The deflateInit_() function shall initialize the compression 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:
a pointer to an alloc_func function, used to allocate state information.
If this is
a pointer to a free_func function, used to free memory
allocated by the
If the version requested is not compatible with
the version implemented, or if the size of the
provided in stream_size does not match the size
in the library
implementation, deflateInit_() shall fail, and return
The level supplied shall be a value between
9, or the value
Z_DEFAULT_COMPRESSION. A level
1 requests the highest speed, while a
9 requests the highest compression.
A level of
0 indicates that no
compression should be used, and the output shall be the same as the input.
The deflateInit_() function is not in the source standard; it is only in the binary standard. Source applications should use the deflateInit() macro.
The deflateInit_() function is equivalent to
deflateInit2_(stream, level, Z_DEFLATED, MAX_WBITS, MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY, version, stream_size);
On success, the deflateInit_() function shall return
Otherwise, deflateInit_() shall return
a value as described below to indicate the error.
On error, deflateInit_() shall return one of the following error indicators:
Insufficient memory available.
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
may be set to an error message.