1 files changed, 129 insertions, 0 deletions
diff --git a/src/routers/vault/types/SessionStore.js b/src/routers/vault/types/SessionStore.js
new file mode 100644
index 0000000..daa71c3
--- /dev/null
+++ b/src/routers/vault/types/SessionStore.js
@@ -0,0 +1,129 @@
+"use strict";
+const Session = require("./Session.js");
+
+/**
+ * we store the timeout directly in Session instances
+ * @type Symbol("session timeout")
+ */
+const timeout_symbol = Symbol("session timeout");
+
+/**
+ * holds the Sessions and re-hydrates them when accessed
+ */
+class SessionStore {
+    /**
+     * a Map of all Session instances
+     * @type Map<string, Session>
+    */
+    sessions = new Map();
+    /** lifetime of an unauthenticated Session, in minutes */
+    base_lifetime = 30;
+    /** lifetime of a properly authenticated Session, in minutes */
+    authed_lifetime = 60 * 6; // 6 hours
+
+    /**
+     * creates a new SessionStore
+     * @param {number} base - the base Session lifetime, in minutes
+     * @param {number} authed - the lifetime of an authenticated Session
+     */
+    constructor (base = 0, authed = 0) {
+        this.base_lifetime = base || this.base_lifetime;
+        this.authed_lifetime = authed || this.authed_lifetime;
+    }
+
+    /**
+     * re-hydrates a Session by resetting the expiration
+     * @param {string} key - the Session key
+     * @param {Session} sess - the Session to hydrate
+     * @returns {Session} the same Session
+     */
+    hydrate (key, sess) {
+        /** the new expiration, in minutes */
+        let minutes = this.base_lifetime;
+
+        if (Reflect.has(sess, timeout_symbol)) {
+            /** clear any existing timeout */
+            clearTimeout(sess[timeout_symbol]);
+        }
+
+        if (sess.authenticated === true) {
+            /** Session is properly authenticated: set lifetime accordingly */
+            minutes = this.authed_lifetime;
+        }
+
+        /** the new expiry Date */
+        const expires = new Date();
+        expires.setUTCMinutes(expires.getUTCMinutes() + minutes); // update it
+        sess.expires = expires; // swap the old for the new expiry
+        sess[timeout_symbol] = setTimeout(() => this.delete(key), minutes * 60000);
+        return sess;
+    }
+
+    /**
+     * checks whether a Session with the given key exists
+     * @param {string} key - the Session key
+     */
+    has (key) {
+        return this.sessions.has(key);
+    }
+
+    /**
+     * returns a Session with the matching key
+     * @param {string} key - the Session key
+     * @returns {Session} the found Session
+     */
+    get (key) {
+        /** lookup the session by key */
+        const sess = this.sessions.get(key);
+
+        if (sess) {
+            /** the Session, re-hydrated */
+            return this.hydrate(key, sess);
+        }
+
+        /** session not found */
+        return null;
+    }
+
+    /**
+     * adds a Session to the store
+     * @param {string} key - the Session key
+     * @param {Session} sess - the Session
+     */
+    set (key, sess) {
+        this.sessions.set(key, this.hydrate(key, sess));
+    }
+
+    /**
+     * removes a Session with the matching key from the store
+     *
+     * NOTE: this does not actually delete the Session instance
+     * @param {string} key - the Session key
+     */
+    delete (key) {
+        /** lookup the session by key */
+        const sess = this.sessions.get(key);
+
+        if (sess) {
+            if (Reflect.has(sess, timeout_symbol)) {
+                /** clear any existing timeout */
+                clearTimeout(sess[timeout_symbol]);
+            }
+
+            return this.sessions.delete(key)
+        }
+
+        /** session not found */
+        return false;
+    }
+
+    /**
+     * iterator for use in for-of
+     * @returns {Iterator<[string, Session]>} the Map iterator of the SessionStore instance
+     */
+    [Symbol.iterator] () {
+        return this.sessions[Symbol.iterator]();
+    }
+}
+
+module.exports = SessionStore;