added status code white list and black listing

Author: Kevin Whitley

lib/apicache.js

@@ -1,9 +1,10 @@
 var message     = require('debug')('apicache');
-var memCache    = require('memory-cache');
 var url         = require('url');
 var _           = require('lodash');
+var MemoryCache = require('./memory-cache');
 
 var t           = {
+  ms:           1,
   second:       1000,
   minute:       60000,
   hour:         3600000,
@@ -13,24 +14,48 @@ var t           = {
   year:         3600000 * 24 * 365,
 };
 
+var instances = [];
+
 function ApiCache() {
+  var memCache = new MemoryCache;
+
   var globalOptions = {
     debug:              false,
     defaultDuration:    3600000,
     enabled:            true,
     appendKey:          [],
     jsonp:              false,
-    redisClient:        false
+    redisClient:        false,
+    statusCodes: {
+      include: [],
+      exclude: [],
+    }
   };
 
   var instance = this;
-
   var index = null;
 
+  instances.push(this);
+  this.id = instances.length;
+
   function debug(msg) {
     return globalOptions.debug ? console.log('[apicache]: ' + msg) : message(msg)
   }
 
+  function shouldCacheResponse(response) {
+    var opt = globalOptions
+    var codes = opt.statusCodes
+
+    // console.log('shouldCacheResponse', response)
+    if (!response) return false
+
+    if (codes.exclude && codes.exclude.length && codes.exclude.indexOf(response.status) !== -1) return false
+    if (codes.include && codes.include.length && codes.include.indexOf(response.status) === -1) return false
+    // console.log('passed!')
+
+    return true
+  }
+
   this.clear = function(target) {
     var group = index.groups[target];
 
@@ -41,7 +66,7 @@ function ApiCache() {
         debug('clearing cached entry for "' + key + '"');
 
         if (!globalOptions.redisClient) {
-          memCache.del(key);
+          memCache.delete(key);
         } else {
           globalOptions.redisClient.del(key);
         }
@@ -53,7 +78,7 @@ function ApiCache() {
       debug('clearing cached entry for "' + target + '"');
 
       if (!globalOptions.redisClient) {
-        memCache.del(target);
+        memCache.delete(target);
       } else {
         globalOptions.redisClient.del(target);
       }
@@ -87,6 +112,9 @@ function ApiCache() {
       if (split.length === 3) {
         var len = parseFloat(split[1]);
         var unit = split[2].replace(/s$/i,'').toLowerCase();
+        if (unit === 'm') {
+          unit = 'ms'
+        }
 
         return (len || 1) * (t[unit] || 0);
       }
@@ -150,7 +178,7 @@ function ApiCache() {
 
         if (!globalOptions.redisClient) {
 
-          debug('returning memCached version of "' + key + '"');
+          debug('returning memory-cached version of "' + key + '"');
 
           res.statusCode = cached.status;
           res.set(cached.headers);
@@ -206,7 +234,7 @@ function ApiCache() {
           responseObj.body    = !_.isUndefined(b) ? b : (!_.isNumber(a) ? a : null);
 
           // last bypass attempt
-          if (!memCache.get(key) && !req.headers['x-apicache-bypass']) {
+          if (shouldCacheResponse(responseObj) && !memCache.get(key) && !req.headers['x-apicache-bypass']) {
             if (req.apicacheGroup) {
               debug('group detected "' + req.apicacheGroup + '"');
 
@@ -226,7 +254,7 @@ function ApiCache() {
             });
 
             if (!globalOptions.redisClient) {
-              memCache.put(key, responseObj, duration);
+              memCache.add(key, responseObj, duration);
             } else {
               globalOptions.redisClient.hset(key, "responseObj", JSON.stringify(responseObj));
               globalOptions.redisClient.hset(key, "duration", duration);
@@ -260,10 +288,22 @@ function ApiCache() {
     };
   };
 
+  this.newInstance = function(config) {
+    var instance = new ApiCache();
+
+    if (config) {
+      instance.options(config)
+    }
+
+    return instance
+  }
+
+  this.clone = function() {
+    return this.newInstance(this.options())
+  }
+
   // initialize index
   this.resetIndex();
-
-  return this;
 }
 
 module.exports = new ApiCache();

lib/memory-cache.js

@@ -0,0 +1,61 @@
+function MemoryCache() {
+	this.cache = {}
+	this.size = 0
+}
+
+MemoryCache.prototype.add = function(key, value, time, timeoutCallback) {
+	var old = this.cache[key]
+	var instance = this
+
+	if (old) {
+		clearTimeout(old.timeout)
+	}
+
+	var entry = {
+		value: value,
+		expire: time + Date.now(),
+		timeout: setTimeout(function() {
+			instance.delete(key)
+			return timeoutCallback && typeof timeoutCallback === 'function' && timeoutCallback(value, key)
+		}, time)
+	}
+
+	this.cache[key] = entry
+	this.size = Object.keys(this.cache).length
+
+	return entry
+}
+
+MemoryCache.prototype.delete = function(key) {
+	var entry = this.cache[key]
+
+	if (entry) {
+		clearTimeout(entry.timeout)
+	}
+
+	delete this.cache[key]
+
+	this.size = Object.keys(this.cache).length
+
+	return null
+}
+
+MemoryCache.prototype.get = function(key) {
+	var entry = this.cache[key]
+
+	if (entry && entry.expire < Date.now()) {
+		return this.delete(key)
+	}
+
+	return entry
+}
+
+MemoryCache.prototype.clear = function() {
+	Object.keys(this.cache).forEach(function(key) {
+		this.delete(key)
+	})
+
+	return true
+}
+
+module.exports = MemoryCache