seasoned_api/src/cache/redis.js

@@ -0,0 +1,46 @@
+const redis = require("redis")
+const client = redis.createClient()
+
+class Cache {
+  /**
+   * Retrieve an unexpired cache entry by key.
+   * @param {String} key of the cache entry
+   * @returns {Promise}
+   */
+  get(key) {
+    return new Promise((resolve, reject) => {
+      client.get(key, (error, reply) => {
+        if (reply == null) {
+          reject()
+        }
+
+        resolve(JSON.parse(reply))
+      })
+    })
+  }
+
+   /**
+   * Insert cache entry with key and value.
+   * @param {String} key of the cache entry
+   * @param {String} value of the cache entry
+   * @param {Number} timeToLive the number of seconds before entry expires
+   * @returns {Object}
+   */
+  set(key, value, timeToLive = 10800) {
+    const json = JSON.stringify(value);
+    client.set(key, json, (error, reply) => {
+      if (reply == 'OK') {
+
+        // successfully set value with key, now set TTL for key
+        client.expire(key, timeToLive, (e) => {
+          if (e) 
+            console.error('Unexpected error while setting expiration for key:', key, '. Error:', error)
+        })
+      }
+    })
+
+    return value
+  }
+}
+
+module.exports = Cache;