|
public static Load ( IBucket bucket, string id, bool metaOnly ) : |
||
| bucket | IBucket | Couchbase bucket to load from |
| id | string | Session ID |
| metaOnly | bool | True to load only meta data |
| return | ||
/// <summary>
/// Releases a lock on an item in the session data store
/// </summary>
/// <param name="context">HttpContext for the current request</param>
/// <param name="id">Session ID for the session</param>
/// <param name="lockId">The lock identifier for the current request</param>
public override void ReleaseItemExclusive(
HttpContext context,
string id,
object lockId)
{
ResponseStatus status;
var retries = 0;
var tmp = (ulong)lockId;
SessionStateItem e;
do
{
// Load the header for the item with CAS
e = SessionStateItem.Load(_bucket, id, true);
// Bail if the entry does not exist, or the lock ID does not match our lock ID
if (e == null || e.LockId != tmp)
{
break;
}
// Attempt to clear the lock for this item and loop around until we succeed
e.LockId = 0;
e.LockTime = DateTime.MinValue;
} while (!e.SaveHeader(_bucket, id, _exclusiveAccess, out status) && retries++ < _maxRetryCount && status != ResponseStatus.KeyNotFound);
}
private static SessionStateItem Get(IMemcachedClient client, bool acquireLock, string id, out bool locked, out TimeSpan lockAge, out object lockId, out SessionStateActions actions)
{
locked = false;
lockId = null;
lockAge = TimeSpan.Zero;
actions = SessionStateActions.None;
var e = SessionStateItem.Load(client, id, false, _compressor, _isLoggingEnabled ? _logger : null);
if (e == null)
{
return(null);
}
if (acquireLock)
{
// repeat until we can update the retrieved
// item (i.e. nobody changes it between the
// time we get it from the store and updates it s attributes)
// Save() will return false if Cas() fails
while (true)
{
if (e.LockId > 0)
{
break;
}
actions = e.Flag;
e.LockId = _exclusiveAccess ? e.HeadCas : 0;
e.LockTime = DateTime.UtcNow;
e.Flag = SessionStateActions.None;
// try to update the item in the store
if (e.Save(client, id, true, _exclusiveAccess, _compressor, _isLoggingEnabled ? _logger : null))
{
locked = true;
lockId = e.LockId;
return(e);
}
// it has been modified between we loaded and tried to save it
e = SessionStateItem.Load(client, id, false, _compressor, _isLoggingEnabled ? _logger : null);
if (e == null)
{
return(null);
}
}
}
locked = true;
lockAge = DateTime.UtcNow - e.LockTime;
lockId = e.LockId;
actions = SessionStateActions.None;
return(acquireLock ? null : e);
}
public override void RemoveItem(HttpContext context, string id, object lockId, SessionStateStoreData item)
{
var tmp = (ulong)lockId;
var e = SessionStateItem.Load(_client, id, true, _compressor, _isLoggingEnabled ? _logger : null);
if (e != null && e.LockId == tmp)
{
SessionStateItem.Remove(_client, id);
}
}
public override void RemoveItem(HttpContext context, string id, object lockId, SessionStateStoreData item)
{
var tmp = (ulong)lockId;
var e = SessionStateItem.Load(client, id, true);
if (e != null && e.LockId == tmp)
{
SessionStateItem.Remove(client, id);
}
}
private SessionStateItem Get(HttpContext context, bool acquireLock, string id, out bool locked, out TimeSpan lockAge, out object lockId, out SessionStateActions actions)
{
locked = false;
lockId = null;
lockAge = TimeSpan.Zero;
actions = SessionStateActions.None;
var e = SessionStateItem.Load(this.client, id, false);
if (e == null) return null;
if (acquireLock)
{
// repeat until we can update the retrieved
// item (i.e. nobody changes it between the
// time we get it from the store and updates its attributes)
// Save() will return false if Cas() fails
while (true)
{
if (e.LockId > 0) break;
actions = e.Flag;
e.LockId = e.HeadCas;
e.LockTime = DateTime.UtcNow;
e.Flag = SessionStateActions.None;
// try to update the item in the store
if (e.Save(this.client, id, true, true))
{
locked = true;
lockId = e.LockId;
return e;
}
// it has been modifed between we loaded and tried to save it
e = SessionStateItem.Load(this.client, id, false);
if (e == null) return null;
}
}
locked = true;
lockAge = DateTime.UtcNow - e.LockTime;
lockId = e.LockId;
actions = SessionStateActions.None;
return acquireLock ? null : e;
}
public override void ResetItemTimeout(HttpContext context, string id)
{
SessionStateItem e;
do
{
// Load the item with CAS
e = SessionStateItem.Load(_client, id, false, _compressor, _isLoggingEnabled ? _logger : null);
if (e == null)
{
break;
}
// Try to save with CAS, and loop around until we succeed
} while (!e.Save(_client, id, false, _exclusiveAccess, _compressor, _isLoggingEnabled ? _logger : null));
}
public override void ResetItemTimeout(HttpContext context, string id)
{
SessionStateItem e;
do
{
// Load the item with CAS
e = SessionStateItem.Load(client, id, false);
if (e == null)
{
break;
}
// Try to save with CAS, and loop around until we succeed
} while (!e.Save(client, id, false, exclusiveAccess));
}
public override void ReleaseItemExclusive(HttpContext context, string id, object lockId)
{
if (!(lockId is ulong))
return;
var tmp = (ulong)lockId;
var e = SessionStateItem.Load(this.client, id, true);
if (e != null && e.LockId == tmp)
{
e.LockId = 0;
e.LockTime = DateTime.MinValue;
e.Save(this.client, id, true, true);
}
}
/// <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">HttpContext for the current request</param>
/// <param name="id">Session ID for the session</param>
/// <param name="item">The session state item to be stored</param>
/// <param name="lockId">The lock identifier for the current request</param>
/// <param name="newItem">True if this is a new session item, false if it is an existing item</param>
public override void SetAndReleaseItemExclusive(
HttpContext context,
string id,
SessionStateStoreData item,
object lockId,
bool newItem)
{
bool keyNotFound;
var retries = 0;
SessionStateItem e;
do
{
if (!newItem)
{
var tmp = (ulong)lockId;
// Load the entire item with CAS (need the DataCas value also for the save)
e = SessionStateItem.Load(_bucket, id, false);
// if we're expecting an existing item, but
// it's not in the cache
// or it's locked by someone else, then quit
if (e == null || e.LockId != tmp)
{
return;
}
}
else
{
// Create a new item if it requested
e = new SessionStateItem();
}
// Set the new data and reset the locks
e.Timeout = item.Timeout;
e.Data = (SessionStateItemCollection)item.Items;
e.Flag = SessionStateActions.None;
e.LockId = 0;
e.LockTime = DateTime.MinValue;
// Attempt to save with CAS and loop around if it fails
} while (!e.SaveAll(_bucket, id, _exclusiveAccess && !newItem, out keyNotFound) && retries++ < _maxRetryCount && !keyNotFound);
}
/// <summary>
/// Updates the expiration date and time of an item in the session data store
/// </summary>
/// <param name="context">HttpContext for the current request</param>
/// <param name="id">Session ID for the session</param>
public override void ResetItemTimeout(
HttpContext context,
string id)
{
bool keyNotFound;
var retries = 0;
SessionStateItem e;
do
{
// Load the item with CAS
e = SessionStateItem.Load(_bucket, id, false);
if (e == null)
{
break;
}
// Try to save with CAS, and loop around until we succeed
} while (!e.SaveAll(_bucket, id, _exclusiveAccess, out keyNotFound) && retries++ < _maxRetryCount && !keyNotFound);
}
public override void ReleaseItemExclusive(HttpContext context, string id, object lockId)
{
var tmp = (ulong)lockId;
SessionStateItem e;
do
{
// Load the header for the item with CAS
e = SessionStateItem.Load(_client, id, true, _compressor, _isLoggingEnabled ? _logger : null);
// Bail if the entry does not exist, or the lock ID does not match our lock ID
if (e == null || e.LockId != tmp)
{
break;
}
// Attempt to clear the lock for this item and loop around until we succeed
e.LockId = 0;
e.LockTime = DateTime.MinValue;
} while (!e.Save(_client, id, true, _exclusiveAccess, _compressor, _isLoggingEnabled ? _logger : null));
}
public override void SetAndReleaseItemExclusive(HttpContext context, string id, SessionStateStoreData item, object lockId, bool newItem)
{
SessionStateItem e = null;
bool existing = false;
if (!newItem)
{
if (!(lockId is ulong))
return;
var tmp = (ulong)lockId;
e = SessionStateItem.Load(this.client, id, true);
existing = e != null;
// if we're expecting an existing item, but
// it's not in the cache
// or it's not locked
// or it's locked by someone else, then quit
if (!newItem
&& (!existing
|| e.LockId == 0
|| e.LockId != tmp))
return;
}
if (!existing) e = new SessionStateItem();
// set the new data and reset the locks
e.Timeout = item.Timeout;
e.Data = (SessionStateItemCollection)item.Items;
e.Flag = SessionStateActions.None;
e.LockId = 0;
e.LockTime = DateTime.MinValue;
e.Save(this.client, id, false, existing && !newItem);
}
/// <summary>
/// Retrieves the session data from the data source. If the lockRecord parameter is true
/// (in the case of GetItemExclusive), then the record is locked and we return a new lockId
/// and lockAge.
/// </summary>
/// <param name="bucket">Reference to the couchbase bucket we are using</param>
/// <param name="context">HttpContext for the current request</param>
/// <param name="acquireLock">True to aquire the lock, false to not aquire it</param>
/// <param name="id">Session ID for the session</param>
/// <param name="locked">Returns true if the session item is locked, otherwise false</param>
/// <param name="lockAge">Returns the amount of time that the item has been locked</param>
/// <param name="lockId">Returns lock identifier for the current request</param>
/// <param name="actions">Indicates whether the current sessions is an uninitialized, cookieless session</param>
/// <returns>SessionStateItem object containing the session state data</returns>
public static SessionStateItem GetSessionStoreItem(
IBucket bucket,
HttpContext context,
bool acquireLock,
string id,
out bool locked,
out TimeSpan lockAge,
out object lockId,
out SessionStateActions actions)
{
locked = false;
lockId = null;
lockAge = TimeSpan.Zero;
actions = SessionStateActions.None;
var e = SessionStateItem.Load(bucket, id, false);
if (e == null)
{
return(null);
}
if (acquireLock)
{
// repeat until we can update the retrieved
// item (i.e. nobody changes it between the
// time we get it from the store and updates it s attributes)
// Save() will return false if Cas() fails
while (true)
{
if (e.LockId > 0)
{
break;
}
actions = e.Flag;
e.LockId = _exclusiveAccess ? e.HeadCas : 0;
e.LockTime = DateTime.UtcNow;
e.Flag = SessionStateActions.None;
ResponseStatus status;
// try to update the item in the store
if (e.SaveHeader(bucket, id, _exclusiveAccess, out status))
{
locked = true;
lockId = e.LockId;
return(e);
}
if (status == ResponseStatus.KeyNotFound)
{
break;
}
// it has been modified between we loaded and tried to save it
e = SessionStateItem.Load(bucket, id, false);
if (e == null)
{
return(null);
}
}
}
locked = true;
lockAge = DateTime.UtcNow - e.LockTime;
lockId = e.LockId;
actions = SessionStateActions.None;
return(acquireLock ? null : e);
}
public override void ResetItemTimeout(HttpContext context, string id)
{
var e = SessionStateItem.Load(this.client, id, false);
if (e != null)
e.Save(this.client, id, false, true);
}