wppaste
WordPress

WP_Token_Map::precomputed_php_source_table( string $indent = "\t" ): string

Since
6.6.0
Source
wp-includes/class-wp-token-map.php:712
Export the token map for quick loading in PHP source code.

Description

This function has a specific purpose, to make loading of static token maps fast.
It's used to ensure that the HTML character reference lookups add a minimal cost to initializing the PHP process.

Example:

echo $smilies->precomputed_php_source_table();

// Output.
WP_Token_Map::from_precomputed_table(
 array(
 "storage_version" => "6.6.0",
 "key_length" => 2,
 "groups" => "",
 "long_words" => array(),
 "small_words" => "8O\x00:)\x00:(\x00:?\x00",
 "small_mappings" => array( "😯", "🙂", "🙁", "😕" )
 )
);

Compatibility

WordPress
since 6.6.0
PHP
7.4–8.6-dev
  • 6.7.7
  • 6.8.8
  • 6.9.7
  • 7.0.4
  • 7.1.0

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$indentstringoptional
Use this string for indentation, or rely on the default horizontal tab character. Default "\t".Default: "\t"

Return value

string
Value which can be pasted into a PHP source file for quick loading of table.

Performance profile

How much work a call to WP_Token_Map::precomputed_php_source_table() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class
Trivial

Touches nothing outside its own arguments.

Scaling
Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions
5–16

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 184.

Plugin surface
None

Nothing here hands control to plugin code.

Called by
0

Nothing in core calls this; the cost is only what you spend yourself.

What one call costs · 2 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost WP_Token_Map::precomputed_php_source_table() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
always5–9none
always11–16ord()

Across PHP versions

PHPCompiledExecutedBranchesNotes
8.6-dev1845–1610
8.51845–1610
8.41845–161027 fewer instructions than PHP 8.3
8.32115–1910
8.22115–19101 more instruction than PHP 8.1
8.12105–181023 more instructions than PHP 7.4
7.418776–807

An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.

Source code

View on Trac View on GitHub 

	public function precomputed_php_source_table( string $indent = "\t" ): string {		$i1 = $indent;		$i2 = $i1 . $indent;		$i3 = $i2 . $indent; 		$class_version = self::STORAGE_VERSION; 		$output  = self::class . "::from_precomputed_table(\n";		$output .= "{$i1}array(\n";		$output .= "{$i2}\"storage_version\" => \"{$class_version}\",\n";		$output .= "{$i2}\"key_length\" => {$this->key_length},\n"; 		$group_line = str_replace( "\x00", "\\x00", $this->groups );		$output    .= "{$i2}\"groups\" => \"{$group_line}\",\n"; 		$output .= "{$i2}\"large_words\" => array(\n"; 		$prefixes = explode( "\x00", $this->groups );		foreach ( $prefixes as $index => $prefix ) {			if ( '' === $prefix ) {				break;			}			$group        = $this->large_words[ $index ];			$group_length = strlen( $group );			$comment_line = "{$i3}//";			$data_line    = "{$i3}\"";			$at           = 0;			while ( $at < $group_length ) {				$token_length   = unpack( 'C', $group[ $at++ ] )[1];				$token          = substr( $group, $at, $token_length );				$at            += $token_length;				$mapping_length = unpack( 'C', $group[ $at++ ] )[1];				$mapping        = substr( $group, $at, $mapping_length );				$at            += $mapping_length; 				$token_digits   = str_pad( dechex( $token_length ), 2, '0', STR_PAD_LEFT );				$mapping_digits = str_pad( dechex( $mapping_length ), 2, '0', STR_PAD_LEFT ); 				$mapping = preg_replace_callback(					"~[\\x00-\\x1f\\x22\\x5c]~",					static function ( $match_result ) {						switch ( $match_result[0] ) {							case '"':								return '\\"'; 							case '\\':								return '\\\\'; 							default:								$hex = dechex( ord( $match_result[0] ) );								return "\\x{$hex}";						}					},					$mapping				); 				$comment_line .= " {$prefix}{$token}[{$mapping}]";				$data_line    .= "\\x{$token_digits}{$token}\\x{$mapping_digits}{$mapping}";			}			$comment_line .= ".\n";			$data_line    .= "\",\n"; 			$output .= $comment_line;			$output .= $data_line;		} 		$output .= "{$i2}),\n"; 		$small_words  = array();		$small_length = strlen( $this->small_words );		$at           = 0;		while ( $at < $small_length ) {			$small_words[] = substr( $this->small_words, $at, $this->key_length + 1 );			$at           += $this->key_length + 1;		} 		$small_text = str_replace( "\x00", '\x00', implode( '', $small_words ) );		$output    .= "{$i2}\"small_words\" => \"{$small_text}\",\n"; 		$output .= "{$i2}\"small_mappings\" => array(\n";

Changelog

Introduced in 6.6.0. Unchanged from 6.7.7 through 7.1.0.

  1. 6.7.7
  2. 6.8.8
  3. 6.9.7
  4. 7.0.4
  5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data
Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/class-wp-token-map.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
Corrections
Something wrong on this page? Report it and it gets fixed in the next regeneration.