Cache

OST Cache is the central cache implementation for all OST products and can easily be plugged-in.

It contains three caching engines. The decision of which caching engine to use is governed while creating the cache object. The caching engines implemented are:

• Memcached
• Redis
• In-process (use with single threaded process in development mode only)

Constructor parameters:

There is 1 parameter required while creating the cache implementer.

• First parameter is mandatory and it specifies the configuration strategy to be used. An example of the configStrategy is:

configStrategy = {
  cache: {
      engine: "none/redis/memcache"
  }
};

Below are the examples:

// import the cache module
const OSTCache = require('@ostdotcom/cache');

// configStrategy for redis engine
configStrategy = {
  cache: {
    engine: "redis",
    host: "localhost",
    port: "6830",
    password: "dsdsdsd",
    enableTsl: "0",
    defaultTtl: 36000,
    consistentBehavior: "1"
  }
}

// configStrategy for memcached engine
configStrategy = {
  cache: {
    engine: "memcached",
    servers: ["127.0.0.1:11211"],
    defaultTtl: 36000,
    consistentBehavior: "1"
  }
}

// configStrategy for in-memory engine
configStrategy = {
  cache: {
    engine: "none",
    namespace: "A",
    defaultTtl: "36000",
    consistentBehavior: "1"
  }
}

Install

npm install @ostdotcom/cache --save

Examples:

Create OST Cache Object:

OSTCache = require('@ostdotcom/cache');
OSTCache = OSTCache.getInstance(configStrategy);

cacheImplementer = OSTCache.cacheInstance;

Store and retrieve data in cache using set and get:

cacheImplementer.set('testKey', 'testValue', 5000).then(function(cacheResponse){
    if (cacheResponse.isSuccess()) {
      console.log(cacheResponse.data.response);
    } else {
      console.log(cacheResponse);
    }
  });
cacheImplementer.get('testKey').then(function(cacheResponse){
    if (cacheResponse.isSuccess()) {
      console.log(cacheResponse.data.response);
    } else {
      console.log(cacheResponse);
    }
  });

Manage objects in cache using setObject and getObject:

cacheImplementer.setObject('testObjKey', {dataK1: 'a', dataK2: 'b'}).then(function(cacheResponse){
    if (cacheResponse.isSuccess()) {
      console.log(cacheResponse.data.response);
    } else {
      console.log(cacheResponse);
    }
  });
cacheImplementer.getObject('testObjKey').then(function(cacheResponse){
    if (cacheResponse.isSuccess()) {
      console.log(cacheResponse.data.response);
    } else {
      console.log(cacheResponse);
    }
  });

Retrieve multiple cache data using multiGet:

* NOTE: Redis returns null from multiGet for objects, even if a value is set in the cache; the other caching engines match this behaviour.

cacheImplementer.set('testKeyOne', 'One').then(console.log);
cacheImplementer.set('testKeyTwo', 'Two').then(console.log);
cacheImplementer.multiGet(['testKeyOne', 'testKeyTwo']).then(function(cacheResponse){
    if (cacheResponse.isSuccess()) {
      console.log(cacheResponse.data.response);
    } else {
      console.log(cacheResponse);
    }
  });

Delete cache using del:

cacheImplementer.set('testKey', 'testValue').then(console.log);
cacheImplementer.del('testKey').then(function(cacheResponse){
    if (cacheResponse.isSuccess()) {
      console.log(cacheResponse.data.response);
    } else {
      console.log(cacheResponse);
    }
  });

Manage counters in cache using increment and decrement:

cacheImplementer.set('testCounterKey', 1).then(console.log);
cacheImplementer.increment('testCounterKey', 10).then(function(cacheResponse){
    if (cacheResponse.isSuccess()) {
      console.log(cacheResponse.data.response);
    } else {
      console.log(cacheResponse);
    }
  });
cacheImplementer.decrement('testCounterKey', 5).then(function(cacheResponse){
    if (cacheResponse.isSuccess()) {
      console.log(cacheResponse.data.response);
    } else {
      console.log(cacheResponse);
    }
  });

Change the cache expiry time using touch:

cacheImplementer.set('testKey', "testData").then(console.log);
cacheImplementer.touch('testKey', 10).then(function(cacheResponse){
    if (cacheResponse.isSuccess()) {
      console.log(cacheResponse.data.response);
    } else {
      console.log(cacheResponse);
    }
  });