PHPMailer::utf8CharBoundary( string $encodedText, int $maxLength ): int
- Source
wp-includes/PHPMailer/PHPMailer.php:2782
Description
Original written by Colin Brown.
Compatibility
- WordPress
- core
- 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
$encodedTextstring- utf-8 QP text
$maxLengthint- Find the last character boundary prior to this length
Return value
int
Performance profile
How much work a call to PHPMailer::utf8CharBoundary() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Scales with input
- Instructions
- 7
- Plugin surface
- None
- Called by
- 0
Touches nothing outside its own arguments.
The body loops, so the work grows with what you pass in.
Executed per call on PHP 8.5. The body compiles to 42.
Nothing here hands control to plugin code.
Nothing in core calls this; the cost is only what you spend yourself.
What one call costs · 1 distinct outcome
One number would be a lie: the work depends on which branch runs. These are every distinct cost PHPMailer::utf8CharBoundary() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 7 | none |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 42 | 7 | 6 | |
| 8.5 | 42 | 7 | 6 | |
| 8.4 | 42 | 7 | 6 | 9 fewer instructions than PHP 8.3 |
| 8.3 | 51 | 7 | 6 | |
| 8.2 | 51 | 7 | 6 | |
| 8.1 | 51 | 7 | 6 | |
| 7.4 | 51 | 7 | 6 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Source code
public function utf8CharBoundary($encodedText, $maxLength) { $foundSplitPos = false; $lookBack = 3; while (!$foundSplitPos) { $lastChunk = substr($encodedText, $maxLength - $lookBack, $lookBack); $encodedCharPos = strpos($lastChunk, '='); if (false !== $encodedCharPos) { //Found start of encoded character byte within $lookBack block. //Check the encoded byte value (the 2 chars after the '=') $hex = substr($encodedText, $maxLength - $lookBack + $encodedCharPos + 1, 2); $dec = hexdec($hex); if ($dec < 128) { //Single byte character. //If the encoded char was found at pos 0, it will fit //otherwise reduce maxLength to start of the encoded char if ($encodedCharPos > 0) { $maxLength -= $lookBack - $encodedCharPos; } $foundSplitPos = true; } elseif ($dec >= 192) { //First byte of a multi byte character //Reduce maxLength to split at start of character $maxLength -= $lookBack - $encodedCharPos; $foundSplitPos = true; } elseif ($dec < 192) { //Middle byte of a multi byte character, look further back $lookBack += 3; } } else { //No encoded character found $foundSplitPos = true; } } return $maxLength; }Changelog
Unchanged from 6.7.7 through 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/PHPMailer/PHPMailer.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.