Converted the gzippoCache object into a replaceable Object with a sim…

…ple get/set API for future extension (such as a MongoDB driver)

lib/staticGzip.js

@@ -36,10 +36,21 @@ var removeContentHeaders = function(res){
 };
 
 /**
- * gzipped cache.
+ * gzipped in-memory cache.
  */
 
-var gzippoCache = {};
+var gzippoCache = (function() {
+	var cache = {};
+	this.get = function(pathname) {
+		return cache[pathname];
+	};
+	this.set = function(pathname, cacheObj) {
+		var oldCache = typeof(cache[pathname]) == "object" ? cache[pathname] : undefined;
+		cache[pathname] = cacheObj;
+		return oldCache;
+	};
+	return this;
+})();
 
 /**
  * gzip file.
@@ -65,6 +76,7 @@ var gzippo = function(filename, charset, callback) {
  *	-	`clientMaxAge`  client cache-control max-age directive, defaulting to 1 week
  *	-	`matchType` - A regular expression tested against the Content-Type header to determine whether the response 
  *		should be gzipped or not. The default value is `/text|javascript|json/`.
+ *	-	`cacheStore` - An object that implements a simple get/set API for storing/retrieving cached data, defaulting to a built-in in-memory store
  *
  * Examples:
  *
@@ -87,6 +99,7 @@ exports = module.exports = function staticGzip(dirPath, options){
 	var maxAge = options.maxAge || 86400000,
 	contentTypeMatch = options.contentTypeMatch || /text|javascript|json/,
 	clientMaxAge = options.clientMaxAge || 604800000;
+	cacheStore = options.cacheStore || gzippoCache;
 
 	if (!dirPath) throw new Error('You need to provide the directory to your static content.');
 	if (!contentTypeMatch.test) throw new Error('contentTypeMatch: must be a regular expression.');
@@ -119,12 +132,13 @@ exports = module.exports = function staticGzip(dirPath, options){
 
 		function gzipAndSend(filename, gzipName, mtime) {
 			gzippo(filename, charset, function(gzippedData) {
-				gzippoCache[gzipName] = {
+				var cacheObj = {
 					'ctime': Date.now(),
 					'mtime': mtime,
 					'content': gzippedData
 				};
-				sendGzipped(gzippoCache[gzipName]);
+				cacheStore.set(gzipName, cacheObj);
+				sendGzipped(cacheObj);
 			});	
 		}
 
@@ -159,26 +173,26 @@ exports = module.exports = function staticGzip(dirPath, options){
 
 			var base = path.basename(filename),
 					dir = path.dirname(filename),
-					gzipName = path.join(dir, base + '.gz');
-
+					gzipName = path.join(dir, base + '.gz'),
+					cacheObj = cacheStore.get(gzipName);
 			if (req.headers['if-modified-since'] &&
-				gzippoCache[gzipName] &&
-				+gzippoCache[gzipName].mtime <= new Date(req.headers['if-modified-since']).getTime()) {
-				setHeaders(gzippoCache[gzipName]);
+				cacheObj &&
+				+cacheObj.mtime <= new Date(req.headers['if-modified-since']).getTime()) {
+				setHeaders(cacheObj);
 				removeContentHeaders(res);
 				res.statusCode = 304;
 				return res.end();
 			}
 
 			//TODO: check for pre-compressed file 
-			if (typeof gzippoCache[gzipName] === 'undefined') {
+			if (typeof cacheObj === 'undefined') {
 				gzipAndSend(filename, gzipName, stat.mtime);
 			} else {
-				if ((gzippoCache[gzipName].mtime < stat.mtime) || 
-				((gzippoCache[gzipName].ctime + maxAge) < Date.now())) {
+				if ((cacheObj.mtime < stat.mtime) || 
+				((cacheObj.ctime + maxAge) < Date.now())) {
 					gzipAndSend(filename, gzipName, stat.mtime);
 				} else {
-					sendGzipped(gzippoCache[gzipName]);
+					sendGzipped(cacheObj);
 				}
 			}
 		});