bzrlib.lockable_files.LockableFiles : API documentation

Object representing a set of related files locked within the same scope.

This coordinates access to the lock along with providing a transaction.

LockableFiles manage a lock count and can be locked repeatedly by a single caller. (The underlying lock implementation generally does not support this.)

Instances of this class are often called control_files.

This class is now deprecated; code should move to using the Transport directly for file operations and using the lock or CountedLock for locking.

Instance Variables	_lock	The real underlying lock (e.g. a LockDir)
	_lock_count	If _lock_mode is true, a positive count of the number of times the lock has been taken (and not yet released) by this process, through this particular object instance.
	_lock_mode	None, or 'r' or 'w'

Method	__init__	Create a LockableFiles group
Method	create_lock	Create the lock.
Method	__repr__	Undocumented
Method	__str__	Undocumented
Method	break_lock	Break the lock of this lockable files group if it is held.
Method	leave_in_place	Set this LockableFiles to not clear the physical lock on unlock.
Method	dont_leave_in_place	Set this LockableFiles to clear the physical lock on unlock.
Method	lock_write	Lock this group of files for writing.
Method	lock_read	Undocumented
Method	unlock	Undocumented
Method	is_locked	Return true if this LockableFiles group is locked
Method	get_physical_lock_status	Return physical lock status.
Method	get_transaction	Return the current active transaction.
Method	_escape	DEPRECATED: Do not use outside this class
Method	_find_modes	Determine the appropriate modes for files and directories.
Method	_set_read_transaction	Setup a read transaction.
Method	_set_write_transaction	Setup a write transaction.
Method	_set_transaction	Set a new active transaction.
Method	_finish_transaction	Exit the current transaction.

def __init__(self, transport, lock_name, lock_class):

overridden in bzrlib.remote.RemoteBranchLockableFiles

Create a LockableFiles group

Parameters	transport	Transport pointing to the directory holding the control files and lock.
	lock_name	Name of the lock guarding these files.
	lock_class	Class of lock strategy to use: typically either LockDir or TransportLock.

def create_lock(self):

Create the lock.

This should normally be called only when the LockableFiles directory is first created on disk.

def break_lock(self):

Break the lock of this lockable files group if it is held.

The current ui factory will be used to prompt for user conformation.

def lock_write(self, token=None):

Lock this group of files for writing.

A token should be passed in if you know that you have locked the object some other way, and need to synchronise this object's state with that fact.

Parameters	token	if this is already locked, then lock_write will fail unless the token matches the existing lock.
Returns	a token if this instance supports tokens, otherwise None.
Raises	TokenLockingNotSupported	when a token is given but this instance doesn't support using token locks.
	MismatchedToken	if the specified token doesn't match the token of the existing lock.

def get_physical_lock_status(self):

Return physical lock status.

Returns true if a lock is held on the transport. If no lock is held, or the underlying locking mechanism does not support querying lock status, false is returned.

def get_transaction(self):

Return the current active transaction.

If no transaction is active, this returns a passthrough object for which all data is immediately flushed and no caching happens.

b.l.LockableFiles(object) : class documentation