Wikimedia\FileBackend\FileOps\FileStatePredicates Class Reference

Helper class for tracking counterfactual file states when pre-checking file operation batches. More...

Public Member Functions
	__construct ()
	assumeFileDoesNotExist (string $path)
	Predicate that no file exists at the path.
	assumeFileExists (string $path, $size, $sha1Base36)
	Predicate that a file exists at the path.
	resolveFileExistence (string $path, $curExistenceFunc)
	Get the hypothetical existance a file given predicated and current state of files.
	resolveFileSha1Base36 (string $path, $curSha1Func)
	Get the hypothetical SHA-1 hash of a file given predicated and current state of files.
	resolveFileSize (string $path, $curSizeFunc)
	Get the hypothetical size of a file given predicated and current state of files.
	snapshot (array $paths)

Protected Attributes
const	EXISTS = 'exists'
const	SHA1 = 'sha1'
const	SIZE = 'size'

Detailed Description

Helper class for tracking counterfactual file states when pre-checking file operation batches.

The file states are represented with (existence,size,sha1) triples. When combined with the current state of files in the backend, this can be used to simulate how a batch of operations would play out as a "dry run". This is used in FileBackend::doOperations() to bail out if any failure can be predicted before modifying any data. This includes file operation batches where the same file gets modified by different operations within the batch.

Access: internal

Only for use within FileBackend

Definition at line 23 of file FileStatePredicates.php.

Constructor & Destructor Documentation

__construct()

Wikimedia\FileBackend\FileOps\FileStatePredicates::__construct

(

)

Definition at line 31 of file FileStatePredicates.php.

Member Function Documentation

assumeFileDoesNotExist()

Wikimedia\FileBackend\FileOps\FileStatePredicates::assumeFileDoesNotExist

(

string

$path

)

Predicate that no file exists at the path.

Parameters

string

$path

Storage path

Definition at line 55 of file FileStatePredicates.php.

References $path.

Referenced by Wikimedia\FileBackend\FileOps\CopyFileOp\doPrecheck(), Wikimedia\FileBackend\FileOps\DeleteFileOp\doPrecheck(), and Wikimedia\FileBackend\FileOps\MoveFileOp\doPrecheck().

assumeFileExists()

Wikimedia\FileBackend\FileOps\FileStatePredicates::assumeFileExists	(	string	$path,
			$size,
			$sha1Base36 )

Predicate that a file exists at the path.

Parameters

string	$path	Storage path
int | false | Closure	$size	File size or idempotent function yielding the size
string | Closure	$sha1Base36	File hash, or, idempotent function yielding the hash

Definition at line 42 of file FileStatePredicates.php.

References $path.

Referenced by Wikimedia\FileBackend\FileOps\CopyFileOp\doPrecheck(), Wikimedia\FileBackend\FileOps\CreateFileOp\doPrecheck(), Wikimedia\FileBackend\FileOps\DescribeFileOp\doPrecheck(), Wikimedia\FileBackend\FileOps\MoveFileOp\doPrecheck(), and Wikimedia\FileBackend\FileOps\StoreFileOp\doPrecheck().

resolveFileExistence()

Wikimedia\FileBackend\FileOps\FileStatePredicates::resolveFileExistence	(	string	$path,
			$curExistenceFunc )

Get the hypothetical existance a file given predicated and current state of files.

Parameters

string	$path	Storage path
Closure	$curExistenceFunc	Function to compute the current existence for a given path

Returns

bool|null Whether the file exists; null on error

Definition at line 70 of file FileStatePredicates.php.

References $path.

Referenced by Wikimedia\FileBackend\FileOps\FileOp\resolveFileExistence().

resolveFileSha1Base36()

Wikimedia\FileBackend\FileOps\FileStatePredicates::resolveFileSha1Base36	(	string	$path,
			$curSha1Func )

Get the hypothetical SHA-1 hash of a file given predicated and current state of files.

Parameters

string	$path	Storage path
Closure	$curSha1Func	Function to compute the current SHA-1 hash for a given path

Returns

string|false Base 36 SHA-1 hash; false on error

Definition at line 92 of file FileStatePredicates.php.

References $path.

Referenced by Wikimedia\FileBackend\FileOps\FileOp\resolveFileSha1Base36().

resolveFileSize()

Wikimedia\FileBackend\FileOps\FileStatePredicates::resolveFileSize	(	string	$path,
			$curSizeFunc )

Get the hypothetical size of a file given predicated and current state of files.

Parameters

string	$path	Storage path
Closure	$curSizeFunc	Function to compute the current size for a given path

Returns

int|false Bytes; false on error

Definition at line 81 of file FileStatePredicates.php.

References $path.

Referenced by Wikimedia\FileBackend\FileOps\FileOp\resolveFileSize().

snapshot()

Wikimedia\FileBackend\FileOps\FileStatePredicates::snapshot

(

array

$paths

)

Parameters

string[]

$paths

List of storage paths

Returns

self Clone predicates limited to the given paths

Definition at line 122 of file FileStatePredicates.php.

References $path.

Referenced by Wikimedia\FileBackend\FileOps\FileOp\precheck().

Member Data Documentation

EXISTS

const Wikimedia\FileBackend\FileOps\FileStatePredicates::EXISTS = 'exists'

protected

Definition at line 24 of file FileStatePredicates.php.

SHA1

const Wikimedia\FileBackend\FileOps\FileStatePredicates::SHA1 = 'sha1'

protected

Definition at line 26 of file FileStatePredicates.php.

SIZE

const Wikimedia\FileBackend\FileOps\FileStatePredicates::SIZE = 'size'

protected

Definition at line 25 of file FileStatePredicates.php.

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The documentation for this class was generated from the following file:

• includes/libs/FileBackend/FileOps/FileStatePredicates.php