You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
132 lines
3.4 KiB
132 lines
3.4 KiB
/*jshint unused:false*/
|
|
// Note: ttls are in seconds
|
|
var cacheManager = require('../');
|
|
var memoryCache = cacheManager.caching({store: 'memory', max: 100, ttl: 10});
|
|
var memoryCache2 = cacheManager.caching({store: 'memory', max: 100, ttl: 100});
|
|
var ttl; //Can't use a different ttl per set() call with memory cache
|
|
|
|
//
|
|
// Basic usage
|
|
//
|
|
memoryCache.set('foo', 'bar', function(err) {
|
|
if (err) { throw err; }
|
|
|
|
memoryCache.get('foo', function(err, result) {
|
|
console.log(result);
|
|
// >> 'bar'
|
|
memoryCache.del('foo', function(err) {
|
|
if (err) {
|
|
console.log(err);
|
|
}
|
|
});
|
|
});
|
|
});
|
|
|
|
function getUser(id, cb) {
|
|
setTimeout(function() {
|
|
console.log("Fetching user from slow database.");
|
|
cb(null, {id: id, name: 'Bob'});
|
|
}, 100);
|
|
}
|
|
|
|
var userId = 123;
|
|
var key = 'user_' + userId;
|
|
|
|
//
|
|
// wrap() example
|
|
//
|
|
|
|
// Instead of manually managing the cache like this:
|
|
function getCachedUserManually(id, cb) {
|
|
memoryCache.get(id, function(err, result) {
|
|
if (err) { return cb(err); }
|
|
|
|
if (result) {
|
|
return cb(null, result);
|
|
}
|
|
|
|
getUser(id, function(err, result) {
|
|
if (err) { return cb(err); }
|
|
memoryCache.set(id, result);
|
|
cb(null, result);
|
|
});
|
|
});
|
|
}
|
|
|
|
// ... you can instead use the `wrap` function:
|
|
function getCachedUser(id, cb) {
|
|
memoryCache.wrap(id, function(cacheCallback) {
|
|
getUser(id, cacheCallback);
|
|
}, cb);
|
|
}
|
|
|
|
getCachedUser(userId, function(err, user) {
|
|
// First time fetches the user from the (fake) database:
|
|
console.log(user);
|
|
|
|
getCachedUser(userId, function(err, user) {
|
|
// Second time fetches from cache.
|
|
console.log(user);
|
|
});
|
|
});
|
|
|
|
// Outputs:
|
|
// Returning user from slow database.
|
|
// { id: 123, name: 'Bob' }
|
|
// { id: 123, name: 'Bob' }
|
|
|
|
// Same as above, but written differently:
|
|
memoryCache.wrap(key, function(cb) {
|
|
getUser(userId, cb);
|
|
}, function(err, user) {
|
|
console.log(user);
|
|
|
|
// Second time fetches user from memoryCache
|
|
memoryCache.wrap(key, function(cb) {
|
|
getUser(userId, cb);
|
|
}, function(err, user) {
|
|
console.log(user);
|
|
});
|
|
});
|
|
|
|
//
|
|
// multi-cache example
|
|
//
|
|
var multiCache = cacheManager.multiCaching([memoryCache, memoryCache2]);
|
|
var userId2 = 456;
|
|
var key2 = 'user_' + userId;
|
|
var ttl2; //Can't use a different ttl per set() call with memory cache
|
|
|
|
multiCache.wrap(key2, function(cb) {
|
|
getUser(userId2, cb);
|
|
}, function(err, user) {
|
|
console.log(user);
|
|
|
|
// Second time fetches user from memoryCache, since it's highest priority.
|
|
// If the data expires in memoryCache, the next fetch would pull it from
|
|
// the memoryCache2, and set the data in memoryCache.
|
|
multiCache.wrap(key2, function(cb) {
|
|
getUser(userId2, cb);
|
|
}, function(err, user) {
|
|
console.log(user);
|
|
});
|
|
|
|
// Sets in all caches.
|
|
multiCache.set('foo2', 'bar2', {ttl: ttl2}, function(err) {
|
|
if (err) { throw err; }
|
|
|
|
// Fetches from highest priority cache that has the key.
|
|
multiCache.get('foo2', function(err, result) {
|
|
console.log(result);
|
|
// >> 'bar2'
|
|
|
|
// Delete from all caches
|
|
multiCache.del('foo2', function(err) {
|
|
if (err) {
|
|
console.log(err);
|
|
}
|
|
process.exit();
|
|
});
|
|
});
|
|
});
|
|
});
|
|
|