public virtual void Clear()
{
log.DebugFormat("clear cache: regionName='{0}'", RegionName);
try
{
var setOfActiveKeysKey = CacheNamespace.GetSetOfActiveKeysKey();
var db = GetDatabase();
db.KeyDelete(setOfActiveKeysKey, fireAndForgetFlags);
}
catch (Exception e)
{
log.ErrorFormat("could not clear cache: regionName='{0}'", RegionName);
var evtArg = new ExceptionEventArgs(RegionName, RedisCacheMethod.Clear, e);
options.OnException(this, evtArg);
if (evtArg.Throw)
{
throw new RedisCacheException(RegionName, "Failed to clear cache. See inner exception.", e);
}
}
}
public async Task ClearCoreAsync(CancellationToken cancellationToken, bool sync = false)
{
cancellationToken.ThrowIfNull("cancellationToken");
if (cancellationToken.IsCancellationRequested)
{
return;
}
log.Debug("clear cache: regionName='{0}'", RegionName);
try
{
var setOfActiveKeysKey = CacheNamespace.GetSetOfActiveKeysKey();
var db = GetDatabase();
if (sync)
{
db.KeyDelete(setOfActiveKeysKey, fireAndForgetFlags);
}
else
{
await db.KeyDeleteAsync(setOfActiveKeysKey, fireAndForgetFlags);
}
}
catch (Exception e)
{
log.Error("could not clear cache: regionName='{0}'", RegionName);
var evtArg = new ExceptionEventArgs(RegionName, RedisCacheMethod.Clear, e);
options.OnException(this, evtArg);
if (evtArg.Throw)
{
throw new RedisCacheException(RegionName, "Failed to clear cache. See inner exception.", e);
}
}
}
private async Task UnlockCoreAsync(object key, CancellationToken cancellationToken, bool sync = false)
{
cancellationToken.ThrowIfNull("cancellationToken");
if (cancellationToken.IsCancellationRequested)
{
return;
}
// Use Remove() instead of Get() because we are releasing the lock
// anyways.
var lockData = acquiredLocks.Remove(Convert.ToString(key)) as LockData;
if (lockData == null)
{
log.Warn("attempted to unlock '{0}' but a previous lock was not acquired or timed out", key);
var unlockFailedEventArgs = new UnlockFailedEventArgs(
RegionName, key, lockKey: null, lockValue: null
);
options.OnUnlockFailed(this, unlockFailedEventArgs);
return;
}
log.Debug("releasing cache lock: regionName='{0}', key='{1}', lockKey='{2}', lockValue='{3}'",
RegionName, lockData.Key, lockData.LockKey, lockData.LockValue
);
try
{
var db = GetDatabase();
var args = new {
lockKey = lockData.LockKey,
lockValue = lockData.LockValue
};
// Don't use IDatabase.LockRelease() because it uses watch/unwatch
// where we prefer an atomic operation (via a script).
var wasLockReleased = sync
? (bool)db.ScriptEvaluate(unlockScript, args)
: (bool)await db.ScriptEvaluateAsync(unlockScript, args);
if (!wasLockReleased)
{
log.Warn("attempted to unlock '{0}' but it could not be released (it maybe timed out or was cleared in Redis)", lockData);
var unlockFailedEventArgs = new UnlockFailedEventArgs(
RegionName, key, lockData.LockKey, lockData.LockValue
);
options.OnUnlockFailed(this, unlockFailedEventArgs);
}
}
catch (Exception e)
{
log.Error("could not release cache lock: regionName='{0}', key='{1}', lockKey='{2}', lockValue='{3}'",
RegionName, lockData.Key, lockData.LockKey, lockData.LockValue
);
var evtArg = new ExceptionEventArgs(RegionName, RedisCacheMethod.Unlock, e);
options.OnException(this, evtArg);
if (evtArg.Throw)
{
throw new RedisCacheException(RegionName, "Failed to unlock item in cache. See inner exception.", e);
}
}
}
private async Task LockCoreAsync(object key, CancellationToken cancellationToken, bool sync = false)
{
cancellationToken.ThrowIfNull("cancellationToken");
if (cancellationToken.IsCancellationRequested)
{
return;
}
log.Debug("acquiring cache lock: regionName='{0}', key='{1}'", RegionName, key);
try
{
var lockKey = CacheNamespace.GetLockKey(key);
var shouldRetry = options.AcquireLockRetryStrategy.GetShouldRetry();
var wasLockAcquired = false;
var shouldTryAcquireLock = true;
while (shouldTryAcquireLock)
{
var lockData = new LockData(
key: Convert.ToString(key),
lockKey: lockKey,
// Recalculated each attempt to ensure a unique value.
lockValue: options.LockValueFactory.GetLockValue()
);
bool lockAquired = sync
? this.TryAcquireLockAsync(lockData, true).ConfigureAwait(false).GetAwaiter().GetResult()
: await this.TryAcquireLockAsync(lockData);
if (lockAquired)
{
wasLockAcquired = true;
shouldTryAcquireLock = false;
}
else
{
var shouldRetryArgs = new ShouldRetryAcquireLockArgs(
RegionName, lockData.Key, lockData.LockKey,
lockData.LockValue, lockTimeout, acquireLockTimeout
);
shouldTryAcquireLock = shouldRetry(shouldRetryArgs);
}
}
if (!wasLockAcquired)
{
var lockFailedArgs = new LockFailedEventArgs(
RegionName, key, lockKey,
lockTimeout, acquireLockTimeout
);
options.OnLockFailed(this, lockFailedArgs);
}
}
catch (Exception e)
{
log.Error("could not acquire cache lock: regionName='{0}', key='{1}'", RegionName, key);
var evtArg = new ExceptionEventArgs(RegionName, RedisCacheMethod.Lock, e);
options.OnException(this, evtArg);
if (evtArg.Throw)
{
throw new RedisCacheException(RegionName, "Failed to lock item in cache. See inner exception.", e);
}
}
}
private async Task <object> GetCoreAsync(object key, CancellationToken cancellationToken, bool sync = false)
{
key.ThrowIfNull();
cancellationToken.ThrowIfNull("cancellationToken");
if (cancellationToken.IsCancellationRequested)
{
return(Task.FromCanceled <object>(cancellationToken));
}
log.Debug("get from cache: regionName='{0}', key='{1}'", RegionName, key);
try
{
var cacheKey = CacheNamespace.GetKey(key);
var setOfActiveKeysKey = CacheNamespace.GetSetOfActiveKeysKey();
var db = GetDatabase();
var args = new {
key = cacheKey,
setOfActiveKeysKey = setOfActiveKeysKey
};
var resultValues = sync
?(RedisValue[])db.ScriptEvaluate(getScript, args)
:(RedisValue[])await db.ScriptEvaluateAsync(getScript, args);
if (resultValues[0].IsNullOrEmpty)
{
log.Debug("cache miss: regionName='{0}', key='{1}'", RegionName, key);
return(null);
}
else
{
var serializedResult = resultValues[0];
var deserializedValue = options.Serializer.Deserialize(serializedResult);
if (deserializedValue != null && slidingExpiration != RedisCacheConfiguration.NoSlidingExpiration)
{
var slidingArgs = new {
key = cacheKey,
expiration = expiration.TotalMilliseconds,
slidingExpiration = slidingExpiration.TotalMilliseconds
};
if (sync)
{
db.ScriptEvaluate(slidingExpirationScript, slidingArgs, fireAndForgetFlags);
}
else
{
await db.ScriptEvaluateAsync(slidingExpirationScript, slidingArgs, fireAndForgetFlags);
}
}
return(deserializedValue);
}
}
catch (Exception e) {
log.Error("could not get from cache: regionName='{0}', key='{1}'", RegionName, key);
var evtArg = new ExceptionEventArgs(RegionName, RedisCacheMethod.Get, e);
options.OnException(this, evtArg);
if (evtArg.Throw)
{
throw new RedisCacheException(RegionName, "Failed to get item from cache. See inner exception.", e);
}
return(null);
}
}
