deflate_add()

版本：php7

(PHP 7)

Incrementally deflate data

说明

deflate_add(resource $context,string $data[,int $flush_mode= ZLIB_SYNC_FLUSH]): string

Incrementally deflates data in the specified context.

参数

$context: A context created with deflate_init().
$data: A chunk of data to compress.
$flush_mode: One of ZLIB_BLOCK,ZLIB_NO_FLUSH,ZLIB_PARTIAL_FLUSH,ZLIB_SYNC_FLUSH(default),ZLIB_FULL_FLUSH,ZLIB_FINISH. Normally you will want to set ZLIB_NO_FLUSH to maximize compression, and ZLIB_FINISH to terminate with the last chunk of data. See the » zlib manual for a detailed description of these constants.

返回值

Returns a chunk of compressed data,或者在失败时返回FALSE.

错误／异常

If invalid arguments are given, an error of level E_WARNING is generated.

参见

deflate_init()Initialize an incremental deflate context

Example about to use deflate functions to write a gzip encoded file in chunks.
<?php
$handler = fopen('/tmp/test.csv', 'w');
$deflateContext = deflate_init(ZLIB_ENCODING_GZIP, ['level' => 9]);
$strings = [
  'Hello, how are you?' . PHP_EOL,
  'I am fine thanks' . PHP_EOL,
  'Hello, how are you?' . PHP_EOL,
];
foreach ($strings as $string) {
  fwrite($handler, deflate_add($deflateContext, $string, ZLIB_NO_FLUSH));
}
fwrite($handler, deflate_add($deflateContext, '', ZLIB_FINISH));
fclose($handler);
echo gzdecode(file_get_contents('/tmp/test.csv'));