_wp_utf8_codepoint_span( string $text, int $byte_offset, int $max_code_points, ?int $found_code_points = 0 ): int
- Since
- 6.9.0
- Source
wp-includes/compat-utf8.php:381
Description
Invalid spans of bytes count as a single code point according to the maximal subpart rule. This function is a fallback method for calling strlen( mb_substr( substr( $text, $at ), 0, $max_code_points ) ).
Compatibility
- WordPress
- since 6.9.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in 3 of the 5 tracked releases, added in 6.9.0, and compiles on PHP 7.4 through 8.6-dev.
Parameters
$textstring- Count bytes of span in this text.
$byte_offsetint- Start counting at this byte offset.
$max_code_pointsint- Stop counting after this many code points have been seen, or at the end of the string.
$found_code_points?intoptional- Will be set to number of found code points in span, as this might be smaller than the maximum count if the string is not long enough.Default:
0
Return value
int- Number of bytes spanned by the code points.
Performance profile
How much work a call to _wp_utf8_codepoint_span() 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
- Light
- Scaling
- Scales with input
- Instructions
- 14–16
- Plugin surface
- None
- Called by
- 1
Touches nothing outside its own arguments.
The body loops, so the work grows with what you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 33.
Nothing here hands control to plugin code.
1 place in core call this, so the cost is paid more often than your own code shows.
What one call costs · 1 distinct outcome
One number would be a lie: the work depends on which branch runs. These are every distinct cost _wp_utf8_codepoint_span() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 14–16 | none |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 33 instructions, 14–16 executed per call, 4 branches. The work does not change between versions.
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.
Uses · 1
- _wp_scan_utf8()Finds spans of valid and invalid UTF-8 bytes in a given string.
Used by · 1
- _mb_substr()Internal compat function to mimic mb_substr().
Source code
function _wp_utf8_codepoint_span( string $text, int $byte_offset, int $max_code_points, ?int &$found_code_points = 0 ): int { $was_at = $byte_offset; $invalid_length = 0; $end = strlen( $text ); $found_code_points = 0; while ( $byte_offset < $end && $found_code_points < $max_code_points ) { $needed = $max_code_points - $found_code_points; $chunk_count = _wp_scan_utf8( $text, $byte_offset, $invalid_length, null, $needed ); $found_code_points += $chunk_count; // Invalid spans only convey one code point count regardless of how long they are. if ( 0 !== $invalid_length && $found_code_points < $max_code_points ) { ++$found_code_points; $byte_offset += $invalid_length; } } return $byte_offset - $was_at;}Changelog
Introduced in 6.9.0. Unchanged from 6.9.7 through 7.1.0.
Signature, return type and hooks compared across 3 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 7.1.0 tag, from
src/wp-includes/compat-utf8.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.