本文整理匯總了C#中ServiceStack.Redis.RedisClient.SetValueIfNotExists方法的典型用法代碼示例。如果您正苦於以下問題：C# RedisClient.SetValueIfNotExists方法的具體用法？C# RedisClient.SetValueIfNotExists怎麽用？C# RedisClient.SetValueIfNotExists使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類ServiceStack.Redis.RedisClient的用法示例。
在下文中一共展示了RedisClient.SetValueIfNotExists方法的1個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的C#代碼示例。
示例1: RedisLock
public RedisLock(RedisClient redisClient, string key, TimeSpan? timeOut)
{
this.redisClient = redisClient;
this.key = key;
ExecExtensions.RetryUntilTrue(
() =>
{
//This pattern is taken from the redis command for SETNX http://redis.io/commands/setnx
//Calculate a unix time for when the lock should expire
TimeSpan realSpan = timeOut ?? new TimeSpan(365, 0, 0, 0); //if nothing is passed in the timeout hold for a year
DateTime expireTime = DateTime.UtcNow.Add(realSpan);
string lockString = (expireTime.ToUnixTimeMs() + 1).ToString();
//Try to set the lock, if it does not exist this will succeed and the lock is obtained
var nx = redisClient.SetValueIfNotExists(key, lockString);
if (nx)
return true;
//If we've gotten here then a key for the lock is present. This could be because the lock is
//correctly acquired or it could be because a client that had acquired the lock crashed (or didn't release it properly).
//Therefore we need to get the value of the lock to see when it should expire
redisClient.Watch(key);
string lockExpireString = redisClient.Get<string>(key);
long lockExpireTime;
if (!long.TryParse(lockExpireString, out lockExpireTime))
{
redisClient.UnWatch(); // since the client is scoped externally
return false;
}
//If the expire time is greater than the current time then we can't let the lock go yet
if (lockExpireTime > DateTime.UtcNow.ToUnixTimeMs())
{
redisClient.UnWatch(); // since the client is scoped externally
return false;
}
//If the expire time is less than the current time then it wasn't released properly and we can attempt to
//acquire the lock. The above call to Watch(_lockKey) enrolled the key in monitoring, so if it changes
//before we call Commit() below, the Commit will fail and return false, which means that another thread
//was able to acquire the lock before we finished processing.
using (var trans = redisClient.CreateTransaction()) // we started the "Watch" above; this tx will succeed if the value has not moved
{
trans.QueueCommand(r => r.Set(key, lockString));
return trans.Commit(); //returns false if Transaction failed
}
},
timeOut
);
}