--- /dev/null
+#ifndef ZNGLIB_H_
+#define ZNGLIB_H_
+/* zlib.h -- interface of the 'zlib-ng' compression library
+ Forked from and compatible with zlib 1.2.11
+
+ Copyright (C) 1995-2016 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 Mark Adler
+ jloup@gzip.org 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 http://tools.ietf.org/html/rfc1950
+ (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
+*/
+
+#include <stdint.h>
+#include "zconf-ng.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define ZLIBNG_VERSION "1.9.9"
+#define ZLIBNG_VERNUM 0x1990
+#define ZLIBNG_VER_MAJOR 1
+#define ZLIBNG_VER_MINOR 9
+#define ZLIBNG_VER_REVISION 9
+#define ZLIBNG_VER_SUBREVISION 0
+
+/*
+ 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,
+ 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 compressed data format used by default by the in-memory functions is
+ the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
+ around a deflate stream, which is itself documented in RFC 1951.
+
+ The library also supports reading and writing files in gzip (.gz) format
+ with an interface similar to that of stdio using the functions that start
+ with "gz". The gzip format is different from the zlib format. gzip is a
+ gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
+
+ This library can optionally read and write gzip and raw deflate streams in
+ memory as well.
+
+ The zlib format was designed to be compact and fast for use in memory
+ and on communications channels. The gzip format was designed for single-
+ file compression on file systems, has a larger header than zlib to maintain
+ directory information, and uses a different, slower check method than zlib.
+
+ 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 the case of corrupted input.
+*/
+
+typedef void *(*alloc_func) (void *opaque, unsigned int items, unsigned int size);
+typedef void (*free_func) (void *opaque, void *address);
+
+struct internal_state;
+
+typedef struct zng_stream_s {
+ const unsigned char *next_in; /* next input byte */
+ uint32_t avail_in; /* number of bytes available at next_in */
+ size_t total_in; /* total number of input bytes read so far */
+
+ unsigned char *next_out; /* next output byte will go here */
+ uint32_t avail_out; /* remaining free space at next_out */
+ size_t total_out; /* total number of bytes output so far */
+
+ const char *msg; /* last error message, NULL if no error */
+ struct internal_state *state; /* not visible by applications */
+
+ alloc_func zalloc; /* used to allocate the internal state */
+ free_func zfree; /* used to free the internal state */
+ void *opaque; /* private data object passed to zalloc and zfree */
+
+ int data_type; /* best guess about the data type: binary or text
+ for deflate, or the decoding state for inflate */
+ uint32_t adler; /* Adler-32 or CRC-32 value of the uncompressed data */
+ unsigned long reserved; /* reserved for future use */
+} zng_stream;
+
+typedef zng_stream *zng_streamp; // Obsolete type, retained for compatability only
+
+/*
+ gzip header information passed to and from zlib routines. See RFC 1952
+ for more details on the meanings of these fields.
+*/
+typedef struct zng_gz_header_s {
+ int text; /* true if compressed data believed to be text */
+ unsigned long time; /* modification time */
+ int xflags; /* extra flags (not used when writing a gzip file) */
+ int os; /* operating system */
+ unsigned char *extra; /* pointer to extra field or NULL if none */
+ unsigned int extra_len; /* extra field length (valid if extra != NULL) */
+ unsigned int extra_max; /* space at extra (only when reading header) */
+ unsigned char *name; /* pointer to zero-terminated file name or NULL */
+ unsigned int name_max; /* space at name (only when reading header) */
+ unsigned char *comment; /* pointer to zero-terminated comment or NULL */
+ unsigned int comm_max; /* space at comment (only when reading header) */
+ int hcrc; /* true if there was or will be a header crc */
+ int done; /* true when done reading gzip header (not used when writing a gzip file) */
+} zng_gz_header;
+
+typedef zng_gz_header *zng_gz_headerp;
+
+/*
+ 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 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. In that case, zlib is thread-safe. When zalloc and zfree are
+ Z_NULL on entry to the initialization function, they are set to internal
+ routines that use the standard library functions malloc() and free().
+
+ 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 by 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
+#define Z_SYNC_FLUSH 2
+#define Z_FULL_FLUSH 3
+#define Z_FINISH 4
+#define Z_BLOCK 5
+#define Z_TREES 6
+/* Allowed flush values; see deflate() and inflate() 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_RLE 3
+#define Z_FIXED 4
+#define Z_DEFAULT_STRATEGY 0
+/* compression strategy; see deflateInit2() below for details */
+
+#define Z_BINARY 0
+#define Z_TEXT 1
+#define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
+#define Z_UNKNOWN 2
+/* Possible values of the data_type field for deflate() */
+
+#define Z_DEFLATED 8
+/* The deflate compression method (the only one supported in this version) */
+
+#define Z_NULL NULL /* for compatibility with zlib, was for initializing zalloc, zfree, opaque */
+
+
+ /* basic functions */
+
+ZEXTERN const char * ZEXPORT zng_version(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.
+ */
+
+/*
+ZEXTERN int ZEXPORT zng_deflateInit (zng_stream *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 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, or
+ 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().
+*/
+
+
+ZEXTERN int ZEXPORT zng_deflate(zng_stream *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().
+
+ - Generate 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. Some output may be provided even if
+ flush is zero.
+
+ 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. See deflatePending(),
+ which can be used if desired to determine whether or not there is more ouput
+ in that case.
+
+ Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
+ decide how much data to accumulate before producing output, in order to
+ maximize compression.
+
+ 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. This
+ completes the current deflate block and follows it with an empty stored block
+ that is three bits plus filler bits to the next byte, followed by four bytes
+ (00 00 ff ff).
+
+ If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
+ output buffer, but the output is not aligned to a byte boundary. All of the
+ input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
+ This completes the current deflate block and follows it with an empty fixed
+ codes block that is 10 bits long. This assures that enough bytes are output
+ in order for the decompressor to finish the block before the empty fixed
+ codes block.
+
+ If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
+ for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
+ seven bits of the current block are held to be written as the next byte after
+ the next deflate block is completed. In this case, the decompressor may not
+ be provided enough bits at this point in order to complete decompression of
+ the data provided so far to the compressor. It may need to wait for the next
+ block to be emitted. This is for advanced applications that need to control
+ the emission of deflate blocks.
+
+ 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
+ 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). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
+ avail_out is greater than six to avoid repeated flush markers due to
+ avail_out == 0 on return.
+
+ 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 or Z_BUF_ERROR, 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 in the first deflate call after deflateInit if all the
+ compression is to be done in a single step. In order to complete in one
+ call, avail_out must be at least the value returned by deflateBound (see
+ below). Then deflate is guaranteed to return Z_STREAM_END. If not enough
+ output space is provided, deflate will not return Z_STREAM_END, and it must
+ be called again as described above.
+
+ deflate() sets strm->adler to the Adler-32 checksum of all input read
+ so far (that is, total_in bytes). If a gzip stream is being generated, then
+ strm->adler will be the CRC-32 checksum of the input read so far. (See
+ deflateInit2 below.)
+
+ deflate() may update strm->data_type if it can make a good guess about
+ the input data type (Z_BINARY or Z_TEXT). If 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) or the state was inadvertently written over
+ by the application), or Z_BUF_ERROR if no progress is possible (for example
+ avail_in or avail_out was zero). Note that Z_BUF_ERROR is not fatal, and
+ deflate() can be called again with more input and more output space to
+ continue compressing.
+*/
+
+
+ZEXTERN int ZEXPORT zng_deflateEnd(zng_stream *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).
+*/
+
+
+/*
+ZEXTERN int ZEXPORT zng_inflateInit (zng_stream *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. In the current version of inflate, the provided input is not
+ read or consumed. The allocation of a sliding window will be deferred to
+ the first call of inflate (if the decompression does not complete on the
+ first call). If zalloc and zfree are set to 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, or Z_STREAM_ERROR if the parameters are
+ invalid, such as a null pointer to the structure. msg is set to null if
+ there is no error message. inflateInit does not perform any decompression.
+ Actual decompression will be done by inflate(). So next_in, and avail_in,
+ next_out, and avail_out are unused and unchanged. The current
+ implementation of inflateInit() does not process any header information --
+ that is deferred until inflate() is called.
+*/
+
+
+ZEXTERN int ZEXPORT zng_inflate(zng_stream *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 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), then next_in and avail_in are updated
+ accordingly, and processing will resume at this point for the next call of
+ inflate().
+
+ - Generate 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. If the
+ caller of inflate() does not provide both available input and available
+ output space, it is possible that there will be no progress made. 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.
+
+ The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
+ Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
+ output as possible to the output buffer. Z_BLOCK requests that inflate()
+ stop if and when it gets to the next deflate block boundary. When decoding
+ the zlib or gzip format, this will cause inflate() to return immediately
+ after the header and before the first block. When doing a raw inflate,
+ inflate() will go ahead and process the first block, and will return when it
+ gets to the end of that block, or when it runs out of data.
+
+ The Z_BLOCK option assists in appending to or combining deflate streams.
+ To assist in this, on return inflate() always sets strm->data_type to the
+ number of unused bits in the last byte taken from strm->next_in, plus 64 if
+ inflate() is currently decoding the last block in the deflate stream, plus
+ 128 if inflate() returned immediately after decoding an end-of-block code or
+ decoding the complete header up to just before the first byte of the deflate
+ stream. The end-of-block will not be indicated until all of the uncompressed
+ data from that block has been written to strm->next_out. The number of
+ unused bits may in general be greater than seven, except when bit 7 of
+ data_type is set, in which case the number of unused bits will be less than
+ eight. data_type is set as noted here every time inflate() returns for all
+ flush options, and so can be used to determine the amount of currently
+ consumed input in bits.
+
+ The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
+ end of each deflate block header is reached, before any actual data in that
+ block is decoded. This allows the caller to determine the length of the
+ deflate block header for later use in random access within a deflate block.
+ 256 is added to the value of strm->data_type when inflate() returns
+ immediately after reaching the end of the deflate block header.
+
+ 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 of the uncompressed data for the
+ operation to complete. (The size of the uncompressed data may have been
+ saved by the compressor for this purpose.) The use of Z_FINISH is not
+ required to perform an inflation in one step. However it may be used to
+ inform inflate that a faster approach can be used for the single inflate()
+ call. Z_FINISH also informs inflate to not maintain a sliding window if the
+ stream completes, which reduces inflate's memory footprint. If the stream
+ does not complete, either because not all of the stream is provided or not
+ enough output space is provided, then a sliding window will be allocated and
+ inflate() can be called again to continue the operation as if Z_NO_FLUSH had
+ been used.
+
+ In this implementation, inflate() always flushes as much output as
+ possible to the output buffer, and always uses the faster approach on the
+ first call. So the effects of the flush parameter in this implementation are
+ on the return value of inflate() as noted below, when inflate() returns early
+ when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
+ memory for a sliding window when Z_FINISH is used.
+
+ If a preset dictionary is needed after this call (see inflateSetDictionary
+ below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
+ chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
+ strm->adler to the Adler-32 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 Adler-32
+ checksum is equal to that saved by the compressor and returns Z_STREAM_END
+ only if the checksum is correct.
+
+ inflate() can decompress and check either zlib-wrapped or gzip-wrapped
+ deflate data. The header type is detected automatically, if requested when
+ initializing with inflateInit2(). Any information contained in the gzip
+ header is not retained unless inflateGetHeader() is used. When processing
+ gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
+ produced so far. The CRC-32 is checked against the gzip trailer, as is the
+ uncompressed length, modulo 2^32.
+
+ 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 check
+ value, in which case strm->msg points to a string with a more specific
+ error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
+ next_in or next_out was NULL, or the state was inadvertently written over
+ by the application), 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. Note that Z_BUF_ERROR is not fatal, and
+ inflate() can be called again with more input and more output space to
+ continue decompressing. If Z_DATA_ERROR is returned, the application may
+ then call inflateSync() to look for a good compression block if a partial
+ recovery of the data is to be attempted.
+*/
+
+
+ZEXTERN int ZEXPORT zng_inflateEnd(zng_stream *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, or Z_STREAM_ERROR if the stream state
+ was inconsistent.
+*/
+
+
+ /* Advanced functions */
+
+/*
+ The following functions are needed only in some special applications.
+*/
+
+/*
+ZEXTERN int ZEXPORT zng_deflateInit2 (zng_stream *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.
+
+ For the current implementation of deflate(), a windowBits value of 8 (a
+ window size of 256 bytes) is not supported. As a result, a request for 8
+ will result in 9 (a 512-byte window). In that case, providing 8 to
+ inflateInit2() will result in an error when the zlib header with 9 is
+ checked against the initialization of inflate(). The remedy is to not use 8
+ with deflateInit2() with this initialization, or at least in that case use 9
+ with inflateInit2().
+
+ windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
+ determines the window size. deflate() will then generate raw deflate data
+ with no zlib header or trailer, and will not compute a check value.
+
+ windowBits can also be greater than 15 for optional gzip encoding. Add
+ 16 to windowBits to write a simple gzip header and trailer around the
+ compressed data instead of a zlib wrapper. The gzip header will have no
+ file name, no extra data, no comment, no modification time (set to zero), no
+ header crc, and the operating system will be set to the appropriate value,
+ if the operating system was determined at compile time. If a gzip stream is
+ being written, strm->adler is a CRC-32 instead of an Adler-32.
+
+ For raw deflate or gzip encoding, a request for a 256-byte window is
+ rejected as invalid, since only the zlib header provides a means of
+ transmitting the window size to the decompressor.
+
+ 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), Z_HUFFMAN_ONLY to force Huffman encoding only (no
+ string match), or Z_RLE to limit match distances to one (run-length
+ encoding). 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_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
+ fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
+ strategy parameter only affects the compression ratio but not the
+ correctness of the compressed output even if it is not set appropriately.
+ Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
+ decoder for special applications.
+
+ deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+ memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
+ method), or 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. deflateInit2 does not perform any
+ compression: this will be done by deflate().
+*/
+
+ZEXTERN int ZEXPORT zng_deflateSetDictionary(zng_stream *strm,
+ const unsigned char *dictionary,
+ unsigned int dictLength);
+/*
+ Initializes the compression dictionary from the given byte sequence
+ without producing any compressed output. When using the zlib format, this
+ function must be called immediately after deflateInit, deflateInit2 or
+ deflateReset, and before any call of deflate. When doing raw deflate, this
+ function must be called either before any call of deflate, or immediately
+ after the completion of a deflate block, i.e. after all input has been
+ consumed and all output has been delivered when using any of the flush
+ options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. 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
+ provided in deflateInit or deflateInit2. Thus the strings most likely to be
+ useful should be put at the end of the dictionary, not at the front. In
+ addition, the current implementation of deflate will use at most the window
+ size minus 262 bytes of the provided dictionary.
+
+ Upon return of this function, strm->adler is set to the Adler-32 value
+ of the dictionary; the decompressor may later use this value to determine
+ which dictionary has been used by the compressor. (The Adler-32 value
+ applies to the whole dictionary even if only a subset of the dictionary is
+ actually used by the compressor.) If a raw deflate was requested, then the
+ Adler-32 value is not computed and strm->adler is not set.
+
+ deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
+ parameter is invalid (e.g. dictionary being NULL) or the stream state is
+ inconsistent (for example if deflate has already been called for this stream
+ or if not at a block boundary for raw deflate). deflateSetDictionary does
+ not perform any compression: this will be done by deflate().
+*/
+
+ZEXTERN int ZEXPORT zng_deflateGetDictionary (zng_stream *strm, unsigned char *dictionary, unsigned int *dictLength);
+/*
+ Returns the sliding dictionary being maintained by deflate. dictLength is
+ set to the number of bytes in the dictionary, and that many bytes are copied
+ to dictionary. dictionary must have enough space, where 32768 bytes is
+ always enough. If deflateGetDictionary() is called with dictionary equal to
+ Z_NULL, then only the dictionary length is returned, and nothing is copied.
+ Similary, if dictLength is Z_NULL, then it is not set.
+
+ deflateGetDictionary() may return a length less than the window size, even
+ when more than the window size in input has been provided. It may return up
+ to 258 bytes less in that case, due to how zlib's implementation of deflate
+ manages the sliding window and lookahead for matches, where matches can be
+ up to 258 bytes long. If the application needs the last window-size bytes of
+ input, then that would need to be saved by the application outside of zlib.
+
+ deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+ stream state is inconsistent.
+*/
+
+ZEXTERN int ZEXPORT zng_deflateCopy(zng_stream *dest, zng_stream *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.
+*/
+
+ZEXTERN int ZEXPORT zng_deflateReset(zng_stream *strm);
+/*
+ This function is equivalent to deflateEnd followed by deflateInit, but
+ does not free and reallocate the internal compression state. The stream
+ will leave the compression level and any other attributes that may have been
+ set unchanged.
+
+ deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent (such as zalloc or state being NULL).
+*/
+
+ZEXTERN int ZEXPORT zng_deflateParams(zng_stream *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 approach (which is a function of the level) or the
+ strategy is changed, and if any input has been consumed in a previous
+ deflate() call, then the input available so far is compressed with the old
+ level and strategy using deflate(strm, Z_BLOCK). There are three approaches
+ for the compression levels 0, 1..3, and 4..9 respectively. The new level
+ and strategy will take effect at the next call of deflate().
+
+ If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
+ not have enough output space to complete, then the parameter change will not
+ take effect. In this case, deflateParams() can be called again with the
+ same parameters and more output space to try again.
+
+ In order to assure a change in the parameters on the first try, the
+ deflate stream should be flushed using deflate() with Z_BLOCK or other flush
+ request until strm.avail_out is not zero, before calling deflateParams().
+ Then no more input data should be provided before the deflateParams() call.
+ If this is done, the old level and strategy will be applied to the data
+ compressed before deflateParams(), and the new level and strategy will be
+ applied to the the data compressed after deflateParams().
+
+ deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
+ state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
+ there was not enough output space to complete the compression of the
+ available input data before a change in the strategy or approach. Note that
+ in the case of a Z_BUF_ERROR, the parameters are not changed. A return
+ value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
+ retried with more output space.
+*/
+
+ZEXTERN int ZEXPORT zng_deflateTune(zng_stream *strm, int good_length, int max_lazy, int nice_length, int max_chain);
+/*
+ Fine tune deflate's internal compression parameters. This should only be
+ used by someone who understands the algorithm used by zlib's deflate for
+ searching for the best matching string, and even then only by the most
+ fanatic optimizer trying to squeeze out the last compressed bit for their
+ specific input data. Read the deflate.c source code for the meaning of the
+ max_lazy, good_length, nice_length, and max_chain parameters.
+
+ deflateTune() can be called after deflateInit() or deflateInit2(), and
+ returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
+ */
+
+ZEXTERN unsigned long ZEXPORT zng_deflateBound(zng_stream *strm, unsigned long sourceLen);
+/*
+ deflateBound() returns an upper bound on the compressed size after
+ deflation of sourceLen bytes. It must be called after deflateInit() or
+ deflateInit2(), and after deflateSetHeader(), if used. This would be used
+ to allocate an output buffer for deflation in a single pass, and so would be
+ called before deflate(). If that first deflate() call is provided the
+ sourceLen input bytes, an output buffer allocated to the size returned by
+ deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
+ to return Z_STREAM_END. Note that it is possible for the compressed size to
+ be larger than the value returned by deflateBound() if flush options other
+ than Z_FINISH or Z_NO_FLUSH are used.
+*/
+
+ZEXTERN int ZEXPORT zng_deflatePending(zng_stream *strm, uint32_t *pending, int *bits);
+/*
+ deflatePending() returns the number of bytes and bits of output that have
+ been generated, but not yet provided in the available output. The bytes not
+ provided would be due to the available output space having being consumed.
+ The number of bits of output not provided are between 0 and 7, where they
+ await more bits to join them in order to fill out a full byte. If pending
+ or bits are NULL, then those values are not set.
+
+ deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent.
+ */
+
+ZEXTERN int ZEXPORT zng_deflatePrime(zng_stream *strm, int bits, int value);
+/*
+ deflatePrime() inserts bits in the deflate output stream. The intent
+ is that this function is used to start off the deflate output with the bits
+ leftover from a previous deflate stream when appending to it. As such, this
+ function can only be used for raw deflate, and must be used before the first
+ deflate() call after a deflateInit2() or deflateReset(). bits must be less
+ than or equal to 16, and that many of the least significant bits of value
+ will be inserted in the output.
+
+ deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
+ room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
+ source stream state was inconsistent.
+*/
+
+ZEXTERN int ZEXPORT zng_deflateSetHeader(zng_stream *strm, zng_gz_headerp head);
+/*
+ deflateSetHeader() provides gzip header information for when a gzip
+ stream is requested by deflateInit2(). deflateSetHeader() may be called
+ after deflateInit2() or deflateReset() and before the first call of
+ deflate(). The text, time, os, extra field, name, and comment information
+ in the provided zng_gz_header structure are written to the gzip header (xflag is
+ ignored -- the extra flags are set according to the compression level). The
+ caller must assure that, if not NULL, name and comment are terminated with
+ a zero byte, and that if extra is not NULL, that extra_len bytes are
+ available there. If hcrc is true, a gzip header crc is included. Note that
+ the current versions of the command-line version of gzip (up through version
+ 1.3.x) do not support header crc's, and will report that it is a "multi-part
+ gzip file" and give up.
+
+ If deflateSetHeader is not used, the default gzip header has text false,
+ the time set to zero, and os set to 255, with no extra, name, or comment
+ fields. The gzip header is returned to the default state by deflateReset().
+
+ deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent.
+*/
+
+/*
+ZEXTERN int ZEXPORT zng_inflateInit2(zng_stream *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. windowBits must be greater than or equal to the windowBits value
+ provided to deflateInit2() while compressing, or it must be equal to 15 if
+ deflateInit2() was not used. 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.
+
+ windowBits can also be zero to request that inflate use the window size in
+ the zlib header of the compressed stream.
+
+ windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
+ determines the window size. inflate() will then process raw deflate data,
+ not looking for a zlib or gzip header, not generating a check value, and not
+ looking for any check values for comparison at the end of the stream. This
+ is for use with other formats that use the deflate compressed data format
+ such as zip. Those formats provide their own check values. If a custom
+ format is developed using the raw deflate format for compressed data, it is
+ recommended that a check value such as an Adler-32 or a CRC-32 be applied to
+ the uncompressed data as is done in the zlib, gzip, and zip formats. For
+ most applications, the zlib format should be used as is. Note that comments
+ above on the use in deflateInit2() applies to the magnitude of windowBits.
+
+ windowBits can also be greater than 15 for optional gzip decoding. Add
+ 32 to windowBits to enable zlib and gzip decoding with automatic header
+ detection, or add 16 to decode only the gzip format (the zlib format will
+ return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
+ CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see
+ below), inflate() will not automatically decode concatenated gzip streams.
+ inflate() will return Z_STREAM_END at the end of the gzip stream. The state
+ would need to be reset to continue decoding a subsequent gzip stream.
+
+ inflateInit2 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, or Z_STREAM_ERROR if the parameters are
+ invalid, such as a null pointer to the structure. msg is set to null if
+ there is no error message. inflateInit2 does not perform any decompression
+ apart from possibly reading the zlib header if present: actual decompression
+ will be done by inflate(). (So next_in and avail_in may be modified, but
+ next_out and avail_out are unused and unchanged.) The current implementation
+ of inflateInit2() does not process any header information -- that is
+ deferred until inflate() is called.
+*/
+
+ZEXTERN int ZEXPORT zng_inflateSetDictionary(zng_stream *strm, const unsigned char *dictionary, unsigned int dictLength);
+/*
+ Initializes the decompression dictionary from the given uncompressed byte
+ sequence. This function must be called immediately after a call of inflate,
+ if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
+ can be determined from the Adler-32 value returned by that call of inflate.
+ The compressor and decompressor must use exactly the same dictionary (see
+ deflateSetDictionary). For raw inflate, this function can be called at any
+ time to set the dictionary. If the provided dictionary is smaller than the
+ window and there is already data in the window, then the provided dictionary
+ will amend what's there. The application must insure that the dictionary
+ that was used for compression is provided.
+
+ inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
+ parameter is invalid (e.g. dictionary being NULL) or the stream state is
+ inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
+ expected one (incorrect Adler-32 value). inflateSetDictionary does not
+ perform any decompression: this will be done by subsequent calls of
+ inflate().
+*/
+
+ZEXTERN int ZEXPORT zng_inflateGetDictionary(zng_stream *strm, unsigned char *dictionary, unsigned int *dictLength);
+/*
+ Returns the sliding dictionary being maintained by inflate. dictLength is
+ set to the number of bytes in the dictionary, and that many bytes are copied
+ to dictionary. dictionary must have enough space, where 32768 bytes is
+ always enough. If inflateGetDictionary() is called with dictionary equal to
+ NULL, then only the dictionary length is returned, and nothing is copied.
+ Similary, if dictLength is NULL, then it is not set.
+
+ inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+ stream state is inconsistent.
+*/
+
+ZEXTERN int ZEXPORT zng_inflateSync(zng_stream *strm);
+/*
+ Skips invalid compressed data until a possible full flush point (see above
+ for the description of deflate with Z_FULL_FLUSH) can be found, or until all
+ available input is skipped. No output is provided.
+
+ inflateSync searches for a 00 00 FF FF pattern in the compressed data.
+ All full flush points have this pattern, but not all occurrences of this
+ pattern are full flush points.
+
+ inflateSync returns Z_OK if a possible 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.
+*/
+
+ZEXTERN int ZEXPORT zng_inflateCopy(zng_stream *dest, zng_stream *source);
+/*
+ Sets the destination stream as a complete copy of the source stream.
+
+ This function can be useful when randomly accessing a large stream. The
+ first pass through the stream can periodically record the inflate state,
+ allowing restarting inflate at those points when randomly accessing the
+ stream.
+
+ inflateCopy 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.
+*/
+
+ZEXTERN int ZEXPORT zng_inflateReset(zng_stream *strm);
+/*
+ This function is equivalent to inflateEnd followed by inflateInit,
+ but does not free and reallocate 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).
+*/
+
+ZEXTERN int ZEXPORT zng_inflateReset2(zng_stream *strm, int windowBits);
+/*
+ This function is the same as inflateReset, but it also permits changing
+ the wrap and window size requests. The windowBits parameter is interpreted
+ the same as it is for inflateInit2. If the window size is changed, then the
+ memory allocated for the window is freed, and the window will be reallocated
+ by inflate() if needed.
+
+ inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent (such as zalloc or state being NULL), or if
+ the windowBits parameter is invalid.
+*/
+
+ZEXTERN int ZEXPORT zng_inflatePrime(zng_stream *strm, int bits, int value);
+/*
+ This function inserts bits in the inflate input stream. The intent is
+ that this function is used to start inflating at a bit position in the
+ middle of a byte. The provided bits will be used before any bytes are used
+ from next_in. This function should only be used with raw inflate, and
+ should be used before the first inflate() call after inflateInit2() or
+ inflateReset(). bits must be less than or equal to 16, and that many of the
+ least significant bits of value will be inserted in the input.
+
+ If bits is negative, then the input stream bit buffer is emptied. Then
+ inflatePrime() can be called again to put bits in the buffer. This is used
+ to clear out bits leftover after feeding inflate a block description prior
+ to feeding inflate codes.
+
+ inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent.
+*/
+
+ZEXTERN long ZEXPORT zng_inflateMark(zng_stream *strm);
+/*
+ This function returns two values, one in the lower 16 bits of the return
+ value, and the other in the remaining upper bits, obtained by shifting the
+ return value down 16 bits. If the upper value is -1 and the lower value is
+ zero, then inflate() is currently decoding information outside of a block.
+ If the upper value is -1 and the lower value is non-zero, then inflate is in
+ the middle of a stored block, with the lower value equaling the number of
+ bytes from the input remaining to copy. If the upper value is not -1, then
+ it is the number of bits back from the current bit position in the input of
+ the code (literal or length/distance pair) currently being processed. In
+ that case the lower value is the number of bytes already emitted for that
+ code.
+
+ A code is being processed if inflate is waiting for more input to complete
+ decoding of the code, or if it has completed decoding but is waiting for
+ more output space to write the literal or match data.
+
+ inflateMark() is used to mark locations in the input data for random
+ access, which may be at bit positions, and to note those cases where the
+ output of a code may span boundaries of random access blocks. The current
+ location in the input stream can be determined from avail_in and data_type
+ as noted in the description for the Z_BLOCK flush parameter for inflate.
+
+ inflateMark returns the value noted above, or -65536 if the provided
+ source stream state was inconsistent.
+*/
+
+ZEXTERN int ZEXPORT zng_inflateGetHeader(zng_stream *strm, zng_gz_headerp head);
+/*
+ inflateGetHeader() requests that gzip header information be stored in the
+ provided zng_gz_header structure. inflateGetHeader() may be called after
+ inflateInit2() or inflateReset(), and before the first call of inflate().
+ As inflate() processes the gzip stream, head->done is zero until the header
+ is completed, at which time head->done is set to one. If a zlib stream is
+ being decoded, then head->done is set to -1 to indicate that there will be
+ no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
+ used to force inflate() to return immediately after header processing is
+ complete and before any actual data is decompressed.
+
+ The text, time, xflags, and os fields are filled in with the gzip header
+ contents. hcrc is set to true if there is a header CRC. (The header CRC
+ was valid if done is set to one.) If extra is not NULL, then extra_max
+ contains the maximum number of bytes to write to extra. Once done is true,
+ extra_len contains the actual extra field length, and extra contains the
+ extra field, or that field truncated if extra_max is less than extra_len.
+ If name is not NULL, then up to name_max characters are written there,
+ terminated with a zero unless the length is greater than name_max. If
+ comment is not NULL, then up to comm_max characters are written there,
+ terminated with a zero unless the length is greater than comm_max. When any
+ of extra, name, or comment are not NULL and the respective field is not
+ present in the header, then that field is set to NULL to signal its
+ absence. This allows the use of deflateSetHeader() with the returned
+ structure to duplicate the header. However if those fields are set to
+ allocated memory, then the application will need to save those pointers
+ elsewhere so that they can be eventually freed.
+
+ If inflateGetHeader is not used, then the header information is simply
+ discarded. The header is always checked for validity, including the header
+ CRC if present. inflateReset() will reset the process to discard the header
+ information. The application would need to call inflateGetHeader() again to
+ retrieve the header from the next gzip stream.
+
+ inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent.
+*/
+
+/*
+ZEXTERN int ZEXPORT zng_inflateBackInit (zng_stream *strm, int windowBits, unsigned char *window);
+
+ Initialize the internal stream state for decompression using inflateBack()
+ calls. The fields zalloc, zfree and opaque in strm must be initialized
+ before the call. If zalloc and zfree are NULL, then the default library-
+ derived memory allocation routines are used. windowBits is the base two
+ logarithm of the window size, in the range 8..15. window is a caller
+ supplied buffer of that size. Except for special applications where it is
+ assured that deflate was used with small window sizes, windowBits must be 15
+ and a 32K byte window must be supplied to be able to decompress general
+ deflate streams.
+
+ See inflateBack() for the usage of these routines.
+
+ inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
+ the parameters are invalid, Z_MEM_ERROR if the internal state could not be
+ allocated, or Z_VERSION_ERROR if the version of the library does not match
+ the version of the header file.
+*/
+
+typedef uint32_t (*in_func) (void *, const unsigned char * *);
+typedef int (*out_func) (void *, unsigned char *, uint32_t);
+
+ZEXTERN int ZEXPORT zng_inflateBack(zng_stream *strm, in_func in, void *in_desc, out_func out, void *out_desc);
+/*
+ inflateBack() does a raw inflate with a single call using a call-back
+ interface for input and output. This is potentially more efficient than
+ inflate() for file i/o applications, in that it avoids copying between the
+ output and the sliding window by simply making the window itself the output
+ buffer. inflate() can be faster on modern CPUs when used with large
+ buffers. inflateBack() trusts the application to not change the output
+ buffer passed by the output function, at least until inflateBack() returns.
+
+ inflateBackInit() must be called first to allocate the internal state
+ and to initialize the state with the user-provided window buffer.
+ inflateBack() may then be used multiple times to inflate a complete, raw
+ deflate stream with each call. inflateBackEnd() is then called to free the
+ allocated state.
+
+ A raw deflate stream is one with no zlib or gzip header or trailer.
+ This routine would normally be used in a utility that reads zip or gzip
+ files and writes out uncompressed files. The utility would decode the
+ header and process the trailer on its own, hence this routine expects only
+ the raw deflate stream to decompress. This is different from the default
+ behavior of inflate(), which expects a zlib header and trailer around the
+ deflate stream.
+
+ inflateBack() uses two subroutines supplied by the caller that are then
+ called by inflateBack() for input and output. inflateBack() calls those
+ routines until it reads a complete deflate stream and writes out all of the
+ uncompressed data, or until it encounters an error. The function's
+ parameters and return types are defined above in the in_func and out_func
+ typedefs. inflateBack() will call in(in_desc, &buf) which should return the
+ number of bytes of provided input, and a pointer to that input in buf. If
+ there is no input available, in() must return zero -- buf is ignored in that
+ case -- and inflateBack() will return a buffer error. inflateBack() will
+ call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
+ out() should return zero on success, or non-zero on failure. If out()
+ returns non-zero, inflateBack() will return with an error. Neither in() nor
+ out() are permitted to change the contents of the window provided to
+ inflateBackInit(), which is also the buffer that out() uses to write from.
+ The length written by out() will be at most the window size. Any non-zero
+ amount of input may be provided by in().
+
+ For convenience, inflateBack() can be provided input on the first call by
+ setting strm->next_in and strm->avail_in. If that input is exhausted, then
+ in() will be called. Therefore strm->next_in must be initialized before
+ calling inflateBack(). If strm->next_in is NULL, then in() will be called
+ immediately for input. If strm->next_in is not NULL, then strm->avail_in
+ must also be initialized, and then if strm->avail_in is not zero, input will
+ initially be taken from strm->next_in[0 .. strm->avail_in - 1].
+
+ The in_desc and out_desc parameters of inflateBack() is passed as the
+ first parameter of in() and out() respectively when they are called. These
+ descriptors can be optionally used to pass any information that the caller-
+ supplied in() and out() functions need to do their job.
+
+ On return, inflateBack() will set strm->next_in and strm->avail_in to
+ pass back any unused input that was provided by the last in() call. The
+ return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
+ if in() or out() returned an error, Z_DATA_ERROR if there was a format error
+ in the deflate stream (in which case strm->msg is set to indicate the nature
+ of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
+ In the case of Z_BUF_ERROR, an input or output error can be distinguished
+ using strm->next_in which will be NULL only if in() returned an error. If
+ strm->next_in is not NULL, then the Z_BUF_ERROR was due to out() returning
+ non-zero. (in() will always be called before out(), so strm->next_in is
+ assured to be defined if out() returns non-zero.) Note that inflateBack()
+ cannot return Z_OK.
+*/
+
+ZEXTERN int ZEXPORT zng_inflateBackEnd(zng_stream *strm);
+/*
+ All memory allocated by inflateBackInit() is freed.
+
+ inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
+ state was inconsistent.
+*/
+
+ZEXTERN unsigned long ZEXPORT zng_zlibCompileFlags(void);
+/* Return flags indicating compile-time options.
+
+ Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
+ 1.0: size of unsigned int
+ 3.2: size of unsigned long
+ 5.4: size of void * (pointer)
+ 7.6: size of z_off_t
+
+ Compiler, assembler, and debug options:
+ 8: ZLIB_DEBUG
+ 9: ASMV or ASMINF -- use ASM code
+ 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
+ 11: 0 (reserved)
+
+ One-time table building (smaller code, but not thread-safe if true):
+ 12: BUILDFIXED -- build static block decoding tables when needed
+ 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
+ 14,15: 0 (reserved)
+
+ Library content (indicates missing functionality):
+ 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
+ deflate code when not needed)
+ 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
+ and decode gzip streams (to avoid linking crc code)
+ 18-19: 0 (reserved)
+
+ Operation variations (changes in library functionality):
+ 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
+ 21: FASTEST -- deflate algorithm with only one, lowest compression level
+ 22,23: 0 (reserved)
+
+ The sprintf variant used by gzprintf (zero is best):
+ 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
+ 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
+ 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
+
+ Remainder:
+ 27-31: 0 (reserved)
+ */
+
+
+ /* 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 be modified if
+ you need special options.
+*/
+
+ZEXTERN int ZEXPORT zng_compress(unsigned char *dest, size_t *destLen, const unsigned char *source, size_t 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 the value returned by
+ compressBound(sourceLen). Upon exit, destLen is the actual size of the
+ compressed data. compress() is equivalent to compress2() with a level
+ parameter of Z_DEFAULT_COMPRESSION.
+
+ 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.
+*/
+
+ZEXTERN int ZEXPORT zng_compress2(unsigned char *dest, size_t *destLen, const unsigned char *source,
+ size_t 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 the value returned by
+ compressBound(sourceLen). Upon exit, destLen is the actual size of the
+ compressed data.
+
+ 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.
+*/
+
+ZEXTERN size_t ZEXPORT zng_compressBound(size_t sourceLen);
+/*
+ compressBound() returns an upper bound on the compressed size after
+ compress() or compress2() on sourceLen bytes. It would be used before a
+ compress() or compress2() call to allocate the destination buffer.
+*/
+
+ZEXTERN int ZEXPORT zng_uncompress(unsigned char *dest, size_t *destLen, const unsigned char *source, size_t 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 uncompressed data.
+
+ 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 or incomplete. In
+ the case where there is not enough room, uncompress() will fill the output
+ buffer with the uncompressed data up to that point.
+*/
+
+
+ZEXTERN int ZEXPORT zng_uncompress2 (unsigned char *dest, size_t *destLen,
+ const unsigned char *source, size_t *sourceLen);
+/*
+ Same as uncompress, except that sourceLen is a pointer, where the
+ length of the source is *sourceLen. On return, *sourceLen is the number of
+ source bytes consumed.
+*/
+
+
+#ifdef WITH_GZFILEOP
+ /* gzip file access functions */
+
+/*
+ This library supports reading and writing files in gzip (.gz) format with
+ an interface similar to that of stdio, using the functions that start with
+ "gz". The gzip format is different from the zlib format. gzip is a gzip
+ wrapper, documented in RFC 1952, wrapped around a deflate stream.
+*/
+
+typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */
+
+/*
+ZEXTERN gzFile ZEXPORT zng_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", 'R' for run-length encoding as in "wb1R", or 'F'
+ for fixed code compression as in "wb9F". (See the description of
+ deflateInit2 for more information about the strategy parameter.) 'T' will
+ request transparent writing or appending with no compression and not using
+ the gzip format.
+
+ "a" can be used instead of "w" to request that the gzip stream that will
+ be written be appended to the file. "+" will result in an error, since
+ reading and writing to the same gzip file is not supported. The addition of
+ "x" when writing will create the file exclusively, which fails if the file
+ already exists. On systems that support it, the addition of "e" when
+ reading or writing will set the flag to close the file on an execve() call.
+
+ These functions, as well as gzip, will read and decode a sequence of gzip
+ streams in a file. The append function of gzopen() can be used to create
+ such a file. (Also see gzflush() for another way to do this.) When
+ appending, gzopen does not test whether the file begins with a gzip stream,
+ nor does it look for the end of the gzip streams to begin appending. gzopen
+ will simply append a gzip stream to the existing file.
+
+ 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. When
+ reading, this will be detected automatically by looking for the magic two-
+ byte gzip header.
+
+ gzopen returns NULL if the file could not be opened, if there was
+ insufficient memory to allocate the gzFile state, or if an invalid mode was
+ specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
+ errno can be checked to determine if the reason gzopen failed was that the
+ file could not be opened.
+*/
+
+ZEXTERN gzFile ZEXPORT zng_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 (if 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 fd = dup(fd_keep); gz = gzdopen(fd,
+ mode);. The duplicated descriptor should be saved to avoid a leak, since
+ gzdopen does not close fd if it fails. If you are using fileno() to get the
+ file descriptor from a FILE *, then you will have to use dup() to avoid
+ double-close()ing the file descriptor. Both gzclose() and fclose() will
+ close the associated file descriptor, so they need to have different file
+ descriptors.
+
+ gzdopen returns NULL if there was insufficient memory to allocate the
+ gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
+ provided, or '+' was provided), or if fd is -1. The file descriptor is not
+ used until the next gz* read, write, seek, or close operation, so gzdopen
+ will not detect if fd is invalid (unless fd is -1).
+*/
+
+ZEXTERN int ZEXPORT zng_gzbuffer(gzFile file, unsigned size);
+/*
+ Set the internal buffer size used by this library's functions. The
+ default buffer size is 8192 bytes. This function must be called after
+ gzopen() or gzdopen(), and before any other calls that read or write the
+ file. The buffer memory allocation is always deferred to the first read or
+ write. Three times that size in buffer space is allocated. A larger buffer
+ size of, for example, 64K or 128K bytes will noticeably increase the speed
+ of decompression (reading).
+
+ The new buffer size also affects the maximum length for gzprintf().
+
+ gzbuffer() returns 0 on success, or -1 on failure, such as being called
+ too late.
+*/
+
+ZEXTERN int ZEXPORT zng_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. Previously provided
+ data is flushed before the parameter change.
+
+ gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
+ opened for writing, Z_ERRNO if there is an error writing the flushed data,
+ or Z_MEM_ERROR if there is a memory allocation error.
+*/
+
+ZEXTERN int ZEXPORT zng_gzread(gzFile file, void *buf, unsigned len);
+/*
+ Reads the given number of uncompressed bytes from the compressed file. If
+ the input file is not in gzip format, gzread copies the given number of
+ bytes into the buffer directly from the file.
+
+ After reaching the end of a gzip stream in the input, gzread will continue
+ to read, looking for another gzip stream. Any number of gzip streams may be
+ concatenated in the input file, and will all be decompressed by gzread().
+ If something other than a gzip stream is encountered after a gzip stream,
+ that remaining trailing garbage is ignored (and no error is returned).
+
+ gzread can be used to read a gzip file that is being concurrently written.
+ Upon reaching the end of the input, gzread will return with the available
+ data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
+ gzclearerr can be used to clear the end of file indicator in order to permit
+ gzread to be tried again. Z_OK indicates that a gzip stream was completed
+ on the last gzread. Z_BUF_ERROR indicates that the input file ended in the
+ middle of a gzip stream. Note that gzread does not return -1 in the event
+ of an incomplete gzip stream. This error is deferred until gzclose(), which
+ will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
+ stream. Alternatively, gzerror can be used before gzclose to detect this
+ case.
+
+ gzread returns the number of uncompressed bytes actually read, less than
+ len for end of file, or -1 for error. If len is too large to fit in an int,
+ then nothing is read, -1 is returned, and the error state is set to
+ Z_STREAM_ERROR.
+*/
+
+ZEXTERN size_t ZEXPORT zng_gzfread (void *buf, size_t size, size_t nitems, gzFile file);
+/*
+ Read up to nitems items of size size from file to buf, otherwise operating
+ as gzread() does. This duplicates the interface of stdio's fread(), with
+ size_t request and return types.
+
+ gzfread() returns the number of full items read of size size, or zero if
+ the end of the file was reached and a full item could not be read, or if
+ there was an error. gzerror() must be consulted if zero is returned in
+ order to determine if there was an error. If the multiplication of size and
+ nitems overflows, i.e. the product does not fit in a size_t, then nothing
+ is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
+
+ In the event that the end of file is reached and only a partial item is
+ available at the end, i.e. the remaining uncompressed data length is not a
+ multiple of size, then the final partial item is nevertheless read into buf
+ and the end-of-file flag is set. The length of the partial item read is not
+ provided, but could be inferred from the result of gztell(). This behavior
+ is the same as the behavior of fread() implementations in common libraries,
+ but it prevents the direct use of gzfread() to read a concurrently written
+ file, reseting and retrying on end-of-file, when size is not 1.
+*/
+
+ZEXTERN int ZEXPORT zng_gzwrite(gzFile file, void const *buf, unsigned len);
+/*
+ Writes the given number of uncompressed bytes into the compressed file.
+ gzwrite returns the number of uncompressed bytes written or 0 in case of
+ error.
+*/
+
+ZEXTERN size_t ZEXPORT zng_gzfwrite(void const *buf, size_t size, size_t nitems, gzFile file);
+/*
+ gzfwrite() writes nitems items of size size from buf to file, duplicating
+ the interface of stdio's fwrite(), with size_t request and return types.
+
+ gzfwrite() returns the number of full items written of size size, or zero
+ if there was an error. If the multiplication of size and nitems overflows,
+ i.e. the product does not fit in a size_t, then nothing is written, zero
+ is returned, and the error state is set to Z_STREAM_ERROR.
+*/
+
+ZEXTERN int ZEXPORTVA zng_gzprintf(gzFile file, const char *format, ...);
+/*
+ Converts, formats, and writes the arguments to the compressed file under
+ control of the format string, as in fprintf. gzprintf returns the number of
+ uncompressed bytes actually written, or a negative zlib error code in case
+ of error. The number of uncompressed bytes written is limited to 8191, or
+ one less than the buffer size given to gzbuffer(). The caller should assure
+ that this limit is not exceeded. If it is exceeded, then gzprintf() will
+ return an error (0) with nothing written. In this case, there may also be a
+ buffer overflow with unpredictable consequences, which is possible only if
+ zlib was compiled with the insecure functions sprintf() or vsprintf()
+ because the secure snprintf() or vsnprintf() functions were not available.
+ This can be determined using zlibCompileFlags().
+*/
+
+ZEXTERN int ZEXPORT zng_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.
+*/
+
+ZEXTERN char * ZEXPORT zng_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. If any characters are read or if len == 1, the
+ string is terminated with a null character. If no characters are read due
+ to an end-of-file or len < 1, then the buffer is left untouched.
+
+ gzgets returns buf which is a null-terminated string, or it returns NULL
+ for end-of-file or in case of error. If there was an error, the contents at
+ buf are indeterminate.
+*/
+
+ZEXTERN int ZEXPORT zng_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.
+*/
+
+ZEXTERN int ZEXPORT zng_gzgetc(gzFile file);
+/*
+ Reads one byte from the compressed file. gzgetc returns this byte or -1
+ in case of end of file or error. This is implemented as a macro for speed.
+ As such, it does not do all of the checking the other functions do. I.e.
+ it does not check to see if file is NULL, nor whether the structure file
+ points to has been clobbered or not.
+*/
+
+ZEXTERN int ZEXPORT zng_gzungetc(int c, gzFile file);
+/*
+ Push one character back onto the stream to be read as the first character
+ on the next read. At least one character of push-back is allowed.
+ gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
+ fail if c is -1, and may fail if a character has been pushed but not read
+ yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
+ output buffer size of pushed characters is allowed. (See gzbuffer above.)
+ The pushed character will be discarded if the stream is repositioned with
+ gzseek() or gzrewind().
+*/
+
+ZEXTERN int ZEXPORT zng_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 is only permitted when writing.
+
+ If the flush parameter is Z_FINISH, the remaining data is written and the
+ gzip stream is completed in the output. If gzwrite() is called again, a new
+ gzip stream will be started in the output. gzread() is able to read such
+ concatenated gzip streams.
+
+ gzflush should be called only when strictly necessary because it will
+ degrade compression if called too often.
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT zng_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.
+*/
+
+ZEXTERN int ZEXPORT zng_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)
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT zng_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, and is zero when starting, even if appending or
+ reading a gzip stream from the middle of a file using gzdopen().
+
+ gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT zng_gzoffset(gzFile file);
+
+ Returns the current offset in the file being read or written. This offset
+ includes the count of bytes that precede the gzip stream, for example when
+ appending or when using gzdopen() for reading. When reading, the offset
+ does not include as yet unused buffered input. This information can be used
+ for a progress indicator. On error, gzoffset() returns -1.
+*/
+
+ZEXTERN int ZEXPORT zng_gzeof(gzFile file);
+/*
+ Returns true (1) if the end-of-file indicator has been set while reading,
+ false (0) otherwise. Note that the end-of-file indicator is set only if the
+ read tried to go past the end of the input, but came up short. Therefore,
+ just like feof(), gzeof() may return false even if there is no more data to
+ read, in the event that the last read request was for the exact number of
+ bytes remaining in the input file. This will happen if the input file size
+ is an exact multiple of the buffer size.
+
+ If gzeof() returns true, then the read functions will return no more data,
+ unless the end-of-file indicator is reset by gzclearerr() and the input file
+ has grown since the previous end of file was detected.
+*/
+
+ZEXTERN int ZEXPORT zng_gzdirect(gzFile file);
+/*
+ Returns true (1) if file is being copied directly while reading, or false
+ (0) if file is a gzip stream being decompressed.
+
+ If the input file is empty, gzdirect() will return true, since the input
+ does not contain a gzip stream.
+
+ If gzdirect() is used immediately after gzopen() or gzdopen() it will
+ cause buffers to be allocated to allow reading the file to determine if it
+ is a gzip file. Therefore if gzbuffer() is used, it should be called before
+ gzdirect().
+
+ When writing, gzdirect() returns true (1) if transparent writing was
+ requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note:
+ gzdirect() is not needed when writing. Transparent writing must be
+ explicitly requested, so the application already knows the answer. When
+ linking statically, using gzdirect() will include all of the zlib code for
+ gzip file reading and decompression, which may not be desired.)
+*/
+
+ZEXTERN int ZEXPORT zng_gzclose(gzFile file);
+/*
+ Flushes all pending output if necessary, closes the compressed file and
+ deallocates the (de)compression state. Note that once file is closed, you
+ cannot call gzerror with file, since its structures have been deallocated.
+ gzclose must not be called more than once on the same file, just as free
+ must not be called more than once on the same allocation.
+
+ gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
+ file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
+ last read ended in the middle of a gzip stream, or Z_OK on success.
+*/
+
+ZEXTERN int ZEXPORT zng_gzclose_r(gzFile file);
+ZEXTERN int ZEXPORT zng_gzclose_w(gzFile file);
+/*
+ Same as gzclose(), but gzclose_r() is only for use when reading, and
+ gzclose_w() is only for use when writing or appending. The advantage to
+ using these instead of gzclose() is that they avoid linking in zlib
+ compression or decompression code that is not used when only reading or only
+ writing respectively. If gzclose() is used, then both compression and
+ decompression code will be included the application when linking to a static
+ zlib library.
+*/
+
+ZEXTERN const char * ZEXPORT zng_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.
+
+ The application must not modify the returned string. Future calls to
+ this function may invalidate the previously returned string. If file is
+ closed, then the string previously returned by gzerror will no longer be
+ available.
+
+ gzerror() should be used to distinguish errors from end-of-file for those
+ functions above that do not distinguish those cases in their return values.
+*/
+
+ZEXTERN void ZEXPORT zng_gzclearerr(gzFile file);
+/*
+ Clears the error and end-of-file flags for file. This is analogous to the
+ clearerr() function in stdio. This is useful for continuing to read a gzip
+ file that is being written concurrently.
+*/
+
+#endif /* WITH_GZFILEOP */
+
+ /* checksum functions */
+
+/*
+ These functions are not related to compression but are exported
+ anyway because they might be useful in applications using the compression
+ library.
+*/
+
+ZEXTERN uint32_t ZEXPORT zng_adler32(uint32_t adler, const unsigned char *buf, uint32_t 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 CRC-32 but can be computed
+ much faster.
+
+ Usage example:
+
+ uint32_t adler = adler32(0L, NULL, 0);
+
+ while (read_buffer(buffer, length) != EOF) {
+ adler = adler32(adler, buffer, length);
+ }
+ if (adler != original_adler) error();
+*/
+
+ZEXTERN uint32_t ZEXPORT zng_adler32_z (uint32_t adler, const unsigned char *buf, size_t len);
+/*
+ Same as adler32(), but with a size_t length.
+*/
+
+/*
+ZEXTERN uint32_t ZEXPORT zng_adler32_combine(uint32_t adler1, uint32_t adler2, z_off_t len2);
+
+ Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
+ and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
+ each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
+ seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note
+ that the z_off_t type (like off_t) is a signed integer. If len2 is
+ negative, the result has no meaning or utility.
+*/
+
+ZEXTERN uint32_t ZEXPORT zng_crc32(uint32_t crc, const unsigned char *buf, uint32_t len);
+/*
+ Update a running CRC-32 with the bytes buf[0..len-1] and return the
+ updated CRC-32. 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:
+
+ uint32_t crc = crc32(0L, NULL, 0);
+
+ while (read_buffer(buffer, length) != EOF) {
+ crc = crc32(crc, buffer, length);
+ }
+ if (crc != original_crc) error();
+*/
+
+ZEXTERN uint32_t ZEXPORT zng_crc32_z (uint32_t crc, const unsigned char *buf, size_t len);
+/*
+ Same as crc32(), but with a size_t length.
+*/
+
+/*
+ZEXTERN uint32_t ZEXPORT zng_crc32_combine(uint32_t crc1, uint32_t crc2, z_off64_t len2);
+
+ Combine two CRC-32 check values into one. For two sequences of bytes,
+ seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
+ calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
+ check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
+ len2.
+*/
+
+
+ /* various hacks, don't look :) */
+
+/* zng_deflateInit and zng_inflateInit are macros to allow checking the zlib version
+ * and the compiler's view of zng_stream:
+ */
+ZEXTERN int ZEXPORT zng_deflateInit_(zng_stream *strm, int level, const char *version, int stream_size);
+ZEXTERN int ZEXPORT zng_inflateInit_(zng_stream *strm, const char *version, int stream_size);
+ZEXTERN int ZEXPORT zng_deflateInit2_(zng_stream *strm, int level, int method, int windowBits, int memLevel,
+ int strategy, const char *version, int stream_size);
+ZEXTERN int ZEXPORT zng_inflateInit2_(zng_stream *strm, int windowBits, const char *version, int stream_size);
+ZEXTERN int ZEXPORT zng_inflateBackInit_(zng_stream *strm, int windowBits, unsigned char *window,
+ const char *version, int stream_size);
+#define zng_deflateInit(strm, level) zng_deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(zng_stream))
+#define zng_inflateInit(strm) zng_inflateInit_((strm), ZLIB_VERSION, (int)sizeof(zng_stream))
+#define zng_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+ zng_deflateInit2_((strm), (level), (method), (windowBits), (memLevel), \
+ (strategy), ZLIB_VERSION, (int)sizeof(zng_stream))
+#define zng_inflateInit2(strm, windowBits) inflateInit2_((strm), (windowBits), ZLIB_VERSION, (int)sizeof(zng_stream))
+#define zng_inflateBackInit(strm, windowBits, window) \
+ zng_inflateBackInit_((strm), (windowBits), (window), ZLIB_VERSION, (int)sizeof(zng_stream))
+
+#ifdef WITH_GZFILEOP
+
+/* gzgetc() macro and its supporting function and exposed data structure. Note
+ * that the real internal state is much larger than the exposed structure.
+ * This abbreviated structure exposes just enough for the gzgetc() macro. The
+ * user should not mess with these exposed elements, since their names or
+ * behavior could change in the future, perhaps even capriciously. They can
+ * only be used by the gzgetc() macro. You have been warned.
+ */
+struct gzFile_s {
+ unsigned have;
+ unsigned char *next;
+ z_off64_t pos;
+};
+ZEXTERN int ZEXPORT zng_gzgetc_(gzFile file); /* backward compatibility */
+# define zng_gzgetc(g) ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (zng_gzgetc)(g))
+
+/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
+ * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
+ * both are true, the application gets the *64 functions, and the regular
+ * functions are changed to 64 bits) -- in case these are set on systems
+ * without large file support, _LFS64_LARGEFILE must also be true
+ */
+#ifdef Z_LARGE64
+ ZEXTERN gzFile ZEXPORT zng_gzopen64(const char *, const char *);
+ ZEXTERN z_off64_t ZEXPORT zng_gzseek64(gzFile, z_off64_t, int);
+ ZEXTERN z_off64_t ZEXPORT zng_gztell64(gzFile);
+ ZEXTERN z_off64_t ZEXPORT zng_gzoffset64(gzFile);
+#endif
+
+#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
+# define gzopen gzopen64
+# define gzseek gzseek64
+# define gztell gztell64
+# define gzoffset gzoffset64
+# ifndef Z_LARGE64
+ ZEXTERN gzFile ZEXPORT zng_gzopen64(const char *, const char *);
+ ZEXTERN z_off_t ZEXPORT zng_gzseek64(gzFile, z_off_t, int);
+ ZEXTERN z_off_t ZEXPORT zng_gztell64(gzFile);
+ ZEXTERN z_off_t ZEXPORT zng_gzoffset64(gzFile);
+# endif
+#else
+ ZEXTERN gzFile ZEXPORT zng_gzopen(const char *, const char *);
+ ZEXTERN z_off_t ZEXPORT zng_gzseek(gzFile, z_off_t, int);
+ ZEXTERN z_off_t ZEXPORT zng_gztell(gzFile);
+ ZEXTERN z_off_t ZEXPORT zng_gzoffset(gzFile);
+#endif
+#endif /* WITH_GZFILEOP */
+
+
+/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
+ * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
+ * both are true, the application gets the *64 functions, and the regular
+ * functions are changed to 64 bits) -- in case these are set on systems
+ * without large file support, _LFS64_LARGEFILE must also be true
+ */
+#ifdef Z_LARGE64
+ ZEXTERN uint32_t ZEXPORT zng_adler32_combine64(uint32_t, uint32_t, z_off64_t);
+ ZEXTERN uint32_t ZEXPORT zng_crc32_combine64(uint32_t, uint32_t, z_off64_t);
+#endif
+
+#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
+# define zng_adler32_combine zng_adler32_combine64
+# define zng_crc32_combine zng_crc32_combine64
+# ifndef Z_LARGE64
+ ZEXTERN uint32_t ZEXPORT zng_adler32_combine64(uint32_t, uint32_t, z_off_t);
+ ZEXTERN uint32_t ZEXPORT zng_crc32_combine64(uint32_t, uint32_t, z_off_t);
+# endif
+#else
+ ZEXTERN uint32_t ZEXPORT zng_adler32_combine(uint32_t, uint32_t, z_off_t);
+ ZEXTERN uint32_t ZEXPORT zng_crc32_combine(uint32_t, uint32_t, z_off_t);
+#endif
+
+
+/* undocumented functions */
+ZEXTERN const char * ZEXPORT zng_zError (int);
+ZEXTERN int ZEXPORT zng_inflateSyncPoint (zng_stream *);
+ZEXTERN const uint32_t * ZEXPORT zng_get_crc_table (void);
+ZEXTERN int ZEXPORT zng_inflateUndermine (zng_stream *, int);
+ZEXTERN int ZEXPORT zng_inflateValidate (zng_stream *, int);
+ZEXTERN unsigned long ZEXPORT zng_inflateCodesUsed (zng_stream *);
+ZEXTERN int ZEXPORT zng_inflateResetKeep (zng_stream *);
+ZEXTERN int ZEXPORT zng_deflateResetKeep (zng_stream *);
+
+#ifdef WITH_GZFILEOP
+# if (defined(WIN32) || defined(__CYGWIN__) || defined(__MINGW__))
+ ZEXTERN gzFile ZEXPORT zng_gzopen_w(const wchar_t *path, const char *mode);
+# endif
+ZEXTERN int ZEXPORTVA zng_gzvprintf(gzFile file, const char *format, va_list va);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZNGLIB_H_ */
projects / thirdparty / zlib-ng.git / commitdiff
