Fix ContentDatabase/AjaxRequest circular dep.

The circular dependency,
ContentDatabase -> RangeRequest -> AjaxRequest -> ContentDatabase,
causes issues for the upstream Closure compiler. This patch breaks that
cycle by factoring out reading and writing operations from ContentDatabase
into ContentDatabaseReader and ContentDatabaseWriter respectively.

The following minor changes have been made to code that has moved:
* Removed retrieveInitSegment() since it's not used.
* Changed .stream_ids to ['stream_ids'] in retriveGroup().
* Reworked deleteGroup() so that it doesn't depend on retrieveGroup().
* Made deleteStream() private.
* Made minor formatting changes to meet the 80 character limit.

Change-Id: Idfc5d04ad32225a915b1531e0f4205137de5cc73

lib/player/offline_video_source.js

@@ -31,7 +31,8 @@ goog.require('shaka.media.SegmentIndex');
 goog.require('shaka.media.SimpleAbrManager');
 goog.require('shaka.media.StreamInfo');
 goog.require('shaka.player.StreamVideoSource');
-goog.require('shaka.util.ContentDatabase');
+goog.require('shaka.util.ContentDatabaseReader');
+goog.require('shaka.util.ContentDatabaseWriter');
 goog.require('shaka.util.IBandwidthEstimator');
 goog.require('shaka.util.LanguageUtils');
 goog.require('shaka.util.TypedBind');
@@ -135,7 +136,7 @@ shaka.player.OfflineVideoSource.prototype.configure = function(config) {
  * @export
  */
 shaka.player.OfflineVideoSource.retrieveGroupIds = function() {
-  var contentDatabase = new shaka.util.ContentDatabase(null, null);
+  var contentDatabase = new shaka.util.ContentDatabaseReader();
 
   var p = contentDatabase.setUpDatabase().then(
       function() {
@@ -347,48 +348,45 @@ shaka.player.OfflineVideoSource.prototype.onSessionReady_ = function(event) {
  */
 shaka.player.OfflineVideoSource.prototype.insertGroup_ =
     function(selectedStreams, drmScheme, duration) {
-  var contentDatabase = new shaka.util.ContentDatabase(this.estimator, this);
+  var contentDatabase =
+      new shaka.util.ContentDatabaseWriter(this.estimator, this);
   if (this.config_['rangeRequestTimeout'] != null) {
     contentDatabase.setRangeRequestTimeout(
         Number(this.config_['rangeRequestTimeout']));
   }
-  var p = contentDatabase.setUpDatabase();
 
   // Insert the group of streams into the database and close the connection.
-  p = p.then(shaka.util.TypedBind(this, function() {
+  return contentDatabase.setUpDatabase().then(shaka.util.TypedBind(this,
+      function() {
         return contentDatabase.insertGroup(
             selectedStreams, this.sessionIds_, duration, drmScheme);
-      })).then(
-          /** @param {number} groupId */
-          function(groupId) {
-            contentDatabase.closeDatabaseConnection();
-            return Promise.resolve(groupId);
-          }
-      ).catch(
-          /** @param {*} e */
-          function(e) {
-            contentDatabase.closeDatabaseConnection();
-            return Promise.reject(e);
-          });
-  return p;
+      })
+  ).then(
+      /** @param {number} groupId */
+      function(groupId) {
+        contentDatabase.closeDatabaseConnection();
+        return Promise.resolve(groupId);
+      }
+  ).catch(
+      /** @param {*} e */
+      function(e) {
+        contentDatabase.closeDatabaseConnection();
+        return Promise.reject(e);
+      }
+  );
 };
 
 
 /** @override */
 shaka.player.OfflineVideoSource.prototype.load = function(preferredLanguage) {
   shaka.asserts.assert(this.groupId_ >= 0);
-  var contentDatabase = new shaka.util.ContentDatabase(null, null);
-  if (this.config_['rangeRequestTimeout'] != null) {
-    contentDatabase.setRangeRequestTimeout(
-        Number(this.config_['rangeRequestTimeout']));
-  }
-  var p = contentDatabase.setUpDatabase();
+  var contentDatabase = new shaka.util.ContentDatabaseReader();
   var duration, keySystem;
 
-  return p.then(shaka.util.TypedBind(this,
+  return contentDatabase.setUpDatabase().then(shaka.util.TypedBind(this,
       function() {
-        return contentDatabase.retrieveGroup(/** @type {number} */(
-            this.groupId_));
+        return contentDatabase.retrieveGroup(
+            /** @type {number} */(this.groupId_));
       })
   ).then(shaka.util.TypedBind(this,
       /** @param {shaka.util.ContentDatabase.GroupInformation} group */
@@ -422,7 +420,8 @@ shaka.player.OfflineVideoSource.prototype.load = function(preferredLanguage) {
       function(e) {
         contentDatabase.closeDatabaseConnection();
         return Promise.reject(e);
-      });
+      }
+  );
 };
 
 
@@ -485,15 +484,13 @@ shaka.player.OfflineVideoSource.prototype.reconstructManifestInfo_ =
  */
 shaka.player.OfflineVideoSource.prototype.deleteGroup = function() {
   shaka.asserts.assert(this.groupId_ >= 0);
-  var contentDatabase = new shaka.util.ContentDatabase(null, null);
-  if (this.config_['rangeRequestTimeout'] != null) {
-    contentDatabase.setRangeRequestTimeout(
-        Number(this.config_['rangeRequestTimeout']));
-  }
-  var p = contentDatabase.setUpDatabase();
-  return p.then(
-      contentDatabase.deleteGroup.bind(
-          contentDatabase, /** @type {number} */(this.groupId_))
+  var contentDatabase = new shaka.util.ContentDatabaseWriter(null, null);
+
+  return contentDatabase.setUpDatabase().then(shaka.util.TypedBind(this,
+      function() {
+        return contentDatabase.deleteGroup(
+            /** @type {number} */(this.groupId_));
+      })
   ).then(
       function() {
         contentDatabase.closeDatabaseConnection();

lib/util/ajax_request.js

@@ -21,6 +21,7 @@ goog.provide('shaka.util.AjaxRequest');
 goog.require('goog.Uri');
 goog.require('shaka.asserts');
 goog.require('shaka.util.Clock');
+goog.require('shaka.util.ContentDatabaseReader');
 goog.require('shaka.util.IBandwidthEstimator');
 goog.require('shaka.util.PublicPromise');
 goog.require('shaka.util.StringUtils');
@@ -328,10 +329,12 @@ shaka.util.AjaxRequest.prototype.handleOfflineUri_ = function() {
   shaka.asserts.assert(!isNaN(streamId));
   shaka.asserts.assert(!isNaN(segmentId));
 
-  var db = new shaka.util.ContentDatabase(null, null);
-  return db.setUpDatabase().then(
+  // TODO: It may be inefficient to keep re-opening the database connection.
+  // Find a way to keep the database connection open between requests.
+  var contentDatabase = new shaka.util.ContentDatabaseReader();
+  return contentDatabase.setUpDatabase().then(
       function() {
-        return db.retrieveSegment(streamId, segmentId);
+        return contentDatabase.retrieveSegment(streamId, segmentId);
       }
   ).then(shaka.util.TypedBind(this,
       /** @param {ArrayBuffer} data */
@@ -344,14 +347,14 @@ shaka.util.AjaxRequest.prototype.handleOfflineUri_ = function() {
 
         var promise = this.promise_;
         promise.resolve(xhr);
-        db.closeDatabaseConnection();
+        contentDatabase.closeDatabaseConnection();
         this.destroy_();
         return promise;
       })
   ).catch(shaka.util.TypedBind(this,
       /** @param {*} e */
       function(e) {
-        db.closeDatabaseConnection();
+        contentDatabase.closeDatabaseConnection();
         this.destroy_();
         return Promise.reject(e);
       })