zcache - npm Package Compare versions

Comparing version 0.2.5 to 0.2.7

lib/CacheInstance.js

@@ -19,2 +19,4 @@ var events = require('events')
   }
+  this._accessCount = 0
+  this._hitCount = 0
 }
@@ -108,2 +110,30 @@ util.inherits(CacheInstance, events.EventEmitter)
 /**
+ * Get the number of cache accesses.
+ *
+ * @return {number}
+ */
+CacheInstance.prototype.getAccessCount = function () {
+  return this._accessCount
+}
+
+/**
+ * Get the number of cache hits.
+ *
+ * @return {number}
+ */
+CacheInstance.prototype.getHitCount = function () {
+  return this._hitCount
+}
+
+/**
+ * Reset the access count and hit count to get counts during time intervals.
+ *
+ * @return {number}
+ */
+CacheInstance.prototype.resetCount = function () {
+  this._hitCount = 0
+  this._accessCount = 0
+}
+
+/**
  * Get service information about this cache instance if it is a standlone service.
@@ -120,2 +150,25 @@ *
 /**
+ * Update the access count and hit count according to the result of get/mget.
+ *
+ * @param {Array.<Object>|Object} data The data fetched by get or mget.
+ * @return {Function} A function that updates the counts and returns the parameter
+ *                    that is passed into it. It is handy to chain to a promise.
+ */
+CacheInstance.prototype.updateCount = function() {
+  var self = this
+  return function (data) {
+    if (Array.isArray(data)) {
+      self._accessCount += data.length
+      for (var i = 0; i < data.length; i++) {
+        if (typeof data[i] !== 'undefined' && data[i] !== null) self._hitCount += 1
+      }
+    } else {
+      self._accessCount += 1
+      if (typeof data !== 'undefined' && data !== null) self._hitCount += 1
+    }
+    return data
+  }
+}
+
+/**
  * Update the stats of a certain operation on this cache.
@@ -122,0 +175,0 @@ *

lib/InMemoryCache.js

@@ -0,1 +1,3 @@
+// Copyright 2013 The Obvious Corporation.
+
 var Q = require('kew')
@@ -5,2 +7,14 @@ var util = require('util')
 
+/**
+ * A complete in-memory in-process cache. It stores all the key/values in memory
+ * and usually keeps them for a short period of time. The purpose is to accommodate
+ * the access patterns where the same piece of data is required for multiple times
+ * in a short period of time.
+ *
+ * You can set the TTL of each invidicual key, and you can also set a global TTL
+ * for all the keys. A reaper is invoked periodically to remove expired keys.
+ *
+ * @constructor
+ * @implements {CacheInstance}
+ */
 function InMemoryCache() {
@@ -28,26 +42,7 @@ CacheInstance.call(this)
 
-// create a reaper which scans through all of the items in _data every
-// this._reaperIntervalMs millisseconds, if the item has expired then
-// it's deleted.
-InMemoryCache.prototype._createReaper = function () {
-  return setInterval(function () {
-    Object.keys(this._expireAt).map(function (key) {
-      if (this._expireAt[key] < Date.now()) this.del(key)
-    }.bind(this))
-  }.bind(this), this._reaperIntervalMs)
-}
-
-// Destroy the reaper interval if it exists
-InMemoryCache.prototype._destroyReaper = function () {
-  if (!!this._reaperInterval) clearInterval(this._reaperInterval)
-}
-
-// Destroy the reaper interval and create a new reaper
-// this is done when you reset the reaper interval
-InMemoryCache.prototype._resetReaper = function () {
-  this._destroyReaper()
-  this._reaperInterval = this._createReaper()
-}
-
-// set the reaper to run every everyMs ms
+/**
+ * Set how frequently the reaper runs.
+ *
+ * @param {number} everyMs The interval of two consecutive runs of the reaper, in milliseconds.
+ */
 InMemoryCache.prototype.setReaperInterval = function (everyMs) {
@@ -58,3 +53,7 @@ this._reaperIntervalMs = everyMs
 
-// set a custom ttl for every object added to the cache from here on out
+/**
+ * Set a custom ttl for every object added to the cache from here on out.
+ *
+ * @param {number} maxAgeMs The TTL of the objects in this cache, in milliseconds.
+ */
 InMemoryCache.prototype.overrideMaxAgeMs = function (maxAgeMs) {
@@ -64,2 +63,3 @@ this._maxAgeOverride = maxAgeMs
 
+/** @inheritDoc */
 InMemoryCache.prototype.isAvailable = function () {
@@ -69,2 +69,3 @@ return this._isAvailable
 
+/** @inheritDoc */
 InMemoryCache.prototype.connect = function () {
@@ -77,2 +78,3 @@ this._isAvailable = true
 
+/** @inheritDoc */
 InMemoryCache.prototype.disconnect = function () {
@@ -84,2 +86,3 @@ this._destroyReaper()
 
+/** @inheritDoc */
 InMemoryCache.prototype.destroy = function () {
@@ -93,10 +96,18 @@ this._destroyReaper()
 
+/** @inheritDoc */
 InMemoryCache.prototype.get = function (key) {
-  return (this._expireAt[key] > Date.now() ? this._data[key] : undefined)
+  return this.mget([key]).then(function (data) {
+    return data[0]
+  })
 }
 
+/** @inheritDoc */
 InMemoryCache.prototype.mget = function (keys) {
   var ret = []
+  this._accessCount += keys.length
   for (var i = 0; i < keys.length; i++) {
-    ret.push(this.get(keys[i]))
+    if (this._expireAt[keys[i]] > Date.now()) {
+      ret[i] = this._data[keys[i]]
+      this._hitCount += 1
+    }
   }
@@ -106,2 +117,3 @@ return Q.resolve(ret)
 
+/** @inheritDoc */
 InMemoryCache.prototype.set = function (key, val, maxAgeMs) {
@@ -112,2 +124,3 @@ this._expireAt[key] = Date.now() + (this._maxAgeOverride || maxAgeMs )
 
+/** @inheritDoc */
 InMemoryCache.prototype.mset = function (items, maxAgeMs) {
@@ -119,2 +132,3 @@ for (var i = 0; i < items.length; i++) {
 
+/** @inheritDoc */
 InMemoryCache.prototype.del = function (key) {
@@ -126,2 +140,25 @@ ;delete this._data[key]
 
+// Create a reaper which scans through all of the items in _data every
+// this._reaperIntervalMs millisseconds, if the item has expired then
+// it's deleted.
+InMemoryCache.prototype._createReaper = function () {
+  return setInterval(function () {
+    Object.keys(this._expireAt).map(function (key) {
+      if (this._expireAt[key] < Date.now()) this.del(key)
+    }.bind(this))
+  }.bind(this), this._reaperIntervalMs)
+}
+
+// Destroy the reaper interval if it exists
+InMemoryCache.prototype._destroyReaper = function () {
+  if (!!this._reaperInterval) clearInterval(this._reaperInterval)
+}
+
+// Destroy the reaper interval and create a new reaper
+// this is done when you reset the reaper interval
+InMemoryCache.prototype._resetReaper = function () {
+  this._destroyReaper()
+  this._reaperInterval = this._createReaper()
+}
+
 module.exports = InMemoryCache

lib/RedisConnection.js

@@ -85,2 +85,3 @@ var redis = require('redis')
   return deferred.promise
+    .then(this.updateCount())
     .then(this.updateStats('mget'))
@@ -87,0 +88,0 @@ }

package.json

 {
   "name": "zcache",
   "description": "AWS zone-aware multi-layer cache",
-  "version": "0.2.5",
+  "version": "0.2.7",
   "homepage": "https://github.com/Obvious/zcache",
@@ -6,0 +6,0 @@ "authors": [

test/test_InMemoryCache.js

@@ -7,2 +7,3 @@ var zcache = require('../index')
   this.cI.connect()
+  this.cI.resetCount()
   callback()
@@ -13,2 +14,3 @@ }
   this.cI.disconnect()
+  this.cI.destroy()
   callback()
@@ -33,5 +35,8 @@ }
   setTimeout(function () {
-    test.equal(this.cI.get('foo'), undefined, 'foo should have expired by now')
-    test.done()
-  }.bind(this), 2501)
+    this.cI.get('foo')
+      .then(function (data) {
+        test.equal(data, undefined, 'foo should have expired by now')
+        test.done()
+      })
+  }.bind(this), 2)
 }
@@ -64,8 +69,14 @@
   this.cI.set('foo', 'bar', 500)
+  var self = this
 
   // undefined should be returned since the item has expired, but before the reaper could clean it
   setTimeout(function () {
-    test.equal(this.cI.get('foo'), undefined, 'foo should still be in the cache')
-    test.done()
-  }.bind(this), 750)
+    self.cI.get('foo')
+      .then(function (data) {
+        test.equal(data, undefined, 'foo should still be in the cache')
+        test.equal(1, self.cI.getAccessCount(), 'The number of accesses is 1')
+        test.equal(0, self.cI.getHitCount(), 'The number of hits is 0 - the cache entry has expired')
+        test.done()
+      })
+  }, 750)
 }
@@ -76,4 +87,10 @@
   this.cI._expireAt['foo'] = Date.now() + 1000
-  test.equal(this.cI.get('foo'), 1, '1 should be returned')
-  test.done()
+  var self = this
+  this.cI.get('foo')
+    .then(function (data) {
+      test.equal(data, 1, '1 should be returned')
+      test.equal(1, self.cI.getAccessCount(), 'The number of accesses is 1')
+      test.equal(1, self.cI.getHitCount(), 'The number of hits is 1')
+      test.done()
+    })
 }
@@ -104,3 +121,3 @@
   this.cI.mset([{key: 'a', value: 1}, {key: 'b', value: 2}, {key: 'c', value: 3}], 1000)
-
+  var self = this
   this.cI.mget(['a', 'b', 'c'])
@@ -112,4 +129,4 @@ .then(function (keys) {
       test.equal(keys[2], 3, 'c should be 3')
-    })
-    .fin(function () {
+      test.equal(3, self.cI.getAccessCount(), 'The number of accesses is 3')
+      test.equal(3, self.cI.getHitCount(), 'The number of hits is 3')
       test.done()
@@ -124,15 +141,14 @@ })
   this.cI.mset([{key: 'a', value: 1}, {key: 'b', value: 2}, {key: 'c', value: 3}], 100)
-
+  var self = this
   setTimeout(function () {
-    this.cI.mget(['a', 'b', 'c'])
+    self.cI.mget(['a', 'b', 'c'])
       .then(function (keys) {
-        if (keys.length != 3) test.fail('there should be 3 items returned')
         test.equal(keys[0], undefined, 'a should be undefined')
         test.equal(keys[1], undefined, 'b should be undefined')
         test.equal(keys[2], undefined, 'c should be undefined')
-      })
-      .fin(function () {
+        test.equal(3, self.cI.getAccessCount(), 'The number of accesses is 3')
+        test.equal(0, self.cI.getHitCount(), 'The number of hits is 0')
         test.done()
       })
-  }.bind(this), 1101)
+  }, 1101)
 }

test/test_RedisConnection.js

@@ -47,3 +47,3 @@ var zcache = require('../index')
       .then(function (vals) {
-        test.equal(vals[0], undefined)
+        test.equal(vals[0], null)
       })
@@ -60,8 +60,9 @@ .then(function () {
       .then(function () {
-        return cacheInstance.mget(['a', 'b'])
+        return cacheInstance.mget(['a', 'b', 'c'])
       })
       .then(function (vals) {
-        test.equal(vals.length, 2, 'Should have precisely 2 results')
+        test.equal(vals.length, 3, 'Should have precisely 3 results')
         test.equal(vals[0], '456')
         test.equal(vals[1], '789')
+        test.equal(vals[2], null)
         test.equal(1, cacheInstance.getStats('set').count(),  'set() is called for once')
@@ -72,2 +73,4 @@ test.equal(1, cacheInstance.getStats('mset').count(), 'mset() is called for once')
         test.equal(1, cacheInstance.getStats('del').count(),  'del() is call for once')
+        test.equal(5, cacheInstance.getAccessCount(), 'The number of cache access is 5')
+        test.equal(3, cacheInstance.getHitCount(), 'The number of cache hit is 3')
         return cacheInstance.getServerInfo()
@@ -74,0 +77,0 @@ })

New alerts

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Found 1 instance in 1 package

Fixed alerts

New author

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A new npm collaborator published a version of the package for the first time. New collaborators are usually benign additions to a project, but do indicate a change to the security surface area of a package.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

87413

increased by3.98%

Number of package files

24

increased by4.35%

Lines of code

2068

increased by5.46%

No dependency changes