commitall

vendor/sebastian/diff/src/LCS/LongestCommonSubsequence.php

@@ -0,0 +1,27 @@
+<?php
+/*
+ * This file is part of sebastian/diff.
+ *
+ * (c) Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace SebastianBergmann\Diff\LCS;
+
+/**
+ * Interface for implementations of longest common subsequence calculation.
+ */
+interface LongestCommonSubsequence
+{
+    /**
+     * Calculates the longest common subsequence of two arrays.
+     *
+     * @param array $from
+     * @param array $to
+     *
+     * @return array
+     */
+    public function calculate(array $from, array $to);
+}

vendor/sebastian/diff/src/LCS/MemoryEfficientLongestCommonSubsequenceImplementation.php

@@ -0,0 +1,95 @@
+<?php
+/*
+ * This file is part of sebastian/diff.
+ *
+ * (c) Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace SebastianBergmann\Diff\LCS;
+
+/**
+ * Memory-efficient implementation of longest common subsequence calculation.
+ */
+class MemoryEfficientImplementation implements LongestCommonSubsequence
+{
+    /**
+     * Calculates the longest common subsequence of two arrays.
+     *
+     * @param array $from
+     * @param array $to
+     *
+     * @return array
+     */
+    public function calculate(array $from, array $to)
+    {
+        $cFrom = \count($from);
+        $cTo   = \count($to);
+
+        if ($cFrom === 0) {
+            return array();
+        }
+
+        if ($cFrom === 1) {
+            if (\in_array($from[0], $to, true)) {
+                return array($from[0]);
+            }
+
+            return array();
+        }
+
+        $i         = (int) ($cFrom / 2);
+        $fromStart = \array_slice($from, 0, $i);
+        $fromEnd   = \array_slice($from, $i);
+        $llB       = $this->length($fromStart, $to);
+        $llE       = $this->length(\array_reverse($fromEnd), \array_reverse($to));
+        $jMax      = 0;
+        $max       = 0;
+
+        for ($j = 0; $j <= $cTo; $j++) {
+            $m = $llB[$j] + $llE[$cTo - $j];
+
+            if ($m >= $max) {
+                $max  = $m;
+                $jMax = $j;
+            }
+        }
+
+        $toStart = \array_slice($to, 0, $jMax);
+        $toEnd   = \array_slice($to, $jMax);
+
+        return \array_merge(
+            $this->calculate($fromStart, $toStart),
+            $this->calculate($fromEnd, $toEnd)
+        );
+    }
+
+    /**
+     * @param array $from
+     * @param array $to
+     *
+     * @return array
+     */
+    private function length(array $from, array $to)
+    {
+        $current = \array_fill(0, \count($to) + 1, 0);
+        $cFrom   = \count($from);
+        $cTo     = \count($to);
+
+        for ($i = 0; $i < $cFrom; $i++) {
+            $prev = $current;
+
+            for ($j = 0; $j < $cTo; $j++) {
+                if ($from[$i] === $to[$j]) {
+                    $current[$j + 1] = $prev[$j] + 1;
+                } else {
+                    $current[$j + 1] = \max($current[$j], $prev[$j + 1]);
+                }
+            }
+        }
+
+        return $current;
+    }
+}

vendor/sebastian/diff/src/LCS/TimeEfficientLongestCommonSubsequenceImplementation.php

@@ -0,0 +1,74 @@
+<?php
+/*
+ * This file is part of sebastian/diff.
+ *
+ * (c) Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace SebastianBergmann\Diff\LCS;
+
+/**
+ * Time-efficient implementation of longest common subsequence calculation.
+ */
+class TimeEfficientImplementation implements LongestCommonSubsequence
+{
+    /**
+     * Calculates the longest common subsequence of two arrays.
+     *
+     * @param array $from
+     * @param array $to
+     *
+     * @return array
+     */
+    public function calculate(array $from, array $to)
+    {
+        $common     = array();
+        $fromLength = \count($from);
+        $toLength   = \count($to);
+        $width      = $fromLength + 1;
+        $matrix     = new \SplFixedArray($width * ($toLength + 1));
+
+        for ($i = 0; $i <= $fromLength; ++$i) {
+            $matrix[$i] = 0;
+        }
+
+        for ($j = 0; $j <= $toLength; ++$j) {
+            $matrix[$j * $width] = 0;
+        }
+
+        for ($i = 1; $i <= $fromLength; ++$i) {
+            for ($j = 1; $j <= $toLength; ++$j) {
+                $o          = ($j * $width) + $i;
+                $matrix[$o] = \max(
+                    $matrix[$o - 1],
+                    $matrix[$o - $width],
+                    $from[$i - 1] === $to[$j - 1] ? $matrix[$o - $width - 1] + 1 : 0
+                );
+            }
+        }
+
+        $i = $fromLength;
+        $j = $toLength;
+
+        while ($i > 0 && $j > 0) {
+            if ($from[$i - 1] === $to[$j - 1]) {
+                $common[] = $from[$i - 1];
+                --$i;
+                --$j;
+            } else {
+                $o = ($j * $width) + $i;
+
+                if ($matrix[$o - $width] > $matrix[$o - 1]) {
+                    --$j;
+                } else {
+                    --$i;
+                }
+            }
+        }
+
+        return \array_reverse($common);
+    }
+}