Add offline storage manager and manifest parser.

This contains two major parts: the Storage class, which manages
storing, listing, and deleting the stored content, and the offline
manifest parser, which loads the stored content into a manifest so the
Player can play it.

This does not include support for storing encrypted content.  The
EME sessions will not be stored properly and will fail to play.

Issue #343

Change-Id: I7ecb3400391ec8100155aa972f9b09bb7ae24d9d

build/types/offline

@@ -1,3 +1,7 @@
 # The offline storage system and manifest parser plugin.
 
 +../../lib/offline/db_engine.js
++../../lib/offline/download_manager.js
++../../lib/offline/offline_manifest_parser.js
++../../lib/offline/offline_scheme.js
++../../lib/offline/storage.js

externs/shaka/offline.js

@@ -0,0 +1,217 @@
+/**
+ * @license
+ * Copyright 2016 Google Inc.
+ *
+ * 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.
+ */
+
+
+/** @externs */
+
+
+/**
+ * @typedef {{
+ *   basic: boolean,
+ *   encrypted: !Object.<string, boolean>
+ * }}
+ *
+ * @property {boolean} basic
+ *   True if offline is usable at all.
+ * @property {!Object.<string, boolean>} encrypted
+ *   A map of key system name to whether it supports offline playback.
+ */
+shakaExtern.OfflineSupport;
+
+
+/**
+ * @typedef {{
+ *   trackSelectionCallback:
+ *       function(!Array.<shakaExtern.Track>):!Array.<shakaExtern.Track>,
+ *   progressCallback: function(shakaExtern.StoredContent,number)
+ * }}
+ *
+ * @property {function(!Array.<shakaExtern.Track>):!Array.<shakaExtern.Track>}
+ *     trackSelectionCallback
+ *   Called inside store() to determine which tracks to save from a manifest.
+ *   It is passed an array of Tracks from the manifest and it should return
+ *   an array of the tracks to store.  This is called for each Period in the
+ *   manifest (in order).
+ * @property {function(shakaExtern.StoredContent,number)} progressCallback
+ *   Called inside store() to give progress info back to the app.  It is given
+ *   the current manifest being stored and the progress of it being stored.
+ */
+shakaExtern.OfflineConfiguration;
+
+
+/**
+ * @typedef {{
+ *   offlineUri: string,
+ *   originalManifestUri: string,
+ *   duration: number,
+ *   size: number,
+ *   tracks: !Array.<shakaExtern.Track>,
+ *   appMetadata: Object
+ * }}
+ *
+ * @property {string} offlineUri
+ *   An offline URI to access the content.  This can be passed directly to
+ *   Player.
+ * @property {string} originalManifestUri
+ *   The original manifest URI of the content stored.
+ * @property {number} duration
+ *   The duration of the content, in seconds.
+ * @property {number} size
+ *   The size of the content, in bytes.
+ * @property {!Array.<shakaExtern.Track>} tracks
+ *   The tracks that are stored.  This only lists those found in the first
+ *   Period.
+ * @property {Object} appMetadata
+ *   The metadata passed to store().
+ */
+shakaExtern.StoredContent;
+
+
+/**
+ * @typedef {{
+ *   key: number,
+ *   originalManifestUri: string,
+ *   duration: number,
+ *   size: number,
+ *   periods: !Array.<shakaExtern.PeriodDB>,
+ *   sessionIds: !Array.<string>,
+ *   drmInfo: ?shakaExtern.DrmInfo,
+ *   appMetadata: Object
+ * }}
+ *
+ * @property {number} key
+ *   The key that uniquely identifies the manifest.
+ * @property {string} originalManifestUri
+ *   The URI that the manifest was originally loaded from.
+ * @property {number} duration
+ *   The total duration of the media, in seconds.
+ * @property {number} size
+ *   The total size of all stored segments, in bytes.
+ * @property {!Array.<shakaExtern.PeriodDB>} periods
+ *   The Periods that are stored.
+ * @property {!Array.<string>} sessionIds
+ *   The DRM offline session IDs for the media.
+ * @property {?shakaExtern.DrmInfo} drmInfo
+ *   The DRM info used to initialize EME.
+ * @property {Object} appMetadata
+ *   A metadata object passed from the application.
+ */
+shakaExtern.ManifestDB;
+
+
+/**
+ * @typedef {{
+ *   startTime: number,
+ *   streams: !Array.<shakaExtern.StreamDB>
+ * }}
+ *
+ * @property {number} startTime
+ *   The start time of the period, in seconds.
+ * @property {!Array.<shakaExtern.StreamDB>} streams
+ *   The streams that define the Period.
+ */
+shakaExtern.PeriodDB;
+
+
+/**
+ * @typedef {{
+ *   id: number,
+ *   primary: boolean,
+ *   presentationTimeOffset: number,
+ *   contentType: string,
+ *   mimeType: string,
+ *   codecs: string,
+ *   kind: (string|undefined),
+ *   language: string,
+ *   width: ?number,
+ *   height: ?number,
+ *   initSegmentUri: ?string,
+ *   encrypted: boolean,
+ *   keyId: ?string,
+ *   segments: !Array.<shakaExtern.SegmentDB>
+ * }}
+ *
+ * @property {number} id
+ *   The unique id of the stream.
+ * @property {boolean} primary
+ *   Whether the stream set was primary.
+ * @property {number} presentationTimeOffset
+ *   The presentation time offset of the stream.
+ * @property {string} contentType
+ *   The type of the stream, 'audio', 'text', or 'video'.
+ * @property {string} mimeType
+ *   The MIME type of the stream.
+ * @property {string} codecs
+ *   The codecs of the stream.
+ * @property {(string|undefined)} kind
+ *   The kind of text stream; undefined for audio/video.
+ * @property {string} language
+ *   The language of the stream; '' for video.
+ * @property {?number} width
+ *   The width of the stream; null for audio/text.
+ * @property {?number} height
+ *   The height of the stream; null for audio/text.
+ * @property  {?string} initSegmentUri
+ *   The offline URI where the init segment is found; null if no init segment.
+ * @property {boolean} encrypted
+ *   Whether this stream is encrypted.
+ * @property {?string} keyId
+ *   The key ID this stream is encrypted with.
+ * @property {!Array.<shakaExtern.SegmentDB>} segments
+ *   An array of segments that make up the stream
+ */
+shakaExtern.StreamDB;
+
+
+/**
+ * @typedef {{
+ *   startTime: number,
+ *   endTime: number,
+ *   uri: string
+ * }}
+ *
+ * @property {number} startTime
+ *   The start time of the segment, in seconds from the start of the Period.
+ * @property {number} endTime
+ *   The end time of the segment, in seconds from the start of the Period.
+ * @property {string} uri
+ *   The offline URI where the segment is found.
+ */
+shakaExtern.SegmentDB;
+
+
+/**
+ * @typedef {{
+ *   key: number,
+ *   data: !ArrayBuffer,
+ *   manifestKey: number,
+ *   streamNumber: number,
+ *   segmentNumber: number
+ * }}
+ *
+ * @property {number} key
+ *   A key that uniquely describes the segment.
+ * @property {!ArrayBuffer} data
+ *   The data contents of the segment.
+ * @property {number} manifestKey
+ *   The key of the manifest this belongs to.
+ * @property {number} streamNumber
+ *   The index of the stream this belongs to.
+ * @property {number} segmentNumber
+ *   The index of the segment within the stream.
+ */
+shakaExtern.SegmentDataDB;