deflate_init()
版本:php7
(PHP 7)
Initialize an incremental deflate context
说明
deflate_init(int $encoding[,array $options= array()]): resource
Initializes an incremental deflate context using the specified$encoding.
Note that thewindowoption here only sets the window size of the algorithm, differently from the zlib filters where the same parameter also sets the encoding to use; the encoding must be set with the$encodingparameter.
Limitation: there is currently no way to set the header information on a GZIP compressed stream, which are set as follows: GZIP signature(x1fx8B); compression method(x08== DEFLATE); 6 zero bytes; the operating system set to the current system(x00= Windows,x03= Unix, etc.)
参数
- $encoding
One of the
ZLIB_ENCODING_*
constants.- $options
An associative array which may contain the following elements:
- level
The compression level in range -1..9; defaults to -1.
- memory
The compression memory level in range 1..9; defaults to 8.
- window
The zlib window size(logarithmic)in range 8..15; defaults to 15.
- strategy
One of
ZLIB_FILTERED
,ZLIB_HUFFMAN_ONLY
,ZLIB_RLE
,ZLIB_FIXED
orZLIB_DEFAULT_STRATEGY
(the default).- dictionary
A string or an array of strings of the preset dictionary(default: no preset dictionary).
返回值
Returns a deflate context resource(zlib.deflate)on success,或者在失败时返回FALSE
.
错误/异常
If an invalid option is passed to$optionsor the context couldn't be created, an error of level E_WARNING
is generated.
参见
deflate_add()
Incrementally deflate datainflate_init()
Initialize an incremental inflate context