/// <summary>
/// Adds a node to the global polling list ONLY IF IT IS NEW
/// If a node with the same unique key was already added, it will not be added again
/// </summary>
/// <param name="node">The node to add to the global polling list</param>
/// <returns>Whether the node was added</returns>
public static bool TryAdd(PollNode node)
{
lock (_addLock)
{
return AllPollNodes.Add(node);
}
}
/// <summary>
/// Adds a node to the global polling list ONLY IF IT IS NEW
/// If a node with the same unique key was already added, it will not be added again
/// </summary>
/// <param name="node">The node to add to the global polling list</param>
/// <returns>Whether the node was added</returns>
public static bool TryAdd(PollNode node)
{
lock (_addLock)
{
return(AllPollNodes.Add(node));
}
}
public static bool TryRemove(PollNode node)
{
if (node == null || !node.AddedToGlobalPollers) return false;
lock (_addLock)
{
return AllPollNodes.Remove(node);
}
}
public static NodeData FromNode(PollNode node, bool includeCache = false)
{
return(new NodeData
{
Name = node.UniqueKey,
Type = node.NodeType,
LastPolled = node.LastPoll,
LastPollDurationMS = node.LastPollDuration.TotalMilliseconds,
Caches = node.DataPollers.Select(c => CacheData.FromCache(c, includeCache))
});
}
public static bool TryRemove(PollNode node)
{
if (node == null || !node.AddedToGlobalPollers)
{
return(false);
}
lock (_addLock)
{
return(AllPollNodes.Remove(node));
}
}
public static NodeData FromNode(PollNode node, bool includeCache = false)
{
return new NodeData
{
Name = node.UniqueKey,
Type = node.NodeType,
LastPolled = node.LastPoll,
LastPollDurationMS = node.LastPollDuration.TotalMilliseconds,
Caches = node.DataPollers.Select(c => CacheData.FromCache(c, includeCache))
};
}
/// <summary>
/// Creates a cache poller
/// </summary>
/// <typeparam name="T">Type of item in the cache</typeparam>
/// <param name="owner">The PollNode owner of this Cache</param>
/// <param name="description">Description of the operation, used purely for profiling</param>
/// <param name="cacheDuration">The length of time to cache data for</param>
/// <param name="getData">The operation used to actually get data, e.g. <code>using (var conn = GetConnectionAsync()) { return getFromConnection(conn); }</code></param>
/// <param name="timeoutMs">The timeout in milliseconds for this poll to complete before aborting.</param>
/// <param name="logExceptions">Whether to log any exceptions to the log</param>
/// <param name="addExceptionData">Optionally add exception data, e.g. <code>e => e.AddLoggedData("Server", Name)</code></param>
/// <param name="afterPoll">An optional action to run after polling has completed successfully</param>
/// <param name="memberName"></param>
/// <param name="sourceFilePath"></param>
/// <param name="sourceLineNumber"></param>
/// <returns>A cache update action, used when creating a <see cref="Cache"/>.</returns>
public Cache(PollNode owner,
string description,
TimeSpan cacheDuration,
Func <Task <T> > getData,
int?timeoutMs = null,
bool?logExceptions = null,
Action <Exception> addExceptionData = null,
Action <Cache <T> > afterPoll = null,
[CallerMemberName] string memberName = "",
[CallerFilePath] string sourceFilePath = "",
[CallerLineNumber] int sourceLineNumber = 0)
: base(cacheDuration, memberName, sourceFilePath, sourceLineNumber)
{
MiniProfilerDescription = "Poll: " + description; // concatenate once
// TODO: Settings via owner
logExceptions = logExceptions ?? LogExceptions;
_updateFunc = async() =>
{
var success = true;
PollStatus = "UpdateCacheItem";
if (EnableProfiling)
{
Profiler = _profilerOptions.StartProfiler(MiniProfilerDescription);
Profiler.Id = UniqueId;
}
using (MiniProfiler.Current.Step(description))
{
try
{
PollStatus = "Fetching";
using (MiniProfiler.Current.Step("Data Fetch"))
{
var task = getData();
if (timeoutMs.HasValue)
{
if (await Task.WhenAny(task, Task.Delay(timeoutMs.Value)) == task)
{
// Re-await for throws.
Data = await task;
}
else
{
// This means the .WhenAny returned the timeout first...boom.
throw new TimeoutException($"Fetch timed out after {timeoutMs} ms.");
}
}
else
{
Data = await task;
}
}
PollStatus = "Fetch Complete";
SetSuccess();
afterPoll?.Invoke(this);
}
catch (Exception e)
{
success = false;
if (logExceptions.Value)
{
addExceptionData?.Invoke(e);
e.Log();
}
var errorMessage = StringBuilderCache.Get()
.Append("Unable to fetch from ")
.Append(owner.NodeType)
.Append(": ")
.Append(e.Message);
#if DEBUG
errorMessage.Append(" @ ").Append(e.StackTrace);
#endif
if (e.InnerException != null)
{
errorMessage.AppendLine().Append(e.InnerException.Message);
}
PollStatus = "Fetch Failed";
SetFail(e, errorMessage.ToStringRecycle());
}
owner.PollComplete(this, success);
}
if (EnableProfiling)
{
Profiler.Stop();
}
PollStatus = "UpdateCacheItem Complete";
return(Data);
};
}