/// <summary>
/// Helper method for serializing objects to Redis
/// </summary>
/// <param name="confirmedChangedObjects">keys and values that have definitely changed</param>
/// <param name="allObjects">keys and values that have been accessed during the current HttpContext</param>
/// <param name="allObjectsOriginalState">keys and serialized values before we tampered with them</param>
/// <param name="deletedObjects">keys that were deleted during the current HttpContext</param>
/// <param name="currentRedisHashId">The current Redis key name</param>
/// <param name="redisConn">A connection to Redis</param>
public static void SerializeToRedis(
HttpContextBase context,
RedisSessionStateItemCollection redisItems,
string currentRedisHashId,
TimeSpan expirationTimeout)
{
var setItems = new List <KeyValuePair <string, string> >();
var delItems = new List <string>();
// Determine if we are adding or removing keys, separate them into their own lists
// note that redisItems.GetChangedObjectsEnumerator contains complex logic
foreach (KeyValuePair <string, string> changedObj in redisItems.GetChangedObjectsEnumerator())
{
if (changedObj.Value != null)
{
setItems.Add(changedObj);
}
else
{
delItems.Add(changedObj.Key);
}
}
var rConnWrap = RedisSessionStateStoreProvider.RedisConnWrapper();
if (setItems.Count > 0)
{
rConnWrap.HashSet(currentRedisHashId, setItems);
// call appropriate delegate if set for changing keys
if (RedisSessionConfig.RedisWriteFieldDel != null)
{
RedisSessionConfig.RedisWriteFieldDel(context, setItems, currentRedisHashId);
}
}
if (delItems != null && delItems.Count > 0)
{
rConnWrap.HashDelete(currentRedisHashId, delItems);
// call appropriate delegate if set for removing keys
if (RedisSessionConfig.RedisRemoveFieldDel != null)
{
RedisSessionConfig.RedisRemoveFieldDel(context, delItems, currentRedisHashId);
}
}
// always refresh the timeout of the session hash
rConnWrap.KeyExpire(currentRedisHashId, expirationTimeout);
}
/// <summary>
/// Gets a Session from Redis, indicating a non-exclusive lock on the Session. Note that GetItemExclusive
/// calls this method internally, meaning we do not support locks at all retrieving the Session.
/// </summary>
/// <param name="context">The HttpContext of the current request</param>
/// <param name="id">The Session Id, which is the key name in Redis</param>
/// <param name="locked">Whether or not the Session is locked to exclusive access for a single request
/// thread</param>
/// <param name="lockAge">The age of the lock</param>
/// <param name="lockId">The object used to lock the Session</param>
/// <param name="actions">Whether or not to initialize the Session (never)</param>
/// <returns>The Session objects wrapped in a SessionStateStoreData object</returns>
public override SessionStateStoreData GetItem(HttpContext context, string id, out bool locked, out TimeSpan lockAge, out object lockId, out SessionStateActions actions)
{
locked = false;
lockAge = new TimeSpan(0);
lockId = null;
actions = SessionStateActions.None;
try
{
string parsedRedisHashId = RedisSessionStateStoreProvider.RedisHashIdFromSessionId(
new HttpContextWrapper(context),
id);
LocalSharedSessionDictionary sharedSessDict = new LocalSharedSessionDictionary();
RedisSessionStateItemCollection items = sharedSessDict.GetSessionForBeginRequest(
parsedRedisHashId,
(redisKey) =>
{
return(RedisSessionStateStoreProvider.GetItemFromRedis(
redisKey,
new HttpContextWrapper(context),
this.SessionTimeout));
});
return(new SessionStateStoreData(
items,
SessionStateUtility.GetSessionStaticObjects(context),
Convert.ToInt32(this.SessionTimeout.TotalMinutes)));
}
catch (Exception e)
{
if (RedisSessionConfig.SessionExceptionLoggingDel != null)
{
RedisSessionConfig.SessionExceptionLoggingDel(e);
}
}
return(this.CreateNewStoreData(context, Convert.ToInt32(this.SessionTimeout.TotalMinutes)));
}
/// <summary>
/// Gets a session for a given redis ID, and increments the count of the number of requests
/// that have accessed this redis ID
/// </summary>
/// <param name="redisHashId">The id of the session in Redis</param>
/// <param name="getDel">The delegate to run to fetch the session from Redis</param>
/// <returns>A RedisSessionStateItemCollection for the session</returns>
public RedisSessionStateItemCollection GetSessionForBeginRequest(
string redisHashId,
Func <string, RedisSessionStateItemCollection> getDel)
{
SessionAndRefCount sessAndCount = LocalSharedSessionDictionary.localCache.AddOrUpdate(
redisHashId,
(redisKey) =>
{
RedisSessionStateItemCollection itms = getDel(redisHashId);
return(new SessionAndRefCount(itms));
},
(redisKey, existingItem) =>
{
Interlocked.Increment(ref existingItem.RequestReferences);
existingItem.LastAccess = DateTime.Now;
return(existingItem);
});
return(sessAndCount.Sess);
}
/// <summary>
/// Checks if any items have changed in the Session, and stores the results to Redis
/// </summary>
/// <param name="context">The HttpContext of the current web request</param>
/// <param name="id">The Session Id and Redis key name</param>
/// <param name="item">The Session properties</param>
/// <param name="lockId">The object used to exclusively lock the Session (there shouldn't be one)</param>
/// <param name="newItem">Whether or not the Session was created in this HttpContext</param>
public override void SetAndReleaseItemExclusive(HttpContext context, string id, SessionStateStoreData item, object lockId, bool newItem)
{
try
{
string currentRedisHashId = RedisSessionStateStoreProvider.RedisHashIdFromSessionId(
new HttpContextWrapper(context),
id);
LocalSharedSessionDictionary sharedSessDict = new LocalSharedSessionDictionary();
RedisSessionStateItemCollection redisItems =
sharedSessDict.GetSessionForEndRequest(currentRedisHashId);
// we were unable to pull it from shared cache, meaning either this is the first request or
// something went wrong with the local cache. We still have all the parts needed to write
// to redis, however, by looking at SessionStateStoreData passed in from the Session module
// and the current hash key provided by the id parameter.
if (redisItems == null)
{
redisItems = (RedisSessionStateItemCollection)item.Items;
}
if (redisItems != null)
{
RedisSessionStateStoreProvider.SerializeToRedis(
new HttpContextWrapper(context),
redisItems,
currentRedisHashId,
this.SessionTimeout);
}
}
catch (Exception e)
{
if (RedisSessionConfig.SessionExceptionLoggingDel != null)
{
RedisSessionConfig.SessionExceptionLoggingDel(e);
}
}
}
private static void ClearRedisItems(RedisSessionStateItemCollection items, int size)
{
items.Clear();
}
/// <summary>
/// Initializes a new instance of the SessionAndRefCount class with a given item collection
/// and count of requests using it
/// </summary>
/// <param name="itms">The items in a session</param>
/// <param name="count">The number of requests accessing this session</param>
public SessionAndRefCount(RedisSessionStateItemCollection itms, int count)
{
this.Sess = itms;
this.RequestReferences = count;
this.LastAccess = DateTime.Now;
}
/// <summary>
/// Initializes a new instance of the SessionAndRefCount class with a given item collection
/// </summary>
/// <param name="itms">The items in a session</param>
public SessionAndRefCount(RedisSessionStateItemCollection itms)
: this(itms, 1)
{
}
