public FileCacheItem Deserialize(Stream stream)
{
var surrogateSelector = new AnonymousTypeSurrogateSelector();
surrogateSelector.AddSurrogate(typeof(CacheItemPolicy), new StreamingContext(StreamingContextStates.All), new CacheItemPolicySurrogate());
BinaryFormatter formatter = new BinaryFormatter();
formatter.SurrogateSelector = surrogateSelector;
formatter.Binder = _binder;
FileCacheItem item = null;
try
{
string key = (string)formatter.Deserialize(stream);
CacheItemPolicy policy = (CacheItemPolicy)formatter.Deserialize(stream);
object payload = formatter.Deserialize(stream);
item = new FileCacheItem(key, policy, payload);
}
catch (SerializationException)
{
}
return(item);
}
public FileCacheItem Deserialize(Stream stream)
{
var surrogateSelector = new AnonymousTypeSurrogateSelector();
surrogateSelector.AddSurrogate(typeof(CacheItemPolicy), new StreamingContext(StreamingContextStates.All), new CacheItemPolicySurrogate());
BinaryFormatter formatter = new BinaryFormatter();
formatter.SurrogateSelector = surrogateSelector;
formatter.Binder = _binder;
FileCacheItem item = null;
try
{
string key = (string)formatter.Deserialize(stream);
CacheItemPolicy policy = (CacheItemPolicy)formatter.Deserialize(stream);
object payload = formatter.Deserialize(stream);
item = new FileCacheItem(key, policy, payload);
}
catch (SerializationException)
{
}
return item;
}
/// <summary>
/// Returns the policy attached to a given cache item.
/// </summary>
/// <param name="key">The key of the item.</param>
/// <param name="regionName">The region in which the key exists.</param>
public CacheItemPolicy GetPolicy(string key, string regionName = null)
{
string cacheItemPath = GetItemPath(key, regionName);
FileCacheItem item = ReadFile(cacheItemPath);
return(item.Policy);
}
public void Serialize(Stream stream, FileCacheItem cacheItem)
{
var surrogateSelector = new AnonymousTypeSurrogateSelector();
surrogateSelector.AddSurrogate(typeof(CacheItemPolicy), new StreamingContext(StreamingContextStates.All), new CacheItemPolicySurrogate());
BinaryFormatter formatter = new BinaryFormatter();
formatter.SurrogateSelector = surrogateSelector;
formatter.Serialize(stream, cacheItem.Key);
formatter.Serialize(stream, cacheItem.Policy);
formatter.Serialize(stream, cacheItem.Payload);
}
public void Serialize(Stream stream, FileCacheItem cacheItem)
{
var surrogateSelector = new AnonymousTypeSurrogateSelector();
surrogateSelector.AddSurrogate(typeof(CacheItemPolicy), new StreamingContext(StreamingContextStates.All), new CacheItemPolicySurrogate());
BinaryFormatter formatter = new BinaryFormatter();
formatter.SurrogateSelector = surrogateSelector;
formatter.Serialize(stream, cacheItem.Key);
formatter.Serialize(stream, cacheItem.Policy);
formatter.Serialize(stream, cacheItem.Payload);
}
/// <summary>
/// This function serves to centralize file reads within this class.
/// </summary>
private FileCacheItem ReadFile(string filePath)
{
FileCacheItem item = null;
if (File.Exists(filePath))
{
using (FileStream stream = GetStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
item = _serializer.Deserialize(stream);
}
}
return(item);
}
public override object AddOrGetExisting(string key, object value, CacheItemPolicy policy, string regionName = null)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
if (value == null)
{
throw new ArgumentNullException("value");
}
// Clone policy object
policy = new CacheItemPolicy
{
AbsoluteExpiration = policy.AbsoluteExpiration,
SlidingExpiration = policy.SlidingExpiration
};
ValidatePolicy(policy);
object oldData = null;
string cacheItemPath = GetItemPath(key, regionName);
// Pull old value if it exists
if (File.Exists(cacheItemPath))
{
try
{
oldData = Get(key, regionName);
}
catch
{
oldData = null;
}
}
// Does the item have a sliding expiration?
if (policy.SlidingExpiration > ObjectCache.NoSlidingExpiration)
{
policy.AbsoluteExpiration = DateTime.Now.Add(policy.SlidingExpiration);
}
FileCacheItem newItem = new FileCacheItem(key, policy, value);
WriteFile(cacheItemPath, newItem);
return(oldData);
}
public override object Get(string key, string regionName = null)
{
string cacheItemPath = GetItemPath(key, regionName);
FileCacheItem item = ReadFile(cacheItemPath);
if (item == null)
{
return(null);
}
// Did the item expire?
if (item.Policy.AbsoluteExpiration < DateTime.Now)
{
// Set the item to null
item.Payload = null;
FileInfo fi = new FileInfo(cacheItemPath);
CurrentCacheSize -= fi.Length;
// Delete the file from the cache
fi.Delete();
}
else
{
// Does the item have a sliding expiration?
if (item.Policy.SlidingExpiration > ObjectCache.NoSlidingExpiration)
{
item.Policy.AbsoluteExpiration = DateTime.Now.Add(item.Policy.SlidingExpiration);;
WriteFile(cacheItemPath, item);
}
}
return(item.Payload);
}
/// <summary>
/// This function serves to centralize file writes within this class
/// </summary>
private void WriteFile(string filePath, FileCacheItem data)
{
// Remove current item from cache size calculations
if (File.Exists(filePath))
{
CurrentCacheSize -= new FileInfo(filePath).Length;
}
else
{
var directoryPath = Path.GetDirectoryName(filePath);
var di = new DirectoryInfo(directoryPath);
if (!di.Exists)
{
di.Create();
}
}
// Write the object payload
using (FileStream stream = GetStream(filePath, FileMode.Create, FileAccess.Write, FileShare.None))
{
_serializer.Serialize(stream, data);
}
// Adjust cache size
CurrentCacheSize += new FileInfo(filePath).Length;
// Check to see if limit was reached
if (CurrentCacheSize > MaxCacheSize)
{
if (MaxCacheSizeReached != null)
{
MaxCacheSizeReached(this, new FileCacheEventArgs(CurrentCacheSize, MaxCacheSize));
}
}
}
