+global\CopyFileBackend::filesAreSame()

Complexity

Conditions	9
Paths	36

Size

Total Lines	41
Code Lines	24

Duplication

Lines	0
Ratio	0 %

Importance

Changes

0

<?php
	protected function filesAreSame( FileBackend $src, FileBackend $dst, $sPath, $dPath ) {
		$skipHash = $this->hasOption( 'skiphash' );
		$srcStat = $src->getFileStat( [ 'src' => $sPath ] );
		$dPathSha1 = sha1( $dPath );
		if ( $this->statCache !== null ) {
			// All dst files are already in stat cache
			$dstStat = isset( $this->statCache[$dPathSha1] )
				? $this->statCache[$dPathSha1]
				: false;
		} else {
			$dstStat = $dst->getFileStat( [ 'src' => $dPath ] );
		}
		// Initial fast checks to see if files are obviously different
		$sameFast = (
			is_array( $srcStat ) // sanity check that source exists
			&& is_array( $dstStat ) // dest exists
			&& $srcStat['size'] === $dstStat['size']
		);
		// More thorough checks against files
		if ( !$sameFast ) {
			$same = false; // no need to look farther
		} elseif ( isset( $srcStat['md5'] ) && isset( $dstStat['md5'] ) ) {
			// If MD5 was already in the stat info, just use it.
			// This is useful as many objects stores can return this in object listing,
			// so we can use it to avoid slow per-file HEADs.
			$same = ( $srcStat['md5'] === $dstStat['md5'] );
		} elseif ( $skipHash ) {
			// This mode is good for copying to a backup location or resyncing clone
			// backends in FileBackendMultiWrite (since they get writes second, they have
			// higher timestamps). However, when copying the other way, this hits loads of
			// false positives (possibly 100%) and wastes a bunch of time on GETs/PUTs.
			$same = ( $srcStat['mtime'] <= $dstStat['mtime'] );
		} else {
			// This is the slowest method which does many per-file HEADs (unless an object
			// store tracks SHA-1 in listings).
			$same = ( $src->getFileSha1Base36( [ 'src' => $sPath, 'latest' => 1 ] )
				=== $dst->getFileSha1Base36( [ 'src' => $dPath, 'latest' => 1 ] ) );
		}

		return $same;
	}
}