Support multiple DefaultDownloadIndex instances

PiperOrigin-RevId: 244226680

Support multiple DefaultDownloadIndex instances
PiperOrigin-RevId: 244226680
0ccda60a · olly · Oliver Woodman · e9413b0d · 0ccda60a · 0ccda60a
Commit 0ccda60a authored Apr 18, 2019 by olly Committed by Oliver Woodman Apr 18, 2019
Showing with 47 additions and 36 deletions
library/core/src/main/java/com/google/android/exoplayer2/offline/DefaultDownloadIndex.java
library/core/src/test/java/com/google/android/exoplayer2/offline/DefaultDownloadIndexTest.java
--- a/library/core/src/main/java/com/google/android/exoplayer2/offline/DefaultDownloadIndex.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/offline/DefaultDownloadIndex.java
@@ -23,6 +23,7 @@ import android.database.sqlite.SQLiteException;
 import android.net.Uri;
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
+import android.text.TextUtils;
 import com.google.android.exoplayer2.database.DatabaseIOException;
 import com.google.android.exoplayer2.database.DatabaseProvider;
 import com.google.android.exoplayer2.database.VersionTable;
@@ -32,18 +33,11 @@ import com.google.android.exoplayer2.util.Util;
 import java.util.ArrayList;
 import java.util.List;
-/**
+/** A {@link DownloadIndex} that uses SQLite to persist {@link Download Downloads}. */
- * A {@link DownloadIndex} which uses SQLite to persist {@link Download}s.
- *
- * <p class="caution">Database access may take a long time, do not call methods of this class from
- * the application main thread.
- */
 public final class DefaultDownloadIndex implements WritableDownloadIndex {
-  private static final String TABLE_NAME = DatabaseProvider.TABLE_PREFIX + "Downloads";
+  private static final String TABLE_PREFIX = DatabaseProvider.TABLE_PREFIX + "Downloads";
-  // TODO: Support multiple instances. Probably using the underlying cache UID.
-  @VisibleForTesting /* package */ static final String INSTANCE_UID = "singleton";
  @VisibleForTesting /* package */ static final int TABLE_VERSION = 1;
  private static final String COLUMN_ID = "id";
@@ -108,11 +102,8 @@ public final class DefaultDownloadIndex implements WritableDownloadIndex {
        COLUMN_UPDATE_TIME_MS
      };
-  private static final String SQL_DROP_TABLE_IF_EXISTS = "DROP TABLE IF EXISTS " + TABLE_NAME;
+  private static final String TABLE_SCHEMA =
-  private static final String SQL_CREATE_TABLE =
+      "("
-      "CREATE TABLE "
-          + TABLE_NAME
-          + " ("
          + COLUMN_ID
          + " TEXT PRIMARY KEY NOT NULL,"
          + COLUMN_TYPE
@@ -148,19 +139,42 @@ public final class DefaultDownloadIndex implements WritableDownloadIndex {
  private static final String TRUE = "1";
+  private final String name;
+  private final String tableName;
  private final DatabaseProvider databaseProvider;
  private boolean initialized;
  /**
-   * Creates a DefaultDownloadIndex which stores the {@link Download}s on a SQLite database provided
+   * Creates an instance that stores the {@link Download Downloads} in an SQLite database provided
-   * by {@code databaseProvider}.
+   * by a {@link DatabaseProvider}.
+   *
+   * <p>Equivalent to calling {@link #DefaultDownloadIndex(DatabaseProvider, String)} with {@code
+   * name=""}.
   *
-   * @param databaseProvider A DatabaseProvider which provides the database which will be used to
+   * <p>Applications that only have one download index may use this constructor. Applications that
-   *     store DownloadStatus table.
+   * have multiple download indices should call {@link #DefaultDownloadIndex(DatabaseProvider,
+   * String)} to specify a unique name for each index.
+   *
+   * @param databaseProvider Provides the SQLite database in which downloads are persisted.
   */
  public DefaultDownloadIndex(DatabaseProvider databaseProvider) {
+    this(databaseProvider, "");
+  }
+  /**
+   * Creates an instance that stores the {@link Download Downloads} in an SQLite database provided
+   * by a {@link DatabaseProvider}.
+   *
+   * @param databaseProvider Provides the SQLite database in which downloads are persisted.
+   * @param name The name of the index. This name is incorporated into the names of the SQLite
+   *     tables in which downloads are persisted.
+   */
+  public DefaultDownloadIndex(DatabaseProvider databaseProvider, String name) {
+    // TODO: Remove this backward compatibility hack for launch.
+    this.name = TextUtils.isEmpty(name) ? "singleton" : name;
    this.databaseProvider = databaseProvider;
+    tableName = TABLE_PREFIX + name;
  }
  @Override
@@ -207,7 +221,7 @@ public final class DefaultDownloadIndex implements WritableDownloadIndex {
    values.put(COLUMN_UPDATE_TIME_MS, download.updateTimeMs);
    try {
      SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
-      writableDatabase.replaceOrThrow(TABLE_NAME, /* nullColumnHack= */ null, values);
+      writableDatabase.replaceOrThrow(tableName, /* nullColumnHack= */ null, values);
    } catch (SQLiteException e) {
      throw new DatabaseIOException(e);
    }
@@ -217,7 +231,7 @@ public final class DefaultDownloadIndex implements WritableDownloadIndex {
  public void removeDownload(String id) throws DatabaseIOException {
    ensureInitialized();
    try {
-      databaseProvider.getWritableDatabase().delete(TABLE_NAME, WHERE_ID_EQUALS, new String[] {id});
+      databaseProvider.getWritableDatabase().delete(tableName, WHERE_ID_EQUALS, new String[] {id});
    } catch (SQLiteException e) {
      throw new DatabaseIOException(e);
    }
@@ -230,7 +244,7 @@ public final class DefaultDownloadIndex implements WritableDownloadIndex {
      ContentValues values = new ContentValues();
      values.put(COLUMN_STOP_REASON, stopReason);
      SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
-      writableDatabase.update(TABLE_NAME, values, WHERE_STATE_TERMINAL, /* whereArgs= */ null);
+      writableDatabase.update(tableName, values, WHERE_STATE_TERMINAL, /* whereArgs= */ null);
    } catch (SQLException e) {
      throw new DatabaseIOException(e);
    }
@@ -244,7 +258,7 @@ public final class DefaultDownloadIndex implements WritableDownloadIndex {
      values.put(COLUMN_STOP_REASON, stopReason);
      SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
      writableDatabase.update(
-          TABLE_NAME, values, WHERE_STATE_TERMINAL + " AND " + WHERE_ID_EQUALS, new String[] {id});
+          tableName, values, WHERE_STATE_TERMINAL + " AND " + WHERE_ID_EQUALS, new String[] {id});
    } catch (SQLException e) {
      throw new DatabaseIOException(e);
    }
@@ -256,16 +270,15 @@ public final class DefaultDownloadIndex implements WritableDownloadIndex {
    }
    try {
      SQLiteDatabase readableDatabase = databaseProvider.getReadableDatabase();
-      int version =
+      int version = VersionTable.getVersion(readableDatabase, VersionTable.FEATURE_OFFLINE, name);
-          VersionTable.getVersion(readableDatabase, VersionTable.FEATURE_OFFLINE, INSTANCE_UID);
      if (version == VersionTable.VERSION_UNSET || version > TABLE_VERSION) {
        SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
        writableDatabase.beginTransaction();
        try {
          VersionTable.setVersion(
-              writableDatabase, VersionTable.FEATURE_OFFLINE, INSTANCE_UID, TABLE_VERSION);
+              writableDatabase, VersionTable.FEATURE_OFFLINE, name, TABLE_VERSION);
-          writableDatabase.execSQL(SQL_DROP_TABLE_IF_EXISTS);
+          writableDatabase.execSQL("DROP TABLE IF EXISTS " + tableName);
-          writableDatabase.execSQL(SQL_CREATE_TABLE);
+          writableDatabase.execSQL("CREATE TABLE " + tableName + " " + TABLE_SCHEMA);
          writableDatabase.setTransactionSuccessful();
        } finally {
          writableDatabase.endTransaction();
@@ -287,7 +300,7 @@ public final class DefaultDownloadIndex implements WritableDownloadIndex {
      return databaseProvider
          .getReadableDatabase()
          .query(
-              TABLE_NAME,
+              tableName,
              COLUMNS,
              selection,
              selectionArgs,

--- a/library/core/src/test/java/com/google/android/exoplayer2/offline/DefaultDownloadIndexTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/offline/DefaultDownloadIndexTest.java
@@ -15,7 +15,6 @@
 */
 package com.google.android.exoplayer2.offline;
-import static com.google.android.exoplayer2.offline.DefaultDownloadIndex.INSTANCE_UID;
 import static com.google.common.truth.Truth.assertThat;
 import android.database.sqlite.SQLiteDatabase;
@@ -33,6 +32,8 @@ import org.junit.runner.RunWith;
 @RunWith(AndroidJUnit4.class)
 public class DefaultDownloadIndexTest {
+  private static final String EMPTY_NAME = "singleton";
  private ExoDatabaseProvider databaseProvider;
  private DefaultDownloadIndex downloadIndex;
@@ -170,14 +171,12 @@ public class DefaultDownloadIndexTest {
  @Test
  public void putDownload_setsVersion() throws DatabaseIOException {
    SQLiteDatabase readableDatabase = databaseProvider.getReadableDatabase();
-    assertThat(
+    assertThat(VersionTable.getVersion(readableDatabase, VersionTable.FEATURE_OFFLINE, EMPTY_NAME))
-            VersionTable.getVersion(readableDatabase, VersionTable.FEATURE_OFFLINE, INSTANCE_UID))
        .isEqualTo(VersionTable.VERSION_UNSET);
    downloadIndex.putDownload(new DownloadBuilder("id1").build());
-    assertThat(
+    assertThat(VersionTable.getVersion(readableDatabase, VersionTable.FEATURE_OFFLINE, EMPTY_NAME))
-            VersionTable.getVersion(readableDatabase, VersionTable.FEATURE_OFFLINE, INSTANCE_UID))
        .isEqualTo(DefaultDownloadIndex.TABLE_VERSION);
  }
@@ -191,15 +190,14 @@ public class DefaultDownloadIndexTest {
    SQLiteDatabase writableDatabase = databaseProvider.getWritableDatabase();
    VersionTable.setVersion(
-        writableDatabase, VersionTable.FEATURE_OFFLINE, INSTANCE_UID, Integer.MAX_VALUE);
+        writableDatabase, VersionTable.FEATURE_OFFLINE, EMPTY_NAME, Integer.MAX_VALUE);
    downloadIndex = new DefaultDownloadIndex(databaseProvider);
    cursor = downloadIndex.getDownloads();
    assertThat(cursor.getCount()).isEqualTo(0);
    cursor.close();
-    assertThat(
+    assertThat(VersionTable.getVersion(writableDatabase, VersionTable.FEATURE_OFFLINE, EMPTY_NAME))
-            VersionTable.getVersion(writableDatabase, VersionTable.FEATURE_OFFLINE, INSTANCE_UID))
        .isEqualTo(DefaultDownloadIndex.TABLE_VERSION);
  }