PhabricatorDifferenceEngine.php
315870d56a33stable

PhabricatorDifferenceEngine.php
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			<?php

			/*
			* Copyright 2012 Facebook, Inc.
			*
			* Licensed under the Apache License, Version 2.0 (the "License");
			* you may not use this file except in compliance with the License.
			* You may obtain a copy of the License at
			*
			* http://www.apache.org/licenses/LICENSE-2.0
			*
			* Unless required by applicable law or agreed to in writing, software
			* distributed under the License is distributed on an "AS IS" BASIS,
			* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
			* See the License for the specific language governing permissions and
			* limitations under the License.
			*/

			/**
			* Utility class which encapsulates some shared behavior between different
			* applications which render diffs.
			*
			* @task config Configuring the Engine
			* @task diff Generating Diffs
			*/
			final class PhabricatorDifferenceEngine {


			private $ignoreWhitespace;
			private $oldName;
			private $newName;


			/* -( Configuring the Engine )--------------------------------------------- */


			/**
			* If true, ignore whitespace when computing differences.
			*
			* @param bool Ignore whitespace?
			* @return this
			* @task config
			*/
			public function setIgnoreWhitespace($ignore_whitespace) {
			$this->ignoreWhitespace = $ignore_whitespace;
			return $this;
			}


			/**
			* Set the name to identify the old file with. Primarily cosmetic.
			*
			* @param string Old file name.
			* @return this
			* @task config
			*/
			public function setOldName($old_name) {
			$this->oldName = $old_name;
			return $this;
			}


			/**
			* Set the name to identify the new file with. Primarily cosmetic.
			*
			* @param string New file name.
			* @return this
			* @task config
			*/
			public function setNewName($new_name) {
			$this->newName = $new_name;
			return $this;
			}


			/* -( Generating Diffs )--------------------------------------------------- */


			/**
			* Generate a raw diff from two raw files. This is a lower-level API than
			* @{method:generateChangesetFromFileContent}, but may be useful if you need
			* to use a custom parser configuration, as with Diffusion.
			*
			* @param string Entire previous file content.
			* @param string Entire current file content.
			* @return string Raw diff between the two files.
			* @task diff
			*/
			public function generateRawDiffFromFileContent($old, $new) {

			$options = array();
			if ($this->ignoreWhitespace) {
			$options[] = '-bw';
			}

			// Generate diffs with full context.
			$options[] = '-U65535';

			$old_name = nonempty($this->oldName, '/dev/universe').' 9999-99-99';
			$new_name = nonempty($this->newName, '/dev/universe').' 9999-99-99';

			$options[] = '-L';
			$options[] = $old_name;
			$options[] = '-L';
			$options[] = $new_name;

			$old_tmp = new TempFile();
			$new_tmp = new TempFile();

			Filesystem::writeFile($old_tmp, $old);
			Filesystem::writeFile($new_tmp, $new);
			list($err, $diff) = exec_manual(
			'/usr/bin/diff %Ls %s %s',
			$options,
			$old_tmp,
			$new_tmp);

			if (!$err) {
			// This indicates that the two files are the same (or, possibly, the
			// same modulo whitespace differences, which is why we can't do this
			// check trivially before running `diff`). Build a synthetic, changeless
			// diff so that we can still render the raw, unchanged file instead of
			// being forced to just say "this file didn't change" since we don't have
			// the content.

			$entire_file = explode("\n", $old);
			foreach ($entire_file as $k => $line) {
			$entire_file[$k] = ' '.$line;
			}

			$len = count($entire_file);
			$entire_file = implode("\n", $entire_file);

			// TODO: If both files were identical but missing newlines, we probably
			// get this wrong. Unclear if it ever matters.

			// This is a bit hacky but the diff parser can handle it.
			$diff = "--- {$old_name}\n".
			"+++ {$new_name}\n".
			"@@ -1,{$len} +1,{$len} @@\n".
			$entire_file."\n";
			} else {
			if ($this->ignoreWhitespace) {

			// Under "-bw", `diff` is inconsistent about emitting "\ No newline
			// at end of file". For instance, a long file with a change in the
			// middle will emit a contextless "\ No newline..." at the end if a
			// newline is removed, but not if one is added. A file with a change
			// at the end will emit the "old" "\ No newline..." block only, even
			// if the newline was not removed. Since we're ostensibly ignoring
			// whitespace changes, just drop these lines if they appear anywhere
			// in the diff.

			$lines = explode("\n", rtrim($diff));
			foreach ($lines as $key => $line) {
			if (isset($line[0]) && $line[0] == '\\') {
			unset($lines[$key]);
			}
			}
			$diff = implode("\n", $lines);
			}
			}

			return $diff;
			}


			/**
			* Generate an @{class:DifferentialChangeset} from two raw files. This is
			* principally useful because you can feed the output to
			* @{class:DifferentialChangesetParser} in order to render it.
			*
			* @param string Entire previous file content.
			* @param string Entire current file content.
			* @return @{class:DifferentialChangeset} Synthetic changeset.
			* @task diff
			*/
			public function generateChangesetFromFileContent($old, $new) {
			$diff = $this->generateRawDiffFromFileContent($old, $new);

			$changes = id(new ArcanistDiffParser())->parseDiff($diff);
			$diff = DifferentialDiff::newFromRawChanges($changes);
			return head($diff->getChangesets());
			}

			}

phab/src/infrastructure/diff/engine/PhabricatorDifferenceEngine.php315870d56a33stable

PhabricatorDifferenceEngine.phpView Options

phab/src/infrastructure/diff/engine/PhabricatorDifferenceEngine.php
315870d56a33stable

PhabricatorDifferenceEngine.php
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