C# IFdbTransaction.Annotate方法代码示例

		private void ClearTask(IFdbTransaction tr, Slice taskId)
		{
			tr.Annotate("Deleting task {0}", taskId.ToAsciiOrHexaString());

			// clear all metadata about the task
			tr.ClearRange(FdbKeyRange.StartsWith(this.TaskStore.Pack(taskId)));
			// decrement pending number of tasks
			this.Counters.Decrement(tr, COUNTER_PENDING_TASKS);
		}

		private void StoreTask(IFdbTransaction tr, Slice taskId, DateTime scheduledUtc, Slice taskBody)
		{
			tr.Annotate("Writing task {0}", taskId.ToAsciiOrHexaString());

			var prefix = this.TaskStore.Partition(taskId);

			// store task body and timestamp
			tr.Set(prefix.Key, taskBody);
			tr.Set(prefix.Pack(TASK_META_SCHEDULED), Slice.FromInt64(scheduledUtc.Ticks));
			// increment total and pending number of tasks
			this.Counters.Increment(tr, COUNTER_TOTAL_TASKS);
			this.Counters.Increment(tr, COUNTER_PENDING_TASKS);
		}

		/// <summary>Remove an existing node from its parents</summary>
		/// <returns>True if the parent node was found, otherwise false</returns>
		private async Task<bool> RemoveFromParent(IFdbTransaction tr, IFdbTuple path)
		{
			Contract.Requires(tr != null && path != null);

			var parent = await FindAsync(tr, path.Substring(0, path.Count - 1)).ConfigureAwait(false);
			if (parent.Exists)
			{
				if (FdbDirectoryLayer.AnnotateTransactions) tr.Annotate("Removing path {0} from its parent folder at {1}", path, parent.Subspace.Key);
				tr.Clear(GetSubDirKey(parent.Subspace, path.Get<string>(-1)));
				return true;
			}
			return false;
		}

		/// <summary>Resursively remove a node (including the content), all its children</summary>
		private async Task RemoveRecursive(IFdbTransaction tr, FdbSubspace node)
		{
			Contract.Requires(tr != null && node != null);

			//note: we could use Task.WhenAll to remove the children, but there is a risk of task explosion if the subtree is very large...
			await SubdirNamesAndNodes(tr, node).ForEachAsync((kvp) => RemoveRecursive(tr, kvp.Value)).ConfigureAwait(false);

			// remove ALL the contents
			if (FdbDirectoryLayer.AnnotateTransactions) tr.Annotate("Removing all content located under {0}", node.Key);
			tr.ClearRange(FdbKeyRange.StartsWith(ContentsOfNode(node, FdbTuple.Empty, Slice.Empty).Key));
			// and all the metadata for this folder
			if (FdbDirectoryLayer.AnnotateTransactions) tr.Annotate("Removing all metadata for folder under {0}", node.Key);
			tr.ClearRange(node.ToRange());
		}

		internal async Task<FdbDirectorySubspace> CreateOrOpenInternalAsync(IFdbReadOnlyTransaction readTrans, IFdbTransaction trans, [NotNull] IFdbTuple path, Slice layer, Slice prefix, bool allowCreate, bool allowOpen, bool throwOnError)
		{
			Contract.Requires(readTrans != null || trans != null, "Need at least one transaction");
			Contract.Requires(path != null, "Path must be specified");
			Contract.Requires(readTrans == null || trans == null || object.ReferenceEquals(readTrans, trans), "The write transaction should be the same as the read transaction");

			if (path.Count == 0)
			{ // Root directory contains node metadata and so may not be opened.
				throw new InvalidOperationException("The root directory may not be opened.");
			}

			// to open an existing directory, we only need the read transaction
			// if none was specified, we can use the writeable transaction
			if (readTrans == null) readTrans = trans;

			await CheckReadVersionAsync(readTrans).ConfigureAwait(false);

			if (prefix.HasValue && this.Path.Count > 0)
				throw new InvalidOperationException("Cannot specify a prefix in a partition.");

			var existingNode = await FindAsync(readTrans, path).ConfigureAwait(false);

			if (existingNode.Exists)
			{
				if (existingNode.IsInPartition(false))
				{
					var subpath = existingNode.PartitionSubPath;
					var dl = GetPartitionForNode(existingNode).DirectoryLayer;
					return await dl.CreateOrOpenInternalAsync(readTrans, trans, subpath, layer, prefix, allowCreate, allowOpen, throwOnError).ConfigureAwait(false);
				}

				if (!allowOpen)
				{
					if (throwOnError) throw new InvalidOperationException(string.Format("The directory {0} already exists.", path));
					return null;
				}

				if (layer.IsPresent && layer != existingNode.Layer)
				{
					throw new InvalidOperationException(String.Format("The directory {0} was created with incompatible layer {1} instead of expected {2}.", path, layer.ToAsciiOrHexaString(), existingNode.Layer.ToAsciiOrHexaString()));
				}
				return ContentsOfNode(existingNode.Subspace, path, existingNode.Layer);
			}

			if (!allowCreate)
			{
				if (throwOnError) throw new InvalidOperationException(string.Format("The directory {0} does not exist.", path));
				return null;
			}

			// from there, we actually do need a wrtieable transaction
			if (trans == null) throw new InvalidOperationException("A writeable transaction is needed to create a new directory");

			await CheckWriteVersionAsync(trans).ConfigureAwait(false);

			if (prefix == null)
			{ // automatically allocate a new prefix inside the ContentSubspace
				long id = await this.Allocator.AllocateAsync(trans).ConfigureAwait(false);
				prefix = this.ContentSubspace.Pack(id);

				// ensure that there is no data already present under this prefix
				if (FdbDirectoryLayer.AnnotateTransactions) trans.Annotate("Ensure that there is no data already present under prefix {0}", prefix);
				if (await trans.GetRange(FdbKeyRange.StartsWith(prefix)).AnyAsync().ConfigureAwait(false))
				{
					throw new InvalidOperationException(String.Format("The database has keys stored at the prefix chosen by the automatic prefix allocator: {0}", prefix.ToAsciiOrHexaString()));
				}

				// ensure that the prefix has not already been allocated
				if (FdbDirectoryLayer.AnnotateTransactions) trans.Annotate("Ensure that the prefix {0} has not already been allocated", prefix);
				if (!(await IsPrefixFree(trans.Snapshot, prefix).ConfigureAwait(false)))
				{
					throw new InvalidOperationException("The directory layer has manually allocated prefixes that conflict with the automatic prefix allocator.");
				}
			}
			else
			{
				if (FdbDirectoryLayer.AnnotateTransactions) trans.Annotate("Ensure that the prefix {0} hasn't already been allocated", prefix);
				// ensure that the prefix has not already been allocated
				if (!(await IsPrefixFree(trans, prefix).ConfigureAwait(false)))
				{
					throw new InvalidOperationException("The given prefix is already in use.");
				}
			}

			// we need to recursively create any missing parents
			FdbSubspace parentNode;
			if (path.Count > 1)
			{
				var parentSubspace = await CreateOrOpenInternalAsync(readTrans, trans, path.Substring(0, path.Count - 1), Slice.Nil, Slice.Nil, true, true, true).ConfigureAwait(false);
				parentNode = NodeWithPrefix(parentSubspace.Key);
			}
			else
			{
				parentNode = this.RootNode;
			}
			if (parentNode == null) throw new InvalidOperationException(string.Format("The parent directory of {0} doesn't exist.", path));

			// initialize the metadata for this new directory
			var node = NodeWithPrefix(prefix);
			if (FdbDirectoryLayer.AnnotateTransactions) trans.Annotate("Registering the new prefix {0} into the folder sub-tree", prefix);
//.........这里部分代码省略.........