Make JavaScript sources compile into the library; convert JavaScript files on the fly

lib/io.js

+//
+// No direct file system access, using FileSystem API
+//
+
+var IO = exports.IO =
+{
+  _getFileEntry: function(file, create, successCallback, errorCallback)
+  {
+    if (file instanceof FakeFile)
+      file = file.path;
+    else if ("spec" in file)
+      file = file.spec;
+
+    // Remove directory path - we operate on a single directory in Chrome
+    file = file.replace(/^.*[\/\\]/, "");
+
+    // We request a gigabyte of space, just in case
+    (window.requestFileSystem || window.webkitRequestFileSystem)(window.PERSISTENT, 1024*1024*1024, function(fs)
+    {
+      fs.root.getFile(file, {create: create}, function(fileEntry)
+      {
+        successCallback(fs, fileEntry);
+      }, errorCallback);
+    }, errorCallback);
+  },
+
+  lineBreak: "\n",
+
+  resolveFilePath: function(path)
+  {
+    return new FakeFile(path);
+  },
+
+  readFromFile: function(file, decode, listener, callback, timeLineID)
+  {
+    if ("spec" in file && /^defaults\b/.test(file.spec))
+    {
+      // Code attempts to read the default patterns.ini, we don't have that.
+      // Make sure to execute first-run actions instead.
+      callback(null);
+      if (localStorage.currentVersion)
+        seenDataCorruption = true;
+      delete localStorage.currentVersion;
+      return;
+    }
+
+    this._getFileEntry(file, false, function(fs, fileEntry)
+    {
+      fileEntry.file(function(file)
+      {
+        var reader = new FileReader();
+        reader.onloadend = function()
+        {
+          if (reader.error)
+            callback(reader.error);
+          else
+          {
+            var lines = reader.result.split(/[\r\n]+/);
+            for (var i = 0; i < lines.length; i++)
+              listener.process(lines[i]);
+            listener.process(null);
+            callback(null);
+          }
+        };
+        reader.readAsText(file);
+      }, callback);
+    }, callback);
+  },
+
+  writeToFile: function(file, encode, data, callback, timeLineID)
+  {
+    this._getFileEntry(file, true, function(fs, fileEntry)
+    {
+      fileEntry.createWriter(function(writer)
+      {
+        var executeWriteOperation = function(op, nextOperation)
+        {
+          writer.onwriteend = function()
+          {
+            if (writer.error)
+              callback(writer.error);
+            else
+              nextOperation();
+          }.bind(this);
+
+          op();
+        }.bind(this);
+
+        executeWriteOperation(writer.truncate.bind(writer, 0), function()
+        {
+          var blob;
+          try
+          {
+            blob = new Blob([data.join(this.lineBreak) + this.lineBreak], {type: "text/plain"});
+          }
+          catch (e)
+          {
+            if (!(e instanceof TypeError))
+              throw e;
+
+            // Blob wasn't a constructor before Chrome 20
+            var builder = new (window.BlobBuilder || window.WebKitBlobBuilder);
+            builder.append(data.join(this.lineBreak) + this.lineBreak);
+            blob = builder.getBlob("text/plain");
+          }
+          executeWriteOperation(writer.write.bind(writer, blob), callback.bind(null, null));
+        }.bind(this));
+      }.bind(this), callback);
+    }.bind(this), callback);
+  },
+
+  copyFile: function(fromFile, toFile, callback)
+  {
+    // Simply combine read and write operations
+    var data = [];
+    this.readFromFile(fromFile, false, {
+      process: function(line)
+      {
+        if (line !== null)
+          data.push(line);
+      }
+    }, function(e)
+    {
+      if (e)
+        callback(e);
+      else
+        this.writeToFile(toFile, false, data, callback);
+    }.bind(this));
+  },
+
+  renameFile: function(fromFile, newName, callback)
+  {
+    this._getFileEntry(fromFile, false, function(fs, fileEntry)
+    {
+      fileEntry.moveTo(fs.root, newName, function()
+      {
+        callback(null);
+      }, callback);
+    }, callback);
+  },
+
+  removeFile: function(file, callback)
+  {
+    this._getFileEntry(file, false, function(fs, fileEntry)
+    {
+      fileEntry.remove(function()
+      {
+        callback(null);
+      }, callback);
+    }, callback);
+  },
+
+  statFile: function(file, callback)
+  {
+    this._getFileEntry(file, false, function(fs, fileEntry)
+    {
+      fileEntry.getMetadata(function(metadata)
+      {
+        callback(null, {
+          exists: true,
+          isDirectory: fileEntry.isDirectory,
+          isFile: fileEntry.isFile,
+          lastModified: metadata.modificationTime.getTime()
+        });
+      }, callback);
+    }, callback);
+  }
+};