Moved contents of seasoned_api up to root folder

src/tmdb/cache.js

@@ -0,0 +1,48 @@
+const assert = require("assert");
+const establishedDatabase = require("../database/database");
+
+class Cache {
+  constructor(database) {
+    this.database = database || establishedDatabase;
+    this.queries = {
+      read:
+        'SELECT value, time_to_live, created_at, DATETIME("now", "localtime") as now, ' +
+        'DATETIME(created_at, "+" || time_to_live || " seconds") as expires ' +
+        "FROM cache WHERE key = ? AND now < expires",
+      create:
+        "INSERT OR REPLACE INTO cache (key, value, time_to_live) VALUES (?, ?, ?)"
+    };
+  }
+
+  /**
+   * Retrieve an unexpired cache entry by key.
+   * @param {String} key of the cache entry
+   * @returns {Object}
+   */
+  get(key) {
+    return Promise.resolve()
+      .then(() => this.database.get(this.queries.read, [key]))
+      .then(row => {
+        assert(row, "Could not find cache entry with that key.");
+        return JSON.parse(row.value);
+      });
+  }
+
+  /**
+   * 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);
+    return Promise.resolve()
+      .then(() =>
+        this.database.run(this.queries.create, [key, json, timeToLive])
+      )
+      .then(() => value);
+  }
+}
+
+module.exports = Cache;