Split database code into it's own module

lib/db.js

@@ -0,0 +1,56 @@
+var sqlite3 = require('sqlite3').verbose();
+var db = new sqlite3.Database("./proxy.db")
+
+/** TODO - MAKE THESE FUNCTIONS THEIR OWN MODULE. VVV 
+ *  FIXME - need to close the database connection
+ *          on exit.
+ */
+
+/**
+ * Initialize our database.
+ */
+exports.initializeDatabase = function() {
+    db.serialize(() => {
+        db.run("create table hosts (hostname TEXT, visitcount Int)", (err, row) => {
+            if (err !== undefined || err !== null) {
+                console.log("Error creating database, it likely exists already.");
+            }
+        });
+    });
+}
+
+/**
+ * Update the visit count for a host logged by the proxy
+ * @param {string} hostname Host logged by proxy
+ */
+function updateVisitCount(hostname) {
+    db.serialize(() => {
+        db.run("update hosts set visitcount = visitcount + 1 where hostname = ?", [hostname]);
+    });
+}
+
+/**
+ * Add a row for a host to the hosts table.
+ * @param {string} hostname Host that was freshly visited.
+ */
+function addHostToTable(hostname) {
+    db.serialize(() => {
+        db.run("insert into hosts (hostname, visitcount) values (?, 0)", [hostname])
+    })
+}
+
+/**
+ * Either initialize a row in the database, or update the visit count for a row.
+ * @param {string} hostname Host that was visited
+ */
+exports.visitHost = function (hostname) {
+    return db.serialize(() => {
+        db.get("select * from hosts where hostname = ?", [hostname], (err, row) => {
+            if (row === undefined) {
+                addHostToTable(hostname);
+            } else {
+                updateVisitCount(hostname);
+            }
+        })
+    });
+}