public bool TryGet(TKey key, out TEntity view)
{
view = default(TEntity);
try
{
var name = GetName(key);
if (!File.Exists(name))
{
return(false);
}
using (var stream = File.Open(name, FileMode.Open, FileAccess.Read, FileShare.Read))
{
if (stream.Length == 0)
{
return(false);
}
view = _strategy.Deserialize <TEntity>(stream);
return(true);
}
}
catch (FileNotFoundException)
{
// if file happened to be deleted between the moment of check and actual read.
return(false);
}
catch (DirectoryNotFoundException)
{
return(false);
}
}
public TEntity AddOrUpdate(TKey key, Func <TEntity> addViewFactory, Func <TEntity, TEntity> updateViewFactory,
AddOrUpdateHint hint)
{
string etag = null;
var blob = GetBlobReference(key);
TEntity view;
try
{
// atomic entities should be small, so we can use the simple method
var bytes = blob.DownloadByteArray();
using (var stream = new MemoryStream(bytes))
{
view = _strategy.Deserialize <TEntity>(stream);
}
view = updateViewFactory(view);
etag = blob.Attributes.Properties.ETag;
}
catch (StorageClientException ex)
{
switch (ex.ErrorCode)
{
case StorageErrorCode.ContainerNotFound:
var s = string.Format(
"Container '{0}' does not exist. You need to initialize this atomic storage and ensure that '{1}' is known to '{2}'.",
blob.Container.Name, typeof(TEntity).Name, _strategy.GetType().Name);
throw new InvalidOperationException(s, ex);
case StorageErrorCode.BlobNotFound:
case StorageErrorCode.ResourceNotFound:
view = addViewFactory();
break;
default:
throw;
}
}
// atomic entities should be small, so we can use the simple method
// http://toolheaven.net/post/Azure-and-blob-write-performance.aspx
using (var memory = new MemoryStream())
{
_strategy.Serialize(view, memory);
// note that upload from stream does weird things
var bro = etag != null
? new BlobRequestOptions {
AccessCondition = AccessCondition.IfMatch(etag)
}
: new BlobRequestOptions {
AccessCondition = AccessCondition.IfNoneMatch("*")
};
// make sure that upload is not rejected due to cashed content MD5
// http://social.msdn.microsoft.com/Forums/hu-HU/windowsazuredata/thread/4764e38f-b200-4efe-ada2-7de442dc4452
blob.Properties.ContentMD5 = null;
blob.UploadByteArray(memory.ToArray(), bro);
}
return(view);
}
public bool TryGet(TKey key, out TEntity entity)
{
var name = GetName(key);
byte[] bytes;
if (_store.TryGetValue(name, out bytes))
{
using (var mem = new MemoryStream(bytes))
{
entity = _strategy.Deserialize <TEntity>(mem);
return(true);
}
}
entity = default(TEntity);
return(false);
}
public bool TryGet(TKey key, out TEntity entity)
{
var blob = GetBlobReference(key);
try
{
// blob request options are cloned from the config
// atomic entities should be small, so we can use the simple method
var bytes = blob.DownloadByteArray();
using (var stream = new MemoryStream(bytes))
{
entity = _strategy.Deserialize <TEntity>(stream);
return(true);
}
}
catch (StorageClientException ex)
{
switch (ex.ErrorCode)
{
case StorageErrorCode.ContainerNotFound:
case StorageErrorCode.BlobNotFound:
case StorageErrorCode.ResourceNotFound:
entity = default(TEntity);
return(false);
default:
throw;
}
}
}
public bool TryGet(TKey key, out TEntity entity)
{
var name = GetName(key);
byte[] bytes;
if (_store.TryGetValue(name, out bytes)) // Get the byte array from the store
{
using (var mem = new MemoryStream(bytes))
{
// Using a memory stream deserialise the stream to an entity
entity = _strategy.Deserialize <TEntity>(mem);
return(true);
}
}
entity = default(TEntity);
return(false);
}
public bool TryGet(TKey key, out TEntity view)
{
view = default(TEntity);
var name = GetName(key);
try
{
if (!File.Exists(name))
{
return(false);
}
using (var stream = File.Open(name, FileMode.Open, FileAccess.Read, FileShare.Read))
{
if (stream.Length == 0)
{
return(false);
}
view = _strategy.Deserialize <TEntity>(stream);
return(true);
}
}
catch (FileNotFoundException)
{
return(false);
}
catch (DirectoryNotFoundException)
{
return(false);
}
catch (IOException) // fix for fast read / slow write concurency
{
_log.WriteLine("File read failed for {0} - {1} with key {2}. Will retry.", _folder, name, key);
Thread.Sleep(2);
TryGet(key, out view);
return(false);
}
}