Differential D20187 Diff 48214 src/infrastructure/diff/PhabricatorDifferenceEngine.php

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src/infrastructure/diff/PhabricatorDifferenceEngine.php

<?php		<?php

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


private $oldName;		private $oldName;
private $newName;		private $newName;
		private $normalize;


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


/**		/**
* Set the name to identify the old file with. Primarily cosmetic.		* Set the name to identify the old file with. Primarily cosmetic.
*		*
Show All 15 Lines	/* -( Configuring the Engine )--------------------------------------------- */
* @task config		* @task config
*/		*/
public function setNewName($new_name) {		public function setNewName($new_name) {
$this->newName = $new_name;		$this->newName = $new_name;
return $this;		return $this;
}		}


		public function setNormalize($normalize) {
		$this->normalize = $normalize;
		return $this;
		}

		public function getNormalize() {
		return $this->normalize;
		}


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


/**		/**
* Generate a raw diff from two raw files. This is a lower-level API than		* Generate a raw diff from two raw files. This is a lower-level API than
* @{method:generateChangesetFromFileContent}, but may be useful if you need		* @{method:generateChangesetFromFileContent}, but may be useful if you need
* to use a custom parser configuration, as with Diffusion.		* to use a custom parser configuration, as with Diffusion.
*		*
Show All 12 Lines	public function generateRawDiffFromFileContent($old, $new) {
$old_name = nonempty($this->oldName, '/dev/universe').' 9999-99-99';		$old_name = nonempty($this->oldName, '/dev/universe').' 9999-99-99';
$new_name = nonempty($this->newName, '/dev/universe').' 9999-99-99';		$new_name = nonempty($this->newName, '/dev/universe').' 9999-99-99';

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

		$normalize = $this->getNormalize();
		if ($normalize) {
		$old = $this->normalizeFile($old);
		$new = $this->normalizeFile($new);
		}

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

Filesystem::writeFile($old_tmp, $old);		Filesystem::writeFile($old_tmp, $old);
Filesystem::writeFile($new_tmp, $new);		Filesystem::writeFile($new_tmp, $new);
list($err, $diff) = exec_manual(		list($err, $diff) = exec_manual(
'diff %Ls %s %s',		'diff %Ls %s %s',
$options,		$options,
▲ Show 20 Lines • Show All 42 Lines • ▼ Show 20 Lines	public function generateChangesetFromFileContent($old, $new) {
$diff = $this->generateRawDiffFromFileContent($old, $new);		$diff = $this->generateRawDiffFromFileContent($old, $new);

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

		private function normalizeFile($corpus) {
		// We can freely apply any other transformations we want to here: we have
		// no constraints on what we need to preserve. If we normalize every line
		// to "cat", the diff will still work, the alignment of the "-" / "+"
		// lines will just be very hard to read.

		// In general, we'll make the diff better if we normalize two lines that
		// humans think are the same.

		// We'll make the diff worse if we normalize two lines that humans think
		// are different.


		// Strip all whitespace present anywhere in the diff, since humans never
		// consider whitespace changes to alter the line into a "different line"
		// even when they're semantic (e.g., in a string constant). This covers
		// indentation changes, trailing whitepspace, and formatting changes
		// like "+/-".
		$corpus = preg_replace('/[ \t]/', '', $corpus);

		return $corpus;
		}

}		}