public virtual void Run()
{
running = true;
HttpClient httpClient;
if (client == null)
{
// This is a race condition that can be reproduced by calling cbpuller.start() and cbpuller.stop()
// directly afterwards. What happens is that by the time the Changetracker thread fires up,
// the cbpuller has already set this.client to null. See issue #109
Log.W(Database.Tag, "ChangeTracker run() loop aborting because client == null");
return;
}
if (mode == ChangeTracker.ChangeTrackerMode.Continuous)
{
// there is a failing unit test for this, and from looking at the code the Replication
// object will never use Continuous mode anyway. Explicitly prevent its use until
// it is demonstrated to actually work.
throw new RuntimeException("ChangeTracker does not correctly support continuous mode"
);
}
httpClient = client.GetHttpClient();
ChangeTrackerBackoff backoff = new ChangeTrackerBackoff();
while (running)
{
Uri url = GetChangesFeedURL();
request = new HttpRequestMessage(url.ToString());
AddRequestHeaders(request);
// if the URL contains user info AND if this a DefaultHttpClient
// then preemptively set the auth credentials
if (url.GetUserInfo() != null)
{
Log.V(Database.Tag, "url.getUserInfo(): " + url.GetUserInfo());
if (url.GetUserInfo().Contains(":") && !url.GetUserInfo().Trim().Equals(":"))
{
string[] userInfoSplit = url.GetUserInfo().Split(":");
throw new NotImplementedException();
// Credentials creds = new UsernamePasswordCredentials(URIUtils.Decode(userInfoSplit
// [0]), URIUtils.Decode(userInfoSplit[1]));
// if (httpClient is DefaultHttpClient)
// {
// DefaultHttpClient dhc = (DefaultHttpClient)httpClient;
// MessageProcessingHandler preemptiveAuth = new _MessageProcessingHandler_212(creds
// );
// dhc.AddRequestInterceptor((HttpWebRequest request, HttpContext context)=>
// {
// AuthState authState = (AuthState)context.GetAttribute(ClientContext.TargetAuthState
// );
// CredentialsProvider credsProvider = (CredentialsProvider)context.GetAttribute(ClientContext
// .CredsProvider);
// HttpHost targetHost = (HttpHost)context.GetAttribute(ExecutionContext.HttpTargetHost
// );
// if (authState.GetAuthScheme() == null)
// {
// AuthScope authScope = new AuthScope(targetHost.GetHostName(), targetHost.GetPort(
// ));
// authState.SetAuthScheme(new BasicScheme());
// authState.SetCredentials(creds);
// }
// }, 0);
// }
}
else
{
Log.W(Database.Tag, "ChangeTracker Unable to parse user info, not setting credentials"
);
}
}
try
{
string maskedRemoteWithoutCredentials = GetChangesFeedURL().ToString();
maskedRemoteWithoutCredentials = maskedRemoteWithoutCredentials.ReplaceAll("://.*:.*@"
, "://---:---@");
Log.V(Database.Tag, "Making request to " + maskedRemoteWithoutCredentials);
HttpResponse response = httpClient.Execute(request);
StatusLine status = response.GetStatusLine();
if (status.GetStatusCode() >= 300)
{
Log.E(Database.Tag, "Change tracker got error " + Sharpen.Extensions.ToString(status
.GetStatusCode()));
string msg = string.Format(status.ToString());
this.error = new CouchbaseLiteException(msg, new Status(status.GetStatusCode()));
Stop();
}
HttpEntity entity = response.GetEntity();
InputStream input = null;
if (entity != null)
{
input = entity.GetContent();
if (mode == ChangeTracker.ChangeTrackerMode.LongPoll)
{
IDictionary <string, object> fullBody = Manager.GetObjectMapper().ReadValue <IDictionary
>(input);
bool responseOK = ReceivedPollResponse(fullBody);
if (mode == ChangeTracker.ChangeTrackerMode.LongPoll && responseOK)
{
Log.V(Database.Tag, "Starting new longpoll");
continue;
}
else
{
Log.W(Database.Tag, "Change tracker calling stop");
Stop();
}
}
else
{
JsonFactory jsonFactory = Manager.GetObjectMapper().GetJsonFactory();
JsonParser jp = jsonFactory.CreateJsonParser(input);
while (jp.CurrentToken() != JsonToken.StartArray)
{
}
// ignore these tokens
while (jp.CurrentToken() == JsonToken.StartObject)
{
IDictionary <string, object> change = (IDictionary)Manager.GetObjectMapper().ReadValue
<IDictionary>(jp);
if (!ReceivedChange(change))
{
Log.W(Database.Tag, string.Format("Received unparseable change line from server: %s"
, change));
}
}
Stop();
break;
}
backoff.ResetBackoff();
}
}
catch (Exception e)
{
if (!running && e is IOException)
{
}
else
{
// in this case, just silently absorb the exception because it
// frequently happens when we're shutting down and have to
// close the socket underneath our read.
Log.E(Database.Tag, "Exception in change tracker", e);
}
backoff.SleepAppropriateAmountOfTime();
}
}
Log.V(Database.Tag, "Change tracker run loop exiting");
}
// TODO: Needs to refactored into smaller calls. Each continuation could be its own method, for example.
public void Run()
{
running = true;
HttpClient httpClient;
if (client == null)
{
// This is a race condition that can be reproduced by calling cbpuller.start() and cbpuller.stop()
// directly afterwards. What happens is that by the time the Changetracker thread fires up,
// the cbpuller has already set this.client to null. See issue #109
Log.W(Tag, this + ": ChangeTracker run() loop aborting because client == null");
return;
}
if (mode == ChangeTracker.ChangeTrackerMode.Continuous)
{
// there is a failing unit test for this, and from looking at the code the Replication
// object will never use Continuous mode anyway. Explicitly prevent its use until
// it is demonstrated to actually work.
throw new RuntimeException("ChangeTracker does not correctly support continuous mode");
}
httpClient = client.GetHttpClient();
backoff = new ChangeTrackerBackoff();
var shouldBreak = false;
while (running)
{
if (tokenSource.Token.IsCancellationRequested)
{
break;
}
var url = GetChangesFeedURL();
Request = new HttpRequestMessage(HttpMethod.Get, url);
AddRequestHeaders(Request);
// if the URL contains user info AND if this a DefaultHttpClient
// then preemptively set/update the auth credentials
if (url.UserInfo != null)
{
Log.V(Tag, "url.getUserInfo(): " + url.GetUserInfo());
var credentials = Request.ToCredentialsFromUri();
if (credentials != null)
{
var handler = client.HttpHandler;
if (handler.Credentials == null || !handler.Credentials.Equals(credentials))
{
client.HttpHandler.Credentials = credentials;
}
}
else
{
Log.W(Tag, this + ": ChangeTracker Unable to parse user info, not setting credentials");
}
}
try
{
var requestStatus = CurrentRequest == null
? TaskStatus.Canceled
: CurrentRequest.Status;
Log.V(Tag, this + ": Current Request Status: " + requestStatus);
if (requestStatus == TaskStatus.Running || requestStatus == TaskStatus.WaitingForActivation)
{
//System.Threading.Thread.Sleep(5000);
continue;
}
var maskedRemoteWithoutCredentials = GetChangesFeedURL().ToString();
maskedRemoteWithoutCredentials = maskedRemoteWithoutCredentials.ReplaceAll("://.*:.*@", "://---:---@");
Log.V(Tag, this + ": Making request to " + maskedRemoteWithoutCredentials);
if (tokenSource.Token.IsCancellationRequested)
{
break;
}
CurrentRequest = httpClient.SendAsync(Request)
.ContinueWith <HttpResponseMessage>(request =>
{
if (request.Status != System.Threading.Tasks.TaskStatus.RanToCompletion && request.IsFaulted)
{
Log.E(Tag, this + ": Change tracker got error " + Extensions.ToString(request.Status));
throw request.Exception;
}
return(request.Result);
}, this.tokenSource.Token)
.ContinueWith <Task <Byte[]> >((request) =>
{
var status = request.Result.StatusCode;
if ((Int32)status >= 300)
{
var msg = String.Format("Change tracker got error: {0}", status);
Log.E(Tag, msg);
Error = new CouchbaseLiteException(msg, new Status(status.GetStatusCode()));
Stop();
}
return(request.Result.Content.ReadAsByteArrayAsync());
}, this.tokenSource.Token)
.ContinueWith((Task <Task <Byte[]> > response) =>
{
if (response.Status != System.Threading.Tasks.TaskStatus.RanToCompletion &&
!response.IsFaulted &&
response.Result != null)
{
return;
}
var result = response.Result.Result;
if (mode == ChangeTrackerMode.LongPoll)
{
var fullBody = Manager.GetObjectMapper().ReadValue <IDictionary <string, object> >(result.AsEnumerable());
var responseOK = ReceivedPollResponse(fullBody);
if (mode == ChangeTracker.ChangeTrackerMode.LongPoll && responseOK)
{
Log.V(Tag, this + ": Starting new longpoll");
backoff.ResetBackoff();
return;
}
else
{
Log.W(Tag, this + ": Change tracker calling stop");
Stop();
}
}
else
{
var results = Manager.GetObjectMapper().ReadValue <IDictionary <String, Object> >(result.AsEnumerable());
var resultsValue = results["results"] as Newtonsoft.Json.Linq.JArray;
foreach (var item in resultsValue)
{
IDictionary <String, Object> change = null;
try {
change = item.ToObject <IDictionary <String, Object> >();
} catch (Exception) {
Log.E(Tag, this + string.Format(": Received unparseable change line from server: {0}", change));
}
if (!ReceivedChange(change))
{
Log.W(Tag, this + string.Format(": Received unparseable change line from server: {0}", change));
}
}
Stop();
shouldBreak = true;
return;
}
backoff.ResetBackoff();
}, tokenSource.Token);
}
catch (Exception e)
{
if (!running && e is IOException)
{
// swallow
}
else
{
// in this case, just silently absorb the exception because it
// frequently happens when we're shutting down and have to
// close the socket underneath our read.
Log.E(Tag, this + ": Exception in change tracker", e);
}
backoff.SleepAppropriateAmountOfTime();
}
if (shouldBreak)
{
break;
}
}
if (!tokenSource.Token.IsCancellationRequested)
{ // Handle cancellation requests while we are waiting.
// e.g. when Stop() is called from another thread.
try {
CurrentRequest.Wait(tokenSource.Token);
} catch (Exception) {
Log.V(Tag, this + ": Run loop was cancelled.");
}
}
Log.V(Tag, this + ": Change tracker run loop exiting");
}
// TODO: Needs to refactored into smaller calls. Each continuation could be its own method, for example.
public void Run()
{
IsRunning = true;
if (client == null)
{
// This is a race condition that can be reproduced by calling cbpuller.start() and cbpuller.stop()
// directly afterwards. What happens is that by the time the Changetracker thread fires up,
// the cbpuller has already set this.client to null. See issue #109
Log.W(Tag, "ChangeTracker run() loop aborting because client == null");
return;
}
if (tokenSource.IsCancellationRequested)
{
tokenSource.Dispose();
tokenSource = new CancellationTokenSource();
}
backoff = new ChangeTrackerBackoff();
while (IsRunning && !tokenSource.Token.IsCancellationRequested)
{
// if (changesRequestTask != null && !changesRequestTask.IsCanceled && !changesRequestTask.IsFaulted)
// {
// Thread.Sleep(500);
// continue;
// }
var httpClient = client.GetHttpClient();
if (Request != null)
{
Request.Dispose();
Request = null;
}
var url = GetChangesFeedURL();
if (UsePost)
{
Request = new HttpRequestMessage(HttpMethod.Post, url);
var body = GetChangesFeedPostBody();
Request.Content = new StringContent(body);
Request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
}
else
{
Request = new HttpRequestMessage(HttpMethod.Get, url);
}
AddRequestHeaders(Request);
var authHeader = AuthUtils.GetAuthenticationHeaderValue(Authenticator, Request.RequestUri);
if (authHeader != null)
{
httpClient.DefaultRequestHeaders.Authorization = authHeader;
}
var maskedRemoteWithoutCredentials = url.ToString();
maskedRemoteWithoutCredentials = maskedRemoteWithoutCredentials.ReplaceAll("://.*:.*@", "://---:---@");
Log.V(Tag, "Making request to " + maskedRemoteWithoutCredentials);
if (tokenSource.Token.IsCancellationRequested)
{
break;
}
Task <HttpResponseMessage> changesRequestTask = null;
Task <HttpResponseMessage> successHandler;
Task <Boolean> errorHandler;
try {
changesFeedRequestTokenSource = CancellationTokenSource.CreateLinkedTokenSource(tokenSource.Token);
var evt = new ManualResetEvent(false);
//successHandler.ConfigureAwait(false).GetAwaiter().OnCompleted(()=>evt.Set());
// ChangeFeedResponseHandler(response);
var info = httpClient.SendAsync(
Request,
HttpCompletionOption.ResponseContentRead,
changesFeedRequestTokenSource.Token
);
var infoAwaiter = info.ConfigureAwait(false).GetAwaiter();
infoAwaiter.OnCompleted(() =>
evt.Set()
);
evt.WaitOne(ManagerOptions.Default.RequestTimeout);
changesRequestTask = info; //Task.FromResult(info.Result);
successHandler = changesRequestTask.ContinueWith <HttpResponseMessage>(
ChangeFeedResponseHandler,
changesFeedRequestTokenSource.Token,
TaskContinuationOptions.LongRunning | TaskContinuationOptions.OnlyOnRanToCompletion,
WorkExecutor.Scheduler
);
errorHandler = changesRequestTask.ContinueWith(t =>
{
if (t.IsCanceled)
{
return(false); // Not a real error.
}
var err = t.Exception.Flatten();
Log.D(Tag, "ChangeFeedResponseHandler faulted.", err.InnerException ?? err);
Error = err.InnerException ?? err;
return(true); // a real error.
}, changesFeedRequestTokenSource.Token, TaskContinuationOptions.OnlyOnFaulted, WorkExecutor.Scheduler);
try {
var completedTask = Task.WhenAll(successHandler, errorHandler);
completedTask.Wait((Int32)ManagerOptions.Default.RequestTimeout.TotalMilliseconds, changesFeedRequestTokenSource.Token);
Log.D(Tag, "Finished processing changes feed.");
} catch (Exception ex) {
// Swallow TaskCancelledExceptions, which will always happen
// if either errorHandler or successHandler don't need to fire.
if (!(ex.InnerException is TaskCanceledException))
{
throw ex;
}
} finally {
changesRequestTask.Dispose();
changesRequestTask = null;
successHandler.Dispose();
successHandler = null;
errorHandler.Dispose();
errorHandler = null;
Request.Dispose();
Request = null;
changesFeedRequestTokenSource.Dispose();
if (httpClient != null)
{
httpClient.Dispose();
}
}
}
catch (Exception e)
{
if (!IsRunning && e.InnerException is IOException)
{
// swallow
}
else
{
// in this case, just silently absorb the exception because it
// frequently happens when we're shutting down and have to
// close the socket underneath our read.
Log.E(Tag, "Exception in change tracker", e);
}
backoff.SleepAppropriateAmountOfTime();
}
finally
{
if (mode == ChangeTrackerMode.OneShot)
{
Stop();
}
}
// var singleRequestTokenSource = CancellationTokenSource.CreateLinkedTokenSource(tokenSource.Token);
// var cTask = httpClient.SendAsync(Request, HttpCompletionOption.ResponseHeadersRead, singleRequestTokenSource.Token);
// var bTask = cTask
// .ContinueWith<HttpResponseMessage>(t =>
// {
// if (!IsRunning)
// {
// return null;
// // swallow
// }
// if (t.IsFaulted && t.Exception.InnerException is IOException)
// {
// // in this case, just silently absorb the exception because it
// // frequently happens when we're shutting down and have to
// // close the socket underneath our read.
// Log.E(Tag, "Exception in change tracker", t.Exception);
// return null;
// }
// if (!singleRequestTokenSource.IsCancellationRequested && t.Exception != null)
// {
// var e = t.Exception.InnerException as WebException;
// var status = (HttpStatusCode)e.Status;
// if ((Int32)status >= 300 && !Misc.IsTransientError(status))
// {
// var response = t.Result;
// var msg = response.Content != null
// ? String.Format("Change tracker got error with status code: {0}", status)
// : String.Format("Change tracker got error with status code: {0} and null response content", status);
// Log.E(Tag, msg);
// Error = new CouchbaseLiteException(msg, new Status(status.GetStatusCode()));
// Stop();
// }
// backoff.SleepAppropriateAmountOfTime();
// }
// return t.Result;
// }, singleRequestTokenSource.Token, TaskContinuationOptions.OnlyOnFaulted, WorkExecutor.Scheduler)
// .ContinueWith<HttpResponseMessage>(ChangeFeedResponseHandler, singleRequestTokenSource.Token, TaskContinuationOptions.OnlyOnRanToCompletion, WorkExecutor.Scheduler)
// .ContinueWith<HttpResponseMessage>(t =>
// {
// Log.D(Tag, "ChangeFeedResponseHandler finished.");
// singleRequestTokenSource.Token.ThrowIfCancellationRequested();
// if (t != null) t.Result.Dispose();
// return null;
// }, singleRequestTokenSource.Token, TaskContinuationOptions.OnlyOnRanToCompletion, WorkExecutor.Scheduler);
// changesRequestTask = bTask;
// .ContinueWith((t) =>
// {
// Log.D(Tag, "ChangeFeedResponseHandler faulted.");
// }, singleRequestTokenSource.Token, TaskContinuationOptions.OnlyOnFaulted | TaskContinuationOptions.AttachedToParent, TaskScheduler.Default);
}
}
// TODO: Needs to refactored into smaller calls. Each continuation could be its own method, for example.
public void Run()
{
IsRunning = true;
if (client == null)
{
// This is a race condition that can be reproduced by calling cbpuller.start() and cbpuller.stop()
// directly afterwards. What happens is that by the time the Changetracker thread fires up,
// the cbpuller has already set this.client to null. See issue #109
Log.W(Tag, "ChangeTracker run() loop aborting because client == null");
return;
}
if (tokenSource.IsCancellationRequested)
{
tokenSource.Dispose();
tokenSource = new CancellationTokenSource();
}
backoff = new ChangeTrackerBackoff();
while (IsRunning && !tokenSource.Token.IsCancellationRequested)
{
if (Request != null)
{
Request.Dispose();
Request = null;
}
var url = GetChangesFeedURL();
if (UsePost)
{
Request = new HttpRequestMessage(HttpMethod.Post, url);
var body = GetChangesFeedPostBody();
Request.Content = new StringContent(body);
Request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
}
else
{
Request = new HttpRequestMessage(HttpMethod.Get, url);
}
AddRequestHeaders(Request);
var maskedRemoteWithoutCredentials = url.ToString();
maskedRemoteWithoutCredentials = maskedRemoteWithoutCredentials.ReplaceAll("://.*:.*@", "://---:---@");
Log.V(Tag, "Making request to " + maskedRemoteWithoutCredentials);
if (tokenSource.Token.IsCancellationRequested)
{
break;
}
Task <HttpResponseMessage> changesRequestTask = null;
Task <HttpResponseMessage> successHandler;
Task <Boolean> errorHandler;
HttpClient httpClient = null;
try {
httpClient = client.GetHttpClient();
var authHeader = AuthUtils.GetAuthenticationHeaderValue(Authenticator, Request.RequestUri);
if (authHeader != null)
{
httpClient.DefaultRequestHeaders.Authorization = authHeader;
}
changesFeedRequestTokenSource = CancellationTokenSource.CreateLinkedTokenSource(tokenSource.Token);
var evt = new ManualResetEvent(false);
// We do this akward set of calls in order
// to help minimize the frequency of the error:
//
// "Cannot re-call start of asynchronous method
// while a previous call is still in progress."
//
// There's got to be a better way to deal with this.
var info = httpClient.SendAsync(
Request,
changesFeedRequestTokenSource.Token
);
var infoAwaiter = info.ConfigureAwait(false).GetAwaiter();
infoAwaiter.OnCompleted(() =>
evt.Set()
);
evt.WaitOne(ManagerOptions.Default.RequestTimeout);
changesRequestTask = info;
successHandler = changesRequestTask.ContinueWith <HttpResponseMessage>(
ChangeFeedResponseHandler,
changesFeedRequestTokenSource.Token,
TaskContinuationOptions.LongRunning | TaskContinuationOptions.OnlyOnRanToCompletion,
WorkExecutor.Scheduler
);
errorHandler = changesRequestTask.ContinueWith(t =>
{
if (t.IsCanceled)
{
return(false); // Not a real error.
}
var err = t.Exception.Flatten();
Log.D(Tag, "ChangeFeedResponseHandler faulted.", err.InnerException ?? err);
Error = err.InnerException ?? err;
backoff.SleepAppropriateAmountOfTime();
return(true); // a real error.
}, changesFeedRequestTokenSource.Token, TaskContinuationOptions.OnlyOnFaulted, WorkExecutor.Scheduler);
try
{
var completedTask = Task.WhenAll(successHandler, errorHandler);
completedTask.Wait((Int32)ManagerOptions.Default.RequestTimeout.TotalMilliseconds, changesFeedRequestTokenSource.Token);
Log.D(Tag, "Finished processing changes feed.");
}
catch (Exception ex) {
// Swallow TaskCancelledExceptions, which will always happen
// if either errorHandler or successHandler don't need to fire.
if (!(ex.InnerException is TaskCanceledException))
{
throw ex;
}
}
finally
{
if (changesRequestTask.IsCompleted)
{
changesRequestTask.Dispose();
}
changesRequestTask = null;
if (successHandler.IsCompleted)
{
successHandler.Dispose();
}
successHandler = null;
if (errorHandler.IsCompleted)
{
errorHandler.Dispose();
}
errorHandler = null;
Request.Dispose();
Request = null;
changesFeedRequestTokenSource.Dispose();
changesFeedRequestTokenSource = null;
}
}
catch (Exception e)
{
if (!IsRunning && e.InnerException is IOException)
{
// swallow
}
else
{
// in this case, just silently absorb the exception because it
// frequently happens when we're shutting down and have to
// close the socket underneath our read.
Log.E(Tag, "Exception in change tracker", e);
}
backoff.SleepAppropriateAmountOfTime();
}
finally
{
if (httpClient != null)
{
httpClient.Dispose();
}
if (mode == ChangeTrackerMode.OneShot)
{
Stop();
}
}
}
}
