Name

inflateInit_ — Initializes the decompression system.

Library

Libz.lib

Synopsis

#include <zlib.h>

int inflateInit_(z_streamp stream, const char * version, int stream_size);

Return Value

On success, the inflateInit_() function shall return Z_OK. Otherwise, inflateInit_() shall return a value as described below to indicate the error.

Detailed Description

The inflateInit_() function shall initialize the decompression system. On entry, stream shall refer to a user supplied z_stream object (a z_stream_s structure). The following fields shall be set on entry:

`zalloc`		a pointer to an alloc_func function, used to allocate state information. If this is `NULL`, a default allocation function will be used.
`zfree`		a pointer to a free_func function, used to free memory allocated by the `zalloc` function. If this is `NULL` a default free function will be used.
`opaque`		If `alloc_func` is not `NULL`, `opaque` is a user supplied pointer to data that will be passed to the `alloc_func` and `free_func` functions.

If the version requested is not compatible with the version implemented, or if the size of the z_stream_s structure provided in stream_size does not match the size in the library implementation, inflateInit_() shall fail, and return Z_VERSION_ERROR.

The inflateInit_() function is not in the source standard; it is only in the binary standard. Source applications should use the inflateInit() macro.

The inflateInit_() shall be equivalent to inflateInit2_(strm, DEF_WBITS, version, stream_size);

Examples

To initialize the decompression system:

#include <stdio.h> 
#include <zlib.h>

void InflateInit_( )
{
z_stream d_stream;
const char * version;
d_stream.zalloc = (alloc_func)0;
d_stream.zfree = (free_func)0;
d_stream.opaque = (voidpf)0;
const char hello[] = "hello, hello!";
Byte *compr, *uncompr;
uLong comprLen = 20*sizeof(int);
uLong uncomprLen = comprLen;
compr = (Byte*)calloc((uInt)comprLen, 1);
uncompr = (Byte*)calloc((uInt)uncomprLen, 1);
uLong len = (uLong)strlen(hello)+1;
compress(compr, &comprLen, (const Bytef*)hello, len);
d_stream.next_in = compr;
d_stream.avail_in = 0;
d_stream.next_out = uncompr;
version=zlibVersion();
int ret = inflateInit_(&d_stream,(char*)version, sizeof(d_stream));
inflateEnd(&d_stream);
free(compr);
free(uncompr);
}

Errors

On error, inflateInit_() shall return one of the following error indicators:

`Z_STREAM_ERROR`		Invalid parameter.
`Z_MEM_ERROR`		Insufficient memory available.
`Z_VERSION_ERROR`		The version requested is not compatible with the library version, or the z_stream size differs from that used by the library.

In addition, the msg field of the strm may be set to an error message.

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