Add support for Job chains.

src/org/thoughtcrime/securesms/jobmanager/ChainParameters.java

@@ -0,0 +1,45 @@
+package org.thoughtcrime.securesms.jobmanager;
+
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import org.whispersystems.libsignal.util.guava.Optional;
+
+public class ChainParameters {
+
+  private final String  groupId;
+  private final boolean ignoreDuplicates;
+
+  private ChainParameters(@NonNull String groupId, boolean ignoreDuplicates) {
+    this.groupId          = groupId;
+    this.ignoreDuplicates = ignoreDuplicates;
+  }
+
+  public Optional<String> getGroupId() {
+    return Optional.fromNullable(groupId);
+  }
+
+  public boolean shouldIgnoreDuplicates() {
+    return ignoreDuplicates;
+  }
+
+  public static class Builder {
+
+    private String groupId;
+    private boolean ignoreDuplicates;
+
+    public Builder setGroupId(@Nullable String groupId) {
+      this.groupId = groupId;
+      return this;
+    }
+
+    public Builder ignoreDuplicates(boolean ignore) {
+      this.ignoreDuplicates = ignore;
+      return this;
+    }
+
+    public ChainParameters build() {
+      return new ChainParameters(groupId, ignoreDuplicates);
+    }
+  }
+}

src/org/thoughtcrime/securesms/jobmanager/Job.java

@@ -12,6 +12,7 @@ import org.thoughtcrime.securesms.jobmanager.requirements.NetworkRequirement;
 import org.thoughtcrime.securesms.jobs.requirements.SqlCipherMigrationRequirement;
 import org.thoughtcrime.securesms.logging.Log;
 import org.thoughtcrime.securesms.service.GenericForegroundService;
+import org.whispersystems.libsignal.util.guava.Optional;
 
 import java.io.Serializable;
 import java.util.Collections;
@@ -33,6 +34,7 @@ public abstract class Job extends Worker implements Serializable {
   static final String KEY_RETRY_COUNT        = "Job_retry_count";
   static final String KEY_RETRY_UNTIL        = "Job_retry_until";
   static final String KEY_SUBMIT_TIME        = "Job_submit_time";
+  static final String KEY_FAILED             = "Job_failed";
   static final String KEY_REQUIRES_NETWORK   = "Job_requires_network";
   static final String KEY_REQUIRES_SQLCIPHER = "Job_requires_sqlcipher";
 
@@ -86,8 +88,21 @@ public abstract class Job extends Worker implements Serializable {
     try {
       initialize(new SafeData(data));
 
-      if (withinRetryLimits(data)) {
-        if (requirementsMet(data)) {
+      if (data.getBoolean(KEY_FAILED, false)) {
+        warn("Failing due to a failure earlier in the chain." + logSuffix());
+        return cancel();
+      }
+
+      if (!withinRetryLimits(data)) {
+        warn("Failing after hitting the retry limit." + logSuffix());
+        return cancel();
+      }
+
+      if (!requirementsMet(data)) {
+        log("Retrying due to unmet requirements." + logSuffix());
+        return retry();
+      }
+
       if (needsForegroundService(data)) {
         Log.i(TAG, "Running a foreground service with description '" + getDescription() + "' to aid in job execution." + logSuffix());
         GenericForegroundService.startForegroundTask(getApplicationContext(), getDescription());
@@ -97,15 +112,7 @@ public abstract class Job extends Worker implements Serializable {
       onRun();
 
       log("Successfully completed." + logSuffix());
-          return Result.success();
-        } else {
-          log("Retrying due to unmet requirements." + logSuffix());
-          return retry();
-        }
-      } else {
-        warn("Failing after hitting the retry limit." + logSuffix());
-        return cancel();
-      }
+      return success();
     } catch (Exception e) {
       if (onShouldRetry(e)) {
         log("Retrying after a retryable exception." + logSuffix(), e);
@@ -197,6 +204,10 @@ public abstract class Job extends Worker implements Serializable {
     return parameters;
   }
 
+  private Result success() {
+    return Result.success();
+  }
+
   private Result retry() {
     onRetry();
     return Result.retry();
@@ -204,7 +215,7 @@ public abstract class Job extends Worker implements Serializable {
 
   private Result cancel() {
     onCanceled();
-    return Result.success();
+    return Result.success(new Data.Builder().putBoolean(KEY_FAILED, true).build());
   }
 
   private boolean requirementsMet(@NonNull Data data) {

src/org/thoughtcrime/securesms/jobmanager/JobManager.java

@@ -3,8 +3,14 @@ package org.thoughtcrime.securesms.jobmanager;
 import android.content.Context;
 import android.support.annotation.NonNull;
 
+import com.annimon.stream.Stream;
+
 import org.thoughtcrime.securesms.logging.Log;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
@@ -16,6 +22,7 @@ import androidx.work.Data;
 import androidx.work.ExistingWorkPolicy;
 import androidx.work.NetworkType;
 import androidx.work.OneTimeWorkRequest;
+import androidx.work.WorkContinuation;
 import androidx.work.WorkManager;
 
 public class JobManager {
@@ -36,7 +43,25 @@ public class JobManager {
     this.workManager = workManager;
   }
 
+  public Chain startChain(@NonNull Job job) {
+    return startChain(Collections.singletonList(job));
+  }
+
+  public Chain startChain(@NonNull List<? extends Job> jobs) {
+    return new Chain(jobs);
+  }
+
   public void add(Job job) {
+    JobParameters jobParameters = job.getJobParameters();
+
+    if (jobParameters == null) {
+      throw new IllegalStateException("Jobs must have JobParameters at this stage. (" + job.getClass().getSimpleName() + ")");
+    }
+
+    startChain(job).enqueue(jobParameters.getSoloChainParameters());
+  }
+
+  private void enqueueChain(@NonNull Chain chain, @NonNull ChainParameters chainParameters) {
     executor.execute(() -> {
       try {
         workManager.pruneWork().getResult().get();
@@ -44,6 +69,38 @@ public class JobManager {
         Log.w(TAG, "Failed to prune work.", e);
       }
 
+      List<List<Job>>                jobListChain     = chain.getJobListChain();
+      List<List<OneTimeWorkRequest>> requestListChain = Stream.of(jobListChain).map(jl -> Stream.of(jl).map(this::toWorkRequest).toList()).toList();
+
+      if (jobListChain.isEmpty()) {
+        throw new IllegalStateException("Enqueued an empty chain.");
+      }
+
+      for (int i = 0; i < jobListChain.size(); i++) {
+        for (int j = 0; j < jobListChain.get(i).size(); j++) {
+          jobListChain.get(i).get(j).onSubmit(context, requestListChain.get(i).get(j).getId());
+        }
+      }
+
+      WorkContinuation continuation;
+
+      if (chainParameters.getGroupId().isPresent()) {
+        ExistingWorkPolicy policy = chainParameters.shouldIgnoreDuplicates() ? ExistingWorkPolicy.KEEP : ExistingWorkPolicy.APPEND;
+        continuation = workManager.beginUniqueWork(chainParameters.getGroupId().get(), policy, requestListChain.get(0));
+      } else {
+        continuation = workManager.beginWith(requestListChain.get(0));
+      }
+
+      for (int i = 1; i < requestListChain.size(); i++) {
+        continuation = continuation.then(requestListChain.get(i));
+      }
+
+      continuation.enqueue();
+    });
+
+  }
+
+  private OneTimeWorkRequest toWorkRequest(@NonNull Job job) {
     JobParameters jobParameters = job.getJobParameters();
 
     if (jobParameters == null) {
@@ -65,17 +122,32 @@ public class JobManager {
       requestBuilder.setConstraints(NETWORK_CONSTRAINT);
     }
 
-      OneTimeWorkRequest request = requestBuilder.build();
+    return requestBuilder.build();
+  }
 
-      job.onSubmit(context, request.getId());
+  public class Chain {
 
-      String groupId = jobParameters.getGroupId();
-      if (groupId != null) {
-        ExistingWorkPolicy policy = jobParameters.shouldIgnoreDuplicates() ? ExistingWorkPolicy.KEEP : ExistingWorkPolicy.APPEND;
-        workManager.beginUniqueWork(groupId, policy, request).enqueue();
-      } else {
-        workManager.beginWith(request).enqueue();
+    private final List<List<Job>> jobs = new LinkedList<>();
+
+    private Chain(@NonNull List<? extends Job> jobs) {
+      this.jobs.add(new ArrayList<>(jobs));
+    }
+
+    public Chain then(@NonNull Job job) {
+      return then(Collections.singletonList(job));
+    }
+
+    public Chain then(@NonNull List<Job> jobs) {
+      this.jobs.add(new ArrayList<>(jobs));
+      return this;
+    }
+
+    public void enqueue(@NonNull ChainParameters chainParameters) {
+      enqueueChain(this, chainParameters);
+    }
+
+    private List<List<Job>> getJobListChain() {
+      return jobs;
     }
-    });
   }
 }

src/org/thoughtcrime/securesms/jobmanager/JobParameters.java

@@ -104,6 +104,13 @@ public class JobParameters implements Serializable {
     return retryUntil;
   }
 
+  public ChainParameters getSoloChainParameters() {
+    return new ChainParameters.Builder()
+                              .setGroupId(groupId)
+                              .ignoreDuplicates(ignoreDuplicates)
+                              .build();
+  }
+
   /**
    * @return a builder used to construct JobParameters.
    */