Save/load calculated cache quotas to a file.

This will prevent us from unnecessarily redoing calculation work
by loading the last caches on boot and shoving them down to
installd.

Bug: 33965858
Test: Framework services tests
Change-Id: Ie94e269aa72bceb1ebe87911eaa42e2d826c1123

1 files changed, 31 insertions, 8 deletions

diff --git a/services/usage/java/com/android/server/usage/StorageStatsService.java b/services/usage/java/com/android/server/usage/StorageStatsService.java
index ed1530a4eddb..89e68a63ac3b 100644
--- a/services/usage/java/com/android/server/usage/StorageStatsService.java
+++ b/services/usage/java/com/android/server/usage/StorageStatsService.java
@@ -55,6 +55,8 @@ import com.android.server.pm.Installer;
 import com.android.server.pm.Installer.InstallerException;
 import com.android.server.storage.CacheQuotaStrategy;
 
+import java.io.IOException;
+
 public class StorageStatsService extends IStorageStatsManager.Stub {
     private static final String TAG = "StorageStatsService";
 
@@ -97,7 +99,7 @@ public class StorageStatsService extends IStorageStatsManager.Stub {
         invalidateMounts();
 
         mHandler = new H(IoThread.get().getLooper());
-        mHandler.sendEmptyMessageDelayed(H.MSG_CHECK_STORAGE_DELTA, DELAY_IN_MILLIS);
+        mHandler.sendEmptyMessageDelayed(H.MSG_LOAD_CACHED_QUOTAS_FROM_FILE, DELAY_IN_MILLIS);
 
         mStorage.registerListener(new StorageEventListener() {
             @Override
@@ -343,12 +345,14 @@ public class StorageStatsService extends IStorageStatsManager.Stub {
 
     private class H extends Handler {
         private static final int MSG_CHECK_STORAGE_DELTA = 100;
+        private static final int MSG_LOAD_CACHED_QUOTAS_FROM_FILE = 101;
         /**
          * By only triggering a re-calculation after the storage has changed sizes, we can avoid
          * recalculating quotas too often. Minimum change delta defines the percentage of change
          * we need to see before we recalculate.
          */
         private static final double MINIMUM_CHANGE_DELTA = 0.05;
+        private static final int UNSET = -1;
         private static final boolean DEBUG = false;
 
         private final StatFs mStats;
@@ -361,7 +365,6 @@ public class StorageStatsService extends IStorageStatsManager.Stub {
             mStats = new StatFs(Environment.getDataDirectory().getAbsolutePath());
             mPreviousBytes = mStats.getFreeBytes();
             mMinimumThresholdBytes = mStats.getTotalBytes() * MINIMUM_CHANGE_DELTA;
-            // TODO: Load cache quotas from a file to avoid re-doing work.
         }
 
         public void handleMessage(Message msg) {
@@ -378,7 +381,26 @@ public class StorageStatsService extends IStorageStatsManager.Stub {
                     long bytesDelta = Math.abs(mPreviousBytes - mStats.getFreeBytes());
                     if (bytesDelta > mMinimumThresholdBytes) {
                         mPreviousBytes = mStats.getFreeBytes();
-                        recalculateQuotas();
+                        recalculateQuotas(getInitializedStrategy());
+                    }
+                    sendEmptyMessageDelayed(MSG_CHECK_STORAGE_DELTA, DELAY_IN_MILLIS);
+                    break;
+                }
+                case MSG_LOAD_CACHED_QUOTAS_FROM_FILE: {
+                    CacheQuotaStrategy strategy = getInitializedStrategy();
+                    mPreviousBytes = UNSET;
+                    try {
+                        mPreviousBytes = strategy.setupQuotasFromFile();
+                    } catch (IOException e) {
+                        Slog.e(TAG, "An error occurred while reading the cache quota file.", e);
+                    } catch (IllegalStateException e) {
+                        Slog.e(TAG, "Cache quota XML file is malformed?", e);
+                    }
+
+                    // If errors occurred getting the quotas from disk, let's re-calc them.
+                    if (mPreviousBytes < 0) {
+                        mPreviousBytes = mStats.getFreeBytes();
+                        recalculateQuotas(strategy);
                     }
                     sendEmptyMessageDelayed(MSG_CHECK_STORAGE_DELTA, DELAY_IN_MILLIS);
                     break;
@@ -391,17 +413,18 @@ public class StorageStatsService extends IStorageStatsManager.Stub {
             }
         }
 
-        private void recalculateQuotas() {
+        private void recalculateQuotas(CacheQuotaStrategy strategy) {
             if (DEBUG) {
                 Slog.v(TAG, ">>> recalculating quotas ");
             }
 
+            strategy.recalculateQuotas();
+        }
+
+        private CacheQuotaStrategy getInitializedStrategy() {
             UsageStatsManagerInternal usageStatsManager =
                     LocalServices.getService(UsageStatsManagerInternal.class);
-            CacheQuotaStrategy strategy = new CacheQuotaStrategy(
-                    mContext, usageStatsManager, mInstaller);
-            // TODO: Save cache quotas to an XML file.
-            strategy.recalculateQuotas();
+            return new CacheQuotaStrategy(mContext, usageStatsManager, mInstaller);
         }
     }