/// <summary>
/// Returns read-only session-state data from the session data store.
/// </summary>
/// <param name="context">The HttpContext for the current request.</param>
/// <param name="id">The SessionID for the current request.</param>
/// <param name="locked">When this method returns, contains a Boolean value that is set to true if a lock is successfully obtained; otherwise, false.</param>
/// <param name="lockAge">When this method returns, contains a TimeSpan object that is set to the amount of time that an item in the session data store has been locked.</param>
/// <param name="lockId">When this method returns, contains an object that is set to the lock identifier for the current request. For details on the lock identifier, see "Locking Session-Store Data" in the SessionStateStoreProviderBase class summary.</param>
/// <param name="actions">When this method returns, contains one of the SessionStateActions values, indicating whether the current session is an uninitialized, cookieless session.</param>
/// <returns>A SessionStateStoreData populated with session values and information from the session data store.</returns>
public override SessionStateStoreData GetItemExclusive(HttpContext context, string id, out bool locked, out TimeSpan lockAge, out object lockId, out SessionStateActions actions)
{
var cacheKey = string.Format(_cacheKey, id, _applicationName);
var now = DateTime.Now;
// Get the current session
DacheSessionState currentSession = null;
_cacheClient.TryGet <DacheSessionState>(cacheKey, out currentSession);
// Obtain a lock if possible. Ignore the record if it is expired.
// Set locked to true if the record was not updated and false if it was
locked = !(currentSession != null && !currentSession.Locked && currentSession.Expires > now);
if (!locked)
{
currentSession.Locked = true;
currentSession.LockDate = now;
_cacheClient.AddOrUpdate(cacheKey, currentSession);
}
return(GetItem(context, id, out locked, out lockAge, out lockId, out actions));
}
/// <summary>
/// Updates the expiration date and time of an item in the session data store.
/// </summary>
/// <param name="context">The HttpContext for the current request.</param>
/// <param name="id">The session identifier for the current request.</param>
public override void ResetItemTimeout(HttpContext context, string id)
{
var cacheKey = string.Format(_cacheKey, id, _applicationName);
DacheSessionState currentSession = null;
if (_cacheClient.TryGet <DacheSessionState>(cacheKey, out currentSession))
{
currentSession.Expires = DateTime.Now.AddMinutes(_sessionStateSection.Timeout.TotalMinutes);
_cacheClient.AddOrUpdate(cacheKey, currentSession);
}
}
/// <summary>
/// Deletes item data from the session data store.
/// </summary>
/// <param name="context">The HttpContext for the current request.</param>
/// <param name="id">The session identifier for the current request.</param>
/// <param name="lockId">The lock identifier for the current request.</param>
/// <param name="item">The SessionStateStoreData that represents the item to delete from the data store.</param>
public override void RemoveItem(HttpContext context, string id, object lockId, SessionStateStoreData item)
{
var cacheKey = string.Format(_cacheKey, id, _applicationName);
var now = DateTime.Now;
// Get the current session
DacheSessionState currentSession = null;
if (_cacheClient.TryGet <DacheSessionState>(cacheKey, out currentSession))
{
if (currentSession.LockId == (int)lockId)
{
_cacheClient.Remove(cacheKey);
}
}
}
/// <summary>
/// Releases a lock on an item in the session data store.
/// </summary>
/// <param name="context">The HttpContext for the current request.</param>
/// <param name="id">The session identifier for the current request.</param>
/// <param name="lockId">The lock identifier for the current request.</param>
public override void ReleaseItemExclusive(HttpContext context, string id, object lockId)
{
var cacheKey = string.Format(_cacheKey, id, _applicationName);
var now = DateTime.Now;
// Get the current session
DacheSessionState currentSession = null;
if (_cacheClient.TryGet <DacheSessionState>(cacheKey, out currentSession))
{
if (currentSession.LockId == (int)lockId)
{
currentSession.Locked = false;
currentSession.Expires = now.AddMinutes(_sessionStateSection.Timeout.TotalMinutes);
_cacheClient.AddOrUpdate(cacheKey, currentSession);
}
}
}
/// <summary>
/// Updates the session-item information in the session-state data store with values from the current request, and clears the lock on the data.
/// </summary>
/// <param name="context">The HttpContext for the current request.</param>
/// <param name="id">The session identifier for the current request.</param>
/// <param name="item">The SessionStateStoreData object that contains the current session values to be stored.</param>
/// <param name="lockId">The lock identifier for the current request.</param>
/// <param name="newItem">true to identify the session item as a new item; false to identify the session item as an existing item.</param>
public override void SetAndReleaseItemExclusive(HttpContext context, string id, SessionStateStoreData item, object lockId, bool newItem)
{
// Serialize the SessionStateItemCollection as a string
var sessionItems = (SessionStateItemCollection)item.Items;
byte[] serializedItems = new byte[0];
if (sessionItems != null)
{
using (var memoryStream = new MemoryStream())
{
using (var writer = new BinaryWriter(memoryStream))
{
sessionItems.Serialize(writer);
writer.Close();
serializedItems = memoryStream.ToArray();
}
}
}
var now = DateTime.UtcNow;
var cacheKey = string.Format(_cacheKey, id, _applicationName);
// Try and get the existing session item
DacheSessionState currentSession = null;
bool success = _cacheClient.TryGet <DacheSessionState>(cacheKey, out currentSession);
// Create or update the session item
_cacheClient.AddOrUpdate(cacheKey, new DacheSessionState
{
SessionId = id,
ApplicationName = _applicationName,
Created = success ? currentSession.Created : now,
Expires = now.AddMinutes(item.Timeout),
LockDate = success ? currentSession.LockDate : now,
LockId = success ? currentSession.LockId : 0,
Timeout = success ? currentSession.Timeout : item.Timeout,
Locked = false,
SessionItems = serializedItems,
Flags = success ? currentSession.Flags : SessionStateActions.None
});
}
/// <summary>
/// Returns read-only session-state data from the session data store.
/// </summary>
/// <param name="context">The HttpContext for the current request.</param>
/// <param name="id">The SessionID for the current request.</param>
/// <param name="locked">When this method returns, contains a Boolean value that is set to true if the requested session item is locked at the session data store; otherwise, false.</param>
/// <param name="lockAge">When this method returns, contains a TimeSpan object that is set to the amount of time that an item in the session data store has been locked.</param>
/// <param name="lockId">When this method returns, contains an object that is set to the lock identifier for the current request. For details on the lock identifier, see "Locking Session-Store Data" in the SessionStateStoreProviderBase class summary.</param>
/// <param name="actions">When this method returns, contains one of the SessionStateActions values, indicating whether the current session is an uninitialized, cookieless session.</param>
/// <returns>A SessionStateStoreData populated with session values and information from the session data store.</returns>
public override SessionStateStoreData GetItem(HttpContext context, string id, out bool locked, out TimeSpan lockAge, out object lockId, out SessionStateActions actions)
{
// Initial values for return value and out parameters
SessionStateStoreData item = null;
lockAge = TimeSpan.Zero;
lockId = null;
locked = false;
actions = 0;
// String to hold serialized SessionStateItemCollection
byte[] serializedItems = null;
// True if a record is found in the database
bool foundRecord = false;
// Timeout value from the data store
int timeout = 0;
var cacheKey = string.Format(_cacheKey, id, _applicationName);
var now = DateTime.Now;
// Get the current session
DacheSessionState currentSession = null;
_cacheClient.TryGet <DacheSessionState>(cacheKey, out currentSession);
if (currentSession != null)
{
if (currentSession.Expires < now)
{
// The record was expired - mark it as not locked
locked = false;
// Delete the current session
_cacheClient.Remove(cacheKey);
}
else
{
foundRecord = true;
}
serializedItems = currentSession.SessionItems;
lockId = currentSession.LockId;
lockAge = now.Subtract(currentSession.LockDate);
actions = currentSession.Flags;
timeout = currentSession.Timeout;
}
// If the record was found and you obtained a lock, then set the lockId, clear the actions, and create the SessionStateStoreItem to return.
if (foundRecord && !locked)
{
var incrementedLockId = (int)lockId + 1;
lockId = incrementedLockId;
currentSession.LockId = incrementedLockId;
currentSession.Flags = SessionStateActions.None;
// If the actions parameter is not InitializeItem,
// deserialize the stored SessionStateItemCollection.
if (actions == SessionStateActions.InitializeItem)
{
item = CreateNewStoreData(context, (int)_sessionStateSection.Timeout.TotalMinutes);
}
else
{
// Deserialize
MemoryStream memoryStream = new MemoryStream(serializedItems);
SessionStateItemCollection sessionItems = new SessionStateItemCollection();
if (memoryStream.Length > 0)
{
BinaryReader reader = new BinaryReader(memoryStream);
sessionItems = SessionStateItemCollection.Deserialize(reader);
}
item = new SessionStateStoreData(sessionItems, SessionStateUtility.GetSessionStaticObjects(context), timeout);
}
}
return(item);
}
