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PHP - Manual: Phar::startBuffering

2024-11-13

Phar::startBuffering

(PHP 5 >= 5.3.0, PHP 7, PHP 8, PECL phar >= 1.0.0)

Phar::startBufferingStart buffering Phar write operations, do not modify the Phar object on disk

说明

public Phar::startBuffering(): void

Although technically unnecessary, the Phar::startBuffering() method can provide a significant performance boost when creating or modifying a Phar archive with a large number of files. Ordinarily, every time a file within a Phar archive is created or modified in any way, the entire Phar archive will be recreated with the changes. In this way, the archive will be up-to-date with the activity performed on it.

However, this can be unnecessary when simply creating a new Phar archive, when it would make more sense to write the entire archive out at once. Similarly, it is often necessary to make a series of changes and to ensure that they all are possible before making any changes on disk, similar to the relational database concept of transactions. the Phar::startBuffering()/Phar::stopBuffering() pair of methods is provided for this purpose.

Phar write buffering is per-archive, buffering active for the foo.phar Phar archive does not affect changes to the bar.phar Phar archive.

参数

此函数没有参数。

返回值

没有返回值。

范例

示例 #1 A Phar::startBuffering() example

<?php
// make sure it doesn't exist
@unlink('brandnewphar.phar');
try {
    
$p = new Phar(dirname(__FILE__) . '/brandnewphar.phar'0'brandnewphar.phar');
} catch (
Exception $e) {
    echo 
'Could not create phar:'$e;
}
echo 
'The new phar has ' $p->count() . " entries\n";
$p->startBuffering();
$p['file.txt'] = 'hi';
$p['file2.txt'] = 'there';
$p['file2.txt']->setCompressedGZ();
$p['file3.txt'] = 'babyface';
$p['file3.txt']->setMetadata(42);
$p->setStub("<?php
function __autoload(
$class)
{
    include 'phar://myphar.phar/' . str_replace('_', '/', 
$class) . '.php';
}
Phar::mapPhar('myphar.phar');
include 'phar://myphar.phar/startup.php';
__HALT_COMPILER();"
);
$p->stopBuffering();
?>

参见

  • Phar::stopBuffering() - Stop buffering write requests to the Phar archive, and save changes to disk
  • Phar::isBuffering() - Used to determine whether Phar write operations are being buffered, or are flushing directly to disk
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User Contributed Notes 1 note

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0
anon at php dot com
1 year ago
To setthe  ini key phar.readonly to 0, from a unix shell script, this is possible on the fly it is possible see below.
The example given on this page has some issues with quoting: (See conversion to simple quotes)

#!/usr/bin/php -d phar.readonly=0
<?php
print(ini_get('phar.readonly')); // Must return 0
// make sure it doesn't exist
@unlink('brandnewphar.phar');
try {
   
$p = new Phar(dirname(__FILE__) . '/brandnewphar.phar', 0, 'brandnewphar.phar');
} catch (
Exception $e) {
    echo
'Could not create phar:', $e;
}
echo
'The new phar has ' . $p->count() . " entries\n";
$p->startBuffering();
$p['file.txt'] = 'hi';
$p['file2.txt'] = 'there';
$p['file2.txt']->compress(Phar::GZ);
$p['file3.txt'] = 'babyface';
$p['file3.txt']->setMetadata(42);
$p->setStub('<?php
function __autoload($class)
{
    include "phar://myphar.phar/" . str_replace("_", "/", $class) . ".php";
}
Phar::mapPhar("myphar.phar");
include "phar://myphar.phar/startup.php";
__HALT_COMPILER();'
);
$p->stopBuffering();

// Test
$m = file_get_contents("phar://brandnewphar.phar/file2.txt");
$m = explode("\n",$m);
var_dump($m);
/* Output:
* there
**/

官方地址:https://www.php.net/manual/en/phar.startbuffering.php

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