private async Task <OptimisticStoreWriteResult> SaveDataInternal(StoreLocation location, Metadata metadata, UpdateAuditInfo audit, Func <IWriteAsyncStream, Task <long?> > savingFunc, CancellationToken token, bool isOptimistic)
{
var blob = GetBlockBlob(location);
// We always want to save the new audit information when saving!
var currentMetadata = await GetBlobMetadata(blob).ConfigureAwait(false);
var auditInfo = TransformAuditInformation(currentMetadata, audit);
metadata = metadata ?? new Metadata();
metadata.Audit = auditInfo;
var result = new OptimisticStoreWriteResult()
{
Result = true
};
try
{
// If the ETag value is empty then the store value must not exist yet...
var condition = isOptimistic ?
(string.IsNullOrEmpty(metadata.ETag) ? AccessCondition.GenerateIfNoneMatchCondition("*") : AccessCondition.GenerateIfMatchCondition(metadata.ETag))
: null;
// Copy the metadata across
blob.Metadata.Clear();
foreach (var m in metadata)
{
blob.Metadata[m.Key] = m.Value;
}
// Always store the version - We use this to do more efficient things on read
blob.Metadata[StoreVersionKey] = StoreVersionValue;
long?length;
using (var stream = new AzureWriteBlockBlobStream(blob, condition))
{
length = await savingFunc(stream).ConfigureAwait(false);
await stream.Complete(token).ConfigureAwait(false);
}
if (length.HasValue && (metadata == null || !metadata.ContentLength.HasValue))
{
blob.Metadata[MetadataConstants.ContentLengthMetadataKey] = length.Value.ToString(CultureInfo.InvariantCulture);
// Save the length straight away before the snapshot...
await blob.SetMetadataAsync(null, null, null, token).ConfigureAwait(false);
}
// Create a snapshot straight away on azure
// Note: this shouldnt matter for cost as any blocks that are the same do not cost extra
if (_enableSnapshots)
{
var snapshotBlob = await blob.CreateSnapshotAsync(blob.Metadata, null, null, null, token).ConfigureAwait(false);
var snapshot = snapshotBlob.SnapshotTime.Value.UtcTicks.ToString(CultureInfo.InvariantCulture);
// Save the snapshot back to original blob...
blob.Metadata[InternalSnapshotKey] = snapshot;
await blob.SetMetadataAsync(null, null, null, token).ConfigureAwait(false);
LeoTrace.WriteLine("Created Snapshot: " + blob.Name);
}
result.Metadata = await GetActualMetadata(blob).ConfigureAwait(false);
}
catch (StorageException exc)
{
if (isOptimistic)
{
// First condition occurrs when the eTags do not match
// Second condition when we specified no eTag (ie must be new blob)
if (exc.RequestInformation.HttpStatusCode == (int)HttpStatusCode.PreconditionFailed ||
(exc.RequestInformation.HttpStatusCode == (int)HttpStatusCode.Conflict && exc.RequestInformation.ExtendedErrorInformation.ErrorCode == "BlobAlreadyExists"))
{
result.Result = false;
}
else
{
// Might have been a different error?
throw exc.Wrap(blob.Name);
}
}
else
{
if (exc.RequestInformation.HttpStatusCode == (int)HttpStatusCode.Conflict ||
exc.RequestInformation.ExtendedErrorInformation.ErrorCode == "LeaseIdMissing")
{
throw new LockException("The underlying storage is currently locked for save");
}
// Might have been a different error?
throw exc.Wrap(blob.Name);
}
}
return(result);
}
private async Task<OptimisticStoreWriteResult> SaveDataInternal(StoreLocation location, Metadata metadata, UpdateAuditInfo audit, Func<IWriteAsyncStream, Task<long?>> savingFunc, CancellationToken token, bool isOptimistic)
{
var blob = GetBlockBlob(location);
// We always want to save the new audit information when saving!
var currentMetadata = await GetBlobMetadata(blob).ConfigureAwait(false);
var auditInfo = TransformAuditInformation(currentMetadata, audit);
metadata = metadata ?? new Metadata();
metadata.Audit = auditInfo;
var result = new OptimisticStoreWriteResult() { Result = true };
try
{
// If the ETag value is empty then the store value must not exist yet...
var condition = isOptimistic ?
(string.IsNullOrEmpty(metadata.ETag) ? AccessCondition.GenerateIfNoneMatchCondition("*") : AccessCondition.GenerateIfMatchCondition(metadata.ETag))
: null;
// Copy the metadata across
blob.Metadata.Clear();
foreach (var m in metadata)
{
blob.Metadata[m.Key] = m.Value;
}
// Always store the version - We use this to do more efficient things on read
blob.Metadata[StoreVersionKey] = StoreVersionValue;
long? length;
using (var stream = new AzureWriteBlockBlobStream(blob, condition))
{
length = await savingFunc(stream).ConfigureAwait(false);
await stream.Complete(token).ConfigureAwait(false);
}
if (length.HasValue && (metadata == null || !metadata.ContentLength.HasValue))
{
blob.Metadata[MetadataConstants.ContentLengthMetadataKey] = length.Value.ToString(CultureInfo.InvariantCulture);
// Save the length straight away before the snapshot...
await blob.SetMetadataAsync(token).ConfigureAwait(false);
}
// Create a snapshot straight away on azure
// Note: this shouldnt matter for cost as any blocks that are the same do not cost extra
if (_enableSnapshots)
{
var snapshotBlob = await blob.CreateSnapshotAsync(token).ConfigureAwait(false);
var snapshot = snapshotBlob.SnapshotTime.Value.UtcTicks.ToString(CultureInfo.InvariantCulture);
// Save the snapshot back to original blob...
blob.Metadata[InternalSnapshotKey] = snapshot;
await blob.SetMetadataAsync(token).ConfigureAwait(false);
LeoTrace.WriteLine("Created Snapshot: " + blob.Name);
}
result.Metadata = await GetActualMetadata(blob).ConfigureAwait(false);
}
catch (StorageException exc)
{
if (isOptimistic)
{
// First condition occurrs when the eTags do not match
// Second condition when we specified no eTag (ie must be new blob)
if (exc.RequestInformation.HttpStatusCode == (int)HttpStatusCode.PreconditionFailed
|| (exc.RequestInformation.HttpStatusCode == (int)HttpStatusCode.Conflict && exc.RequestInformation.ExtendedErrorInformation.ErrorCode == "BlobAlreadyExists"))
{
result.Result = false;
}
else
{
// Might have been a different error?
throw exc.Wrap(blob.Name);
}
}
else
{
if (exc.RequestInformation.HttpStatusCode == (int)HttpStatusCode.Conflict
|| exc.RequestInformation.ExtendedErrorInformation.ErrorCode == "LeaseIdMissing")
{
throw new LockException("The underlying storage is currently locked for save");
}
// Might have been a different error?
throw exc.Wrap(blob.Name);
}
}
return result;
}
private async Task <OptimisticStoreWriteResult> SaveDataInternal(StoreLocation location, Metadata metadata, UpdateAuditInfo audit, Func <IWriteAsyncStream, Task <long?> > savingFunc, CancellationToken token, bool isOptimistic)
{
var blob = GetBlockBlob(location);
// We always want to save the new audit information when saving!
var props = await GetBlobProperties(blob);
var currentMetadata = await GetActualMetadata(blob, props, null);
var auditInfo = TransformAuditInformation(currentMetadata, audit);
metadata = metadata ?? new Metadata();
metadata.Audit = auditInfo;
var result = new OptimisticStoreWriteResult()
{
Result = true
};
try
{
// If the ETag value is empty then the store value must not exist yet...
var condition = isOptimistic ?
(string.IsNullOrEmpty(metadata.ETag) ? new BlobRequestConditions {
IfNoneMatch = ETag.All
} : new BlobRequestConditions {
IfMatch = new ETag(metadata.ETag)
})
: null;
// Copy the metadata across
var newMeta = new Dictionary <string, string>();
foreach (var m in metadata)
{
newMeta[m.Key] = AzureStoreMetadataEncoder.EncodeMetadata(m.Value);
}
// Always store the version - We use this to do more efficient things on read
newMeta[StoreVersionKey] = StoreVersionValue;
long?length;
using (var stream = new AzureWriteBlockBlobStream(blob, condition, newMeta))
{
length = await savingFunc(stream);
await stream.Complete(token);
}
if (length.HasValue && (metadata == null || !metadata.ContentLength.HasValue))
{
newMeta[MetadataConstants.ContentLengthMetadataKey] = length.Value.ToString(CultureInfo.InvariantCulture);
// Save the length straight away before the snapshot...
await blob.SetMetadataAsync(newMeta, cancellationToken : token);
}
// Create a snapshot straight away on azure
// Note: this shouldnt matter for cost as any blocks that are the same do not cost extra
if (_enableSnapshots)
{
var snapshotBlob = await blob.CreateSnapshotAsync(cancellationToken : token);
// Save the snapshot back to original blob...
newMeta[InternalSnapshotKey] = snapshotBlob.Value.Snapshot;
await blob.SetMetadataAsync(newMeta, cancellationToken : token);
LeoTrace.WriteLine("Created Snapshot: " + blob.Name);
}
var newProps = await blob.GetPropertiesAsync();
result.Metadata = await GetActualMetadata(blob, newProps, null);
}
catch (RequestFailedException e)
{
if (isOptimistic)
{
// First condition occurrs when the eTags do not match
// Second condition when we specified no eTag (ie must be new blob)
if (e.Status == (int)HttpStatusCode.PreconditionFailed ||
(e.Status == (int)HttpStatusCode.Conflict && e.ErrorCode == BlobErrorCode.BlobAlreadyExists))
{
result.Result = false;
}
else
{
// Might have been a different error?
throw;
}
}
else
{
if (e.Status == (int)HttpStatusCode.Conflict || e.ErrorCode == BlobErrorCode.LeaseIdMissing)
{
throw new LockException("The underlying storage is currently locked for save");
}
// Might have been a different error?
throw;
}
}
return(result);
}
