From 7baa3d795c87c11550f1686488c968320428cbf9 Mon Sep 17 00:00:00 2001 From: marha Date: Fri, 22 Jun 2012 15:53:45 +0200 Subject: Switch to zlib 1.2.7 --- zlib/old/Makefile.emx | 69 ++++ zlib/old/zlib.html | 971 -------------------------------------------------- 2 files changed, 69 insertions(+), 971 deletions(-) create mode 100644 zlib/old/Makefile.emx delete mode 100644 zlib/old/zlib.html (limited to 'zlib/old') diff --git a/zlib/old/Makefile.emx b/zlib/old/Makefile.emx new file mode 100644 index 000000000..4d6ab0efa --- /dev/null +++ b/zlib/old/Makefile.emx @@ -0,0 +1,69 @@ +# Makefile for zlib. Modified for emx/rsxnt by Chr. Spieler, 6/16/98. +# Copyright (C) 1995-1998 Jean-loup Gailly. +# For conditions of distribution and use, see copyright notice in zlib.h + +# To compile, or to compile and test, type: +# +# make -fmakefile.emx; make test -fmakefile.emx +# + +CC=gcc -Zwin32 + +#CFLAGS=-MMD -O +#CFLAGS=-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7 +#CFLAGS=-MMD -g -DDEBUG +CFLAGS=-MMD -O3 $(BUTT) -Wall -Wwrite-strings -Wpointer-arith -Wconversion \ + -Wstrict-prototypes -Wmissing-prototypes + +# If cp.exe is available, replace "copy /Y" with "cp -fp" . +CP=copy /Y +# If gnu install.exe is available, replace $(CP) with ginstall. +INSTALL=$(CP) +# The default value of RM is "rm -f." If "rm.exe" is found, comment out: +RM=del +LDLIBS=-L. -lzlib +LD=$(CC) -s -o +LDSHARED=$(CC) + +INCL=zlib.h zconf.h +LIBS=zlib.a + +AR=ar rcs + +prefix=/usr/local +exec_prefix = $(prefix) + +OBJS = adler32.o compress.o crc32.o deflate.o gzclose.o gzlib.o gzread.o \ + gzwrite.o infback.o inffast.o inflate.o inftrees.o trees.o uncompr.o zutil.o + +TEST_OBJS = example.o minigzip.o + +all: example.exe minigzip.exe + +test: all + ./example + echo hello world | .\minigzip | .\minigzip -d + +%.o : %.c + $(CC) $(CFLAGS) -c $< -o $@ + +zlib.a: $(OBJS) + $(AR) $@ $(OBJS) + +%.exe : %.o $(LIBS) + $(LD) $@ $< $(LDLIBS) + + +.PHONY : clean + +clean: + $(RM) *.d + $(RM) *.o + $(RM) *.exe + $(RM) zlib.a + $(RM) foo.gz + +DEPS := $(wildcard *.d) +ifneq ($(DEPS),) +include $(DEPS) +endif diff --git a/zlib/old/zlib.html b/zlib/old/zlib.html deleted file mode 100644 index 8c1b190c3..000000000 --- a/zlib/old/zlib.html +++ /dev/null @@ -1,971 +0,0 @@ - - - - zlib general purpose compression library version 1.1.4 - - - - - -

zlib 1.1.4 Manual

-
-

Contents

-
    -
  1. Prologue -
  2. Introduction -
  3. Utility functions -
  4. Basic functions -
  5. Advanced functions -
  6. Constants -
  7. struct z_stream_s -
  8. Checksum functions -
  9. Misc -
-
-

Prologue

- 'zlib' general purpose compression library version 1.1.4, March 11th, 2002 -

- Copyright (C) 1995-2002 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 - arising from the use of this software. -

- Permission is granted to anyone to use this software for any purpose, - including commercial applications, and to alter it and redistribute it - freely, subject to the following restrictions: -

    -
  1. The origin of this software must not be misrepresented ; you must not - claim that you wrote the original software. If you use this software - in a product, an acknowledgment in the product documentation would be - appreciated but is not required. -
  2. Altered source versions must be plainly marked as such, and must not be - misrepresented as being the original software. -
  3. This notice may not be removed or altered from any source distribution. -
- -
-
Jean-loup Gailly -
jloup@gzip.org -
Mark Adler -
madler@alumni.caltech.edu -
- - The data format used by the zlib library is described by RFCs (Request for - Comments) 1950 to 1952 in the files - - ftp://ds.internic.net/rfc/rfc1950.txt - (zlib format), - - rfc1951.txt - (deflate format) and - - rfc1952.txt - (gzip format). -

- This manual is converted from zlib.h by - piaip -

- Visit - http://ftp.cdrom.com/pub/infozip/zlib/ - for the official zlib web page. -

- -

-

Introduction

- The 'zlib' compression library provides in-memory compression and - decompression functions, including integrity checks of the uncompressed - data. This version of the library supports only one compression method - (deflation) but other algorithms will be added later and will have the same - stream interface. -

- - Compression can be done in a single step if the buffers are large - enough (for example if an input file is mmap'ed), or can be done by - repeated calls of the compression function. In the latter case, the - application must provide more input and/or consume the output - (providing more output space) before each call. -

- - The library also supports reading and writing files in gzip (.gz) format - with an interface similar to that of stdio. -

- - The library does not install any signal handler. The decoder checks - the consistency of the compressed data, so the library should never - crash even in case of corrupted input. -

- -

-

Utility functions

- The following utility functions are implemented on top of the - basic stream-oriented functions. - To simplify the interface, some - default options are assumed (compression level and memory usage, - standard memory allocation functions). The source code of these - utility functions can easily be modified if you need special options. -

Function list

- -

Function description

-
-
int compress (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen); -
- Compresses the source buffer into the destination buffer. sourceLen is - the byte length of the source buffer. Upon entry, destLen is the total - size of the destination buffer, which must be at least 0.1% larger than - sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the - compressed buffer.

- This function can be used to compress a whole file at once if the - input file is mmap'ed.

- compress returns Z_OK if success, Z_MEM_ERROR if there was not - enough memory, Z_BUF_ERROR if there was not enough room in the output - buffer.

- -

int compress2 (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level); -
- Compresses the source buffer into the destination buffer. The level - parameter has the same meaning as in deflateInit. sourceLen is the byte - length of the source buffer. Upon entry, destLen is the total size of the - destination buffer, which must be at least 0.1% larger than sourceLen plus - 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. -

- - compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough - memory, Z_BUF_ERROR if there was not enough room in the output buffer, - Z_STREAM_ERROR if the level parameter is invalid. -

- -

int uncompress (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen); -
- Decompresses the source buffer into the destination buffer. sourceLen is - the byte length of the source buffer. Upon entry, destLen is the total - size of the destination buffer, which must be large enough to hold the - entire uncompressed data. (The size of the uncompressed data must have - been saved previously by the compressor and transmitted to the decompressor - by some mechanism outside the scope of this compression library.) - Upon exit, destLen is the actual size of the compressed buffer.

- This function can be used to decompress a whole file at once if the - input file is mmap'ed. -

- - uncompress returns Z_OK if success, Z_MEM_ERROR if there was not - enough memory, Z_BUF_ERROR if there was not enough room in the output - buffer, or Z_DATA_ERROR if the input data was corrupted. -

- -

typedef voidp gzFile; -

- -

gzFile gzopen (const char *path, const char *mode); -
- Opens a gzip (.gz) file for reading or writing. The mode parameter - is as in fopen ("rb" or "wb") but can also include a compression level - ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for - Huffman only compression as in "wb1h". (See the description - of deflateInit2 for more information about the strategy parameter.) -

- - gzopen can be used to read a file which is not in gzip format ; in this - case gzread will directly read from the file without decompression. -

- - gzopen returns NULL if the file could not be opened or if there was - insufficient memory to allocate the (de)compression state ; errno - can be checked to distinguish the two cases (if errno is zero, the - zlib error is Z_MEM_ERROR). -

- -

gzFile gzdopen (int fd, const char *mode); -
- gzdopen() associates a gzFile with the file descriptor fd. File - descriptors are obtained from calls like open, dup, creat, pipe or - fileno (in the file has been previously opened with fopen). - The mode parameter is as in gzopen. -

- The next call of gzclose on the returned gzFile will also close the - file descriptor fd, just like fclose(fdopen(fd), mode) closes the file - descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode). -

- gzdopen returns NULL if there was insufficient memory to allocate - the (de)compression state. -

- -

int gzsetparams (gzFile file, int level, int strategy); -
- Dynamically update the compression level or strategy. See the description - of deflateInit2 for the meaning of these parameters. -

- gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not - opened for writing. -

- -

int gzread (gzFile file, voidp buf, unsigned len); -
- Reads the given number of uncompressed bytes from the compressed file. - If the input file was not in gzip format, gzread copies the given number - of bytes into the buffer. -

- gzread returns the number of uncompressed bytes actually read (0 for - end of file, -1 for error). -

- -

int gzwrite (gzFile file, const voidp buf, unsigned len); -
- Writes the given number of uncompressed bytes into the compressed file. - gzwrite returns the number of uncompressed bytes actually written - (0 in case of error). -

- -

int VA gzprintf (gzFile file, const char *format, ...); -
- Converts, formats, and writes the args to the compressed file under - control of the format string, as in fprintf. gzprintf returns the number of - uncompressed bytes actually written (0 in case of error). -

- -

int gzputs (gzFile file, const char *s); -
- Writes the given null-terminated string to the compressed file, excluding - the terminating null character. -

- gzputs returns the number of characters written, or -1 in case of error. -

- -

char * gzgets (gzFile file, char *buf, int len); -
- Reads bytes from the compressed file until len-1 characters are read, or - a newline character is read and transferred to buf, or an end-of-file - condition is encountered. The string is then terminated with a null - character. -

- gzgets returns buf, or Z_NULL in case of error. -

- -

int gzputc (gzFile file, int c); -
- Writes c, converted to an unsigned char, into the compressed file. - gzputc returns the value that was written, or -1 in case of error. -

- -

int gzgetc (gzFile file); -
- Reads one byte from the compressed file. gzgetc returns this byte - or -1 in case of end of file or error. -

- -

int gzflush (gzFile file, int flush); -
- Flushes all pending output into the compressed file. The parameter - flush is as in the deflate() function. The return value is the zlib - error number (see function gzerror below). gzflush returns Z_OK if - the flush parameter is Z_FINISH and all output could be flushed. -

- gzflush should be called only when strictly necessary because it can - degrade compression. -

- -

z_off_t gzseek (gzFile file, z_off_t offset, int whence); -
- Sets the starting position for the next gzread or gzwrite on the - given compressed file. The offset represents a number of bytes in the - uncompressed data stream. The whence parameter is defined as in lseek(2); - the value SEEK_END is not supported. -

- If the file is opened for reading, this function is emulated but can be - extremely slow. If the file is opened for writing, only forward seeks are - supported ; gzseek then compresses a sequence of zeroes up to the new - starting position. -

- gzseek returns the resulting offset location as measured in bytes from - the beginning of the uncompressed stream, or -1 in case of error, in - particular if the file is opened for writing and the new starting position - would be before the current position. -

- -

int gzrewind (gzFile file); -
- Rewinds the given file. This function is supported only for reading. -

- gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) -

- -

z_off_t gztell (gzFile file); -
- Returns the starting position for the next gzread or gzwrite on the - given compressed file. This position represents a number of bytes in the - uncompressed data stream. -

- - gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) -

- -

int gzeof (gzFile file); -
- Returns 1 when EOF has previously been detected reading the given - input stream, otherwise zero. -

- -

int gzclose (gzFile file); -
- Flushes all pending output if necessary, closes the compressed file - and deallocates all the (de)compression state. The return value is the zlib - error number (see function gzerror below). -

- -

const char * gzerror (gzFile file, int *errnum); -
- Returns the error message for the last error which occurred on the - given compressed file. errnum is set to zlib error number. If an - error occurred in the file system and not in the compression library, - errnum is set to Z_ERRNO and the application may consult errno - to get the exact error code. -

-

-
-

Basic functions

-

Function list

- - -

Function description

-
-
const char * zlibVersion (void); -
The application can compare zlibVersion and ZLIB_VERSION for consistency. - If the first character differs, the library code actually used is - not compatible with the zlib.h header file used by the application. - This check is automatically made by deflateInit and inflateInit. -

- -

int deflateInit (z_streamp strm, int level); -
- Initializes the internal stream state for compression. The fields - zalloc, zfree and opaque must be initialized before by the caller. - If zalloc and zfree are set to Z_NULL, deflateInit updates them to - use default allocation functions. -

- - The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: - 1 gives best speed, 9 gives best compression, 0 gives no compression at - all (the input data is simply copied a block at a time). -

- - Z_DEFAULT_COMPRESSION requests a default compromise between speed and - compression (currently equivalent to level 6). -

- - deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not - enough memory, Z_STREAM_ERROR if level is not a valid compression level, - Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible - with the version assumed by the caller (ZLIB_VERSION). - msg is set to null if there is no error message. deflateInit does not - perform any compression: this will be done by deflate(). -

- -

int deflate (z_streamp strm, int flush); -
- deflate compresses as much data as possible, and stops when the input - buffer becomes empty or the output buffer becomes full. It may introduce some - output latency (reading input without producing any output) except when - forced to flush.

- - The detailed semantics are as follows. deflate performs one or both of the - following actions: - -

    -
  • Compress more input starting at next_in and update next_in and avail_in - accordingly. If not all input can be processed (because there is not - enough room in the output buffer), next_in and avail_in are updated and - processing will resume at this point for the next call of deflate(). - -
  • - Provide more output starting at next_out and update next_out and avail_out - accordingly. This action is forced if the parameter flush is non zero. - Forcing flush frequently degrades the compression ratio, so this parameter - should be set only when necessary (in interactive applications). - Some output may be provided even if flush is not set. -

- - Before the call of deflate(), the application should ensure that at least - one of the actions is possible, by providing more input and/or consuming - more output, and updating avail_in or avail_out accordingly ; avail_out - should never be zero before the call. The application can consume the - compressed output when it wants, for example when the output buffer is full - (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK - and with zero avail_out, it must be called again after making room in the - output buffer because there might be more output pending. -

- - If the parameter flush is set to Z_SYNC_FLUSH, all pending output is - flushed to the output buffer and the output is aligned on a byte boundary, so - that the decompressor can get all input data available so far. (In particular - avail_in is zero after the call if enough output space has been provided - before the call.) Flushing may degrade compression for some compression - algorithms and so it should be used only when necessary. -

- - If flush is set to Z_FULL_FLUSH, all output is flushed as with - Z_SYNC_FLUSH, and the compression state is reset so that decompression can - restart from this point if previous compressed data has been damaged or if - random access is desired. Using Z_FULL_FLUSH too often can seriously degrade - the compression. -

- - If deflate returns with avail_out == 0, this function must be called again - with the same value of the flush parameter and more output space (updated - avail_out), until the flush is complete (deflate returns with non-zero - avail_out). -

- - If the parameter flush is set to Z_FINISH, pending input is processed, - pending output is flushed and deflate returns with Z_STREAM_END if there - was enough output space ; if deflate returns with Z_OK, this function must be - called again with Z_FINISH and more output space (updated avail_out) but no - more input data, until it returns with Z_STREAM_END or an error. After - deflate has returned Z_STREAM_END, the only possible operations on the - stream are deflateReset or deflateEnd. -

- - Z_FINISH can be used immediately after deflateInit if all the compression - is to be done in a single step. In this case, avail_out must be at least - 0.1% larger than avail_in plus 12 bytes. If deflate does not return - Z_STREAM_END, then it must be called again as described above. -

- - deflate() sets strm-> adler to the adler32 checksum of all input read - so far (that is, total_in bytes). -

- - deflate() may update data_type if it can make a good guess about - the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered - binary. This field is only for information purposes and does not affect - the compression algorithm in any manner. -

- - deflate() returns Z_OK if some progress has been made (more input - processed or more output produced), Z_STREAM_END if all input has been - consumed and all output has been produced (only when flush is set to - Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example - if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible - (for example avail_in or avail_out was zero). -

- -

int deflateEnd (z_streamp strm); -
- All dynamically allocated data structures for this stream are freed. - This function discards any unprocessed input and does not flush any - pending output. -

- - deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the - stream state was inconsistent, Z_DATA_ERROR if the stream was freed - prematurely (some input or output was discarded). In the error case, - msg may be set but then points to a static string (which must not be - deallocated). -

- -

int inflateInit (z_streamp strm); -
- Initializes the internal stream state for decompression. The fields - next_in, avail_in, zalloc, zfree and opaque must be initialized before by - the caller. If next_in is not Z_NULL and avail_in is large enough (the exact - value depends on the compression method), inflateInit determines the - compression method from the zlib header and allocates all data structures - accordingly ; otherwise the allocation will be deferred to the first call of - inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to - use default allocation functions. -

- - inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough - memory, Z_VERSION_ERROR if the zlib library version is incompatible with the - version assumed by the caller. msg is set to null if there is no error - message. inflateInit does not perform any decompression apart from reading - the zlib header if present: this will be done by inflate(). (So next_in and - avail_in may be modified, but next_out and avail_out are unchanged.) -

- -

int inflate (z_streamp strm, int flush); -
- inflate decompresses as much data as possible, and stops when the input - buffer becomes empty or the output buffer becomes full. It may some - introduce some output latency (reading input without producing any output) - except when forced to flush. -

- - The detailed semantics are as follows. inflate performs one or both of the - following actions: - -

    -
  • Decompress more input starting at next_in and update next_in and avail_in - accordingly. If not all input can be processed (because there is not - enough room in the output buffer), next_in is updated and processing - will resume at this point for the next call of inflate(). - -
  • Provide more output starting at next_out and update next_out and - avail_out accordingly. inflate() provides as much output as possible, - until there is no more input data or no more space in the output buffer - (see below about the flush parameter). -

- - Before the call of inflate(), the application should ensure that at least - one of the actions is possible, by providing more input and/or consuming - more output, and updating the next_* and avail_* values accordingly. - The application can consume the uncompressed output when it wants, for - example when the output buffer is full (avail_out == 0), or after each - call of inflate(). If inflate returns Z_OK and with zero avail_out, it - must be called again after making room in the output buffer because there - might be more output pending. -

- - If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much - output as possible to the output buffer. The flushing behavior of inflate is - not specified for values of the flush parameter other than Z_SYNC_FLUSH - and Z_FINISH, but the current implementation actually flushes as much output - as possible anyway. -

- - inflate() should normally be called until it returns Z_STREAM_END or an - error. However if all decompression is to be performed in a single step - (a single call of inflate), the parameter flush should be set to - Z_FINISH. In this case all pending input is processed and all pending - output is flushed ; avail_out must be large enough to hold all the - uncompressed data. (The size of the uncompressed data may have been saved - by the compressor for this purpose.) The next operation on this stream must - be inflateEnd to deallocate the decompression state. The use of Z_FINISH - is never required, but can be used to inform inflate that a faster routine - may be used for the single inflate() call. -

- - If a preset dictionary is needed at this point (see inflateSetDictionary - below), inflate sets strm-adler to the adler32 checksum of the - dictionary chosen by the compressor and returns Z_NEED_DICT ; otherwise - it sets strm-> adler to the adler32 checksum of all output produced - so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or - an error code as described below. At the end of the stream, inflate() - checks that its computed adler32 checksum is equal to that saved by the - compressor and returns Z_STREAM_END only if the checksum is correct. -

- - inflate() returns Z_OK if some progress has been made (more input processed - or more output produced), Z_STREAM_END if the end of the compressed data has - been reached and all uncompressed output has been produced, Z_NEED_DICT if a - preset dictionary is needed at this point, Z_DATA_ERROR if the input data was - corrupted (input stream not conforming to the zlib format or incorrect - adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent - (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not - enough memory, Z_BUF_ERROR if no progress is possible or if there was not - enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR - case, the application may then call inflateSync to look for a good - compression block. -

- -

int inflateEnd (z_streamp strm); -
- All dynamically allocated data structures for this stream are freed. - This function discards any unprocessed input and does not flush any - pending output. -

- - inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state - was inconsistent. In the error case, msg may be set but then points to a - static string (which must not be deallocated). -

-
-

Advanced functions

- The following functions are needed only in some special applications. -

Function list

- -

Function description

-
-
int deflateInit2 (z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy); - -
This is another version of deflateInit with more compression options. The - fields next_in, zalloc, zfree and opaque must be initialized before by - the caller.

- - The method parameter is the compression method. It must be Z_DEFLATED in - this version of the library.

- - The windowBits parameter is the base two logarithm of the window size - (the size of the history buffer). It should be in the range 8..15 for this - version of the library. Larger values of this parameter result in better - compression at the expense of memory usage. The default value is 15 if - deflateInit is used instead.

- - The memLevel parameter specifies how much memory should be allocated - for the internal compression state. memLevel=1 uses minimum memory but - is slow and reduces compression ratio ; memLevel=9 uses maximum memory - for optimal speed. The default value is 8. See zconf.h for total memory - usage as a function of windowBits and memLevel.

- - The strategy parameter is used to tune the compression algorithm. Use the - value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a - filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no - string match). Filtered data consists mostly of small values with a - somewhat random distribution. In this case, the compression algorithm is - tuned to compress them better. The effect of Z_FILTERED is to force more - Huffman coding and less string matching ; it is somewhat intermediate - between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects - the compression ratio but not the correctness of the compressed output even - if it is not set appropriately.

- - deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough - memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid - method). msg is set to null if there is no error message. deflateInit2 does - not perform any compression: this will be done by deflate().

- -

int deflateSetDictionary (z_streamp strm, const Bytef *dictionary, uInt dictLength); -
- Initializes the compression dictionary from the given byte sequence - without producing any compressed output. This function must be called - immediately after deflateInit, deflateInit2 or deflateReset, before any - call of deflate. The compressor and decompressor must use exactly the same - dictionary (see inflateSetDictionary).

- - The dictionary should consist of strings (byte sequences) that are likely - to be encountered later in the data to be compressed, with the most commonly - used strings preferably put towards the end of the dictionary. Using a - dictionary is most useful when the data to be compressed is short and can be - predicted with good accuracy ; the data can then be compressed better than - with the default empty dictionary.

- - Depending on the size of the compression data structures selected by - deflateInit or deflateInit2, a part of the dictionary may in effect be - discarded, for example if the dictionary is larger than the window size in - deflate or deflate2. Thus the strings most likely to be useful should be - put at the end of the dictionary, not at the front.

- - Upon return of this function, strm-> adler is set to the Adler32 value - of the dictionary ; the decompressor may later use this value to determine - which dictionary has been used by the compressor. (The Adler32 value - applies to the whole dictionary even if only a subset of the dictionary is - actually used by the compressor.)

- - deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a - parameter is invalid (such as NULL dictionary) or the stream state is - inconsistent (for example if deflate has already been called for this stream - or if the compression method is bsort). deflateSetDictionary does not - perform any compression: this will be done by deflate().

- -

int deflateCopy (z_streamp dest, z_streamp source); -
- Sets the destination stream as a complete copy of the source stream.

- - This function can be useful when several compression strategies will be - tried, for example when there are several ways of pre-processing the input - data with a filter. The streams that will be discarded should then be freed - by calling deflateEnd. Note that deflateCopy duplicates the internal - compression state which can be quite large, so this strategy is slow and - can consume lots of memory.

- - deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not - enough memory, Z_STREAM_ERROR if the source stream state was inconsistent - (such as zalloc being NULL). msg is left unchanged in both source and - destination.

- -

int deflateReset (z_streamp strm); -
This function is equivalent to deflateEnd followed by deflateInit, - but does not free and reallocate all the internal compression state. - The stream will keep the same compression level and any other attributes - that may have been set by deflateInit2.

- - deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source - stream state was inconsistent (such as zalloc or state being NULL).

- -

int deflateParams (z_streamp strm, int level, int strategy); -
- Dynamically update the compression level and compression strategy. The - interpretation of level and strategy is as in deflateInit2. This can be - used to switch between compression and straight copy of the input data, or - to switch to a different kind of input data requiring a different - strategy. If the compression level is changed, the input available so far - is compressed with the old level (and may be flushed); the new level will - take effect only at the next call of deflate().

- - Before the call of deflateParams, the stream state must be set as for - a call of deflate(), since the currently available input may have to - be compressed and flushed. In particular, strm-> avail_out must be - non-zero.

- - deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source - stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR - if strm->avail_out was zero.

- -

int inflateInit2 (z_streamp strm, int windowBits); - -
This is another version of inflateInit with an extra parameter. The - fields next_in, avail_in, zalloc, zfree and opaque must be initialized - before by the caller.

- - The windowBits parameter is the base two logarithm of the maximum window - size (the size of the history buffer). It should be in the range 8..15 for - this version of the library. The default value is 15 if inflateInit is used - instead. If a compressed stream with a larger window size is given as - input, inflate() will return with the error code Z_DATA_ERROR instead of - trying to allocate a larger window.

- - inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough - memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative - memLevel). msg is set to null if there is no error message. inflateInit2 - does not perform any decompression apart from reading the zlib header if - present: this will be done by inflate(). (So next_in and avail_in may be - modified, but next_out and avail_out are unchanged.)

- -

int inflateSetDictionary (z_streamp strm, const Bytef *dictionary, uInt dictLength); -
- Initializes the decompression dictionary from the given uncompressed byte - sequence. This function must be called immediately after a call of inflate - if this call returned Z_NEED_DICT. The dictionary chosen by the compressor - can be determined from the Adler32 value returned by this call of - inflate. The compressor and decompressor must use exactly the same - dictionary (see deflateSetDictionary).

- - inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a - parameter is invalid (such as NULL dictionary) or the stream state is - inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the - expected one (incorrect Adler32 value). inflateSetDictionary does not - perform any decompression: this will be done by subsequent calls of - inflate().

- -

int inflateSync (z_streamp strm); - -
Skips invalid compressed data until a full flush point (see above the - description of deflate with Z_FULL_FLUSH) can be found, or until all - available input is skipped. No output is provided.

- - inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR - if no more input was provided, Z_DATA_ERROR if no flush point has been found, - or Z_STREAM_ERROR if the stream structure was inconsistent. In the success - case, the application may save the current current value of total_in which - indicates where valid compressed data was found. In the error case, the - application may repeatedly call inflateSync, providing more input each time, - until success or end of the input data.

- -

int inflateReset (z_streamp strm); -
- This function is equivalent to inflateEnd followed by inflateInit, - but does not free and reallocate all the internal decompression state. - The stream will keep attributes that may have been set by inflateInit2. -

- - inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source - stream state was inconsistent (such as zalloc or state being NULL). -

-

- -
-

Checksum functions

- These functions are not related to compression but are exported - anyway because they might be useful in applications using the - compression library. -

Function list

- -

Function description

-
-
uLong adler32 (uLong adler, const Bytef *buf, uInt len); -
- Update a running Adler-32 checksum with the bytes buf[0..len-1] and - return the updated checksum. If buf is NULL, this function returns - the required initial value for the checksum. -

- An Adler-32 checksum is almost as reliable as a CRC32 but can be computed - much faster. Usage example: - 

-
-     uLong adler = adler32(0L, Z_NULL, 0);
-
-     while (read_buffer(buffer, length) != EOF) {
-       adler = adler32(adler, buffer, length);
-     }
-     if (adler != original_adler) error();
-
- -
uLong crc32 (uLong crc, const Bytef *buf, uInt len); -
- Update a running crc with the bytes buf[0..len-1] and return the updated - crc. If buf is NULL, this function returns the required initial value - for the crc. Pre- and post-conditioning (one's complement) is performed - within this function so it shouldn't be done by the application. - Usage example: - 
-
-     uLong crc = crc32(0L, Z_NULL, 0);
-
-     while (read_buffer(buffer, length) != EOF) {
-       crc = crc32(crc, buffer, length);
-     }
-     if (crc != original_crc) error();
-
-
-
-

struct z_stream_s

- - -
-typedef struct z_stream_s {
-    Bytef    *next_in;  /* next input byte */
-    uInt     avail_in;  /* number of bytes available at next_in */
-    uLong    total_in;  /* total nb of input bytes read so far */
-
-    Bytef    *next_out; /* next output byte should be put there */
-    uInt     avail_out; /* remaining free space at next_out */
-    uLong    total_out; /* total nb of bytes output so far */
-
-    char     *msg;      /* last error message, NULL if no error */
-    struct internal_state FAR *state; /* not visible by applications */
-
-    alloc_func zalloc;  /* used to allocate the internal state */
-    free_func  zfree;   /* used to free the internal state */
-    voidpf     opaque;  /* private data object passed to zalloc and zfree */
-
-    int     data_type;  /* best guess about the data type: ascii or binary */
-    uLong   adler;      /* adler32 value of the uncompressed data */
-    uLong   reserved;   /* reserved for future use */
-} z_stream ;
-
-typedef z_stream FAR * z_streamp;  ÿ
-
- - The application must update next_in and avail_in when avail_in has - dropped to zero. It must update next_out and avail_out when avail_out - has dropped to zero. The application must initialize zalloc, zfree and - opaque before calling the init function. All other fields are set by the - compression library and must not be updated by the application.

- - The opaque value provided by the application will be passed as the first - parameter for calls of zalloc and zfree. This can be useful for custom - memory management. The compression library attaches no meaning to the - opaque value.

- - zalloc must return Z_NULL if there is not enough memory for the object. - If zlib is used in a multi-threaded application, zalloc and zfree must be - thread safe.

- - On 16-bit systems, the functions zalloc and zfree must be able to allocate - exactly 65536 bytes, but will not be required to allocate more than this - if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, - pointers returned by zalloc for objects of exactly 65536 bytes *must* - have their offset normalized to zero. The default allocation function - provided by this library ensures this (see zutil.c). To reduce memory - requirements and avoid any allocation of 64K objects, at the expense of - compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). -

- - The fields total_in and total_out can be used for statistics or - progress reports. After compression, total_in holds the total size of - the uncompressed data and may be saved for use in the decompressor - (particularly if the decompressor wants to decompress everything in - a single step).

- -

-

Constants

- -
-#define Z_NO_FLUSH      0
-#define Z_PARTIAL_FLUSH 1
-	/* will be removed, use Z_SYNC_FLUSH instead */
-#define Z_SYNC_FLUSH    2
-#define Z_FULL_FLUSH    3
-#define Z_FINISH        4
-/* Allowed flush values ; see deflate() below for details */
-
-#define Z_OK            0
-#define Z_STREAM_END    1
-#define Z_NEED_DICT     2
-#define Z_ERRNO        (-1)
-#define Z_STREAM_ERROR (-2)
-#define Z_DATA_ERROR   (-3)
-#define Z_MEM_ERROR    (-4)
-#define Z_BUF_ERROR    (-5)
-#define Z_VERSION_ERROR (-6)
-/* Return codes for the compression/decompression functions. Negative
- * values are errors, positive values are used for special but normal events.
- */
-
-#define Z_NO_COMPRESSION         0
-#define Z_BEST_SPEED             1
-#define Z_BEST_COMPRESSION       9
-#define Z_DEFAULT_COMPRESSION  (-1)
-/* compression levels */
-
-#define Z_FILTERED            1
-#define Z_HUFFMAN_ONLY        2
-#define Z_DEFAULT_STRATEGY    0
-/* compression strategy ; see deflateInit2() below for details */
-
-#define Z_BINARY   0
-#define Z_ASCII    1
-#define Z_UNKNOWN  2
-/* Possible values of the data_type field */
-
-#define Z_DEFLATED   8
-/* The deflate compression method (the only one supported in this version) */
-
-#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
-
-#define zlib_version zlibVersion()
-/* for compatibility with versions less than 1.0.2 */
-
- - -
-

Misc

- deflateInit and inflateInit are macros to allow checking the zlib version - and the compiler's view of z_stream. -

- Other functions: -

-
const char * zError (int err); -
int inflateSyncPoint (z_streamp z); -
const uLongf * get_crc_table (void); -
-
- - Last update: Wed Oct 13 20:42:34 1999
- piapi@csie.ntu.edu.tw - - - - -- cgit v1.2.3