The Tor Browser: mobile/android/base/sync/synchronizer/SynchronizerSession.java@6474c204b198 (annotated)

mobile/android/base/sync/synchronizer/SynchronizerSession.java@6474c204b198 (annotated)

mobile/android/base/sync/synchronizer/SynchronizerSession.java

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 package org.mozilla.gecko.sync.synchronizer;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.atomic.AtomicInteger;
 import org.mozilla.gecko.background.common.log.Logger;
 import org.mozilla.gecko.sync.repositories.InactiveSessionException;
 import org.mozilla.gecko.sync.repositories.InvalidSessionTransitionException;
 import org.mozilla.gecko.sync.repositories.RepositorySession;
 import org.mozilla.gecko.sync.repositories.RepositorySessionBundle;
 import org.mozilla.gecko.sync.repositories.delegates.DeferrableRepositorySessionCreationDelegate;
 import org.mozilla.gecko.sync.repositories.delegates.DeferredRepositorySessionFinishDelegate;
 import org.mozilla.gecko.sync.repositories.delegates.RepositorySessionFinishDelegate;
 import android.content.Context;
 /**
  * I coordinate the moving parts of a sync started by
  * {@link Synchronizer#synchronize}.
  *
  * I flow records twice: first from A to B, and then from B to A. I provide
  * fine-grained feedback by calling my delegate's callback methods.
  *
  * Initialize me by creating me with a Synchronizer and a
  * SynchronizerSessionDelegate. Kick things off by calling `init` with two
  * RepositorySessionBundles, and then call `synchronize` in your `onInitialized`
  * callback.
  *
  * I always call exactly one of my delegate's `onInitialized` or
  * `onSessionError` callback methods from `init`.
  *
  * I call my delegate's `onSynchronizeSkipped` callback method if there is no
  * data to be synchronized in `synchronize`.
  *
  * In addition, I call `onFetchError`, `onStoreError`, and `onSessionError` when
  * I encounter a fetch, store, or session error while synchronizing.
  *
  * Typically my delegate will call `abort` in its error callbacks, which will
  * call my delegate's `onSynchronizeAborted` method and halt the sync.
  *
  * I always call exactly one of my delegate's `onSynchronized` or
  * `onSynchronizeFailed` callback methods if I have not seen an error.
  */
 public class SynchronizerSession
 extends DeferrableRepositorySessionCreationDelegate
 implements RecordsChannelDelegate,
            RepositorySessionFinishDelegate {
   protected static final String LOG_TAG = "SynchronizerSession";
   protected Synchronizer synchronizer;
   protected SynchronizerSessionDelegate delegate;
   protected Context context;
   /*
    * Computed during init.
    */
   private RepositorySession sessionA;
   private RepositorySession sessionB;
   private RepositorySessionBundle bundleA;
   private RepositorySessionBundle bundleB;
   // Bug 726054: just like desktop, we track our last interaction with the server,
   // not the last record timestamp that we fetched. This ensures that we don't re-
   // download the records we just uploaded, at the cost of skipping any records
   // that a concurrently syncing client has uploaded.
   private long pendingATimestamp = -1;
   private long pendingBTimestamp = -1;
   private long storeEndATimestamp = -1;
   private long storeEndBTimestamp = -1;
   private boolean flowAToBCompleted = false;
   private boolean flowBToACompleted = false;
   protected final AtomicInteger numInboundRecords = new AtomicInteger(-1);
   protected final AtomicInteger numOutboundRecords = new AtomicInteger(-1);
   /*
    * Public API: constructor, init, synchronize.
    */
   public SynchronizerSession(Synchronizer synchronizer, SynchronizerSessionDelegate delegate) {
     this.setSynchronizer(synchronizer);
     this.delegate = delegate;
   }
   public Synchronizer getSynchronizer() {
     return synchronizer;
   }
   public void setSynchronizer(Synchronizer synchronizer) {
     this.synchronizer = synchronizer;
   }
   public void init(Context context, RepositorySessionBundle bundleA, RepositorySessionBundle bundleB) {
     this.context = context;
     this.bundleA = bundleA;
     this.bundleB = bundleB;
     // Begin sessionA and sessionB, call onInitialized in callbacks.
     this.getSynchronizer().repositoryA.createSession(this, context);
   }
   /**
    * Get the number of records fetched from the first repository (usually the
    * server, hence inbound).
    * <p>
    * Valid only after first flow has completed.
    *
    * @return number of records, or -1 if not valid.
    */
   public int getInboundCount() {
     return numInboundRecords.get();
   }
   /**
    * Get the number of records fetched from the second repository (usually the
    * local store, hence outbound).
    * <p>
    * Valid only after second flow has completed.
    *
    * @return number of records, or -1 if not valid.
    */
   public int getOutboundCount() {
     return numOutboundRecords.get();
   }
   // These are accessed by `abort` and `synchronize`, both of which are synchronized.
   // Guarded by `this`.
   protected RecordsChannel channelAToB;
   protected RecordsChannel channelBToA;
   /**
    * Please don't call this until you've been notified with onInitialized.
    */
   public synchronized void synchronize() {
     numInboundRecords.set(-1);
     numOutboundRecords.set(-1);
     // First thing: decide whether we should.
     if (sessionA.shouldSkip() ||
         sessionB.shouldSkip()) {
       Logger.info(LOG_TAG, "Session requested skip. Short-circuiting sync.");
       sessionA.abort();
       sessionB.abort();
       this.delegate.onSynchronizeSkipped(this);
       return;
     }
     final SynchronizerSession session = this;
     // TODO: failed record handling.
     // This is the *second* record channel to flow.
     // I, SynchronizerSession, am the delegate for the *second* flow.
     channelBToA = new RecordsChannel(this.sessionB, this.sessionA, this);
     // This is the delegate for the *first* flow.
     RecordsChannelDelegate channelAToBDelegate = new RecordsChannelDelegate() {
       public void onFlowCompleted(RecordsChannel recordsChannel, long fetchEnd, long storeEnd) {
         session.onFirstFlowCompleted(recordsChannel, fetchEnd, storeEnd);
       }
       @Override
       public void onFlowBeginFailed(RecordsChannel recordsChannel, Exception ex) {
         Logger.warn(LOG_TAG, "First RecordsChannel onFlowBeginFailed. Logging session error.", ex);
         session.delegate.onSynchronizeFailed(session, ex, "Failed to begin first flow.");
       }
       @Override
       public void onFlowFetchFailed(RecordsChannel recordsChannel, Exception ex) {
         Logger.warn(LOG_TAG, "First RecordsChannel onFlowFetchFailed. Logging remote fetch error.", ex);
       }
       @Override
       public void onFlowStoreFailed(RecordsChannel recordsChannel, Exception ex, String recordGuid) {
         Logger.warn(LOG_TAG, "First RecordsChannel onFlowStoreFailed. Logging local store error.", ex);
       }
       @Override
       public void onFlowFinishFailed(RecordsChannel recordsChannel, Exception ex) {
         Logger.warn(LOG_TAG, "First RecordsChannel onFlowFinishedFailed. Logging session error.", ex);
         session.delegate.onSynchronizeFailed(session, ex, "Failed to finish first flow.");
       }
     };
     // This is the *first* channel to flow.
     channelAToB = new RecordsChannel(this.sessionA, this.sessionB, channelAToBDelegate);
     Logger.trace(LOG_TAG, "Starting A to B flow. Channel is " + channelAToB);
     try {
       channelAToB.beginAndFlow();
     } catch (InvalidSessionTransitionException e) {
       onFlowBeginFailed(channelAToB, e);
     }
   }
   /**
    * Called after the first flow completes.
    * <p>
    * By default, any fetch and store failures are ignored.
    * @param recordsChannel the <code>RecordsChannel</code> (for error testing).
    * @param fetchEnd timestamp when fetches completed.
    * @param storeEnd timestamp when stores completed.
    */
   public void onFirstFlowCompleted(RecordsChannel recordsChannel, long fetchEnd, long storeEnd) {
     Logger.trace(LOG_TAG, "First RecordsChannel onFlowCompleted.");
     Logger.debug(LOG_TAG, "Fetch end is " + fetchEnd + ". Store end is " + storeEnd + ". Starting next.");
     pendingATimestamp = fetchEnd;
     storeEndBTimestamp = storeEnd;
     numInboundRecords.set(recordsChannel.getFetchCount());
     flowAToBCompleted = true;
     channelBToA.flow();
   }
   /**
    * Called after the second flow completes.
    * <p>
    * By default, any fetch and store failures are ignored.
    * @param recordsChannel the <code>RecordsChannel</code> (for error testing).
    * @param fetchEnd timestamp when fetches completed.
    * @param storeEnd timestamp when stores completed.
    */
   public void onSecondFlowCompleted(RecordsChannel recordsChannel, long fetchEnd, long storeEnd) {
     Logger.trace(LOG_TAG, "Second RecordsChannel onFlowCompleted.");
     Logger.debug(LOG_TAG, "Fetch end is " + fetchEnd + ". Store end is " + storeEnd + ". Finishing.");
     pendingBTimestamp = fetchEnd;
     storeEndATimestamp = storeEnd;
     numOutboundRecords.set(recordsChannel.getFetchCount());
     flowBToACompleted = true;
     // Finish the two sessions.
     try {
       this.sessionA.finish(this);
     } catch (InactiveSessionException e) {
       this.onFinishFailed(e);
       return;
     }
   }
   @Override
   public void onFlowCompleted(RecordsChannel recordsChannel, long fetchEnd, long storeEnd) {
     onSecondFlowCompleted(recordsChannel, fetchEnd, storeEnd);
   }
   @Override
   public void onFlowBeginFailed(RecordsChannel recordsChannel, Exception ex) {
     Logger.warn(LOG_TAG, "Second RecordsChannel onFlowBeginFailed. Logging session error.", ex);
     this.delegate.onSynchronizeFailed(this, ex, "Failed to begin second flow.");
   }
   @Override
   public void onFlowFetchFailed(RecordsChannel recordsChannel, Exception ex) {
     Logger.warn(LOG_TAG, "Second RecordsChannel onFlowFetchFailed. Logging local fetch error.", ex);
   }
   @Override
   public void onFlowStoreFailed(RecordsChannel recordsChannel, Exception ex, String recordGuid) {
     Logger.warn(LOG_TAG, "Second RecordsChannel onFlowStoreFailed. Logging remote store error.", ex);
   }
   @Override
   public void onFlowFinishFailed(RecordsChannel recordsChannel, Exception ex) {
     Logger.warn(LOG_TAG, "Second RecordsChannel onFlowFinishedFailed. Logging session error.", ex);
     this.delegate.onSynchronizeFailed(this, ex, "Failed to finish second flow.");
   }
   /*
    * RepositorySessionCreationDelegate methods.
    */
   /**
    * I could be called twice: once for sessionA and once for sessionB.
    *
    * I try to clean up sessionA if it is not null, since the creation of
    * sessionB must have failed.
    */
   @Override
   public void onSessionCreateFailed(Exception ex) {
     // Attempt to finish the first session, if the second is the one that failed.
     if (this.sessionA != null) {
       try {
         // We no longer need a reference to our context.
         this.context = null;
         this.sessionA.finish(this);
       } catch (Exception e) {
         // Never mind; best-effort finish.
       }
     }
     // We no longer need a reference to our context.
     this.context = null;
     this.delegate.onSynchronizeFailed(this, ex, "Failed to create session");
   }
   /**
    * I should be called twice: first for sessionA and second for sessionB.
    *
    * If I am called for sessionB, I call my delegate's `onInitialized` callback
    * method because my repository sessions are correctly initialized.
    */
   // TODO: some of this "finish and clean up" code can be refactored out.
   @Override
   public void onSessionCreated(RepositorySession session) {
     if (session == null ||
         this.sessionA == session) {
       // TODO: clean up sessionA.
       this.delegate.onSynchronizeFailed(this, new UnexpectedSessionException(session), "Failed to create session.");
       return;
     }
     if (this.sessionA == null) {
       this.sessionA = session;
       // Unbundle.
       try {
         this.sessionA.unbundle(this.bundleA);
       } catch (Exception e) {
         this.delegate.onSynchronizeFailed(this, new UnbundleError(e, sessionA), "Failed to unbundle first session.");
         // TODO: abort
         return;
       }
       this.getSynchronizer().repositoryB.createSession(this, this.context);
       return;
     }
     if (this.sessionB == null) {
       this.sessionB = session;
       // We no longer need a reference to our context.
       this.context = null;
       // Unbundle. We unbundled sessionA when that session was created.
       try {
         this.sessionB.unbundle(this.bundleB);
       } catch (Exception e) {
         this.delegate.onSynchronizeFailed(this, new UnbundleError(e, sessionA), "Failed to unbundle second session.");
         return;
       }
       this.delegate.onInitialized(this);
       return;
     }
     // TODO: need a way to make sure we don't call any more delegate methods.
     this.delegate.onSynchronizeFailed(this, new UnexpectedSessionException(session), "Failed to create session.");
   }
   /*
    * RepositorySessionFinishDelegate methods.
    */
   /**
    * I could be called twice: once for sessionA and once for sessionB.
    *
    * If sessionB couldn't be created, I don't fail again.
    */
   @Override
   public void onFinishFailed(Exception ex) {
     if (this.sessionB == null) {
       // Ah, it was a problem cleaning up. Never mind.
       Logger.warn(LOG_TAG, "Got exception cleaning up first after second session creation failed.", ex);
       return;
     }
     String session = (this.sessionA == null) ? "B" : "A";
     this.delegate.onSynchronizeFailed(this, ex, "Finish of session " + session + " failed.");
   }
   /**
    * I should be called twice: first for sessionA and second for sessionB.
    *
    * If I am called for sessionA, I try to finish sessionB.
    *
    * If I am called for sessionB, I call my delegate's `onSynchronized` callback
    * method because my flows should have completed.
    */
   @Override
   public void onFinishSucceeded(RepositorySession session,
                                 RepositorySessionBundle bundle) {
     Logger.debug(LOG_TAG, "onFinishSucceeded. Flows? " + flowAToBCompleted + ", " + flowBToACompleted);
     if (session == sessionA) {
       if (flowAToBCompleted) {
         Logger.debug(LOG_TAG, "onFinishSucceeded: bumping session A's timestamp to " + pendingATimestamp + " or " + storeEndATimestamp);
         bundle.bumpTimestamp(Math.max(pendingATimestamp, storeEndATimestamp));
         this.synchronizer.bundleA = bundle;
       } else {
         // Should not happen!
         this.delegate.onSynchronizeFailed(this, new UnexpectedSessionException(sessionA), "Failed to finish first session.");
         return;
       }
       if (this.sessionB != null) {
         Logger.trace(LOG_TAG, "Finishing session B.");
         // On to the next.
         try {
           this.sessionB.finish(this);
         } catch (InactiveSessionException e) {
           this.onFinishFailed(e);
           return;
         }
       }
     } else if (session == sessionB) {
       if (flowBToACompleted) {
         Logger.debug(LOG_TAG, "onFinishSucceeded: bumping session B's timestamp to " + pendingBTimestamp + " or " + storeEndBTimestamp);
         bundle.bumpTimestamp(Math.max(pendingBTimestamp, storeEndBTimestamp));
         this.synchronizer.bundleB = bundle;
         Logger.trace(LOG_TAG, "Notifying delegate.onSynchronized.");
         this.delegate.onSynchronized(this);
       } else {
         // Should not happen!
         this.delegate.onSynchronizeFailed(this, new UnexpectedSessionException(sessionB), "Failed to finish second session.");
         return;
       }
     } else {
       // TODO: hurrrrrr...
     }
     if (this.sessionB == null) {
       this.sessionA = null; // We're done.
     }
   }
   @Override
   public RepositorySessionFinishDelegate deferredFinishDelegate(final ExecutorService executor) {
     return new DeferredRepositorySessionFinishDelegate(this, executor);
   }
 }

The Tor Browser / annotate

mobile/android/base/sync/synchronizer/SynchronizerSession.java@6474c204b198 (annotated)

mobile/android/base/sync/synchronizer/SynchronizerSession.java