Merge pull request #11325 from dhylands/dhylands-893282-mediadb

Bug 893282 - Fix mediadb to scan all device storage areas. r=djf

shared/js/mediadb.js

@@ -621,11 +621,6 @@ var MediaDB = (function() {
     function initDeviceStorage() {
       var details = media.details;
 
-      // Get the composite storage object that agregates all files of the
-      // specified media type. We use this object when scanning and when
-      // retrieving files using their fully-qualifed names.
-      media.storage = navigator.getDeviceStorage(mediaType);
-
       // Get the individual device storage objects, so that we can listen
       // for events on the different volumes separately.
       details.storages = navigator.getDeviceStorages(mediaType);
@@ -923,13 +918,16 @@ var MediaDB = (function() {
         throw Error('MediaDB is not ready. State: ' + this.state);
 
       var media = this;
+      // Refetch the default storage area, since the user can change it
+      // in the settings app.
+      var storage = navigator.getDeviceStorage(media.mediaType);
 
       // Delete any existing file by this name, then save the file.
-      var deletereq = media.storage.delete(filename);
+      var deletereq = storage.delete(filename);
       deletereq.onsuccess = deletereq.onerror = save;
 
       function save() {
-        var request = media.storage.addNamed(file, filename);
+        var request = storage.addNamed(file, filename);
         request.onerror = function() {
           console.error('MediaDB: Failed to store', filename,
                         'in DeviceStorage:', request.error);
@@ -1241,6 +1239,60 @@ var MediaDB = (function() {
     return (path[0] === '.' || path.indexOf('/.') !== -1);
   }
 
+  // With the removal of composite storage, this function emulates
+  // the composite storage enumeration (i.e. return files from
+  // all of the storage areas).
+  function enumerateAll(storages, dir, options) {
+    var storageIndex = 0;
+    var ds_cursor = null;
+
+    var cursor = {
+      continue: function cursor_continue() {
+        ds_cursor.continue();
+      }
+    };
+
+    function enumerateNextStorage() {
+      ds_cursor = storages[storageIndex].enumerate(dir, options);
+      ds_cursor.onsuccess = onsuccess;
+      ds_cursor.onerror = onerror;
+    };
+
+    function onsuccess(e) {
+      cursor.result = e.target.result;
+      if (!cursor.result) {
+        storageIndex++;
+        if (storageIndex < storages.length) {
+          enumerateNextStorage();
+          return;
+        }
+        // If we've run out of storages, then we fall through and call
+        // onsuccess with the null result.
+      }
+      if (cursor.onsuccess) {
+        try {
+          cursor.onsuccess(e);
+        } catch (err) {
+          console.warn('enumerateAll onsuccess threw', err);
+        }
+      }
+    };
+
+    function onerror(e) {
+      cursor.error = e.target.error;
+      if (cursor.onerror) {
+        try {
+          cursor.onerror(e);
+        } catch (err) {
+          console.warn('enumerateAll onerror threw', err);
+        }
+      }
+    };
+
+    enumerateNextStorage();
+    return cursor;
+  }
+
   // Tell the db to start a manual scan. I think we don't do
   // this automatically from the constructor, but most apps will start
   // a scan right after calling the constructor and then will proceed to
@@ -1279,7 +1331,7 @@ var MediaDB = (function() {
       var cursor;
       if (timestamp > 0) {
         media.details.firstscan = false;
-        cursor = media.storage.enumerate('', {
+        cursor = enumerateAll(media.details.storages, '', {
           // add 1 so we don't find the same newest file again
           since: new Date(timestamp + 1)
         });
@@ -1290,7 +1342,7 @@ var MediaDB = (function() {
         // allows important optimizations during the scanning process
         media.details.firstscan = true;
         media.details.records = [];
-        cursor = media.storage.enumerate('');
+        cursor = enumerateAll(media.details.storages, '');
       }
 
       cursor.onsuccess = function() {
@@ -1346,7 +1398,7 @@ var MediaDB = (function() {
       // were found during the quick scan.  So we'll start off by
       // enumerating all files in device storage
       var dsfiles = [];
-      var cursor = media.storage.enumerate('');
+      var cursor = enumerateAll(media.details.storages, '');
       cursor.onsuccess = function() {
         if (!media.scanning)  // Abort if scanning has been cancelled
           return;
@@ -1598,7 +1650,11 @@ var MediaDB = (function() {
 
       // If we got a filename, look up the file in device storage
       if (typeof f === 'string') {
-        var getreq = media.storage.get(f);
+        // Note: Even though we're using the default storage area, if the
+        //       filename is fully qualified, it will get redirected to the
+        //       appropriate storage area.
+        var storage = navigator.getDeviceStorage(media.mediaType);
+        var getreq = storage.get(f);
         getreq.onerror = function() {
           console.warn('MediaDB: Unknown file in insertRecord:',
                        f, getreq.error);