Handle 428 rate limiting.

app/src/main/java/org/thoughtcrime/securesms/jobmanager/JobController.java

@@ -176,6 +176,23 @@ class JobController {
           .forEach(this::cancelJob);
   }
 
+  @WorkerThread
+  synchronized void update(@NonNull JobUpdater updater) {
+    List<JobSpec> allJobs     = jobStorage.getAllJobSpecs();
+    List<JobSpec> updatedJobs = new LinkedList<>();
+
+    for (JobSpec job : allJobs) {
+      JobSpec updated = updater.update(job, dataSerializer);
+      if (updated != job) {
+        updatedJobs.add(updated);
+      }
+    }
+
+    jobStorage.updateJobs(updatedJobs);
+
+    notifyAll();
+  }
+
   @WorkerThread
   synchronized void onRetry(@NonNull Job job, long backoffInterval) {
     if (backoffInterval <= 0) {

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

@@ -223,6 +223,15 @@ public class JobManager implements ConstraintObserver.Notifier {
     runOnExecutor(() -> jobController.cancelAllInQueue(queue));
   }
 
+  /**
+   * Perform an arbitrary update on enqueued jobs. Will not apply to jobs that are already running.
+   * You shouldn't use this if you can help it. You give yourself an opportunity to really screw
+   * things up.
+   */
+  public void update(@NonNull JobUpdater updater) {
+    runOnExecutor(() -> jobController.update(updater));
+  }
+
   /**
    * Runs the specified job synchronously. Beware: All normal dependencies are respected, meaning
    * you must take great care where you call this. It could take a very long time to complete!

app/src/main/java/org/thoughtcrime/securesms/jobmanager/JobUpdater.java

@@ -0,0 +1,19 @@
+package org.thoughtcrime.securesms.jobmanager;
+
+import androidx.annotation.NonNull;
+
+import org.thoughtcrime.securesms.jobmanager.persistence.JobSpec;
+
+public interface JobUpdater {
+  /**
+   * Called for each enqueued job, giving you an opportunity to update each one.
+   *
+   * @param jobSpec An object representing data about an enqueued job.
+   * @param serializer An object that can be used to serialize/deserialize data if necessary for
+   *                   your update.
+   *
+   * @return The updated JobSpec you want persisted. If you do not wish to make an update, return
+   *         the literal same JobSpec instance you were provided.
+   */
+  @NonNull JobSpec update(@NonNull JobSpec jobSpec, @NonNull Data.Serializer serializer);
+}

app/src/main/java/org/thoughtcrime/securesms/jobmanager/persistence/JobSpec.java

@@ -49,6 +49,10 @@ public final class JobSpec {
     this.memoryOnly          = memoryOnly;
   }
 
+  public @NonNull JobSpec withNextRunAttemptTime(long updated) {
+    return new JobSpec(id, factoryKey, queueKey, createTime, updated, runAttempt, maxAttempts, lifespan, serializedData, serializedInputData, isRunning, memoryOnly);
+  }
+
   public @NonNull String getId() {
     return id;
   }