public async Task SoftDelete(StoreLocation location, UpdateAuditInfo audit)
{
// In Azure we cannot delete the blob as this will loose the snapshots
// Instead we will just add some metadata
var blob = GetBlockBlob(location);
var props = await GetBlobProperties(blob);
var meta = await GetActualMetadata(blob, props, null);
// If already deleted don't worry about it!
if (meta == null || meta.ContainsKey(_deletedKey))
{
return;
}
var fullInfo = TransformAuditInformation(meta, audit);
meta.Audit = fullInfo;
props.Metadata[MetadataConstants.AuditMetadataKey] = AzureStoreMetadataEncoder.EncodeMetadata(meta[MetadataConstants.AuditMetadataKey]);
props.Metadata[_deletedKey] = DateTime.UtcNow.Ticks.ToString();
await blob.SetMetadataAsync(props.Metadata);
LeoTrace.WriteLine("Soft deleted (2 calls): " + blob.Name);
}
public async Task <Metadata> SaveMetadata(StoreLocation location, Metadata metadata)
{
var blob = GetBlockBlob(location);
var props = await GetBlobProperties(blob);
if (props == null)
{
return(null);
}
foreach (var m in metadata)
{
// Do not override audit information!
if (m.Key != MetadataConstants.AuditMetadataKey)
{
props.Metadata[m.Key] = AzureStoreMetadataEncoder.EncodeMetadata(m.Value);
}
}
await blob.SetMetadataAsync(props.Metadata);
return(await GetActualMetadata(blob, props, null));
}
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);
}