refactored redis example store, added ttl function to caching.js

examples/redis_example/example.js

@@ -3,6 +3,7 @@
 // node examples/redis_example/example.js
 
 var util = require('util');
+var assert = require('assert');
 var cacheManager = require('../../');
 var redisStore = require('./redis_store');
 // Note: ttl is in seconds
@@ -18,8 +19,14 @@ redisCache.set('foo', 'bar', {ttl: ttl}, function(err) {
         if (err) { throw err; }
         console.log("result fetched from cache: " + result);
         // >> 'bar'
-        redisCache.del('foo', function(err) {
+
+        redisCache.ttl('foo', function(err, result) {
             if (err) { throw err; }
+            assert.ok(result > 59 && result < 61);
+
+            redisCache.del('foo', function(err) {
+                if (err) { throw err; }
+            });
         });
     });
 });
@@ -32,8 +39,14 @@ redisCache.set('foo-no-ttl', 'bar-no-ttl', function(err) {
         if (err) { throw err; }
         console.log("result fetched from cache: " + result);
         // >> 'bar'
-        redisCache.del('foo-no-ttl', function(err) {
+
+        redisCache.ttl('foo-no-ttl', function(err, result) {
             if (err) { throw err; }
+            assert.ok(result > 99 && result < 101);
+
+            redisCache.del('foo-no-ttl', function(err) {
+                if (err) { throw err; }
+            });
         });
     });
 });
@@ -46,8 +59,14 @@ redisCache.set('foo-zero-ttl', 'bar-zero-ttl', {ttl: 0}, function(err) {
         if (err) { throw err; }
         console.log("result fetched from cache: " + result);
         // >> 'bar'
-        redisCache.del('foo-zero-ttl', function(err) {
+
+        redisCache.ttl('foo-zero-ttl', function(err, result) {
             if (err) { throw err; }
+            assert.ok(result < 0);
+
+            redisCache.del('foo-zero-ttl', function(err) {
+                if (err) { throw err; }
+            });
         });
     });
 });

examples/redis_example/redis_store.js

@@ -33,6 +33,22 @@ function redisStore(args) {
         });
     }
 
+    function handleResponse(conn, cb, opts) {
+        opts = opts || {};
+
+        return function(err, result) {
+            pool.release(conn);
+
+            if (err) { return cb(err); }
+
+            if (opts.parse) {
+                result = JSON.parse(result);
+            }
+
+            cb(null, result);
+        };
+    }
+
     self.get = function(key, options, cb) {
         if (typeof options === 'function') {
             cb = options;
@@ -40,12 +56,7 @@ function redisStore(args) {
 
         connect(function(err, conn) {
             if (err) { return cb(err); }
-
-            conn.get(key, function(err, result) {
-                pool.release(conn);
-                if (err) { return cb(err); }
-                cb(null, JSON.parse(result));
-            });
+            conn.get(key, handleResponse(conn, cb, {parse: true}));
         });
     };
 
@@ -60,17 +71,12 @@ function redisStore(args) {
 
         connect(function(err, conn) {
             if (err) { return cb(err); }
+            var val = JSON.stringify(value);
 
             if (ttl) {
-                conn.setex(key, ttl, JSON.stringify(value), function(err, result) {
-                    pool.release(conn);
-                    cb(err, result);
-                });
+                conn.setex(key, ttl, val, handleResponse(conn, cb));
             } else {
-                conn.set(key, JSON.stringify(value), function(err, result) {
-                    pool.release(conn);
-                    cb(err, result);
-                });
+                conn.set(key, val, handleResponse(conn, cb));
             }
         });
     };
@@ -78,11 +84,14 @@ function redisStore(args) {
     self.del = function(key, cb) {
         connect(function(err, conn) {
             if (err) { return cb(err); }
+            conn.del(key, handleResponse(conn, cb));
+        });
+    };
 
-            conn.del(key, function(err, result) {
-                pool.release(conn);
-                cb(err, result);
-            });
+    self.ttl = function(key, cb) {
+        connect(function(err, conn) {
+            if (err) { return cb(err); }
+            conn.ttl(key, handleResponse(conn, cb));
         });
     };
 
@@ -94,11 +103,7 @@ function redisStore(args) {
 
         connect(function(err, conn) {
             if (err) { return cb(err); }
-
-            conn.keys(pattern, function(err, result) {
-                pool.release(conn);
-                cb(err, result);
-            });
+            conn.keys(pattern, handleResponse(conn, cb));
         });
     };
 

lib/caching.js

@@ -95,6 +95,10 @@ var caching = function(args) {
         self.keys = self.store.keys.bind(self.store);
     }
 
+    if (typeof self.store.ttl === 'function') {
+        self.ttl = self.store.ttl.bind(self.store);
+    }
+
     return self;
 };
 

test/caching.unit.js

@@ -194,6 +194,28 @@ describe("caching", function() {
         });
     });
 
+    describe("ttl()", function() {
+        var fakeStore;
+
+        beforeEach(function() {
+            fakeStore = {
+                get: function() {},
+                set: function() {},
+                del: function() {},
+                ttl: function() {}
+            };
+
+            sinon.stub(fakeStore, 'ttl');
+
+            cache = caching({store: fakeStore});
+        });
+
+        it("passes the params to the underlying store's ttl() method", function() {
+            cache.ttl('foo');
+            assert.ok(fakeStore.ttl.calledWith('foo'));
+        });
+    });
+
     describe("keys()", function() {
         var keyCount;
         var savedKeys = [];