rc definition file for Windows DLL
|
||||
|
||||
nt/Makefile.nt makefile for Windows NT
|
||||
nt/zlib.dnt definition file for Windows NT DLL
|
||||
nt/Makefile.emx makefile for EMX 0.9c/RSXNT 1.41 (Win32 Intel)
|
||||
nt/Makefile.gcc makefile for Windows NT using GCC (mingw32)
|
||||
|
||||
|
||||
zlib public header files (must be kept):
|
||||
zlib public header files (must be kept):
|
||||
zconf.h
|
||||
zlib.h
|
||||
|
||||
private source files used to build the zlib library:
|
||||
private source files used to build the zlib library:
|
||||
adler32.c
|
||||
compress.c
|
||||
crc32.c
|
||||
crc32.h
|
||||
deflate.c
|
||||
deflate.h
|
||||
gzio.c
|
||||
infblock.c
|
||||
infblock.h
|
||||
infcodes.c
|
||||
infcodes.h
|
||||
infback.c
|
||||
inffast.c
|
||||
inffast.h
|
||||
inffixed.h
|
||||
inflate.c
|
||||
inflate.h
|
||||
inftrees.c
|
||||
inftrees.h
|
||||
infutil.c
|
||||
infutil.h
|
||||
maketree.c
|
||||
trees.c
|
||||
trees.h
|
||||
uncompr.c
|
||||
zutil.c
|
||||
zutil.h
|
||||
|
||||
source files for sample programs:
|
||||
source files for sample programs:
|
||||
example.c
|
||||
minigzip.c
|
||||
|
||||
unsupported contribution by third parties
|
||||
|
||||
contrib/asm386/ by Gilles Vollant <info@winimage.com>
|
||||
386 asm code replacing longest_match().
|
||||
|
||||
contrib/minizip/ by Gilles Vollant <info@winimage.com>
|
||||
Mini zip and unzip based on zlib
|
||||
See http://www.winimage.com/zLibDll/unzip.html
|
||||
|
||||
contrib/iostream/ by Kevin Ruland <kevin@rodin.wustl.edu>
|
||||
A C++ I/O streams interface to the zlib gz* functions
|
||||
|
||||
contrib/iostream2/ by Tyge L<>vset <Tyge.Lovset@cmr.no>
|
||||
Another C++ I/O streams interface
|
||||
|
||||
contrib/untgz/ by "Pedro A. Aranda Guti\irrez" <paag@tid.es>
|
||||
A very simple tar.gz extractor using zlib
|
||||
|
||||
contrib/visual-basic.txt by Carlos Rios <c_rios@sonda.cl>
|
||||
How to use compress(), uncompress() and the gz* functions from VB.
|
||||
unsupported contribution by third parties
|
||||
See contrib/README.contrib
|
||||
|
||||
131
src/zlib/README
131
src/zlib/README
@@ -1,110 +1,87 @@
|
||||
zlib 1.1.4 is a general purpose data compression library. All the code
|
||||
is thread safe. The data format used by the zlib library
|
||||
is described by RFCs (Request for Comments) 1950 to 1952 in the files
|
||||
http://www.ietf.org/rfc/rfc1950.txt (zlib format), rfc1951.txt (deflate
|
||||
format) and rfc1952.txt (gzip format). These documents are also available in
|
||||
other formats from ftp://ftp.uu.net/graphics/png/documents/zlib/zdoc-index.html
|
||||
ZLIB DATA COMPRESSION LIBRARY
|
||||
|
||||
zlib 1.2.1 is a general purpose data compression library. All the code is
|
||||
thread safe. The data format used by the zlib library is described by RFCs
|
||||
(Request for Comments) 1950 to 1952 in the files
|
||||
http://www.ietf.org/rfc/rfc1950.txt (zlib format), rfc1951.txt (deflate format)
|
||||
and rfc1952.txt (gzip format). These documents are also available in other
|
||||
formats from ftp://ftp.uu.net/graphics/png/documents/zlib/zdoc-index.html
|
||||
|
||||
All functions of the compression library are documented in the file zlib.h
|
||||
(volunteer to write man pages welcome, contact jloup@gzip.org). A usage
|
||||
example of the library is given in the file example.c which also tests that
|
||||
the library is working correctly. Another example is given in the file
|
||||
minigzip.c. The compression library itself is composed of all source files
|
||||
except example.c and minigzip.c.
|
||||
(volunteer to write man pages welcome, contact zlib@gzip.org). A usage example
|
||||
of the library is given in the file example.c which also tests that the library
|
||||
is working correctly. Another example is given in the file minigzip.c. The
|
||||
compression library itself is composed of all source files except example.c and
|
||||
minigzip.c.
|
||||
|
||||
To compile all files and run the test program, follow the instructions
|
||||
given at the top of Makefile. In short "make test; make install"
|
||||
should work for most machines. For Unix: "./configure; make test; make install"
|
||||
For MSDOS, use one of the special makefiles such as Makefile.msc.
|
||||
For VMS, use Make_vms.com or descrip.mms.
|
||||
To compile all files and run the test program, follow the instructions given at
|
||||
the top of Makefile. In short "make test; make install" should work for most
|
||||
machines. For Unix: "./configure; make test; make install" For MSDOS, use one
|
||||
of the special makefiles such as Makefile.msc. For VMS, use Make_vms.com or
|
||||
descrip.mms.
|
||||
|
||||
Questions about zlib should be sent to <zlib@gzip.org>, or to
|
||||
Gilles Vollant <info@winimage.com> for the Windows DLL version.
|
||||
The zlib home page is http://www.zlib.org or http://www.gzip.org/zlib/
|
||||
Before reporting a problem, please check this site to verify that
|
||||
you have the latest version of zlib; otherwise get the latest version and
|
||||
check whether the problem still exists or not.
|
||||
Questions about zlib should be sent to <zlib@gzip.org>, or to Gilles Vollant
|
||||
<info@winimage.com> for the Windows DLL version. The zlib home page is
|
||||
http://www.zlib.org or http://www.gzip.org/zlib/ Before reporting a problem,
|
||||
please check this site to verify that you have the latest version of zlib;
|
||||
otherwise get the latest version and check whether the problem still exists or
|
||||
not.
|
||||
|
||||
PLEASE read the zlib FAQ http://www.gzip.org/zlib/zlib_faq.html
|
||||
before asking for help.
|
||||
PLEASE read the zlib FAQ http://www.gzip.org/zlib/zlib_faq.html before asking
|
||||
for help.
|
||||
|
||||
Mark Nelson <markn@ieee.org> wrote an article about zlib for the Jan. 1997
|
||||
issue of Dr. Dobb's Journal; a copy of the article is available in
|
||||
http://dogma.net/markn/articles/zlibtool/zlibtool.htm
|
||||
|
||||
The changes made in version 1.1.4 are documented in the file ChangeLog.
|
||||
The only changes made since 1.1.3 are bug corrections:
|
||||
|
||||
- ZFREE was repeated on same allocation on some error conditions.
|
||||
This creates a security problem described in
|
||||
http://www.zlib.org/advisory-2002-03-11.txt
|
||||
- Returned incorrect error (Z_MEM_ERROR) on some invalid data
|
||||
- Avoid accesses before window for invalid distances with inflate window
|
||||
less than 32K.
|
||||
- force windowBits > 8 to avoid a bug in the encoder for a window size
|
||||
of 256 bytes. (A complete fix will be available in 1.1.5).
|
||||
|
||||
The beta version 1.1.5beta includes many more changes. A new official
|
||||
version 1.1.5 will be released as soon as extensive testing has been
|
||||
completed on it.
|
||||
|
||||
The changes made in version 1.2.1 are documented in the file ChangeLog.
|
||||
|
||||
Unsupported third party contributions are provided in directory "contrib".
|
||||
|
||||
A Java implementation of zlib is available in the Java Development Kit
|
||||
http://www.javasoft.com/products/JDK/1.1/docs/api/Package-java.util.zip.html
|
||||
http://java.sun.com/j2se/1.4.2/docs/api/java/util/zip/package-summary.html
|
||||
See the zlib home page http://www.zlib.org for details.
|
||||
|
||||
A Perl interface to zlib written by Paul Marquess <pmarquess@bfsec.bt.co.uk>
|
||||
is in the CPAN (Comprehensive Perl Archive Network) sites
|
||||
A Perl interface to zlib written by Paul Marquess <pmqs@cpan.org> is in the
|
||||
CPAN (Comprehensive Perl Archive Network) sites
|
||||
http://www.cpan.org/modules/by-module/Compress/
|
||||
|
||||
A Python interface to zlib written by A.M. Kuchling <amk@magnet.com>
|
||||
is available in Python 1.5 and later versions, see
|
||||
A Python interface to zlib written by A.M. Kuchling <amk@magnet.com> is
|
||||
available in Python 1.5 and later versions, see
|
||||
http://www.python.org/doc/lib/module-zlib.html
|
||||
|
||||
A zlib binding for TCL written by Andreas Kupries <a.kupries@westend.com>
|
||||
is availlable at http://www.westend.com/~kupries/doc/trf/man/man.html
|
||||
A zlib binding for TCL written by Andreas Kupries <a.kupries@westend.com> is
|
||||
availlable at http://www.oche.de/~akupries/soft/trf/trf_zip.html
|
||||
|
||||
An experimental package to read and write files in .zip format,
|
||||
written on top of zlib by Gilles Vollant <info@winimage.com>, is
|
||||
available at http://www.winimage.com/zLibDll/unzip.html
|
||||
and also in the contrib/minizip directory of zlib.
|
||||
An experimental package to read and write files in .zip format, written on top
|
||||
of zlib by Gilles Vollant <info@winimage.com>, is available in the
|
||||
contrib/minizip directory of zlib.
|
||||
|
||||
|
||||
Notes for some targets:
|
||||
|
||||
- To build a Windows DLL version, include in a DLL project zlib.def, zlib.rc
|
||||
and all .c files except example.c and minigzip.c; compile with -DZLIB_DLL
|
||||
The zlib DLL support was initially done by Alessandro Iacopetti and is
|
||||
now maintained by Gilles Vollant <info@winimage.com>. Check the zlib DLL
|
||||
home page at http://www.winimage.com/zLibDll
|
||||
- For Windows DLL versions, please see win32/DLL_FAQ.txt
|
||||
|
||||
From Visual Basic, you can call the DLL functions which do not take
|
||||
a structure as argument: compress, uncompress and all gz* functions.
|
||||
See contrib/visual-basic.txt for more information, or get
|
||||
http://www.tcfb.com/dowseware/cmp-z-it.zip
|
||||
- For 64-bit Irix, deflate.c must be compiled without any optimization. With
|
||||
-O, one libpng test fails. The test works in 32 bit mode (with the -n32
|
||||
compiler flag). The compiler bug has been reported to SGI.
|
||||
|
||||
- For 64-bit Irix, deflate.c must be compiled without any optimization.
|
||||
With -O, one libpng test fails. The test works in 32 bit mode (with
|
||||
the -n32 compiler flag). The compiler bug has been reported to SGI.
|
||||
- zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1 it works
|
||||
when compiled with cc.
|
||||
|
||||
- zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1
|
||||
it works when compiled with cc.
|
||||
- On Digital Unix 4.0D (formely OSF/1) on AlphaServer, the cc option -std1 is
|
||||
necessary to get gzprintf working correctly. This is done by configure.
|
||||
|
||||
- on Digital Unix 4.0D (formely OSF/1) on AlphaServer, the cc option -std1
|
||||
is necessary to get gzprintf working correctly. This is done by configure.
|
||||
|
||||
- zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works
|
||||
with other compilers. Use "make test" to check your compiler.
|
||||
- zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works with
|
||||
other compilers. Use "make test" to check your compiler.
|
||||
|
||||
- gzdopen is not supported on RISCOS, BEOS and by some Mac compilers.
|
||||
|
||||
- For Turbo C the small model is supported only with reduced performance to
|
||||
avoid any far allocation; it was tested with -DMAX_WBITS=11 -DMAX_MEM_LEVEL=3
|
||||
- For PalmOs, see http://palmzlib.sourceforge.net/
|
||||
|
||||
- For PalmOs, see http://www.cs.uit.no/~perm/PASTA/pilot/software.html
|
||||
Per Harald Myrvang <perm@stud.cs.uit.no>
|
||||
- When building a shared, i.e. dynamic library on Mac OS X, the library must be
|
||||
installed before testing (do "make install" before "make test"), since the
|
||||
library location is specified in the library.
|
||||
|
||||
|
||||
Acknowledgments:
|
||||
@@ -116,7 +93,7 @@ Acknowledgments:
|
||||
|
||||
Copyright notice:
|
||||
|
||||
(C) 1995-2002 Jean-loup Gailly and Mark Adler
|
||||
(C) 1995-2003 Jean-loup Gailly and Mark Adler
|
||||
|
||||
This software is provided 'as-is', without any express or implied
|
||||
warranty. In no event will the authors be held liable for any damages
|
||||
@@ -144,4 +121,6 @@ entirely written by Jean-loup Gailly and Mark Adler; it does not
|
||||
include third-party code.
|
||||
|
||||
If you redistribute modified sources, we would appreciate that you include
|
||||
in the file ChangeLog history information documenting your changes.
|
||||
in the file ChangeLog history information documenting your changes. Please
|
||||
read the FAQ for more information on the distribution of modified source
|
||||
versions.
|
||||
|
||||
@@ -59,10 +59,10 @@ but saves time since there are both fewer insertions and fewer searches.
|
||||
|
||||
2.1 Introduction
|
||||
|
||||
The real question is, given a Huffman tree, how to decode fast. The most
|
||||
important realization is that shorter codes are much more common than
|
||||
longer codes, so pay attention to decoding the short codes fast, and let
|
||||
the long codes take longer to decode.
|
||||
The key question is how to represent a Huffman code (or any prefix code) so
|
||||
that you can decode fast. The most important characteristic is that shorter
|
||||
codes are much more common than longer codes, so pay attention to decoding the
|
||||
short codes fast, and let the long codes take longer to decode.
|
||||
|
||||
inflate() sets up a first level table that covers some number of bits of
|
||||
input less than the length of longest code. It gets that many bits from the
|
||||
@@ -77,58 +77,54 @@ table took no time (and if you had infinite memory), then there would only
|
||||
be a first level table to cover all the way to the longest code. However,
|
||||
building the table ends up taking a lot longer for more bits since short
|
||||
codes are replicated many times in such a table. What inflate() does is
|
||||
simply to make the number of bits in the first table a variable, and set it
|
||||
for the maximum speed.
|
||||
simply to make the number of bits in the first table a variable, and then
|
||||
to set that variable for the maximum speed.
|
||||
|
||||
inflate() sends new trees relatively often, so it is possibly set for a
|
||||
smaller first level table than an application that has only one tree for
|
||||
all the data. For inflate, which has 286 possible codes for the
|
||||
literal/length tree, the size of the first table is nine bits. Also the
|
||||
distance trees have 30 possible values, and the size of the first table is
|
||||
six bits. Note that for each of those cases, the table ended up one bit
|
||||
longer than the ``average'' code length, i.e. the code length of an
|
||||
approximately flat code which would be a little more than eight bits for
|
||||
286 symbols and a little less than five bits for 30 symbols. It would be
|
||||
interesting to see if optimizing the first level table for other
|
||||
applications gave values within a bit or two of the flat code size.
|
||||
For inflate, which has 286 possible codes for the literal/length tree, the size
|
||||
of the first table is nine bits. Also the distance trees have 30 possible
|
||||
values, and the size of the first table is six bits. Note that for each of
|
||||
those cases, the table ended up one bit longer than the ``average'' code
|
||||
length, i.e. the code length of an approximately flat code which would be a
|
||||
little more than eight bits for 286 symbols and a little less than five bits
|
||||
for 30 symbols.
|
||||
|
||||
|
||||
2.2 More details on the inflate table lookup
|
||||
|
||||
Ok, you want to know what this cleverly obfuscated inflate tree actually
|
||||
looks like. You are correct that it's not a Huffman tree. It is simply a
|
||||
lookup table for the first, let's say, nine bits of a Huffman symbol. The
|
||||
symbol could be as short as one bit or as long as 15 bits. If a particular
|
||||
Ok, you want to know what this cleverly obfuscated inflate tree actually
|
||||
looks like. You are correct that it's not a Huffman tree. It is simply a
|
||||
lookup table for the first, let's say, nine bits of a Huffman symbol. The
|
||||
symbol could be as short as one bit or as long as 15 bits. If a particular
|
||||
symbol is shorter than nine bits, then that symbol's translation is duplicated
|
||||
in all those entries that start with that symbol's bits. For example, if the
|
||||
symbol is four bits, then it's duplicated 32 times in a nine-bit table. If a
|
||||
in all those entries that start with that symbol's bits. For example, if the
|
||||
symbol is four bits, then it's duplicated 32 times in a nine-bit table. If a
|
||||
symbol is nine bits long, it appears in the table once.
|
||||
|
||||
If the symbol is longer than nine bits, then that entry in the table points
|
||||
to another similar table for the remaining bits. Again, there are duplicated
|
||||
If the symbol is longer than nine bits, then that entry in the table points
|
||||
to another similar table for the remaining bits. Again, there are duplicated
|
||||
entries as needed. The idea is that most of the time the symbol will be short
|
||||
and there will only be one table look up. (That's whole idea behind data
|
||||
compression in the first place.) For the less frequent long symbols, there
|
||||
will be two lookups. If you had a compression method with really long
|
||||
symbols, you could have as many levels of lookups as is efficient. For
|
||||
and there will only be one table look up. (That's whole idea behind data
|
||||
compression in the first place.) For the less frequent long symbols, there
|
||||
will be two lookups. If you had a compression method with really long
|
||||
symbols, you could have as many levels of lookups as is efficient. For
|
||||
inflate, two is enough.
|
||||
|
||||
So a table entry either points to another table (in which case nine bits in
|
||||
the above example are gobbled), or it contains the translation for the symbol
|
||||
and the number of bits to gobble. Then you start again with the next
|
||||
So a table entry either points to another table (in which case nine bits in
|
||||
the above example are gobbled), or it contains the translation for the symbol
|
||||
and the number of bits to gobble. Then you start again with the next
|
||||
ungobbled bit.
|
||||
|
||||
You may wonder: why not just have one lookup table for how ever many bits the
|
||||
longest symbol is? The reason is that if you do that, you end up spending
|
||||
more time filling in duplicate symbol entries than you do actually decoding.
|
||||
At least for deflate's output that generates new trees every several 10's of
|
||||
kbytes. You can imagine that filling in a 2^15 entry table for a 15-bit code
|
||||
would take too long if you're only decoding several thousand symbols. At the
|
||||
You may wonder: why not just have one lookup table for how ever many bits the
|
||||
longest symbol is? The reason is that if you do that, you end up spending
|
||||
more time filling in duplicate symbol entries than you do actually decoding.
|
||||
At least for deflate's output that generates new trees every several 10's of
|
||||
kbytes. You can imagine that filling in a 2^15 entry table for a 15-bit code
|
||||
would take too long if you're only decoding several thousand symbols. At the
|
||||
other extreme, you could make a new table for every bit in the code. In fact,
|
||||
that's essentially a Huffman tree. But then you spend two much time
|
||||
that's essentially a Huffman tree. But then you spend two much time
|
||||
traversing the tree while decoding, even for short symbols.
|
||||
|
||||
So the number of bits for the first lookup table is a trade of the time to
|
||||
So the number of bits for the first lookup table is a trade of the time to
|
||||
fill out the table vs. the time spent looking at the second level and above of
|
||||
the table.
|
||||
|
||||
@@ -158,7 +154,7 @@ Let's make the first table three bits long (eight entries):
|
||||
110: -> table X (gobble 3 bits)
|
||||
111: -> table Y (gobble 3 bits)
|
||||
|
||||
Each entry is what the bits decode to and how many bits that is, i.e. how
|
||||
Each entry is what the bits decode as and how many bits that is, i.e. how
|
||||
many bits to gobble. Or the entry points to another table, with the number of
|
||||
bits to gobble implicit in the size of the table.
|
||||
|
||||
@@ -170,7 +166,7 @@ long:
|
||||
10: D,2
|
||||
11: E,2
|
||||
|
||||
Table Y is three bits long since the longest code starting with 111 is six
|
||||
Table Y is three bits long since the longest code starting with 111 is six
|
||||
bits long:
|
||||
|
||||
000: F,2
|
||||
@@ -182,20 +178,20 @@ bits long:
|
||||
110: I,3
|
||||
111: J,3
|
||||
|
||||
So what we have here are three tables with a total of 20 entries that had to
|
||||
be constructed. That's compared to 64 entries for a single table. Or
|
||||
compared to 16 entries for a Huffman tree (six two entry tables and one four
|
||||
entry table). Assuming that the code ideally represents the probability of
|
||||
So what we have here are three tables with a total of 20 entries that had to
|
||||
be constructed. That's compared to 64 entries for a single table. Or
|
||||
compared to 16 entries for a Huffman tree (six two entry tables and one four
|
||||
entry table). Assuming that the code ideally represents the probability of
|
||||
the symbols, it takes on the average 1.25 lookups per symbol. That's compared
|
||||
to one lookup for the single table, or 1.66 lookups per symbol for the
|
||||
to one lookup for the single table, or 1.66 lookups per symbol for the
|
||||
Huffman tree.
|
||||
|
||||
There, I think that gives you a picture of what's going on. For inflate, the
|
||||
meaning of a particular symbol is often more than just a letter. It can be a
|
||||
byte (a "literal"), or it can be either a length or a distance which
|
||||
indicates a base value and a number of bits to fetch after the code that is
|
||||
added to the base value. Or it might be the special end-of-block code. The
|
||||
data structures created in inftrees.c try to encode all that information
|
||||
There, I think that gives you a picture of what's going on. For inflate, the
|
||||
meaning of a particular symbol is often more than just a letter. It can be a
|
||||
byte (a "literal"), or it can be either a length or a distance which
|
||||
indicates a base value and a number of bits to fetch after the code that is
|
||||
added to the base value. Or it might be the special end-of-block code. The
|
||||
data structures created in inftrees.c try to encode all that information
|
||||
compactly in the tables.
|
||||
|
||||
|
||||
@@ -210,4 +206,4 @@ Compression,'' IEEE Transactions on Information Theory, Vol. 23, No. 3,
|
||||
pp. 337-343.
|
||||
|
||||
``DEFLATE Compressed Data Format Specification'' available in
|
||||
ftp://ds.internic.net/rfc/rfc1951.txt
|
||||
http://www.ietf.org/rfc/rfc1951.txt
|
||||
|
||||
Reference in New Issue
Block a user