comparison vendor/sebastian/diff/src/Differ.php @ 0:4c8ae668cc8c

Initial import (non-working)
author Chris Cannam
date Wed, 29 Nov 2017 16:09:58 +0000
parents
children 7a779792577d
comparison
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-1:000000000000 0:4c8ae668cc8c
1 <?php
2 /*
3 * This file is part of the Diff package.
4 *
5 * (c) Sebastian Bergmann <sebastian@phpunit.de>
6 *
7 * For the full copyright and license information, please view the LICENSE
8 * file that was distributed with this source code.
9 */
10
11 namespace SebastianBergmann\Diff;
12
13 use SebastianBergmann\Diff\LCS\LongestCommonSubsequence;
14 use SebastianBergmann\Diff\LCS\TimeEfficientImplementation;
15 use SebastianBergmann\Diff\LCS\MemoryEfficientImplementation;
16
17 /**
18 * Diff implementation.
19 */
20 class Differ
21 {
22 /**
23 * @var string
24 */
25 private $header;
26
27 /**
28 * @var bool
29 */
30 private $showNonDiffLines;
31
32 /**
33 * @param string $header
34 */
35 public function __construct($header = "--- Original\n+++ New\n", $showNonDiffLines = true)
36 {
37 $this->header = $header;
38 $this->showNonDiffLines = $showNonDiffLines;
39 }
40
41 /**
42 * Returns the diff between two arrays or strings as string.
43 *
44 * @param array|string $from
45 * @param array|string $to
46 * @param LongestCommonSubsequence $lcs
47 *
48 * @return string
49 */
50 public function diff($from, $to, LongestCommonSubsequence $lcs = null)
51 {
52 if (!is_array($from) && !is_string($from)) {
53 $from = (string) $from;
54 }
55
56 if (!is_array($to) && !is_string($to)) {
57 $to = (string) $to;
58 }
59
60 $buffer = $this->header;
61 $diff = $this->diffToArray($from, $to, $lcs);
62
63 $inOld = false;
64 $i = 0;
65 $old = array();
66
67 foreach ($diff as $line) {
68 if ($line[1] === 0 /* OLD */) {
69 if ($inOld === false) {
70 $inOld = $i;
71 }
72 } elseif ($inOld !== false) {
73 if (($i - $inOld) > 5) {
74 $old[$inOld] = $i - 1;
75 }
76
77 $inOld = false;
78 }
79
80 ++$i;
81 }
82
83 $start = isset($old[0]) ? $old[0] : 0;
84 $end = count($diff);
85
86 if ($tmp = array_search($end, $old)) {
87 $end = $tmp;
88 }
89
90 $newChunk = true;
91
92 for ($i = $start; $i < $end; $i++) {
93 if (isset($old[$i])) {
94 $buffer .= "\n";
95 $newChunk = true;
96 $i = $old[$i];
97 }
98
99 if ($newChunk) {
100 if ($this->showNonDiffLines === true) {
101 $buffer .= "@@ @@\n";
102 }
103 $newChunk = false;
104 }
105
106 if ($diff[$i][1] === 1 /* ADDED */) {
107 $buffer .= '+' . $diff[$i][0] . "\n";
108 } elseif ($diff[$i][1] === 2 /* REMOVED */) {
109 $buffer .= '-' . $diff[$i][0] . "\n";
110 } elseif ($this->showNonDiffLines === true) {
111 $buffer .= ' ' . $diff[$i][0] . "\n";
112 }
113 }
114
115 return $buffer;
116 }
117
118 /**
119 * Returns the diff between two arrays or strings as array.
120 *
121 * Each array element contains two elements:
122 * - [0] => string $token
123 * - [1] => 2|1|0
124 *
125 * - 2: REMOVED: $token was removed from $from
126 * - 1: ADDED: $token was added to $from
127 * - 0: OLD: $token is not changed in $to
128 *
129 * @param array|string $from
130 * @param array|string $to
131 * @param LongestCommonSubsequence $lcs
132 *
133 * @return array
134 */
135 public function diffToArray($from, $to, LongestCommonSubsequence $lcs = null)
136 {
137 preg_match_all('(\r\n|\r|\n)', $from, $fromMatches);
138 preg_match_all('(\r\n|\r|\n)', $to, $toMatches);
139
140 if (is_string($from)) {
141 $from = preg_split('(\r\n|\r|\n)', $from);
142 }
143
144 if (is_string($to)) {
145 $to = preg_split('(\r\n|\r|\n)', $to);
146 }
147
148 $start = array();
149 $end = array();
150 $fromLength = count($from);
151 $toLength = count($to);
152 $length = min($fromLength, $toLength);
153
154 for ($i = 0; $i < $length; ++$i) {
155 if ($from[$i] === $to[$i]) {
156 $start[] = $from[$i];
157 unset($from[$i], $to[$i]);
158 } else {
159 break;
160 }
161 }
162
163 $length -= $i;
164
165 for ($i = 1; $i < $length; ++$i) {
166 if ($from[$fromLength - $i] === $to[$toLength - $i]) {
167 array_unshift($end, $from[$fromLength - $i]);
168 unset($from[$fromLength - $i], $to[$toLength - $i]);
169 } else {
170 break;
171 }
172 }
173
174 if ($lcs === null) {
175 $lcs = $this->selectLcsImplementation($from, $to);
176 }
177
178 $common = $lcs->calculate(array_values($from), array_values($to));
179 $diff = array();
180
181 if (isset($fromMatches[0]) && $toMatches[0] &&
182 count($fromMatches[0]) === count($toMatches[0]) &&
183 $fromMatches[0] !== $toMatches[0]) {
184 $diff[] = array(
185 '#Warning: Strings contain different line endings!', 0
186 );
187 }
188
189 foreach ($start as $token) {
190 $diff[] = array($token, 0 /* OLD */);
191 }
192
193 reset($from);
194 reset($to);
195
196 foreach ($common as $token) {
197 while ((($fromToken = reset($from)) !== $token)) {
198 $diff[] = array(array_shift($from), 2 /* REMOVED */);
199 }
200
201 while ((($toToken = reset($to)) !== $token)) {
202 $diff[] = array(array_shift($to), 1 /* ADDED */);
203 }
204
205 $diff[] = array($token, 0 /* OLD */);
206
207 array_shift($from);
208 array_shift($to);
209 }
210
211 while (($token = array_shift($from)) !== null) {
212 $diff[] = array($token, 2 /* REMOVED */);
213 }
214
215 while (($token = array_shift($to)) !== null) {
216 $diff[] = array($token, 1 /* ADDED */);
217 }
218
219 foreach ($end as $token) {
220 $diff[] = array($token, 0 /* OLD */);
221 }
222
223 return $diff;
224 }
225
226 /**
227 * @param array $from
228 * @param array $to
229 *
230 * @return LongestCommonSubsequence
231 */
232 private function selectLcsImplementation(array $from, array $to)
233 {
234 // We do not want to use the time-efficient implementation if its memory
235 // footprint will probably exceed this value. Note that the footprint
236 // calculation is only an estimation for the matrix and the LCS method
237 // will typically allocate a bit more memory than this.
238 $memoryLimit = 100 * 1024 * 1024;
239
240 if ($this->calculateEstimatedFootprint($from, $to) > $memoryLimit) {
241 return new MemoryEfficientImplementation;
242 }
243
244 return new TimeEfficientImplementation;
245 }
246
247 /**
248 * Calculates the estimated memory footprint for the DP-based method.
249 *
250 * @param array $from
251 * @param array $to
252 *
253 * @return int
254 */
255 private function calculateEstimatedFootprint(array $from, array $to)
256 {
257 $itemSize = PHP_INT_SIZE == 4 ? 76 : 144;
258
259 return $itemSize * pow(min(count($from), count($to)), 2);
260 }
261 }