private void ProcessLongPollStream(Task <Stream> t)
{
Log.D(TAG, "Got stream from change tracker response");
bool beforeFirstItem = true;
bool responseOK = false;
using (var jsonReader = Manager.GetObjectMapper().StartIncrementalParse(t.Result)) {
responseOK = ReceivedPollResponse(jsonReader, ref beforeFirstItem);
}
Log.D(TAG, "Finished polling change tracker");
if (responseOK)
{
Log.V(TAG, "Starting new longpoll");
backoff.ResetBackoff();
WorkExecutor.StartNew(Run);
}
else
{
backoff.SleepAppropriateAmountOfTime();
if (beforeFirstItem)
{
var elapsed = DateTime.Now - _startTime;
Log.W(TAG, "Longpoll connection closed (by proxy?) after {0} sec", elapsed.TotalSeconds);
// Looks like the connection got closed by a proxy (like AWS' load balancer) while the
// server was waiting for a change to send, due to lack of activity.
// Lower the heartbeat time to work around this, and reconnect:
_heartbeatMilliseconds = (int)(elapsed.TotalMilliseconds * 0.75f);
Log.V(TAG, " Starting new longpoll");
backoff.ResetBackoff();
WorkExecutor.StartNew(Run);
}
else
{
Log.W(TAG, "Change tracker calling stop");
WorkExecutor.StartNew(Stop);
}
}
}
public void Run()
{
IsRunning = true;
var clientCopy = client;
if (clientCopy == 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();
_startTime = DateTime.Now;
if (Request != null)
{
Request.Dispose();
Request = null;
}
var url = GetChangesFeedURL();
Request = new HttpRequestMessage(HttpMethod.Post, url);
var body = GetChangesFeedPostBody();
Request.Content = new StringContent(body);
Request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
AddRequestHeaders(Request);
var maskedRemoteWithoutCredentials = url.ToString();
maskedRemoteWithoutCredentials = maskedRemoteWithoutCredentials.ReplaceAll("://.*:.*@", "://---:---@");
Log.V(TAG, "Making request to " + maskedRemoteWithoutCredentials);
if (tokenSource.Token.IsCancellationRequested) {
return;
}
HttpClient httpClient = null;
try {
httpClient = clientCopy.GetHttpClient(mode == ChangeTrackerMode.LongPoll);
var challengeResponseAuth = Authenticator as IChallengeResponseAuthenticator;
if(challengeResponseAuth != null) {
challengeResponseAuth.PrepareWithRequest(Request);
}
var authHeader = AuthUtils.GetAuthenticationHeaderValue(Authenticator, Request.RequestUri);
if (authHeader != null)
{
httpClient.DefaultRequestHeaders.Authorization = authHeader;
}
changesFeedRequestTokenSource = CancellationTokenSource.CreateLinkedTokenSource(tokenSource.Token);
var option = mode == ChangeTrackerMode.LongPoll ? HttpCompletionOption.ResponseHeadersRead : HttpCompletionOption.ResponseContentRead;
var info = httpClient.SendAsync(
Request,
option,
changesFeedRequestTokenSource.Token
);
info.ContinueWith(t1 => {
ChangeFeedResponseHandler(t1).ContinueWith(t2 =>
{
if(httpClient != null) {
httpClient.Dispose();
}
});
}, changesFeedRequestTokenSource.Token,
TaskContinuationOptions.LongRunning,
TaskScheduler.Default);
}
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();
}
}
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");
}
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, 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();
while (running)
{
Uri url = GetChangesFeedURL();
request = new HttpGet(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, this + ": url.getUserInfo(): " + url.GetUserInfo());
if (url.GetUserInfo().Contains(":") && !url.GetUserInfo().Trim().Equals(":"))
{
string[] userInfoSplit = url.GetUserInfo().Split(":");
Credentials creds = new UsernamePasswordCredentials(URIUtils.Decode(userInfoSplit
[0]), URIUtils.Decode(userInfoSplit[1]));
if (httpClient is DefaultHttpClient)
{
DefaultHttpClient dhc = (DefaultHttpClient)httpClient;
MessageProcessingHandler preemptiveAuth = new _MessageProcessingHandler_221(creds
);
dhc.AddRequestInterceptor(preemptiveAuth, 0);
}
}
else
{
Log.W(Database.Tag, this + ": ChangeTracker Unable to parse user info, not setting credentials"
);
}
}
try
{
string maskedRemoteWithoutCredentials = GetChangesFeedURL().ToString();
maskedRemoteWithoutCredentials = maskedRemoteWithoutCredentials.ReplaceAll("://.*:.*@"
, "://---:---@");
Log.V(Database.Tag, this + ": Making request to " + maskedRemoteWithoutCredentials
);
HttpResponse response = httpClient.Execute(request);
StatusLine status = response.GetStatusLine();
if (status.GetStatusCode() >= 300)
{
Log.E(Database.Tag, this + ": 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)
{
try
{
input = entity.GetContent();
if (mode == ChangeTracker.ChangeTrackerMode.LongPoll)
{
// continuous replications
IDictionary<string, object> fullBody = Manager.GetObjectMapper().ReadValue<IDictionary
>(input);
bool responseOK = ReceivedPollResponse(fullBody);
if (mode == ChangeTracker.ChangeTrackerMode.LongPoll && responseOK)
{
Log.V(Database.Tag, this + ": Starting new longpoll");
backoff.ResetBackoff();
continue;
}
else
{
Log.W(Database.Tag, this + ": Change tracker calling stop (LongPoll)");
Stop();
}
}
else
{
// one-shot replications
JsonFactory jsonFactory = Manager.GetObjectMapper().GetJsonFactory();
JsonParser jp = jsonFactory.CreateJsonParser(input);
while (jp.NextToken() != JsonToken.StartArray)
{
}
// ignore these tokens
while (jp.NextToken() == 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));
}
}
Log.W(Database.Tag, this + ": Change tracker calling stop (OneShot)");
Stop();
break;
}
backoff.ResetBackoff();
}
finally
{
try
{
entity.ConsumeContent();
}
catch (IOException)
{
}
}
}
}
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, this + ": Exception in change tracker", e);
}
backoff.SleepAppropriateAmountOfTime();
}
}
Log.V(Database.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;
var clientCopy = client;
if (clientCopy == 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)
{
_startTime = DateTime.Now;
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 successHandler;
Task errorHandler;
HttpClient httpClient = null;
try {
httpClient = clientCopy.GetHttpClient(mode == ChangeTrackerMode.LongPoll);
var authHeader = AuthUtils.GetAuthenticationHeaderValue(Authenticator, Request.RequestUri);
if (authHeader != null)
{
httpClient.DefaultRequestHeaders.Authorization = authHeader;
}
changesFeedRequestTokenSource = CancellationTokenSource.CreateLinkedTokenSource(tokenSource.Token);
var option = mode == ChangeTrackerMode.LongPoll ? HttpCompletionOption.ResponseHeadersRead : HttpCompletionOption.ResponseContentRead;
var info = httpClient.SendAsync(
Request,
option,
changesFeedRequestTokenSource.Token
);
successHandler = info.ContinueWith(
ChangeFeedResponseHandler,
changesFeedRequestTokenSource.Token,
TaskContinuationOptions.LongRunning | TaskContinuationOptions.OnlyOnRanToCompletion,
WorkExecutor.Scheduler
);
errorHandler = info.ContinueWith(t =>
{
if (t.IsCanceled)
{
return; // Not a real error.
}
var err = t.Exception.Flatten();
Log.D(Tag, "ChangeFeedResponseHandler faulted.", err.InnerException ?? err);
Error = err.InnerException ?? err;
backoff.SleepAppropriateAmountOfTime();
}, changesFeedRequestTokenSource.Token, TaskContinuationOptions.NotOnRanToCompletion, WorkExecutor.Scheduler);
try
{
Task.WaitAll(successHandler, errorHandler);
Log.D(Tag, "Finished processing changes feed.");
}
catch (Exception ex) {
var e = ex.InnerException ?? ex;
// Swallow TaskCancelledExceptions, which will always happen
// if either errorHandler or successHandler don't need to fire.
if (!(e is OperationCanceledException))
throw ex;
}
finally
{
if (changesRequestTask != null)
{
if(changesRequestTask.IsCompleted)
{
changesRequestTask.Dispose();
}
changesRequestTask = null;
}
if (successHandler != null)
{
if(successHandler.IsCompleted)
{
successHandler.Dispose();
}
successHandler = null;
}
if (errorHandler != null)
{
if(errorHandler.IsCompleted)
{
errorHandler.Dispose();
}
errorHandler = null;
}
if(Request != null)
{
Request.Dispose();
Request = null;
}
if(changesFeedRequestTokenSource != 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();
}
}
}
}
HttpResponseMessage ChangeFeedResponseHandler(Task <HttpResponseMessage> responseTask)
{
var response = responseTask.Result;
if (response == null)
{
return(null);
}
var status = response.StatusCode;
if ((Int32)status >= 300 && !Misc.IsTransientError(status))
{
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();
return(response);
}
switch (mode)
{
case ChangeTrackerMode.LongPoll:
{
if (response.Content == null)
{
throw new CouchbaseLiteException("Got empty change tracker response", status.GetStatusCode());
}
var content = response.Content.ReadAsByteArrayAsync().Result;
IDictionary <string, object> fullBody;
try
{
fullBody = Manager.GetObjectMapper().ReadValue <IDictionary <string, object> >(content) ?? new Dictionary <string, object>();
}
catch (JsonSerializationException ex)
{
const string timeoutContent = "{\"results\":[";
if (!Encoding.UTF8.GetString(content).Trim().Equals(timeoutContent))
{
throw ex;
}
Log.V(Tag, "Timeout while waiting for changes.");
backoff.SleepAppropriateAmountOfTime();
return(response);
}
var responseOK = ReceivedPollResponse(fullBody);
if (responseOK)
{
Log.V(Tag, "Starting new longpoll");
backoff.ResetBackoff();
return(response);
}
else
{
Log.W(Tag, "Change tracker calling stop");
Stop();
}
}
break;
default:
{
var content = response.Content.ReadAsByteArrayAsync().Result;
var results = Manager.GetObjectMapper().ReadValue <IDictionary <String, Object> >(content.AsEnumerable());
Log.D(Tag, "Received results from changes feed: {0}", results);
var resultsValue = results["results"] as 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));
}
}
// As ReceivedChange() dispatches the change event to its client via WorkExecutor,
// to avoid the Stop() to be called before the client is done handling the change event,
// we need to setup the Stop() call with the WorkExecutor as well
// (Assuming that the WorkExecutor is a single thread executor).
WorkExecutor.StartNew(Stop);
return(response);
}
}
backoff.ResetBackoff();
return(response);
}
// TODO: Needs to refactored into smaller calls. Each continuation could be its own method, for example.
public void Run()
{
IsRunning = true;
var clientCopy = client;
if (clientCopy == 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 = clientCopy.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
);
info.ContinueWith((t) =>
evt.Set()
);
if (evt.WaitOne(ManagerOptions.Default.RequestTimeout) == false)
{
Log.W(Tag, "SendAsync timeout");
continue;
}
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
{
Task.WaitAll(new Task[] { successHandler, errorHandler }, (Int32)ManagerOptions.Default.RequestTimeout.TotalMilliseconds, changesFeedRequestTokenSource.Token);
Log.D(Tag, "Finished processing changes feed.");
}
catch (Exception ex) {
var e = ex.InnerException ?? ex;
// Swallow TaskCancelledExceptions, which will always happen
// if either errorHandler or successHandler don't need to fire.
if (!(e is OperationCanceledException))
{
throw ex;
}
}
finally
{
if (changesRequestTask != null)
{
if (changesRequestTask.IsCompleted)
{
changesRequestTask.Dispose();
}
changesRequestTask = null;
}
if (successHandler != null)
{
if (successHandler.IsCompleted)
{
successHandler.Dispose();
}
successHandler = null;
}
if (errorHandler != null)
{
if (errorHandler.IsCompleted)
{
errorHandler.Dispose();
}
errorHandler = null;
}
if (Request != null)
{
Request.Dispose();
Request = null;
}
if (changesFeedRequestTokenSource != 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();
}
}
}
}
// 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 = TaskEx.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 OperationCanceledException))
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();
}
}
}
}
public void Run()
{
IsRunning = true;
var clientCopy = client;
if (clientCopy == 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();
_startTime = DateTime.Now;
if (Request != null)
{
Request.Dispose();
Request = null;
}
var url = GetChangesFeedURL();
Request = new HttpRequestMessage(HttpMethod.Post, url);
var body = GetChangesFeedPostBody();
Request.Content = new StringContent(body);
Request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
AddRequestHeaders(Request);
var maskedRemoteWithoutCredentials = url.ToString();
maskedRemoteWithoutCredentials = maskedRemoteWithoutCredentials.ReplaceAll("://.*:.*@", "://---:---@");
Log.V(TAG, "Making request to " + maskedRemoteWithoutCredentials);
if (tokenSource.Token.IsCancellationRequested)
{
return;
}
HttpClient httpClient = null;
try {
httpClient = clientCopy.GetHttpClient(mode == ChangeTrackerMode.LongPoll);
var challengeResponseAuth = Authenticator as IChallengeResponseAuthenticator;
if (challengeResponseAuth != null)
{
challengeResponseAuth.PrepareWithRequest(Request);
}
var authHeader = AuthUtils.GetAuthenticationHeaderValue(Authenticator, Request.RequestUri);
if (authHeader != null)
{
httpClient.DefaultRequestHeaders.Authorization = authHeader;
}
changesFeedRequestTokenSource = CancellationTokenSource.CreateLinkedTokenSource(tokenSource.Token);
var option = mode == ChangeTrackerMode.LongPoll ? HttpCompletionOption.ResponseHeadersRead : HttpCompletionOption.ResponseContentRead;
var info = httpClient.SendAsync(
Request,
option,
changesFeedRequestTokenSource.Token
);
info.ContinueWith(t1 => {
ChangeFeedResponseHandler(t1).ContinueWith(t2 =>
{
if (httpClient != null)
{
httpClient.Dispose();
}
});
}, changesFeedRequestTokenSource.Token,
TaskContinuationOptions.LongRunning,
TaskScheduler.Default);
}
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();
}
}
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(Log.TagChangeTracker, "%s: ChangeTracker run() loop aborting because client == null"
, this);
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();
while (running)
{
Uri url = GetChangesFeedURL();
if (usePOST)
{
HttpPost postRequest = new HttpPost(url.ToString());
postRequest.SetHeader("Content-Type", "application/json");
StringEntity entity;
try
{
entity = new StringEntity(ChangesFeedPOSTBody());
}
catch (UnsupportedEncodingException e)
{
throw new RuntimeException(e);
}
postRequest.SetEntity(entity);
request = postRequest;
}
else
{
request = new HttpGet(url.ToString());
}
AddRequestHeaders(request);
// Perform BASIC Authentication if needed
bool isUrlBasedUserInfo = false;
// If the URL contains user info AND if this a DefaultHttpClient then preemptively set the auth credentials
string userInfo = url.GetUserInfo();
if (userInfo != null)
{
isUrlBasedUserInfo = true;
}
else
{
if (authenticator != null)
{
AuthenticatorImpl auth = (AuthenticatorImpl)authenticator;
userInfo = auth.AuthUserInfo();
}
}
if (userInfo != null)
{
if (userInfo.Contains(":") && !userInfo.Trim().Equals(":"))
{
string[] userInfoElements = userInfo.Split(":");
string username = isUrlBasedUserInfo ? URIUtils.Decode(userInfoElements[0]) : userInfoElements
[0];
string password = isUrlBasedUserInfo ? URIUtils.Decode(userInfoElements[1]) : userInfoElements
[1];
Credentials credentials = new UsernamePasswordCredentials(username, password);
if (httpClient is DefaultHttpClient)
{
DefaultHttpClient dhc = (DefaultHttpClient)httpClient;
MessageProcessingHandler preemptiveAuth = new _MessageProcessingHandler_285(credentials
);
dhc.AddRequestInterceptor(preemptiveAuth, 0);
}
}
else
{
Log.W(Log.TagChangeTracker, "RemoteRequest Unable to parse user info, not setting credentials"
);
}
}
try
{
string maskedRemoteWithoutCredentials = GetChangesFeedURL().ToString();
maskedRemoteWithoutCredentials = maskedRemoteWithoutCredentials.ReplaceAll("://.*:.*@"
, "://---:---@");
Log.V(Log.TagChangeTracker, "%s: Making request to %s", this, maskedRemoteWithoutCredentials
);
HttpResponse response = httpClient.Execute(request);
StatusLine status = response.GetStatusLine();
if (status.GetStatusCode() >= 300 && !Utils.IsTransientError(status))
{
Log.E(Log.TagChangeTracker, "%s: Change tracker got error %d", this, status.GetStatusCode
());
this.error = new HttpResponseException(status.GetStatusCode(), status.GetReasonPhrase
());
Stop();
}
HttpEntity entity = response.GetEntity();
InputStream input = null;
if (entity != null)
{
try
{
input = entity.GetContent();
if (mode == ChangeTracker.ChangeTrackerMode.LongPoll)
{
// continuous replications
IDictionary <string, object> fullBody = Manager.GetObjectMapper().ReadValue <IDictionary
>(input);
bool responseOK = ReceivedPollResponse(fullBody);
if (mode == ChangeTracker.ChangeTrackerMode.LongPoll && responseOK)
{
Log.V(Log.TagChangeTracker, "%s: Starting new longpoll", this);
backoff.ResetBackoff();
continue;
}
else
{
Log.W(Log.TagChangeTracker, "%s: Change tracker calling stop (LongPoll)", this);
Stop();
}
}
else
{
// one-shot replications
JsonFactory jsonFactory = Manager.GetObjectMapper().GetJsonFactory();
JsonParser jp = jsonFactory.CreateJsonParser(input);
while (jp.NextToken() != JsonToken.StartArray)
{
}
// ignore these tokens
while (jp.NextToken() == JsonToken.StartObject)
{
IDictionary <string, object> change = (IDictionary)Manager.GetObjectMapper().ReadValue
<IDictionary>(jp);
if (!ReceivedChange(change))
{
Log.W(Log.TagChangeTracker, "Received unparseable change line from server: %s", change
);
}
}
Log.W(Log.TagChangeTracker, "%s: Change tracker calling stop (OneShot)", this);
Stop();
break;
}
backoff.ResetBackoff();
}
finally
{
try
{
entity.ConsumeContent();
}
catch (IOException)
{
}
}
}
}
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(Log.TagChangeTracker, this + ": Exception in change tracker", e);
}
backoff.SleepAppropriateAmountOfTime();
}
}
Log.V(Log.TagChangeTracker, "%s: Change tracker run loop exiting", this);
}
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(Log.TagChangeTracker, "%s: ChangeTracker run() loop aborting because client == null"
, this);
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();
while (running)
{
Uri url = GetChangesFeedURL();
if (usePOST)
{
HttpPost postRequest = new HttpPost(url.ToString());
postRequest.SetHeader("Content-Type", "application/json");
StringEntity entity;
try
{
entity = new StringEntity(ChangesFeedPOSTBody());
}
catch (UnsupportedEncodingException e)
{
throw new RuntimeException(e);
}
postRequest.SetEntity(entity);
request = postRequest;
}
else
{
request = new HttpGet(url.ToString());
}
AddRequestHeaders(request);
// Perform BASIC Authentication if needed
bool isUrlBasedUserInfo = false;
// If the URL contains user info AND if this a DefaultHttpClient then preemptively set the auth credentials
string userInfo = url.GetUserInfo();
if (userInfo != null)
{
isUrlBasedUserInfo = true;
}
else
{
if (authenticator != null)
{
AuthenticatorImpl auth = (AuthenticatorImpl)authenticator;
userInfo = auth.AuthUserInfo();
}
}
if (userInfo != null)
{
if (userInfo.Contains(":") && !userInfo.Trim().Equals(":"))
{
string[] userInfoElements = userInfo.Split(":");
string username = isUrlBasedUserInfo ? URIUtils.Decode(userInfoElements[0]) : userInfoElements
[0];
string password = isUrlBasedUserInfo ? URIUtils.Decode(userInfoElements[1]) : userInfoElements
[1];
Credentials credentials = new UsernamePasswordCredentials(username, password);
if (httpClient is DefaultHttpClient)
{
DefaultHttpClient dhc = (DefaultHttpClient)httpClient;
MessageProcessingHandler preemptiveAuth = new _MessageProcessingHandler_285(credentials
);
dhc.AddRequestInterceptor(preemptiveAuth, 0);
}
}
else
{
Log.W(Log.TagChangeTracker, "RemoteRequest Unable to parse user info, not setting credentials"
);
}
}
try
{
string maskedRemoteWithoutCredentials = GetChangesFeedURL().ToString();
maskedRemoteWithoutCredentials = maskedRemoteWithoutCredentials.ReplaceAll("://.*:.*@"
, "://---:---@");
Log.V(Log.TagChangeTracker, "%s: Making request to %s", this, maskedRemoteWithoutCredentials
);
HttpResponse response = httpClient.Execute(request);
StatusLine status = response.GetStatusLine();
if (status.GetStatusCode() >= 300 && !Utils.IsTransientError(status))
{
Log.E(Log.TagChangeTracker, "%s: Change tracker got error %d", this, status.GetStatusCode
());
this.error = new HttpResponseException(status.GetStatusCode(), status.GetReasonPhrase
());
Stop();
}
HttpEntity entity = response.GetEntity();
InputStream input = null;
if (entity != null)
{
try
{
input = entity.GetContent();
if (mode == ChangeTracker.ChangeTrackerMode.LongPoll)
{
// continuous replications
IDictionary<string, object> fullBody = Manager.GetObjectMapper().ReadValue<IDictionary
>(input);
bool responseOK = ReceivedPollResponse(fullBody);
if (mode == ChangeTracker.ChangeTrackerMode.LongPoll && responseOK)
{
Log.V(Log.TagChangeTracker, "%s: Starting new longpoll", this);
backoff.ResetBackoff();
continue;
}
else
{
Log.W(Log.TagChangeTracker, "%s: Change tracker calling stop (LongPoll)", this);
Stop();
}
}
else
{
// one-shot replications
JsonFactory jsonFactory = Manager.GetObjectMapper().GetJsonFactory();
JsonParser jp = jsonFactory.CreateJsonParser(input);
while (jp.NextToken() != JsonToken.StartArray)
{
}
// ignore these tokens
while (jp.NextToken() == JsonToken.StartObject)
{
IDictionary<string, object> change = (IDictionary)Manager.GetObjectMapper().ReadValue
<IDictionary>(jp);
if (!ReceivedChange(change))
{
Log.W(Log.TagChangeTracker, "Received unparseable change line from server: %s", change
);
}
}
Log.W(Log.TagChangeTracker, "%s: Change tracker calling stop (OneShot)", this);
Stop();
break;
}
backoff.ResetBackoff();
}
finally
{
try
{
entity.ConsumeContent();
}
catch (IOException)
{
}
}
}
}
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(Log.TagChangeTracker, this + ": Exception in change tracker", e);
}
backoff.SleepAppropriateAmountOfTime();
}
}
Log.V(Log.TagChangeTracker, "%s: Change tracker run loop exiting", this);
}
// 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 (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()
{
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");
}
void ChangeFeedResponseHandler(Task <HttpResponseMessage> responseTask)
{
if (responseTask.IsCanceled || responseTask.IsFaulted)
{
if (!responseTask.IsCanceled)
{
var err = responseTask.Exception.Flatten();
Log.D(Tag, "ChangeFeedResponseHandler faulted.", err.InnerException ?? err);
Error = err.InnerException ?? err;
backoff.SleepAppropriateAmountOfTime();
responseTask.Result.Dispose();
}
return;
}
var response = responseTask.Result;
if (response == null)
{
return;
}
var status = response.StatusCode;
if ((Int32)status >= 300 && !Misc.IsTransientError(status))
{
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();
response.Dispose();
return;
}
try {
switch (mode)
{
case ChangeTrackerMode.LongPoll:
{
if (response.Content == null)
{
throw new CouchbaseLiteException("Got empty change tracker response", status.GetStatusCode());
}
Log.D(Tag, "Getting stream from change tracker response");
Stream stream = response.Content.ReadAsStreamAsync().Result;
Log.D(Tag, "Got stream from change tracker response");
bool beforeFirstItem = true;
bool responseOK = false;
using (var jsonReader = Manager.GetObjectMapper().StartIncrementalParse(stream)) {
responseOK = ReceivedPollResponse(jsonReader, ref beforeFirstItem);
}
Log.D(Tag, "Finished polling change tracker");
if (responseOK)
{
Log.V(Tag, "Starting new longpoll");
backoff.ResetBackoff();
}
else
{
backoff.SleepAppropriateAmountOfTime();
if (beforeFirstItem)
{
var elapsed = DateTime.Now - _startTime;
Log.W(Tag, "Longpoll connection closed (by proxy?) after {0} sec", elapsed.TotalSeconds);
// Looks like the connection got closed by a proxy (like AWS' load balancer) while the
// server was waiting for a change to send, due to lack of activity.
// Lower the heartbeat time to work around this, and reconnect:
_heartbeatMilliseconds = (int)(elapsed.TotalMilliseconds * 0.75f);
Log.V(Tag, " Starting new longpoll");
backoff.ResetBackoff();
}
else
{
Log.W(Tag, "Change tracker calling stop");
WorkExecutor.StartNew(Stop);
}
}
}
break;
default:
{
Stream content = response.Content.ReadAsStreamAsync().Result;
using (var jsonReader = Manager.GetObjectMapper().StartIncrementalParse(content)) {
bool timedOut = false;
ReceivedPollResponse(jsonReader, ref timedOut);
}
IsRunning = false;
Stopped();
}
break;
}
backoff.ResetBackoff();
} finally {
response.Dispose();
}
}
// 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");
}