Automated g4 rollback of changelist 237051112.

*** Original change description ***

Add SimpleCache deletion functionality

This is needed now that index data may be stored outside
of the cache directory.

***

PiperOrigin-RevId: 239294713

library/core/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheFileMetadataIndex.java

@@ -61,34 +61,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
   @MonotonicNonNull private String tableName;
 
-  /**
-   * Deletes index data for the specified cache.
-   *
-   * @param databaseProvider Provides the database in which the index is stored.
-   * @param uid The cache UID.
-   * @throws DatabaseIOException If an error occurs deleting the index data.
-   */
-  public static void delete(DatabaseProvider databaseProvider, long uid)
-      throws DatabaseIOException {
-    String hexUid = Long.toHexString(uid);
-    try {
-      String tableName = getTableName(hexUid);
-      SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
-      writableDatabase.beginTransaction();
-      try {
-        VersionTable.removeVersion(
-            writableDatabase, VersionTable.FEATURE_CACHE_FILE_METADATA, hexUid);
-        dropTable(writableDatabase, tableName);
-        writableDatabase.setTransactionSuccessful();
-      } finally {
-        writableDatabase.endTransaction();
-      }
-    } catch (SQLException e) {
-      throw new DatabaseIOException(e);
-    }
-  }
-
-  /** @param databaseProvider Provides the database in which the index is stored. */
   public CacheFileMetadataIndex(DatabaseProvider databaseProvider) {
     this.databaseProvider = databaseProvider;
   }
@@ -96,13 +68,12 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
   /**
    * Initializes the index for the given cache UID.
    *
-   * @param uid The cache UID.
    * @throws DatabaseIOException If an error occurs initializing the index.
    */
   public void initialize(long uid) throws DatabaseIOException {
     try {
       String hexUid = Long.toHexString(uid);
-      tableName = getTableName(hexUid);
+      tableName = TABLE_PREFIX + hexUid;
       SQLiteDatabase readableDatabase = databaseProvider.getReadableDatabase();
       int version =
           VersionTable.getVersion(
@@ -113,7 +84,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
         try {
           VersionTable.setVersion(
               writableDatabase, VersionTable.FEATURE_CACHE_FILE_METADATA, hexUid, TABLE_VERSION);
-          dropTable(writableDatabase, tableName);
+          writableDatabase.execSQL("DROP TABLE IF EXISTS " + tableName);
           writableDatabase.execSQL("CREATE TABLE " + tableName + " " + TABLE_SCHEMA);
           writableDatabase.setTransactionSuccessful();
         } finally {
@@ -225,12 +196,4 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
             /* having= */ null,
             /* orderBy= */ null);
   }
-
-  private static void dropTable(SQLiteDatabase writableDatabase, String tableName) {
-    writableDatabase.execSQL("DROP TABLE IF EXISTS " + tableName);
-  }
-
-  private static String getTableName(String hexUid) {
-    return TABLE_PREFIX + hexUid;
-  }
 }

library/core/src/main/java/com/google/android/exoplayer2/upstream/cache/CachedContentIndex.java

@@ -103,18 +103,6 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     return fileName.startsWith(FILE_NAME_ATOMIC);
   }
 
-  /**
-   * Deletes index data for the specified cache.
-   *
-   * @param databaseProvider Provides the database in which the index is stored.
-   * @param uid The cache UID.
-   * @throws DatabaseIOException If an error occurs deleting the index data.
-   */
-  public static void delete(DatabaseProvider databaseProvider, long uid)
-      throws DatabaseIOException {
-    DatabaseStorage.delete(databaseProvider, uid);
-  }
-
   /**
    * Creates an instance supporting database storage only.
    *
@@ -729,11 +717,6 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     private String hexUid;
     private String tableName;
 
-    public static void delete(DatabaseProvider databaseProvider, long uid)
-        throws DatabaseIOException {
-      delete(databaseProvider, Long.toHexString(uid));
-    }
-
     public DatabaseStorage(DatabaseProvider databaseProvider) {
       this.databaseProvider = databaseProvider;
       pendingUpdates = new SparseArray<>();
@@ -742,7 +725,7 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     @Override
     public void initialize(long uid) {
       hexUid = Long.toHexString(uid);
-      tableName = getTableName(hexUid);
+      tableName = TABLE_PREFIX + hexUid;
     }
 
     @Override
@@ -756,7 +739,20 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
 
     @Override
     public void delete() throws DatabaseIOException {
-      delete(databaseProvider, hexUid);
+      try {
+        SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
+        writableDatabase.beginTransaction();
+        try {
+          VersionTable.removeVersion(
+              writableDatabase, VersionTable.FEATURE_CACHE_CONTENT_METADATA, hexUid);
+          dropTable(writableDatabase);
+          writableDatabase.setTransactionSuccessful();
+        } finally {
+          writableDatabase.endTransaction();
+        }
+      } catch (SQLException e) {
+        throw new DatabaseIOException(e);
+      }
     }
 
     @Override
@@ -879,10 +875,14 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     private void initializeTable(SQLiteDatabase writableDatabase) throws DatabaseIOException {
       VersionTable.setVersion(
           writableDatabase, VersionTable.FEATURE_CACHE_CONTENT_METADATA, hexUid, TABLE_VERSION);
-      dropTable(writableDatabase, tableName);
+      dropTable(writableDatabase);
       writableDatabase.execSQL("CREATE TABLE " + tableName + " " + TABLE_SCHEMA);
     }
 
+    private void dropTable(SQLiteDatabase writableDatabase) {
+      writableDatabase.execSQL("DROP TABLE IF EXISTS " + tableName);
+    }
+
     private void deleteRow(SQLiteDatabase writableDatabase, int key) {
       writableDatabase.delete(tableName, WHERE_ID_EQUALS, new String[] {Integer.toString(key)});
     }
@@ -899,32 +899,5 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
       values.put(COLUMN_METADATA, data);
       writableDatabase.replaceOrThrow(tableName, /* nullColumnHack= */ null, values);
     }
-
-    private static void delete(DatabaseProvider databaseProvider, String hexUid)
-        throws DatabaseIOException {
-      try {
-        String tableName = getTableName(hexUid);
-        SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
-        writableDatabase.beginTransaction();
-        try {
-          VersionTable.removeVersion(
-              writableDatabase, VersionTable.FEATURE_CACHE_CONTENT_METADATA, hexUid);
-          dropTable(writableDatabase, tableName);
-          writableDatabase.setTransactionSuccessful();
-        } finally {
-          writableDatabase.endTransaction();
-        }
-      } catch (SQLException e) {
-        throw new DatabaseIOException(e);
-      }
-    }
-
-    private static void dropTable(SQLiteDatabase writableDatabase, String tableName) {
-      writableDatabase.execSQL("DROP TABLE IF EXISTS " + tableName);
-    }
-
-    private static String getTableName(String hexUid) {
-      return TABLE_PREFIX + hexUid;
-    }
   }
 }

library/core/src/main/java/com/google/android/exoplayer2/upstream/cache/SimpleCache.java

@@ -19,11 +19,9 @@ import android.os.ConditionVariable;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.database.DatabaseIOException;
 import com.google.android.exoplayer2.database.DatabaseProvider;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
-import com.google.android.exoplayer2.util.Util;
 import java.io.File;
 import java.io.IOException;
 import java.security.SecureRandom;
@@ -38,13 +36,8 @@ import java.util.TreeSet;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /**
- * A {@link Cache} implementation that maintains an in-memory representation.
+ * A {@link Cache} implementation that maintains an in-memory representation. Note, only one
- *
+ * instance of SimpleCache is allowed for a given directory at a given time.
- * <p>Only one instance of SimpleCache is allowed for a given directory at a given time.
- *
- * <p>To delete a SimpleCache, use {@link #delete(File, DatabaseProvider)} rather than deleting the
- * directory and its contents directly. This is necessary to ensure that associated index data is
- * also removed.
  */
 public final class SimpleCache implements Cache {
 
@@ -100,45 +93,6 @@ public final class SimpleCache implements Cache {
     lockedCacheDirs.clear();
   }
 
-  /**
-   * Deletes all content belonging to a cache instance.
-   *
-   * @param cacheDir The cache directory.
-   * @param databaseProvider The database in which index data is stored, or {@code null} if the
-   *     cache used a legacy index.
-   */
-  public static void delete(File cacheDir, @Nullable DatabaseProvider databaseProvider) {
-    if (!cacheDir.exists()) {
-      return;
-    }
-
-    File[] files = cacheDir.listFiles();
-    if (files == null) {
-      cacheDir.delete();
-      return;
-    }
-
-    if (databaseProvider != null) {
-      // Make a best effort to read the cache UID and delete associated index data before deleting
-      // cache directory itself.
-      long uid = loadUid(files);
-      if (uid != -1) {
-        try {
-          CacheFileMetadataIndex.delete(databaseProvider, uid);
-        } catch (DatabaseIOException e) {
-          Log.w(TAG, "Failed to delete file metadata: " + uid);
-        }
-        try {
-          CachedContentIndex.delete(databaseProvider, uid);
-        } catch (DatabaseIOException e) {
-          Log.w(TAG, "Failed to delete file metadata: " + uid);
-        }
-      }
-    }
-
-    Util.recursiveDelete(cacheDir);
-  }
-
   /**
    * Constructs the cache. The cache will delete any unrecognized files from the directory. Hence
    * the directory cannot be used to store other files.
@@ -570,14 +524,11 @@ public final class SimpleCache implements Cache {
       return;
     }
 
-    uid = loadUid(files);
+    try {
-    if (uid == -1) {
+      uid = loadUid(cacheDir, files);
-      try {
+    } catch (IOException e) {
-        uid = createUid(cacheDir);
+      initializationException = new CacheException("Failed to load cache UID: " + cacheDir);
-      } catch (IOException e) {
+      return;
-        initializationException = new CacheException("Failed to create cache UID: " + cacheDir);
-        return;
-      }
     }
 
     try {
@@ -735,13 +686,14 @@ public final class SimpleCache implements Cache {
   }
 
   /**
-   * Loads the cache UID from the files belonging to the root directory.
+   * Loads the cache UID from the files belonging to the root directory, generating one if needed.
    *
+   * @param directory The root directory.
    * @param files The files belonging to the root directory.
-   * @return The loaded UID, or -1 if a UID has not yet been created.
+   * @return The cache loaded UID.
    * @throws IOException If there is an error loading or generating the UID.
    */
-  private static long loadUid(File[] files) {
+  private static long loadUid(File directory, File[] files) throws IOException {
     for (File file : files) {
       String fileName = file.getName();
       if (fileName.endsWith(UID_FILE_SUFFIX)) {
@@ -754,7 +706,7 @@ public final class SimpleCache implements Cache {
         }
       }
     }
-    return -1;
+    return createUid(directory);
   }
 
   @SuppressWarnings("TrulyRandom")