commit f9084ecae2e0f042730ab32b9c94204a0e21bb2a
author Jorim Jaggi <jjaggi@google.com> Mon Jan 16 13:16:59 2017 +0100
committer Jorim Jaggi <jjaggi@google.com> Thu Jan 19 17:06:42 2017 +0100
tree c4044f48e01a0821fe95d0768f531f96abccdbeb
parent 7a1f1d8a8579278048c044b7aca5d0d58ece57e4

Persist task snapshots to disk

So they can be used again after rebooting or when the process gets
killed, but the snapshot is still used for recents.

Also implement TaskSnapshotLoader, to restore it from disk. The
infrastructure around restoring and caching snapshots for recents
will be implemented in the next CL.

Test: runtest frameworks-services -c
com.android.server.wm.TaskSnapshotPersisterLoaderTest

Bug: 31339431
Change-Id: Iaec03c4cc92e04b6dd7e623bca755ddc92613bce

services/core/java/com/android/server/wm/TaskSnapshotController.java

diff --git a/services/core/java/com/android/server/wm/TaskSnapshotController.java b/services/core/java/com/android/server/wm/TaskSnapshotController.java
index df8679d..10ecf3b 100644
--- a/services/core/java/com/android/server/wm/TaskSnapshotController.java
+++ b/services/core/java/com/android/server/wm/TaskSnapshotController.java
@@ -22,11 +22,13 @@
 import android.app.ActivityManager.StackId;
 import android.app.ActivityManager.TaskSnapshot;
 import android.graphics.GraphicBuffer;
+import android.os.Environment;
 import android.util.ArraySet;
 import android.view.WindowManagerPolicy.StartingSurface;
 
 import com.android.internal.annotations.VisibleForTesting;
 
+import java.io.File;
 import java.io.PrintWriter;
 
 /**
@@ -45,14 +47,21 @@
 class TaskSnapshotController {
 
     private final WindowManagerService mService;
-    private final TaskSnapshotCache mCache = new TaskSnapshotCache();
 
+    private final TaskSnapshotCache mCache = new TaskSnapshotCache();
+    private final TaskSnapshotPersister mPersister = new TaskSnapshotPersister(
+            Environment::getDataSystemCeDirectory);
+    private final TaskSnapshotLoader mLoader = new TaskSnapshotLoader(mPersister);
     private final ArraySet<Task> mTmpTasks = new ArraySet<>();
 
     TaskSnapshotController(WindowManagerService service) {
         mService = service;
     }
 
+    void systemReady() {
+        mPersister.start();
+    }
+
     void onTransitionStarting() {
         if (!ENABLE_TASK_SNAPSHOTS) {
             return;
@@ -69,6 +78,7 @@
             final TaskSnapshot snapshot = snapshotTask(task);
             if (snapshot != null) {
                 mCache.putSnapshot(task, snapshot);
+                mPersister.persistSnapshot(task.mTaskId, task.mUserId, snapshot);
                 if (task.getController() != null) {
                     task.getController().reportSnapshotChanged(snapshot);
                 }
@@ -141,6 +151,17 @@
         mCache.cleanCache(wtoken);
     }
 
+    void notifyTaskRemovedFromRecents(int taskId, int userId) {
+        mPersister.onTaskRemovedFromRecents(taskId, userId);
+    }
+
+    /**
+     * See {@link TaskSnapshotPersister#removeObsoleteFiles}
+     */
+    void removeObsoleteTaskFiles(ArraySet<Integer> persistentTaskIds, int[] runningUserIds) {
+        mPersister.removeObsoleteFiles(persistentTaskIds, runningUserIds);
+    }
+
     void dump(PrintWriter pw, String prefix) {
         mCache.dump(pw, prefix);
     }