1 files changed, 252 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/cache/CacheFileMetadataIndex.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/cache/CacheFileMetadataIndex.java
new file mode 100644
index 0000000000..cd69336ff4
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/cache/CacheFileMetadataIndex.java
@@ -0,0 +1,252 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.cache;
+
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.SQLException;
+import android.database.sqlite.SQLiteDatabase;
+import androidx.annotation.WorkerThread;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.database.DatabaseIOException;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.database.DatabaseProvider;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.database.VersionTable;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/** Maintains an index of cache file metadata. */
+/* package */ final class CacheFileMetadataIndex {
+
+  private static final String TABLE_PREFIX = DatabaseProvider.TABLE_PREFIX + "CacheFileMetadata";
+  private static final int TABLE_VERSION = 1;
+
+  private static final String COLUMN_NAME = "name";
+  private static final String COLUMN_LENGTH = "length";
+  private static final String COLUMN_LAST_TOUCH_TIMESTAMP = "last_touch_timestamp";
+
+  private static final int COLUMN_INDEX_NAME = 0;
+  private static final int COLUMN_INDEX_LENGTH = 1;
+  private static final int COLUMN_INDEX_LAST_TOUCH_TIMESTAMP = 2;
+
+  private static final String WHERE_NAME_EQUALS = COLUMN_NAME + " = ?";
+
+  private static final String[] COLUMNS =
+      new String[] {
+        COLUMN_NAME, COLUMN_LENGTH, COLUMN_LAST_TOUCH_TIMESTAMP,
+      };
+  private static final String TABLE_SCHEMA =
+      "("
+          + COLUMN_NAME
+          + " TEXT PRIMARY KEY NOT NULL,"
+          + COLUMN_LENGTH
+          + " INTEGER NOT NULL,"
+          + COLUMN_LAST_TOUCH_TIMESTAMP
+          + " INTEGER NOT NULL)";
+
+  private final DatabaseProvider databaseProvider;
+
+  private @MonotonicNonNull String tableName;
+
+  /**
+   * Deletes index data for the specified cache.
+   *
+   * <p>This method may be slow and shouldn't normally be called on the main thread.
+   *
+   * @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.
+   */
+  @WorkerThread
+  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.beginTransactionNonExclusive();
+      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;
+  }
+
+  /**
+   * Initializes the index for the given cache UID.
+   *
+   * <p>This method may be slow and shouldn't normally be called on the main thread.
+   *
+   * @param uid The cache UID.
+   * @throws DatabaseIOException If an error occurs initializing the index.
+   */
+  @WorkerThread
+  public void initialize(long uid) throws DatabaseIOException {
+    try {
+      String hexUid = Long.toHexString(uid);
+      tableName = getTableName(hexUid);
+      SQLiteDatabase readableDatabase = databaseProvider.getReadableDatabase();
+      int version =
+          VersionTable.getVersion(
+              readableDatabase, VersionTable.FEATURE_CACHE_FILE_METADATA, hexUid);
+      if (version != TABLE_VERSION) {
+        SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
+        writableDatabase.beginTransactionNonExclusive();
+        try {
+          VersionTable.setVersion(
+              writableDatabase, VersionTable.FEATURE_CACHE_FILE_METADATA, hexUid, TABLE_VERSION);
+          dropTable(writableDatabase, tableName);
+          writableDatabase.execSQL("CREATE TABLE " + tableName + " " + TABLE_SCHEMA);
+          writableDatabase.setTransactionSuccessful();
+        } finally {
+          writableDatabase.endTransaction();
+        }
+      }
+    } catch (SQLException e) {
+      throw new DatabaseIOException(e);
+    }
+  }
+
+  /**
+   * Returns all file metadata keyed by file name. The returned map is mutable and may be modified
+   * by the caller.
+   *
+   * <p>This method may be slow and shouldn't normally be called on the main thread.
+   *
+   * @return The file metadata keyed by file name.
+   * @throws DatabaseIOException If an error occurs loading the metadata.
+   */
+  @WorkerThread
+  public Map<String, CacheFileMetadata> getAll() throws DatabaseIOException {
+    try (Cursor cursor = getCursor()) {
+      Map<String, CacheFileMetadata> fileMetadata = new HashMap<>(cursor.getCount());
+      while (cursor.moveToNext()) {
+        String name = cursor.getString(COLUMN_INDEX_NAME);
+        long length = cursor.getLong(COLUMN_INDEX_LENGTH);
+        long lastTouchTimestamp = cursor.getLong(COLUMN_INDEX_LAST_TOUCH_TIMESTAMP);
+        fileMetadata.put(name, new CacheFileMetadata(length, lastTouchTimestamp));
+      }
+      return fileMetadata;
+    } catch (SQLException e) {
+      throw new DatabaseIOException(e);
+    }
+  }
+
+  /**
+   * Sets metadata for a given file.
+   *
+   * <p>This method may be slow and shouldn't normally be called on the main thread.
+   *
+   * @param name The name of the file.
+   * @param length The file length.
+   * @param lastTouchTimestamp The file last touch timestamp.
+   * @throws DatabaseIOException If an error occurs setting the metadata.
+   */
+  @WorkerThread
+  public void set(String name, long length, long lastTouchTimestamp) throws DatabaseIOException {
+    Assertions.checkNotNull(tableName);
+    try {
+      SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
+      ContentValues values = new ContentValues();
+      values.put(COLUMN_NAME, name);
+      values.put(COLUMN_LENGTH, length);
+      values.put(COLUMN_LAST_TOUCH_TIMESTAMP, lastTouchTimestamp);
+      writableDatabase.replaceOrThrow(tableName, /* nullColumnHack= */ null, values);
+    } catch (SQLException e) {
+      throw new DatabaseIOException(e);
+    }
+  }
+
+  /**
+   * Removes metadata.
+   *
+   * <p>This method may be slow and shouldn't normally be called on the main thread.
+   *
+   * @param name The name of the file whose metadata is to be removed.
+   * @throws DatabaseIOException If an error occurs removing the metadata.
+   */
+  @WorkerThread
+  public void remove(String name) throws DatabaseIOException {
+    Assertions.checkNotNull(tableName);
+    try {
+      SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
+      writableDatabase.delete(tableName, WHERE_NAME_EQUALS, new String[] {name});
+    } catch (SQLException e) {
+      throw new DatabaseIOException(e);
+    }
+  }
+
+  /**
+   * Removes metadata.
+   *
+   * <p>This method may be slow and shouldn't normally be called on the main thread.
+   *
+   * @param names The names of the files whose metadata is to be removed.
+   * @throws DatabaseIOException If an error occurs removing the metadata.
+   */
+  @WorkerThread
+  public void removeAll(Set<String> names) throws DatabaseIOException {
+    Assertions.checkNotNull(tableName);
+    try {
+      SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
+      writableDatabase.beginTransactionNonExclusive();
+      try {
+        for (String name : names) {
+          writableDatabase.delete(tableName, WHERE_NAME_EQUALS, new String[] {name});
+        }
+        writableDatabase.setTransactionSuccessful();
+      } finally {
+        writableDatabase.endTransaction();
+      }
+    } catch (SQLException e) {
+      throw new DatabaseIOException(e);
+    }
+  }
+
+  private Cursor getCursor() {
+    Assertions.checkNotNull(tableName);
+    return databaseProvider
+        .getReadableDatabase()
+        .query(
+            tableName,
+            COLUMNS,
+            /* selection */ null,
+            /* selectionArgs= */ null,
+            /* groupBy= */ null,
+            /* 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;
+  }
+}