Support for job "group ids."

A job can specify a group id, and jobs with the same group id
will run sequentially.

jobqueue/src/androidTest/java/org/whispersystems/jobqueue/JobManagerTest.java

@@ -86,5 +86,45 @@ public class JobManagerTest extends AndroidTestCase {
     assertTrue(PersistentResult.getInstance().isRan());
   }
 
+  public void testGroupIdExecution() throws InterruptedException {
+    final Object lock = new Object();
+
+    Runnable waitRunnable = new Runnable() {
+      @Override
+      public void run() {
+        try {
+          synchronized (lock) {
+            lock.wait();
+          }
+        } catch (InterruptedException e) {
+          throw new AssertionError(e);
+        }
+      }
+    };
+
+    TestJob    testJobOne   = new TestJob(JobParameters.newBuilder().withGroupId("foo").create(), waitRunnable);
+    TestJob    testJobTwo   = new TestJob(JobParameters.newBuilder().withGroupId("foo").create());
+    TestJob    testJobThree = new TestJob(JobParameters.newBuilder().withGroupId("bar").create());
+    JobManager jobManager   = new JobManager(getContext(), "transient-test", null, null, 3);
+
+    jobManager.add(testJobOne);
+    jobManager.add(testJobTwo);
+    jobManager.add(testJobThree);
+
+    assertTrue(testJobOne.isAdded());
+    assertTrue(testJobTwo.isAdded());
+    assertTrue(testJobThree.isAdded());
+
+    assertTrue(testJobOne.isRan());
+    assertTrue(!testJobTwo.isRan());
+    assertTrue(testJobThree.isRan());
+
+    synchronized (lock) {
+      lock.notifyAll();
+    }
+
+    assertTrue(testJobTwo.isRan());
+  }
+
 
 }

jobqueue/src/androidTest/java/org/whispersystems/jobqueue/jobs/TestJob.java

@@ -13,6 +13,8 @@ public class TestJob extends Job {
   private boolean ran      = false;
   private boolean canceled = false;
 
+  private Runnable runnable;
+
   public TestJob() {
     this(JobParameters.newBuilder().create());
   }
@@ -21,6 +23,11 @@ public class TestJob extends Job {
     super(parameters);
   }
 
+  public TestJob(JobParameters parameters, Runnable runnable) {
+    super(parameters);
+    this.runnable = runnable;
+  }
+
   @Override
   public void onAdded() {
     synchronized (ADDED_LOCK) {
@@ -34,6 +41,9 @@ public class TestJob extends Job {
     synchronized (RAN_LOCK) {
       this.ran = true;
     }
+
+    if (runnable != null)
+      runnable.run();
   }
 
   @Override

jobqueue/src/main/java/org/whispersystems/jobqueue/Job.java

@@ -27,6 +27,10 @@ public abstract class Job implements Serializable {
     return true;
   }
 
+  public String getGroupId() {
+    return parameters.getGroupId();
+  }
+
   public boolean isPersistent() {
     return parameters.isPersistent();
   }

jobqueue/src/main/java/org/whispersystems/jobqueue/JobConsumer.java

@@ -25,6 +25,10 @@ public class JobConsumer extends Thread {
       if (job.isPersistent()) {
         persistentStorage.remove(job.getPersistentId());
       }
+
+      if (job.getGroupId() != null) {
+        jobQueue.setGroupIdAvailable(job.getGroupId());
+      }
     }
   }
 

jobqueue/src/main/java/org/whispersystems/jobqueue/JobParameters.java

@@ -13,14 +13,16 @@ public class JobParameters implements Serializable {
   private final List<Requirement> requirements;
   private final boolean           isPersistent;
   private final int               retryCount;
+  private final String            groupId;
 
   private JobParameters(List<Requirement> requirements,
-                       boolean isPersistent,
+                       boolean isPersistent, String groupId,
                        EncryptionKeys encryptionKeys,
                        int retryCount)
   {
     this.requirements   = requirements;
     this.isPersistent   = isPersistent;
+    this.groupId        = groupId;
     this.encryptionKeys = encryptionKeys;
     this.retryCount     = retryCount;
   }
@@ -49,11 +51,16 @@ public class JobParameters implements Serializable {
     return new Builder();
   }
 
+  public String getGroupId() {
+    return groupId;
+  }
+
   public static class Builder {
     private List<Requirement> requirements   = new LinkedList<>();
     private boolean           isPersistent   = false;
     private EncryptionKeys    encryptionKeys = null;
     private int               retryCount     = 100;
+    private String            groupId        = null;
 
     public Builder withRequirement(Requirement requirement) {
       this.requirements.add(requirement);
@@ -75,8 +82,13 @@ public class JobParameters implements Serializable {
       return this;
     }
 
+    public Builder withGroupId(String groupId) {
+      this.groupId = groupId;
+      return this;
+    }
+
     public JobParameters create() {
-      return new JobParameters(requirements, isPersistent, encryptionKeys, retryCount);
+      return new JobParameters(requirements, isPersistent, groupId, encryptionKeys, retryCount);
     }
   }
 }

jobqueue/src/main/java/org/whispersystems/jobqueue/JobQueue.java

@@ -1,11 +1,16 @@
 package org.whispersystems.jobqueue;
 
+import java.util.HashMap;
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.ListIterator;
+import java.util.Map;
+import java.util.Set;
 
 public class JobQueue {
 
+  private final Set<String>     activeGroupIds = new HashSet<>();
   private final LinkedList<Job> jobQueue       = new LinkedList<>();
 
   public synchronized void onRequirementStatusChanged() {
@@ -36,6 +41,13 @@ public class JobQueue {
     }
   }
 
+  public synchronized void setGroupIdAvailable(String groupId) {
+    if (groupId != null) {
+      activeGroupIds.remove(groupId);
+      notifyAll();
+    }
+  }
+
   private Job getNextAvailableJob() {
     if (jobQueue.isEmpty()) return null;
 
@@ -43,12 +55,23 @@ public class JobQueue {
     while (iterator.hasNext()) {
       Job job = iterator.next();
 
-      if (job.isRequirementsMet()) {
+      if (job.isRequirementsMet() && isGroupIdAvailable(job.getGroupId())) {
         iterator.remove();
+        setGroupIdUnavailable(job.getGroupId());
         return job;
       }
     }
 
     return null;
   }
+
+  private boolean isGroupIdAvailable(String groupId) {
+    return groupId == null || !activeGroupIds.contains(groupId);
+  }
+
+  private void setGroupIdUnavailable(String groupId) {
+    if (groupId != null) {
+      activeGroupIds.add(groupId);
+    }
+  }
 }