DirectoryStore improvements:

- close() function (does nothing in DirectoryStore)
- writes the actual namespace names and keys so we can later generate a list of keys

Author: guanix

lib/store.js

@@ -60,13 +60,25 @@ var DirectoryStore = exports.DirectoryStore = function (location) {
         // Our cache of already created namespaces
         if (validNamespaces.hasOwnProperty(namespace)) {
             return true;
-        } else {
         }
 
         var namespacePath = path.join(location, sha1.hex_sha1(namespace));
-        
+        var nameFile = namespacePath + ".namespace";
+        var p;
+                
         // TODO: rewrite to use promises
         try {
+            try {
+                nameStats = posix.stat(nameFile).wait();
+            } catch (e) {
+                if (e.message !== "No such file or directory") {
+                    throw e;
+                } else {
+                    p = atomicWrite(nameFile, JSON.stringify(namespace), 0600);
+                    p.wait();
+                }
+            }
+
             stats = posix.stat(namespacePath).wait();
 
             if (!stats.isDirectory()) {
@@ -134,21 +146,20 @@ var DirectoryStore = exports.DirectoryStore = function (location) {
      */
     var unset = function(namespace, key) {
         var filename = valuePath(namespace, key);
+        var key_filename = filename + ".key";
+        posix.unlink(key_filename);
         return posix.unlink(filename);
     }
     this.unset = unset;
 
-    /* set(namespace, key, value)
-     *
-     * Save a value to the directory store indexed by namespace and key.
-     * Both namespace and key SHOULD be strings. value can be any value that
-     * can be serialized by JSON.stringify.
-     */
-    var set = function(namespace, key, value) {
-        assertNamespace(namespace);
+    var atomicWrite = function(filename, value, mode) {
+        if (typeof value !== "string") {
+            throw {
+                message: "Value must be a string"
+            }
+        }
 
         var p = new events.Promise();
-        var filename = valuePath(namespace, key);
 
         /* Create a proper temp filename */
         var date = new Date();
@@ -158,10 +169,10 @@ var DirectoryStore = exports.DirectoryStore = function (location) {
         var filenameTmp = filename + "." + tmp + ".tmp";
 
         var openPromise = posix.open(filenameTmp,
-            process.O_CREAT|process.O_WRONLY, 0600);
+            process.O_CREAT|process.O_WRONLY, mode);
 
         openPromise.addCallback(function(fd) {
-            var writePromise = posix.write(fd, JSON.stringify(value));
+            var writePromise = posix.write(fd, value);
             writePromise.addCallback(function(written) {
                 var closePromise = posix.close(fd);
                 closePromise.addCallback(function() {
@@ -203,10 +214,53 @@ var DirectoryStore = exports.DirectoryStore = function (location) {
             p.emitError(e);
         });
 
+        return p;
+    }
+    
+    /* set(namespace, key, value)
+     *
+     * Save a value to the directory store indexed by namespace and key.
+     * Both namespace and key SHOULD be strings. value can be any value that
+     * can be serialized by JSON.stringify.
+     */
+    var set = function(namespace, key, value) {
+        assertNamespace(namespace);
+        var filename = valuePath(namespace, key);
+        var key_filename = filename + ".key";
+        
+        var p = new events.Promise();
+        
+        var keyPromise = atomicWrite(key_filename, JSON.stringify(key), 0600);
+        keyPromise.addCallback(function() {
+            var writePromise = atomicWrite(filename, JSON.stringify(value), 0600);
+            writePromise.addCallback(function() {
+                p.emitSuccess();
+            });
+            writePromise.addErrback(function(e) {
+                p.emitError(e);
+            });
+        });
+        keyPromise.addErrback(function(e) {
+            p.emitError(e);
+        });
+        
         return p;
     };
     this.set = set;
 
+    
+    
+    /* close()
+     * 
+     * This is a NOOP in DirectoryStore, but may be useful for other types of
+     * data stores.
+     */
+    var close = function() {
+        /* we need to do something; we'll stat the readme file. */
+        return posix.stat(readmePath);
+    };
+    this.close = close;
+    
     // If the file exists, make sure that it is a directory and that it
     // writable.
     try {