FS.loadFilesFromDB|saveFilesToDB

1 files changed, 84 insertions, 0 deletions

diff --git a/src/library_fs.js b/src/library_fs.js
index e1397356..9c8223ab 100644
--- a/src/library_fs.js
+++ b/src/library_fs.js
@@ -802,6 +802,90 @@ mergeInto(LibraryManager.library, {
       }
     },
 
+    indexedDB: function() {
+      return window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB || window.msIndexedDB;
+    },
+
+    DB_NAME: function() {
+      return 'EM_FS_' + window.location.pathname;
+    },
+    DB_VERSION: 20,
+    DB_STORE_NAME: 'FILE_DATA',
+
+    // asynchronously saves a list of files to an IndexedDB. The DB will be created if not already existing.
+    saveFilesToDB: function(paths, onload, onerror) {
+      onload = onload || function(){};
+      onerror = onerror || function(){};
+      var indexedDB = FS.indexedDB();
+      try {
+        var openRequest = indexedDB.open(FS.DB_NAME(), FS.DB_VERSION);
+      } catch (e) {
+        return onerror(e);
+      }
+      openRequest.onupgradeneeded = function() {
+        console.log('creating db');
+        var db = openRequest.result;
+        db.createObjectStore(FS.DB_STORE_NAME);
+      };
+      openRequest.onsuccess = function() {
+        var db = openRequest.result;
+        var transaction = db.transaction([FS.DB_STORE_NAME], 'readwrite');
+        var files = transaction.objectStore(FS.DB_STORE_NAME);
+        var ok = 0, fail = 0, total = paths.length;
+        function finish() {
+          if (fail == 0) onload(); else onerror();
+        }
+        paths.forEach(function(path) {
+          var putRequest = files.put(FS.analyzePath(path).object.contents, path);
+          putRequest.onsuccess = function() { ok++; if (ok + fail == total) finish() };
+          putRequest.onerror = function() { fail++; if (ok + fail == total) finish() };
+        });
+        transaction.onerror = onerror;
+      };
+      openRequest.onerror = onerror;
+    },
+
+    // asychronously loads a file from IndexedDB.
+    loadFilesFromDB: function(paths, onload, onerror) {
+      onload = onload || function(){};
+      onerror = onerror || function(){};
+      var indexedDB = FS.indexedDB();
+      try {
+        var openRequest = indexedDB.open(FS.DB_NAME(), FS.DB_VERSION);
+      } catch (e) {
+        return onerror(e);
+      }
+      openRequest.onupgradeneeded = onerror; // no database to load from
+      openRequest.onsuccess = function() {
+        var db = openRequest.result;
+        try {
+          var transaction = db.transaction([FS.DB_STORE_NAME], 'readonly');
+        } catch(e) {
+          onerror(e);
+          return;
+        }
+        var files = transaction.objectStore(FS.DB_STORE_NAME);
+        var ok = 0, fail = 0, total = paths.length;
+        function finish() {
+          if (fail == 0) onload(); else onerror();
+        }
+        paths.forEach(function(path) {
+          var getRequest = files.get(path);
+          getRequest.onsuccess = function() {
+            if (FS.analyzePath(path).exists) {
+              FS.unlink(path);
+            }
+            FS.createDataFile(PATH.dirname(path), PATH.basename(path), getRequest.result, true, true, true);
+            ok++;
+            if (ok + fail == total) finish();
+          };
+          getRequest.onerror = function() { fail++; if (ok + fail == total) finish() };
+        });
+        transaction.onerror = onerror;
+      };
+      openRequest.onerror = onerror;
+    },
+
     //
     // general
     //