/// <summary>
/// Get from cache
/// </summary>
/// <param name="key"></param>
/// <param name="value"></param>
/// <returns></returns>
public bool TryGetValue(TKey key, out TValue value)
{
bool result;
lock (cache)
{
TimedCacheValue <TValue> cacheValue = null;
if (cache.TryGetValue(key, out cacheValue))
{
// check if the cached value has expired
DateTime now = DateTime.UtcNow;
if (cacheValue.TimeOut < now)
{
// cached info expired
this.cache.Remove(key);
result = false;
value = default(TValue);
}
else
{
// cached value valid
result = true;
value = cacheValue.Value;
}
}
else
{
// value not cached
result = false;
value = default(TValue);
}
}
return(result);
}
/// <summary>
/// Add to chache
/// </summary>
/// <param name="key"></param>
/// <param name="value"></param>
public void Add(TKey key, TValue value)
{
DateTime validUntilDateTime = this.GetValidUntilDateTime();
TimedCacheValue <TValue> cacheValue = new TimedCacheValue <TValue>(validUntilDateTime, value);
lock (cache) {
this.cache.Add(key, cacheValue);
}
}
/// <summary>
/// Try adds the key-value pair to the cache.
/// If the key/value does not exist, it is added, and returned
/// If the key/value does exist, the already existing value is returned
/// </summary>
/// <param name="key">The key</param>
/// <param name="value">The value to cache</param>
public TValue TryAddValue(TKey key, TValue value)
{
TValue result;
if (key == null)
{
throw new ArgumentNullException("key");
}
else
{
lock (cache)
{
TimedCacheValue <TValue> cacheValue = null;
if (cache.TryGetValue(key, out cacheValue))
{
// check if the cached value has expired
DateTime now = DateTime.UtcNow;
if (cacheValue.TimeOut < now)
{
// cached info expired
// so adding the new value instead
this.cache.Remove(key);
DateTime validUntilDateTime = this.GetValidUntilDateTime();
cacheValue = new TimedCacheValue <TValue>(validUntilDateTime, value);
this.cache.Add(key, cacheValue);
result = value;
}
else
{
// cached value valid
result = cacheValue.Value;
}
}
else
{
// value not cached
// adding the information
DateTime validUntilDateTime = this.GetValidUntilDateTime();
cacheValue = new TimedCacheValue <TValue>(validUntilDateTime, value);
this.cache.Add(key, cacheValue);
result = value;
}
}
}
return(result);
}
