commit 17d24400906235a172fc760e98656589692f798a
author Jean-Michel Trivi <jmtrivi@google.com> Wed Sep 14 12:37:40 2016 -0700
committer Jean-Michel Trivi <jmtrivi@google.com> Wed Sep 14 12:48:50 2016 -0700
tree 9bc97c809e5246d2d772c1c28c65e7d2c5c65520
parent 8c83edc43b3c5c5dc5b756acd0bacb0e8348db9f

MediaScanner: check build fingerprint for system sound scan

Always scan notification, ringtones and alarm files under /system
  when the build fingerprint has changed since the last scan,
  because the dates on those files is not set correctly
  (by design), and hence cannot be trusted in the date-based
  scanning logic.
Remove some dead code

Bug 30476971

Change-Id: I638c787dc177f7f5fb17c1c2a576be190c1c85f9

media/java/android/media/MediaScanner.java

diff --git a/media/java/android/media/MediaScanner.java b/media/java/android/media/MediaScanner.java
index c8ab5f9..0fafe4b 100644
--- a/media/java/android/media/MediaScanner.java
+++ b/media/java/android/media/MediaScanner.java
@@ -21,12 +21,14 @@
 import android.content.ContentUris;
 import android.content.ContentValues;
 import android.content.Context;
+import android.content.SharedPreferences;
 import android.database.Cursor;
 import android.database.SQLException;
 import android.drm.DrmManagerClient;
 import android.graphics.BitmapFactory;
 import android.mtp.MtpConstants;
 import android.net.Uri;
+import android.os.Build;
 import android.os.Environment;
 import android.os.RemoteException;
 import android.os.SystemProperties;
@@ -153,6 +155,11 @@
     private static final String MUSIC_DIR = "/music/";
     private static final String PODCAST_DIR = "/podcasts/";
 
+    public static final String SCANNED_BUILD_PREFS_NAME = "MediaScanBuild";
+    public static final String LAST_INTERNAL_SCAN_FINGERPRINT = "lastScanFingerprint";
+    private static final String SYSTEM_SOUNDS_DIR = "/system/media/audio";
+    private static String sLastInternalScanFingerprint;
+
     private static final String[] ID3_GENRES = {
         // ID3v1 Genres
         "Blues",
@@ -402,6 +409,13 @@
         mMediaProvider = mContext.getContentResolver()
                 .acquireContentProviderClient(MediaStore.AUTHORITY);
 
+        if (sLastInternalScanFingerprint == null) {
+            final SharedPreferences scanSettings =
+                    mContext.getSharedPreferences(SCANNED_BUILD_PREFS_NAME, Context.MODE_PRIVATE);
+            sLastInternalScanFingerprint =
+                    scanSettings.getString(LAST_INTERNAL_SCAN_FINGERPRINT, new String());
+        }
+
         mAudioUri = Audio.Media.getContentUri(volumeName);
         mVideoUri = Video.Media.getContentUri(volumeName);
         mImagesUri = Images.Media.getContentUri(volumeName);
@@ -585,16 +599,24 @@
                     entry.mRowId = 0;
                 }
 
-                if (entry.mPath != null &&
-                        ((!mDefaultNotificationSet &&
+                if (entry.mPath != null) {
+                    if (((!mDefaultNotificationSet &&
                                 doesPathHaveFilename(entry.mPath, mDefaultNotificationFilename))
                         || (!mDefaultRingtoneSet &&
                                 doesPathHaveFilename(entry.mPath, mDefaultRingtoneFilename))
                         || (!mDefaultAlarmSet &&
                                 doesPathHaveFilename(entry.mPath, mDefaultAlarmAlertFilename)))) {
-                    Log.w(TAG, "forcing rescan of " + entry.mPath +
-                            "since ringtone setting didn't finish");
-                    scanAlways = true;
+                        Log.w(TAG, "forcing rescan of " + entry.mPath +
+                                "since ringtone setting didn't finish");
+                        scanAlways = true;
+                    } else if (isSystemSoundWithMetadata(entry.mPath)
+                            && !Build.FINGERPRINT.equals(sLastInternalScanFingerprint)) {
+                        // file is located on the system partition where the date cannot be trusted:
+                        // rescan if the build fingerprint has changed since the last scan.
+                        Log.i(TAG, "forcing rescan of " + entry.mPath
+                                + " since build fingerprint changed");
+                        scanAlways = true;
+                    }
                 }
 
                 // rescan for metadata if file was modified since last scan
@@ -1128,6 +1150,15 @@
 
     }; // end of anonymous MediaScannerClient instance
 
+    private static boolean isSystemSoundWithMetadata(String path) {
+        if (path.startsWith(SYSTEM_SOUNDS_DIR + ALARMS_DIR)
+                || path.startsWith(SYSTEM_SOUNDS_DIR + RINGTONES_DIR)
+                || path.startsWith(SYSTEM_SOUNDS_DIR + NOTIFICATIONS_DIR)) {
+            return true;
+        }
+        return false;
+    }
+
     private String settingSetIndicatorName(String base) {
         return base + "_set";
     }
@@ -1252,16 +1283,6 @@
         }
     }
 
-    private boolean inScanDirectory(String path, String[] directories) {
-        for (int i = 0; i < directories.length; i++) {
-            String directory = directories[i];
-            if (path.startsWith(directory)) {
-                return true;
-            }
-        }
-        return false;
-    }
-
     private void pruneDeadThumbnailFiles() {
         HashSet<String> existingFiles = new HashSet<String>();
         String directory = "/sdcard/DCIM/.thumbnails";