From 83cb68ada26d05ef174a1149cfe5bf3ea5e6565d Mon Sep 17 00:00:00 2001
From: John Crepezzi <john.crepezzi@gmail.com>
Date: Mon, 21 Nov 2011 22:19:43 -0500
Subject: [PATCH] cache static assets in memory

---
 TODO                  |  6 ++++--
 lib/static_handler.js | 22 ++++++++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/TODO b/TODO
index 2b52991..41ff748 100644
--- a/TODO
+++ b/TODO
@@ -1,10 +1,12 @@
 cache headers for static assets (and on document GET)
 tests
 add FAVICON (or force 404)
-cache static in memory
 add feedback for errors to UI - esp. too long
-copy URL to clipboard button
 add about page
+make asset caching optional
+todo store buffer instead of string while grabbing contents (if possible)
+write cache to use callback instead of using non-DRY code
 
 # shared version only
 some way to do announcements easily (and use for ads)
+copy URL to clipboard button
diff --git a/lib/static_handler.js b/lib/static_handler.js
index 89b93c0..07e2f47 100644
--- a/lib/static_handler.js
+++ b/lib/static_handler.js
@@ -16,6 +16,8 @@ var StaticHandler = function(path) {
   }
 };
 
+StaticHandler.cache = {};
+
 // Determine the content type for a given extension
 StaticHandler.contentTypeFor = function(ext) {
   if (ext == '.js') return 'text/javascript';
@@ -34,6 +36,16 @@ StaticHandler.prototype.handle = function(incPath, response) {
   if (!this.availablePaths[incPath]) incPath = this.defaultPath;
   var filePath = this.basePath + (incPath == '/' ? this.defaultPath : incPath);
   // And then stream the file back
+  if (StaticHandler.cache[filePath]) {
+    this.serveCached(filePath, response);
+  }
+  else {
+    this.retrieve(filePath, response);
+  }
+};
+
+// Retrieve from the file
+StaticHandler.prototype.retrieve = function(filePath, response) {
   var _this = this;
   fs.readFile(filePath, function(error, content) {
     if (error) {
@@ -45,8 +57,18 @@ StaticHandler.prototype.handle = function(incPath, response) {
       var contentType = StaticHandler.contentTypeFor(path.extname(filePath));
       response.writeHead(200, { 'content-type': contentType });
       response.end(content, 'utf-8');
+      // Stick it in the cache
+      StaticHandler.cache[filePath] = content;
     }
   });    
 };
 
+// Retrieve from memory cache
+StaticHandler.prototype.serveCached = function(filePath, response) {
+  var contentType = StaticHandler.contentTypeFor(path.extname(filePath));
+  response.writeHead(200, { 'content-type': contentType });
+  response.end(StaticHandler.cache[filePath], 'utf-8');
+};
+
+
 module.exports = StaticHandler;