Forked storage.js

browser-version/browser-specific/lib/storage.js

@@ -0,0 +1,80 @@
+/**
+ * Way data is stored for this database
+ * For a Node.js/Node Webkit database it's the file system
+ * For a browser-side database it's localStorage when supported
+ *
+ * This version is the Node.js/Node Webkit version
+ */
+
+
+
+function exists (filename, callback) {
+  // In this specific case this always answers that the file doesn't exist
+  if (typeof localStorage === 'undefined') { console.log("WARNING - This browser doesn't support localStorage, no data will be saved in NeDB!"); return callback(); }
+
+  if (localStorage.getItem(filename) !== null) {
+    return callback(true);
+  } else {
+    return callback(false);
+  }
+}
+
+
+function rename (filename, newFilename, callback) {
+  if (typeof localStorage === 'undefined') { console.log("WARNING - This browser doesn't support localStorage, no data will be saved in NeDB!"); return callback(); }
+
+  if (localStorage.getItem(filename) === null) {
+    localStorage.removeItem(newFilename);
+  } else {
+    localStorage.setItem(newFilename, localStorage.getItem(filename));
+    localStorage.removeItem(filename);
+  }
+
+  return callback();
+}
+
+
+function writeFile (filename, contents, options, callback) {
+  if (typeof localStorage === 'undefined') { console.log("WARNING - This browser doesn't support localStorage, no data will be saved in NeDB!"); return callback(); }
+  
+  // Options do not matter in browser setup
+  if (typeof options === 'function') { callback = options; }
+
+  localStorage.setItem(filename, contents);
+  return callback();
+}
+
+
+function appendFile (filename, toAppend, options, callback) {
+  if (typeof localStorage === 'undefined') { console.log("WARNING - This browser doesn't support localStorage, no data will be saved in NeDB!"); return callback(); }
+  
+  // Options do not matter in browser setup
+  if (typeof options === 'function') { callback = options; }
+
+  var contents = localStorage.getItem(filename) || '';
+  contents += toAppend;
+
+  localStorage.setItem(filename, contents);
+  return callback();
+}
+
+
+function readFile (filename, options, callback) {
+  if (typeof localStorage === 'undefined') { console.log("WARNING - This browser doesn't support localStorage, no data will be saved in NeDB!"); return callback(); }
+  
+  // Options do not matter in browser setup
+  if (typeof options === 'function') { callback = options; }
+
+  var contents = localStorage.getItem(filename) || '';
+  return callback(null, contents);
+}
+
+
+// Interface
+module.exports.exists = exists;
+module.exports.rename = rename;
+module.exports.writeFile = writeFile;
+module.exports.appendFile = appendFile;
+module.exports.readFile = readFile;
+
+

lib/persistence.js

@@ -6,6 +6,7 @@
  */
 
 var fs = require('fs')
+  , storage = require('./storage')
   , path = require('path')
   , model = require('./model')
   , async = require('async')
@@ -123,19 +124,19 @@ Persistence.prototype.persistCachedDatabase = function (cb) {
     async.apply(customUtils.ensureFileDoesntExist, self.tempFilename)
   , async.apply(customUtils.ensureFileDoesntExist, self.oldFilename)
   , function (cb) {
-      fs.exists(self.filename, function (exists) {
+      storage.exists(self.filename, function (exists) {
         if (exists) {
-          fs.rename(self.filename, self.oldFilename, function (err) { return cb(err); });
+          storage.rename(self.filename, self.oldFilename, function (err) { return cb(err); });
         } else {
           return cb();
         }
       });  
   }
   , function (cb) {
-      fs.writeFile(self.tempFilename, toPersist, function (err) { return cb(err); });
+      storage.writeFile(self.tempFilename, toPersist, function (err) { return cb(err); });
     }
   , function (cb) {
-      fs.rename(self.tempFilename, self.filename, function (err) { return cb(err); });
+      storage.rename(self.tempFilename, self.filename, function (err) { return cb(err); });
     }
   , async.apply(customUtils.ensureFileDoesntExist, self.oldFilename)
   ], function (err) { if (err) { return callback(err); } else { return callback(null); } })
@@ -197,7 +198,7 @@ Persistence.prototype.persistNewState = function (newDocs, cb) {
 
   if (toPersist.length === 0) { return callback(null); }
 
-  fs.appendFile(self.filename, toPersist, 'utf8', function (err) {
+  storage.appendFile(self.filename, toPersist, 'utf8', function (err) {
     return callback(err);
   });
 };
@@ -250,18 +251,18 @@ Persistence.treatRawData = function (rawData) {
 Persistence.prototype.ensureDatafileIntegrity = function (callback) {
   var self = this  ;
 
-  fs.exists(self.filename, function (filenameExists) {
+  storage.exists(self.filename, function (filenameExists) {
     // Write was successful
     if (filenameExists) { return callback(null); }
   
-    fs.exists(self.oldFilename, function (oldFilenameExists) {
+    storage.exists(self.oldFilename, function (oldFilenameExists) {
       // New database
       if (!oldFilenameExists) {
-        return fs.writeFile(self.filename, '', 'utf8', function (err) { callback(err); });            
+        return storage.writeFile(self.filename, '', 'utf8', function (err) { callback(err); });            
       }
     
       // Write failed, use old version
-      fs.rename(self.oldFilename, self.filename, function (err) { return callback(err); });
+      storage.rename(self.oldFilename, self.filename, function (err) { return callback(err); });
     });
   });
 };
@@ -291,7 +292,7 @@ Persistence.prototype.loadDatabase = function (cb) {
     function (cb) {
       Persistence.ensureDirectoryExists(path.dirname(self.filename), function (err) {
         self.ensureDatafileIntegrity(function (exists) {
-          fs.readFile(self.filename, 'utf8', function (err, rawData) {
+          storage.readFile(self.filename, 'utf8', function (err, rawData) {
             if (err) { return cb(err); }
             var treatedData = Persistence.treatRawData(rawData);
 

lib/storage.js

@@ -0,0 +1,13 @@
+/**
+ * Way data is stored for this database
+ * For a Node.js/Node Webkit database it's the file system
+ * For a browser-side database it's localStorage when supported
+ *
+ * This version is the Node.js/Node Webkit version
+ */
+
+var fs = require('fs');
+
+
+module.exports = fs;
+