/// <summary>
///
/// </summary>
/// <param name="fileToLock"></param>
/// <param name="lockKind"></param>
/// <returns></returns>
/// <exception cref="CannotAcquireLockException"></exception>
/// <exception cref="ArgumentNullException"></exception>
/// <exception cref="ArgumentException"></exception>
public Guid AcquireLock(NodeWithSurroundingsResolvingResult <FileNode> fileToLock, LockKind lockKind)
{
if (fileToLock == null)
{
throw new ArgumentNullException("fileToLock");
}
lock (_operationExecutionCriticalSection)
{
var idOfFileToLock = fileToLock.ResolvedNode.Id;
FileLockable fileLockable;
Guid newLockId;
if (_fileIdsToLocks.ContainsKey(idOfFileToLock))
{
fileLockable = _fileIdsToLocks[idOfFileToLock];
}
else
{
fileLockable = new FileLockable(fileToLock.ResolvedNode, fileToLock.FoldersPassedWhileResolving);
_fileIdsToLocks[idOfFileToLock] = fileLockable;
}
newLockId = LockTheFile(fileLockable, lockKind);
ReportToAllFolderNodesLockableThatTheyHaveANewLock(fileToLock, fileLockable, newLockId);
_lockIdsToLocks[newLockId] = fileLockable;
return(newLockId);
}
}
/// <summary>
///
/// </summary>
/// <param name="fileLockable"></param>
/// <param name="lockKind"></param>
/// <returns></returns>
/// <exception cref="ArgumentException"></exception>
/// <exception cref="CannotAcquireLockException"></exception>
private static Guid LockTheFile(FileLockable fileLockable, LockKind lockKind)
{
Guid newLockId;
if (lockKind == LockKind.Read)
{
newLockId = fileLockable.LockForReading();
}
else if (lockKind == LockKind.Write)
{
newLockId = fileLockable.LockForWriting();
}
else
{
throw new ArgumentException("Вид блокировки {0} не поддерживается.".FormatWith(lockKind.ToString()));
}
return(newLockId);
}
/// <summary>
///
/// </summary>
/// <param name="associatedFileLock"></param>
/// <param name="lockId"></param>
/// <exception cref="ArgumentNullException"></exception>
/// <exception cref="LockAlreadyHeldException"></exception>
/// <exception cref="ArgumentException"></exception>
public void AddLock(FileLockable associatedFileLock, Guid lockId)
{
if (associatedFileLock == null)
{
throw new ArgumentNullException("associatedFileLock");
}
MethodArgumentValidator.ThrowIfIsDefault <Guid>(lockId, "lockId");
if (_idsOfAssociatedFileLocks.Contains(lockId))
{
throw new LockAlreadyHeldException("Блокировка с идентификатором {0} уже привязана к блокировке папки.".FormatWith(associatedFileLock.FileId));
}
if (!associatedFileLock.IdsOfParentFoldersUpToRoot.Contains(_idOfLockedNode))
{
throw new ArgumentException("Папка (идентификатор - {0}) не содержится в списке зависимых для файловой блокировки, которую вы хотите связать с блокировкой этой папки.".FormatWith(_idOfLockedNode));
}
_idsOfAssociatedFileLocks.Add(lockId);
}
/// <summary>
///
/// </summary>
/// <param name="lockId"></param>
/// <exception cref="ArgumentException"></exception>
/// <exception cref="LockNotFoundException"></exception>
public void ReleaseLock(Guid lockId)
{
MethodArgumentValidator.ThrowIfIsDefault <Guid>(lockId, "lockId");
lock (_operationExecutionCriticalSection)
{
if (_lockIdsToLocks.ContainsKey(lockId))
{
FileLockable fileLockable = _lockIdsToLocks[lockId];
fileLockable.ReleaseLock(lockId);
if (fileLockable.IsFreeForTaking)
{
_fileIdsToLocks.Remove(fileLockable.FileId); // все: файл разблокирован
}
// еще и все ветки отпускаем - если их больше ничто не держит.
foreach (Guid nodeId in fileLockable.IdsOfParentFoldersUpToRoot)
{
FolderNodeLockable folderNodeLockable = _nodeIdsToLocks[nodeId];
folderNodeLockable.ReleaseLock(lockId);
if (!folderNodeLockable.IsLocked)
{
_nodeIdsToLocks.Remove(folderNodeLockable.IdOfLockedNode);
}
}
_lockIdsToLocks.Remove(lockId);
}
else
{
throw new LockNotFoundException("Не найдена блокировка с идентификатором {0}".FormatWith(lockId));
}
}
}
private void ReportToAllFolderNodesLockableThatTheyHaveANewLock(NodeWithSurroundingsResolvingResult <FileNode> fileToLock, FileLockable fileLockable, Guid newLockId)
{
foreach (FolderNode node in fileToLock.FoldersPassedWhileResolving)
{
FolderNodeLockable folderNodeLockableToAdjust;
if (_nodeIdsToLocks.ContainsKey(node.Id))
{
folderNodeLockableToAdjust = _nodeIdsToLocks[node.Id];
}
else
{
folderNodeLockableToAdjust = new FolderNodeLockable(node);
_nodeIdsToLocks[node.Id] = folderNodeLockableToAdjust;
}
folderNodeLockableToAdjust.AddLock(fileLockable, newLockId);
}
}
