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ServerEventsFeature.cs
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2173 lines (1789 loc) · 84.4 KB
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#if NETCORE
using ServiceStack.Host;
#else
using System.Web;
#endif
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using ServiceStack.Auth;
using ServiceStack.DataAnnotations;
using ServiceStack.Host.Handlers;
using ServiceStack.Internal;
using ServiceStack.Logging;
using ServiceStack.Text;
using ServiceStack.Web;
namespace ServiceStack
{
public class ServerEventsFeature : IPlugin, Model.IHasStringId
{
public string Id { get; set; } = Plugins.ServerEvents;
public string StreamPath { get; set; }
public string HeartbeatPath { get; set; }
public string SubscribersPath { get; set; }
public string UnRegisterPath { get; set; }
public TimeSpan IdleTimeout { get; set; }
public TimeSpan HeartbeatInterval { get; set; }
public TimeSpan HouseKeepingInterval { get; set; }
public Action<IRequest> OnInit { get; set; }
public Action<IRequest> OnHeartbeatInit { get; set; }
public Action<IEventSubscription, IRequest> OnCreated { get; set; }
public Action<IEventSubscription, Dictionary<string, string>> OnConnect { get; set; }
public Action<IEventSubscription> OnSubscribe { get; set; }
public Action<IEventSubscription, IRequest> OnDispose { get; set; }
/// <summary>
/// Calls sync OnSubscribe if exists by default
/// </summary>
public Func<IEventSubscription, Task> OnSubscribeAsync { get; set; }
public Action<IEventSubscription> OnUnsubscribe { get; set; }
/// <summary>
/// Calls sync OnUnsubscribe if exists by default
/// </summary>
public Func<IEventSubscription,Task> OnUnsubscribeAsync { get; set; }
/// <summary>
/// Fired for both Sync/Async Notifications
/// </summary>
public Action<IEventSubscription, IResponse, string> OnPublish { get; set; }
/// <summary>
/// Only fired for async notifications. Calls sync OnPublish if exists by default.
/// </summary>
public Func<IEventSubscription, IResponse, string, Task> OnPublishAsync { get; set; }
/// <summary>
/// Fired when a subscription is updated
/// </summary>
public Func<IEventSubscription, Task> OnUpdateAsync { get; set; }
/// <summary>
/// Replace the default ServiceStack.Text JSON Serializer with an alternative JSON Serializer
/// </summary>
public Func<object, string> Serialize { get; set; }
public Action<IResponse, string> WriteEvent { get; private set; }
public Func<IResponse, string, Task> WriteEventAsync { get; private set; }
/// <summary>
/// Invoked when a connection
/// </summary>
public Action<IEventSubscription> OnHungConnection { get; set; }
public Action<IEventSubscription, Exception> OnError { get; set; }
public bool NotifyChannelOfSubscriptions { get; set; }
public bool LimitToAuthenticatedUsers { get; set; }
public bool ValidateUserAddress { get; set; }
public int ThrottlePublisherAfterBufferExceedsBytes { get; set; } = 1000 * 1024;
internal readonly ConcurrentDictionary<string, long> Counters = new();
public void IncrementCounter(string name)
{
Counters.AddOrUpdate(name, 1, (key, oldValue) => oldValue + 1);
}
public ServerEventsFeature()
{
StreamPath = "/event-stream";
HeartbeatPath = "/event-heartbeat";
UnRegisterPath = "/event-unregister";
SubscribersPath = "/event-subscribers";
WriteEvent = (res, frame) =>
{
if (res is IWriteEvent writeEvent)
{
writeEvent.WriteEvent(frame);
}
else
{
MemoryProvider.Instance.Write(res.AllowSyncIO().OutputStream, frame.AsMemory());
res.Flush();
}
};
WriteEventAsync = async (res, frame) =>
{
if (res is IWriteEventAsync writeEvent)
{
await writeEvent.WriteEventAsync(frame).ConfigAwait();
}
else
{
await MemoryProvider.Instance.WriteAsync(res.OutputStream, frame.AsMemory()).ConfigAwait();
await res.FlushAsync().ConfigAwait();
}
};
OnHungConnection = sub => {
var mse = HostContext.Resolve<IServerEvents>().GetMemoryServerEvents();
mse?.RegisterHungConnection(sub);
OnError?.Invoke(sub, new TimeoutException("Hung connection was detected"));
};
Serialize = JsonSerializer.SerializeToString;
IdleTimeout = TimeSpan.FromSeconds(30);
HeartbeatInterval = TimeSpan.FromSeconds(10);
HouseKeepingInterval = TimeSpan.FromSeconds(5);
NotifyChannelOfSubscriptions = true;
ValidateUserAddress = true;
OnSubscribeAsync = sub => {
OnSubscribe?.Invoke(sub);
return TypeConstants.EmptyTask;
};
OnUnsubscribeAsync = sub => {
OnUnsubscribe?.Invoke(sub);
return TypeConstants.EmptyTask;
};
OnPublishAsync = (sub, res, msg) => {
OnPublish?.Invoke(sub, res, msg);
return TypeConstants.EmptyTask;
};
}
public void Register(IAppHost appHost)
{
var container = appHost.GetContainer();
if (!container.Exists<IServerEvents>())
{
var broker = new MemoryServerEvents
{
IdleTimeout = IdleTimeout,
HouseKeepingInterval = HouseKeepingInterval,
OnSubscribeAsync = OnSubscribeAsync,
OnUnsubscribeAsync = OnUnsubscribeAsync,
OnUpdateAsync = OnUpdateAsync,
NotifyChannelOfSubscriptions = NotifyChannelOfSubscriptions,
Serialize = Serialize,
OnError = OnError,
};
container.Register<IServerEvents>(broker);
}
appHost.RawHttpHandlers.Add(httpReq =>
httpReq.PathInfo.EndsWith(StreamPath)
? (IHttpHandler)new ServerEventsHandler()
: httpReq.PathInfo.EndsWith(HeartbeatPath)
? new ServerEventsHeartbeatHandler()
: null);
if (UnRegisterPath != null)
{
appHost.RegisterService(typeof(ServerEventsUnRegisterService), UnRegisterPath);
}
if (SubscribersPath != null)
{
appHost.RegisterService(typeof(ServerEventsSubscribersService), SubscribersPath);
}
appHost.OnDisposeCallbacks.Add(host => container.Resolve<IServerEvents>().Stop());
}
internal bool CanAccessSubscription(IRequest req, SubscriptionInfo sub)
{
if (!ValidateUserAddress)
return true;
return sub.UserAddress == null || sub.UserAddress == req.UserHostAddress;
}
}
public class ServerEventsHandler : HttpAsyncTaskHandler
{
public override bool RunAsAsync()
{
return true;
}
/// <summary>
/// Call IServerEvents.RemoveExpiredSubscriptions() after every count
/// </summary>
public static int RemoveExpiredSubscriptionsEvery { get; } = 1000;
private static int ConnectionsCount = 0;
public const string EventStreamDenyNoAuth = nameof(EventStreamDenyNoAuth);
public const string EventStreamDenyOnInit = nameof(EventStreamDenyOnInit);
public const string EventStreamDenyOnCreated = nameof(EventStreamDenyOnCreated);
public override async Task ProcessRequestAsync(IRequest req, IResponse res, string operationName)
{
if (HostContext.ApplyCustomHandlerRequestFilters(req, res))
return;
var feature = HostContext.AssertPlugin<ServerEventsFeature>();
var session = await req.GetSessionAsync().ConfigAwait();
if (feature.LimitToAuthenticatedUsers && !session.IsAuthenticated)
{
feature.IncrementCounter(EventStreamDenyNoAuth);
await session.ReturnFailedAuthentication(req).ConfigAwait();
return;
}
var serverEvents = req.TryResolve<IServerEvents>();
if ((Interlocked.Increment(ref ConnectionsCount) % RemoveExpiredSubscriptionsEvery) == 0)
{
await serverEvents.RemoveExpiredSubscriptionsAsync().ConfigAwait();
}
EventSubscription subscription = null;
try
{
res.ContentType = MimeTypes.ServerSentEvents;
res.AddHeader(HttpHeaders.CacheControl, "no-cache");
res.ApplyGlobalResponseHeaders();
res.UseBufferedStream = false;
res.KeepAlive = true;
feature.OnInit?.Invoke(req);
if (req.Response.IsClosed)
{
feature.IncrementCounter(EventStreamDenyOnInit);
return; //Allow short-circuiting in OnInit callback
}
await res.FlushAsync().ConfigAwait();
var userAuthId = session?.UserAuthId;
var anonUserId = serverEvents.GetNextSequence("anonUser");
var userId = userAuthId ?? ("-" + anonUserId);
var displayName = session.GetSafeDisplayName()
?? "user" + anonUserId;
var now = DateTime.UtcNow;
var subscriptionId = SessionExtensions.CreateRandomSessionId();
//Handle both ?channel=A,B,C or ?channels=A,B,C
var channels = new List<string>();
var channel = req.QueryString["channel"];
if (!string.IsNullOrEmpty(channel))
channels.AddRange(channel.Split(','));
channel = req.QueryString["channels"];
if (!string.IsNullOrEmpty(channel))
channels.AddRange(channel.Split(','));
if (channels.Count == 0)
channels = EventSubscription.UnknownChannel.ToList();
subscription = new EventSubscription(res)
{
CreatedAt = now,
LastPulseAt = now,
Channels = channels.ToArray(),
SubscriptionId = subscriptionId,
UserId = userId,
UserName = session?.UserName,
DisplayName = displayName,
SessionId = req.GetSessionId(),
IsAuthenticated = session != null && session.IsAuthenticated,
UserAddress = req.UserHostAddress,
OnPublish = feature.OnPublish,
OnPublishAsync = feature.OnPublishAsync,
OnError = feature.OnError,
Meta = new Dictionary<string, string> {
{ "userId", userId },
{ "isAuthenticated", session != null && session.IsAuthenticated ? "true": "false" },
{ "displayName", displayName },
{ "channels", string.Join(",", channels) },
{ "createdAt", now.ToUnixTimeMs().ToString() },
{ AuthMetadataProvider.ProfileUrlKey, session.GetProfileUrl() ?? Svg.GetDataUri(Svg.Icons.DefaultProfile) },
}.ToConcurrentDictionary(),
ServerArgs = new Dictionary<string, string>(),
};
subscription.ConnectArgs = subscription.Meta.ToDictionary();
feature.OnCreated?.Invoke(subscription, req);
if (req.Response.IsClosed)
{
feature.IncrementCounter(EventStreamDenyOnCreated);
return; //Allow short-circuiting in OnCreated callback
}
var heartbeatUrl = feature.HeartbeatPath != null
? req.ResolveAbsoluteUrl("~/".CombineWith(feature.HeartbeatPath)).AddQueryParam("id", subscriptionId)
: null;
var unRegisterUrl = feature.UnRegisterPath != null
? req.ResolveAbsoluteUrl("~/".CombineWith(feature.UnRegisterPath)).AddQueryParam("id", subscriptionId)
: null;
heartbeatUrl = AddSessionParamsIfAny(heartbeatUrl, req);
unRegisterUrl = AddSessionParamsIfAny(unRegisterUrl, req);
subscription.ConnectArgs = new Dictionary<string, string>(subscription.ConnectArgs) {
{"id", subscriptionId },
{"unRegisterUrl", unRegisterUrl},
{"heartbeatUrl", heartbeatUrl},
{"updateSubscriberUrl", req.ResolveAbsoluteUrl("~/".CombineWith(feature.SubscribersPath, subscriptionId)) },
{"heartbeatIntervalMs", ((long)feature.HeartbeatInterval.TotalMilliseconds).ToString(CultureInfo.InvariantCulture) },
{"idleTimeoutMs", ((long)feature.IdleTimeout.TotalMilliseconds).ToString(CultureInfo.InvariantCulture)}
};
feature.OnConnect?.Invoke(subscription, subscription.ConnectArgs);
}
catch (Exception e)
{
feature.IncrementCounter("Error.EventStream." + e.GetType().Name);
res.StatusCode = 500;
throw;
}
await serverEvents.RegisterAsync(subscription, subscription.ConnectArgs).ConfigAwait();
if (req.Response is IWriteEventAsync) // gRPC
{
subscription.OnDispose = sub =>
{
try
{
feature.OnDispose?.Invoke(sub, req);
} catch { }
};
return;
}
var tcs = new TaskCompletionSource<bool>();
//Only invoked by subscription.Dispose()
subscription.OnDispose = sub =>
{
try
{
feature.OnDispose?.Invoke(sub, req);
} catch { }
if (!res.IsClosed)
System.Diagnostics.Debug.Fail("Should already be closed");
if (!tcs.Task.IsCompleted)
tcs.SetResult(true);
};
await tcs.Task.ConfigAwait();
}
static string AddSessionParamsIfAny(string url, IRequest req)
{
if (url != null && HostContext.Config.AllowSessionIdsInHttpParams)
{
var sessionKeys = new[] { "ss-id", "ss-pid", "ss-opt" };
foreach (var key in sessionKeys)
{
var value = req.QueryString[key];
if (value != null)
url = url.AddQueryParam(key, value);
}
}
return url;
}
}
public class ServerEventsHeartbeatHandler : HttpAsyncTaskHandler
{
public override bool RunAsAsync() { return true; }
private const string HeartbeatSubNotExists = nameof(HeartbeatSubNotExists);
private const string HeartbeatInvalidAccess = nameof(HeartbeatInvalidAccess);
public override async Task ProcessRequestAsync(IRequest req, IResponse res, string operationName)
{
if (HostContext.ApplyCustomHandlerRequestFilters(req, res))
return;
res.ApplyGlobalResponseHeaders();
var serverEvents = req.TryResolve<IServerEvents>();
await serverEvents.RemoveExpiredSubscriptionsAsync().ConfigAwait();
var feature = HostContext.GetPlugin<ServerEventsFeature>();
feature.OnHeartbeatInit?.Invoke(req);
if (req.Response.IsClosed)
return;
var subscriptionId = req.QueryString["id"];
var subscription = serverEvents.GetSubscriptionInfo(subscriptionId);
if (subscription == null)
{
res.StatusCode = 404;
res.StatusDescription = ErrorMessages.SubscriptionNotExistsFmt.LocalizeFmt(req, subscriptionId.SafeInput());
feature.IncrementCounter(HeartbeatSubNotExists);
}
else if (!feature.CanAccessSubscription(req, subscription))
{
res.StatusCode = 403;
res.StatusDescription = "Invalid User Address";
feature.IncrementCounter(HeartbeatInvalidAccess);
}
else if (!await serverEvents.PulseAsync(subscriptionId).ConfigAwait())
{
res.StatusCode = 404;
res.StatusDescription = ErrorMessages.SubscriptionNotExistsFmt.LocalizeFmt(req, subscriptionId.SafeInput());
feature.IncrementCounter(HeartbeatSubNotExists);
}
await res.EndHttpHandlerRequestAsync(skipHeaders: true).ConfigAwait();
}
}
[DefaultRequest(typeof(GetEventSubscribers))]
[Restrict(VisibilityTo = RequestAttributes.None)]
public class ServerEventsSubscribersService : Service
{
public IServerEvents ServerEvents { get; set; }
public object Any(GetEventSubscribers request)
{
var channels = new List<string>();
var deprecatedChannels = Request.QueryString["channel"];
if (!string.IsNullOrEmpty(deprecatedChannels))
channels.AddRange(deprecatedChannels.Split(','));
if (request.Channels != null)
channels.AddRange(request.Channels);
return channels.Count > 0
? ServerEvents.GetSubscriptionsDetails(channels.ToArray())
: ServerEvents.GetAllSubscriptionsDetails();
}
}
[ExcludeMetadata]
public class UnRegisterEventSubscriber : IReturn<Dictionary<string, string>>
{
public string Id { get; set; }
}
[DefaultRequest(typeof(UnRegisterEventSubscriber))]
[Restrict(VisibilityTo = RequestAttributes.None)]
public class ServerEventsUnRegisterService : Service
{
public IServerEvents ServerEvents { get; set; }
public const string UnRegisterSubNotExists = nameof(UnRegisterSubNotExists);
private const string UnRegisterInvalidAccess = nameof(UnRegisterInvalidAccess);
private const string UnRegisterApi = nameof(UnRegisterApi);
[AddHeader(ContentType = MimeTypes.Json)]
public async Task<object> Any(UnRegisterEventSubscriber request)
{
var subscription = ServerEvents.GetSubscriptionInfo(request.Id);
var feature = HostContext.GetPlugin<ServerEventsFeature>();
if (subscription == null)
{
feature.IncrementCounter(UnRegisterSubNotExists);
throw HttpError.NotFound(ErrorMessages.SubscriptionNotExistsFmt.LocalizeFmt(Request, request.Id).SafeInput());
}
if (!feature.CanAccessSubscription(base.Request, subscription))
{
feature.IncrementCounter(UnRegisterInvalidAccess);
throw HttpError.Forbidden(ErrorMessages.SubscriptionForbiddenFmt.LocalizeFmt(Request, request.Id.SafeInput()));
}
feature.IncrementCounter(UnRegisterApi);
await ServerEvents.UnRegisterAsync(subscription.SubscriptionId).ConfigAwait();
return subscription.Meta;
}
public const string UpdateEventSubNotExists = nameof(UpdateEventSubNotExists);
private const string UpdateEventInvalidAccess = nameof(UpdateEventInvalidAccess);
public async Task<object> Any(UpdateEventSubscriber request)
{
var subscription = ServerEvents.GetSubscriptionInfo(request.Id);
var feature = HostContext.GetPlugin<ServerEventsFeature>();
if (subscription == null)
{
feature.IncrementCounter(UpdateEventSubNotExists);
throw HttpError.NotFound(ErrorMessages.SubscriptionNotExistsFmt.LocalizeFmt(Request, request.Id).SafeInput());
}
if (!feature.CanAccessSubscription(base.Request, subscription))
{
feature.IncrementCounter(UpdateEventInvalidAccess);
throw HttpError.Forbidden(ErrorMessages.SubscriptionForbiddenFmt.LocalizeFmt(Request, request.Id.SafeInput()));
}
if (request.UnsubscribeChannels != null)
await ServerEvents.UnsubscribeFromChannelsAsync(subscription.SubscriptionId, request.UnsubscribeChannels).ConfigAwait();
if (request.SubscribeChannels != null)
await ServerEvents.SubscribeToChannelsAsync(subscription.SubscriptionId, request.SubscribeChannels).ConfigAwait();
return new UpdateEventSubscriberResponse();
}
}
/*
# Commands
cmd.announce This is your captain speaking ...
cmd.toggle$#channels
# CSS
css.background #eceff1
css.background$#top #673ab7
css.background$#right #fffde7
css.background$#bottom #0091ea
css.color$#me #ff0
css.display$img none
css.display$img inline
# Receivers
document.title New Window Title
window.location http://google.com
cmd.removeReceiver window
cmd.addReceiver window
tv.watch http://youtu.be/518XP8prwZo
tv.watch https://servicestack.net/img/logo-220.png
tv.off
# Triggers
trigger.customEvent arg
*/
public class EventSubscription : SubscriptionInfo, IEventSubscription, IServiceStackAsyncDisposable
{
private static ILog Log = LogManager.GetLogger(typeof(EventSubscription));
public static string[] UnknownChannel = { "*" };
private long LastPulseAtTicks = DateTime.UtcNow.Ticks;
public DateTime LastPulseAt
{
get
{
// assume gRPC connection is always active unless response is closed
return !response.IsClosed && (response is IWriteEvent || response is IWriteEventAsync)
? DateTime.UtcNow
: new DateTime(Interlocked.Read(ref LastPulseAtTicks), DateTimeKind.Utc);
}
set => Interlocked.Exchange(ref LastPulseAtTicks, value.Ticks);
}
/// <summary>
/// How long to wait to obtain lock before force disposing subscription connection
/// </summary>
public static int DisposeMaxWaitMs { get; set; } = 30 * 1000;
private long subscribed = 1;
private long isDisposed = 0;
private long disposing = 0;
public bool IsDisposed => Interlocked.Read(ref isDisposed) != 0;
private bool Disposing => Interlocked.Read(ref disposing) != 0;
private readonly IResponse response;
private long msgId;
public IResponse Response => this.response;
public IRequest Request => this.response.Request;
public long LastMessageId => Interlocked.Read(ref msgId);
public string[] MergedChannels { set; get; }
public EventSubscription(IResponse response)
{
this.response = response;
this.Meta = new ConcurrentDictionary<string, string>();
this.feature = HostContext.GetPlugin<ServerEventsFeature>();
this.WriteEvent = feature.WriteEvent;
this.WriteEventAsync = feature.WriteEventAsync;
this.OnHungConnection = feature.OnHungConnection;
}
public void UpdateChannels(string[] channels)
{
// combine old and new channels
var mergedChannels = new HashSet<string>(this.Channels);
channels.Each(x => mergedChannels.Add(x));
this.Channels = channels;
this.MergedChannels = mergedChannels.ToArray();
this.Meta["channels"] = string.Join(",", channels);
jsonArgs = null; //refresh
}
public Func<IEventSubscription, Task> OnUnsubscribeAsync { get; set; }
public Action<IEventSubscription> OnUnsubscribe { get; set; }
public Action<IEventSubscription, IResponse, string> OnPublish { get; set; }
public Func<IEventSubscription, IResponse, string, Task> OnPublishAsync { get; set; }
public Action<IEventSubscription> OnHungConnection { get; set; }
public Action<IEventSubscription> OnDispose { get; set; }
private ServerEventsFeature feature;
public Action<IResponse, string> WriteEvent { get; set; }
public Func<IResponse, string, Task> WriteEventAsync { get; set; }
public Action<IEventSubscription, Exception> OnError { get; set; }
public bool IsClosed => this.response.IsClosed;
private readonly StringBuilder buffer = new();
public void Pulse()
{
LastPulseAt = DateTime.UtcNow;
}
private string jsonArgs;
public string JsonArgs => jsonArgs ??= SerializeDictionary(Meta);
string CreateFrame(string selector, string message)
{
var msg = message ?? "";
var frame = "id: " + Interlocked.Increment(ref msgId) + "\n"
+ "data: " + selector + " " + msg + "\n\n";
return frame;
}
public void Publish(string selector)
{
Publish(selector, null);
}
private long semaphore = 0;
public bool IsLocked => Interlocked.Read(ref semaphore) != 0;
int GetThrottleMs()
{
// throttle publisher if buffer gets too full
lock (buffer)
return buffer.Length < this.feature.ThrottlePublisherAfterBufferExceedsBytes
? 0
: (int) Math.Ceiling(buffer.Length / 1000d);
}
#if DEBUG
private int threadIdWithLock = 0;
#endif
internal static long NotificationsSent = 0;
public Task PublishAsync(string selector, string message, CancellationToken token = default) =>
PublishRawAsync(CreateFrame(selector, message), token);
public async Task PublishRawAsync(string frame, CancellationToken token = default)
{
if (Disposing)
return;
if (response.IsClosed)
{
await DisposeAsync().ConfigAwait();
return;
}
Exception writeEx = null;
var hasLock = Interlocked.CompareExchange(ref semaphore, 1, 0) == 0;
try
{
if (hasLock)
{
#if DEBUG
Interlocked.Exchange(ref threadIdWithLock, Thread.CurrentThread.ManagedThreadId);
#endif
if (CanWrite())
{
try
{
var pendingWrites = GetAndResetBuffer();
if (pendingWrites != null)
frame = pendingWrites + frame;
if (OnPublishAsync != null)
await OnPublishAsync(this, response, frame).ConfigAwait();
Interlocked.Increment(ref NotificationsSent);
await WriteEventAsync(response, frame).ConfigAwait();
}
catch (Exception ex)
{
writeEx = ex;
this.feature.IncrementCounter("Error.Sub." + ex.GetType().Name);
}
}
}
else
{
var waitMs = GetThrottleMs();
if (waitMs > 0)
await Task.Delay(waitMs, token).ConfigAwait();
lock (buffer)
buffer.Append(frame);
}
}
finally
{
if (hasLock)
{
Interlocked.CompareExchange(ref semaphore, 0, semaphore);
#if DEBUG
Interlocked.Exchange(ref threadIdWithLock, 0);
#endif
if (writeEx != null)
await HandleWriteExceptionAsync(frame, writeEx, token).ConfigAwait();
}
}
if (response.IsClosed)
await DisposeAsync().ConfigAwait();
}
public void Publish(string selector, string message) => PublishRaw(CreateFrame(selector, message));
public void PublishRaw(string frame)
{
if (Disposing)
return;
if (response.IsClosed)
{
Dispose();
return;
}
Exception writeEx = null;
var hasLock = Interlocked.CompareExchange(ref semaphore, 1, 0) == 0;
try
{
if (hasLock)
{
if (CanWrite())
{
try
{
var pendingWrites = GetAndResetBuffer();
if (pendingWrites != null)
frame = pendingWrites + frame;
OnPublish?.Invoke(this, response, frame);
Interlocked.Increment(ref NotificationsSent);
WriteEvent(response, frame);
}
catch (Exception ex)
{
writeEx = ex;
this.feature.IncrementCounter("Error.Sub." + ex.GetType().Name);
}
}
}
else
{
var waitMs = GetThrottleMs();
if (waitMs > 0)
Thread.Sleep(waitMs);
lock (buffer)
buffer.Append(frame);
}
}
finally
{
if (hasLock)
{
Interlocked.CompareExchange(ref semaphore, 0, semaphore);
if (writeEx != null)
TaskExt.RunSync(() => HandleWriteExceptionAsync(frame, writeEx));
}
}
if (response.IsClosed)
Dispose();
}
string GetAndResetBuffer()
{
lock (buffer)
{
if (buffer.Length == 0)
return null;
var ret = buffer.ToString();
buffer.Length = 0;
return ret;
}
}
Task HandleWriteExceptionAsync(string frame, Exception ex, CancellationToken token=default)
{
if (ex != null)
{
Log.Warn("Could not publish notification to: " + frame.SafeSubstring(0, 50), ex);
OnError?.Invoke(this, ex);
}
if (Env.IsMono)
{
// Mono: If we explicitly close OutputStream after the error socket wont leak (response.Close() doesn't work)
try
{
// This will throw an exception, but on Mono (Linux/OSX) the socket will leak if we not close the OutputStream
response.OutputStream.Close();
}
catch (Exception innerEx)
{
Log.Error("OutputStream.Close()", innerEx);
this.feature.IncrementCounter("Error.SubClose." + innerEx.GetType().Name);
}
}
return UnsubscribeAsync();
}
private bool CanWrite() => !Disposing && !response.IsClosed;
[Obsolete("Use UnsubscribeAsync. Will be removed in future.")]
public void Unsubscribe()
{
if (Interlocked.CompareExchange(ref subscribed, 0, 1) == 1)
{
var fn = OnUnsubscribeAsync;
OnUnsubscribeAsync = null;
response.Request.TryResolve<IServerEvents>()?.QueueAsyncTask(() => fn(this));
}
Dispose();
}
public Task UnsubscribeAsync()
{
if (Interlocked.CompareExchange(ref subscribed, 0, 1) == 1)
{
var fn = OnUnsubscribeAsync;
OnUnsubscribeAsync = null;
if (fn != null)
return fn(this);
}
return DisposeAsync();
}
public static string SerializeDictionary(IDictionary<string, string> map)
{
if (map == null)
return null;
var sw = new System.IO.StringWriter();
sw.Write('{');
var i = 0;
foreach (var entry in map)
{
if (entry.Value == null)
continue;
if (i++ > 0)
sw.Write(',');
Text.Json.JsonUtils.WriteString(sw, entry.Key);
sw.Write(':');
Text.Json.JsonUtils.WriteString(sw, entry.Value);
}
sw.Write('}');
var json = sw.ToString();
return json;
}
Task IServiceStackAsyncDisposable.DisposeAsync() => DisposeAsync();
private async Task DisposeAsync()
{
if (Disposing)
return;
Interlocked.CompareExchange(ref disposing, 1, 0);
if (Interlocked.CompareExchange(ref isDisposed, 1, 0) == 0)
{
var totalWaitMs = 0;
var retries = 0;
while (Interlocked.CompareExchange(ref semaphore, 1, 0) != 0)
{
var waitMs = ExecUtils.CalculateMemoryLockDelay(++retries);
#if DEBUG
var msg = $"threadIdWithLock: {threadIdWithLock}, Current: {Thread.CurrentThread.ManagedThreadId}, waitMs: {waitMs}, total: {totalWaitMs}";
Log.Debug(msg);
#endif
await Task.Delay(waitMs).ConfigAwait();
totalWaitMs += waitMs;
if (DisposeMaxWaitMs >= 0 && totalWaitMs >= DisposeMaxWaitMs)
break;
}
var hasLock = DisposeMaxWaitMs < 0 || totalWaitMs < DisposeMaxWaitMs;
if (!hasLock)
{
Log.Error($"Hung connection detected: Could not acquire semaphore within {DisposeMaxWaitMs}ms.");
OnHungConnection(this);
return;
}
Release();
}
}
public void Dispose()
{
if (Disposing)
return;
Interlocked.CompareExchange(ref disposing, 1, 0);
if (Interlocked.CompareExchange(ref isDisposed, 1, 0) == 0)
{
var totalWaitMs = 0;
var retries = 0;
while (Interlocked.CompareExchange(ref semaphore, 1, 0) != 0)
{
var waitMs = ExecUtils.CalculateMemoryLockDelay(++retries);
Thread.Sleep(waitMs);
totalWaitMs += waitMs;
if (DisposeMaxWaitMs >= 0 && totalWaitMs >= DisposeMaxWaitMs)
break;
}
var hasLock = DisposeMaxWaitMs < 0 || totalWaitMs < DisposeMaxWaitMs;
if (!hasLock)
{
Log.Error($"Hung connection detected: Could not acquire semaphore within {DisposeMaxWaitMs}ms.");
OnHungConnection(this);
return;
}
Release();
}
}
public void Release()
{
try
{
response.EndHttpHandlerRequest(skipHeaders: true);
}
catch (Exception ex)
{
Log.Error("Error ending subscription response", ex);
this.feature.IncrementCounter("Error.SubRelease." + ex.GetType().Name);
}
var fn = OnDispose;
fn?.Invoke(this);
OnDispose = null;
}
}
public interface IEventSubscription : IDisposable
{
DateTime CreatedAt { get; set; }
DateTime LastPulseAt { get; set; }
long LastMessageId { get; }
string[] Channels { get; }
string[] MergedChannels { get; } //both current and previous channels
string UserId { get; }
string UserName { get; }
string DisplayName { get; }
string SessionId { get; }
string SubscriptionId { get; }
string UserAddress { get; set; }
bool IsAuthenticated { get; set; }
bool IsClosed { get; }
void UpdateChannels(string[] channels);