Text_Diff_Engine_string::parseContextDiff( array $diff ): array

Compatibility

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

Parameters

$diffarray

Array of lines.

Return value

array

List of all diff operations.

Performance profile

How much work a call to Text_Diff_Engine_string::parseContextDiff() 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

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

12

Executed per call on PHP 8.5. The body compiles to 254.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

1

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 Text_Diff_Engine_string::parseContextDiff() can have, taken from its control-flow graph on PHP 8.5.

This body has more branch combinations than are worth enumerating, so the table covers the outcomes found first rather than every one that exists.

Uses · 4

• Text_Diff_Op_copy::__construct()PHP5 constructor.
• Text_Diff_Op_change::__construct()PHP5 constructor.
• Text_Diff_Op_add::__construct()PHP5 constructor.
• Text_Diff_Op_delete::__construct()PHP5 constructor.

Used by · 1

• Text_Diff_Engine_string::diff()Parses a unified or context diff.

Source code

View on Trac ↗View on GitHub ↗

146    function parseContextDiff(&$diff)147    {148        $edits = array();149        $i = $max_i = $j = $max_j = 0;150        $end = count($diff) - 1;151        while ($i < $end && $j < $end) {152            while ($i >= $max_i && $j >= $max_j) {153                // Find the boundaries of the diff output of the two files154                for ($i = $j;155                     $i < $end && substr($diff[$i], 0, 3) == '***';156                     $i++);157                for ($max_i = $i;158                     $max_i < $end && substr($diff[$max_i], 0, 3) != '---';159                     $max_i++);160                for ($j = $max_i;161                     $j < $end && substr($diff[$j], 0, 3) == '---';162                     $j++);163                for ($max_j = $j;164                     $max_j < $end && substr($diff[$max_j], 0, 3) != '***';165                     $max_j++);166            }167 168            // find what hasn't been changed169            $array = array();170            while ($i < $max_i &&171                   $j < $max_j &&172                   strcmp($diff[$i], $diff[$j]) == 0) {173                $array[] = substr($diff[$i], 2);174                $i++;175                $j++;176            }177 178            while ($i < $max_i && ($max_j-$j) <= 1) {179                if ($diff[$i] != '' && substr($diff[$i], 0, 1) != ' ') {180                    break;181                }182                $array[] = substr($diff[$i++], 2);183            }184 185            while ($j < $max_j && ($max_i-$i) <= 1) {186                if ($diff[$j] != '' && substr($diff[$j], 0, 1) != ' ') {187                    break;188                }189                $array[] = substr($diff[$j++], 2);190            }191            if (count($array) > 0) {192                $edits[] = new Text_Diff_Op_copy($array);193            }194 195            if ($i < $max_i) {196                $diff1 = array();197                switch (substr($diff[$i], 0, 1)) {198                case '!':199                    $diff2 = array();200                    do {201                        $diff1[] = substr($diff[$i], 2);202                        if ($j < $max_j && substr($diff[$j], 0, 1) == '!') {203                            $diff2[] = substr($diff[$j++], 2);204                        }205                    } while (++$i < $max_i && substr($diff[$i], 0, 1) == '!');206                    $edits[] = new Text_Diff_Op_change($diff1, $diff2);207                    break;208 209                case '+':210                    do {211                        $diff1[] = substr($diff[$i], 2);212                    } while (++$i < $max_i && substr($diff[$i], 0, 1) == '+');213                    $edits[] = new Text_Diff_Op_add($diff1);214                    break;215 216                case '-':217                    do {218                        $diff1[] = substr($diff[$i], 2);219                    } while (++$i < $max_i && substr($diff[$i], 0, 1) == '-');220                    $edits[] = new Text_Diff_Op_delete($diff1);221                    break;222                }223            }224 225            if ($j < $max_j) {

Changelog

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/Text/Diff/Engine/string.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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