Split database code into it's own module

index.js

@@ -1,8 +1,7 @@
 var http = require('http');
 var winston = require("winston");
 var fs = require("fs");
-var sqlite3 = require('sqlite3').verbose();
+var myDb = require("./lib/db.js");
-var db = new sqlite3.Database("./proxy.db");
 const url = require("url");
 
 // Rudimentary logger.
@@ -38,7 +37,7 @@ const processRequest = (request, response) => {
         logger.info({message: "Requesting: " + req.url});
 
         const hostUrl = new url.URL(req.url);
-        visitHost(hostUrl.hostname);
+        myDb.visitHost(hostUrl.hostname);
         // Complicated line of JS to forward request, and pipe it to the
         // response object.
         req.pipe(http.request(req.url, (resp) => {resp.pipe(res)}));
@@ -57,54 +56,6 @@ function startServer() {
     return server;
 }
 
-/** TODO - MAKE THESE FUNCTIONS THEIR OWN MODULE. VVV 
+myDb.initializeDatabase();
- *  FIXME - need to close the database connection
- *          on exit.
- */
-
-/**
- * Initialize our database.
- */
-function initializeDatabase() {
-    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.");
-            }
-        });
-    });
-    // db.close();
-}
-
-/**
- * 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]);
-    });
-    // db.close();
-}
-
-function addHostToTable(hostname) {
-    db.serialize(() => {
-        db.run("insert into hosts (hostname, visitcount) values (?, 0)", [hostname])
-    })
-    // db.close();
-}
-
-function visitHost(hostname) {
-    return db.serialize(() => {
-        db.get("select * from hosts where hostname = ?", [hostname], (err, row) => {
-            if (row === undefined) {
-                addHostToTable(hostname);
-            } else {
-                updateVisitCount(hostname);
-            }
-        })
-    });
-}
-
-initializeDatabase();
 startServer();
+

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);
+            }
+        })
+    });
+}