public async Task <BlobReceipt> TryReadAsync(CloudBlockBlob blob, CancellationToken cancellationToken)
        {
            if (!await blob.TryFetchAttributesAsync(cancellationToken))
            {
                return(null);
            }

            return(BlobReceipt.FromMetadata(blob.Metadata));
        }
        public async Task <BlobReceipt> TryReadAsync(BlockBlobClient blob, CancellationToken cancellationToken)
        {
            var properties = await blob.FetchPropertiesOrNullIfNotExistAsync(cancellationToken).ConfigureAwait(false);

            if (properties == null)
            {
                return(null);
            }

            return(BlobReceipt.FromMetadata(properties.Metadata));
        }
예제 #3
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        public async Task <FunctionResult> ExecuteAsync(IStorageBlob value, CancellationToken cancellationToken)
        {
            // Avoid unnecessary network calls for non-matches. First, check to see if the blob matches this trigger.
            IReadOnlyDictionary <string, object> bindingData = _input.CreateBindingData(value.ToBlobPath());

            if (bindingData == null)
            {
                // Blob is not a match for this trigger.
                return(new FunctionResult(true));
            }

            // Next, check to see if the blob currently exists (and, if so, what the current ETag is).
            string possibleETag = await _eTagReader.GetETagAsync(value, cancellationToken);

            if (possibleETag == null)
            {
                // If the blob doesn't exist and have an ETag, don't trigger on it.
                return(new FunctionResult(true));
            }

            IStorageBlockBlob receiptBlob = _receiptManager.CreateReference(_hostId, _functionId, value.Container.Name,
                                                                            value.Name, possibleETag);

            // Check for the completed receipt. If it's already there, noop.
            BlobReceipt unleasedReceipt = await _receiptManager.TryReadAsync(receiptBlob, cancellationToken);

            if (unleasedReceipt != null && unleasedReceipt.IsCompleted)
            {
                return(new FunctionResult(true));
            }
            else if (unleasedReceipt == null)
            {
                // Try to create (if not exists) an incomplete receipt.
                if (!await _receiptManager.TryCreateAsync(receiptBlob, cancellationToken))
                {
                    // Someone else just created the receipt; wait to try to trigger until later.
                    // Alternatively, we could just ignore the return result and see who wins the race to acquire the
                    // lease.
                    return(new FunctionResult(false));
                }
            }

            string leaseId = await _receiptManager.TryAcquireLeaseAsync(receiptBlob, cancellationToken);

            if (leaseId == null)
            {
                // If someone else owns the lease and just took over this receipt or deleted it;
                // wait to try to trigger until later.
                return(new FunctionResult(false));
            }

            ExceptionDispatchInfo exceptionInfo;

            try
            {
                // Check again for the completed receipt. If it's already there, noop.
                BlobReceipt receipt = await _receiptManager.TryReadAsync(receiptBlob, cancellationToken);

                Debug.Assert(receipt != null); // We have a (30 second) lease on the blob; it should never disappear on us.

                if (receipt.IsCompleted)
                {
                    await _receiptManager.ReleaseLeaseAsync(receiptBlob, leaseId, cancellationToken);

                    return(new FunctionResult(true));
                }

                // We've successfully acquired a lease to enqueue the message for this blob trigger. Enqueue the message,
                // complete the receipt and release the lease.

                // Enqueue a message: function ID + blob path + ETag
                BlobTriggerMessage message = new BlobTriggerMessage
                {
                    FunctionId    = _functionId,
                    BlobType      = value.BlobType,
                    ContainerName = value.Container.Name,
                    BlobName      = value.Name,
                    ETag          = possibleETag
                };
                await _queueWriter.EnqueueAsync(message, cancellationToken);

                // Complete the receipt & release the lease
                await _receiptManager.MarkCompletedAsync(receiptBlob, leaseId, cancellationToken);

                await _receiptManager.ReleaseLeaseAsync(receiptBlob, leaseId, cancellationToken);

                return(new FunctionResult(true));
            }
            catch (Exception exception)
            {
                exceptionInfo = ExceptionDispatchInfo.Capture(exception);
            }

            Debug.Assert(exceptionInfo != null);
            await _receiptManager.ReleaseLeaseAsync(receiptBlob, leaseId, cancellationToken);

            exceptionInfo.Throw();

            FunctionResult result = new FunctionResult(exceptionInfo.SourceException);

            return(result); // Keep the compiler happy; we'll never get here.
        }
        public async Task <FunctionResult> ExecuteAsync(BlobTriggerExecutorContext context, CancellationToken cancellationToken)
        {
            BlobBaseClient    value         = context.Blob.BlobClient;
            BlobTriggerSource triggerSource = context.TriggerSource;
            string            pollId        = context.PollId;

            // Avoid unnecessary network calls for non-matches. First, check to see if the blob matches this trigger.
            IReadOnlyDictionary <string, object> bindingData = _input.CreateBindingData(value.ToBlobPath());

            if (bindingData == null)
            {
                string pattern = new BlobPath(_input.ContainerNamePattern, _input.BlobNamePattern).ToString();
                Logger.BlobDoesNotMatchPattern(_logger, _functionDescriptor.LogName, value.Name, pattern, pollId, triggerSource);

                // Blob is not a match for this trigger.
                return(new FunctionResult(true));
            }

            // Next, check to see if the blob currently exists (and, if so, what the current ETag is).
            BlobProperties blobProperties = await value.FetchPropertiesOrNullIfNotExistAsync(cancellationToken).ConfigureAwait(false);

            string possibleETag = null;

            if (blobProperties != null)
            {
                possibleETag = blobProperties.ETag.ToString();
            }

            if (possibleETag == null)
            {
                Logger.BlobHasNoETag(_logger, _functionDescriptor.LogName, value.Name, pollId, triggerSource);

                // If the blob doesn't exist and have an ETag, don't trigger on it.
                return(new FunctionResult(true));
            }

            var receiptBlob = _receiptManager.CreateReference(_hostId, _functionDescriptor.Id, value.BlobContainerName,
                                                              value.Name, possibleETag);

            // Check for the completed receipt. If it's already there, noop.
            BlobReceipt unleasedReceipt = await _receiptManager.TryReadAsync(receiptBlob, cancellationToken).ConfigureAwait(false);

            if (unleasedReceipt != null && unleasedReceipt.IsCompleted)
            {
                Logger.BlobAlreadyProcessed(_logger, _functionDescriptor.LogName, value.Name, possibleETag, pollId, triggerSource);

                return(new FunctionResult(true));
            }
            else if (unleasedReceipt == null)
            {
                // Try to create (if not exists) an incomplete receipt.
                if (!await _receiptManager.TryCreateAsync(receiptBlob, cancellationToken).ConfigureAwait(false))
                {
                    // Someone else just created the receipt; wait to try to trigger until later.
                    // Alternatively, we could just ignore the return result and see who wins the race to acquire the
                    // lease.
                    return(new FunctionResult(false));
                }
            }

            string leaseId = await _receiptManager.TryAcquireLeaseAsync(receiptBlob, cancellationToken).ConfigureAwait(false);

            if (leaseId == null)
            {
                // If someone else owns the lease and just took over this receipt or deleted it;
                // wait to try to trigger until later.
                return(new FunctionResult(false));
            }

            try
            {
                // Check again for the completed receipt. If it's already there, noop.
                BlobReceipt receipt = await _receiptManager.TryReadAsync(receiptBlob, cancellationToken).ConfigureAwait(false);

                Debug.Assert(receipt != null); // We have a (30 second) lease on the blob; it should never disappear on us.

                if (receipt.IsCompleted)
                {
                    Logger.BlobAlreadyProcessed(_logger, _functionDescriptor.LogName, value.Name, possibleETag, pollId, triggerSource);

                    await _receiptManager.ReleaseLeaseAsync(receiptBlob, leaseId, cancellationToken).ConfigureAwait(false);

                    return(new FunctionResult(true));
                }

                // We've successfully acquired a lease to enqueue the message for this blob trigger. Enqueue the message,
                // complete the receipt and release the lease.

                // Enqueue a message: function ID + blob path + ETag
                BlobTriggerMessage message = new BlobTriggerMessage
                {
                    FunctionId    = _functionDescriptor.Id,
                    BlobType      = blobProperties.BlobType,
                    ContainerName = value.BlobContainerName,
                    BlobName      = value.Name,
                    ETag          = possibleETag
                };

                var(queueName, messageId) = await _queueWriter.EnqueueAsync(message, cancellationToken).ConfigureAwait(false);

                Logger.BlobMessageEnqueued(_logger, _functionDescriptor.LogName, value.Name, messageId, queueName, pollId, triggerSource);

                // Complete the receipt
                await _receiptManager.MarkCompletedAsync(receiptBlob, leaseId, cancellationToken).ConfigureAwait(false);

                return(new FunctionResult(true));
            }
            finally
            {
                await _receiptManager.ReleaseLeaseAsync(receiptBlob, leaseId, cancellationToken).ConfigureAwait(false);
            }
        }