add a SQL database adaptor

storage/sql.js

@@ -0,0 +1,58 @@
+var Knex = require("knex");
+
+var getMessages = function (knex, channel, msgHandler, cb) {
+    return knex('messages')
+        .where({
+            channel: channel,
+        })
+        .select('*')
+        .then(function (rows) {
+            rows.forEach(function (row) {
+                msgHandler(row.content);
+            });
+            cb();
+        })
+        .catch(function (e) {
+            console.error(e);
+            cb();
+        });
+};
+
+var insert = function (knex, channel, content, cb) {
+    knex.table('messages').insert({
+        channel: channel,
+        content: content,
+    })
+    .then(function () {
+        cb();
+    });
+};
+
+module.exports.create = function (conf, cb) {
+    var knex = Knex({
+        dialect: 'sqlite3',
+        connection: conf.dbConnection,
+        useNullAsDefault: true,
+    });
+
+    knex.schema.hasTable('messages').then(function (exists) {
+        if (exists) { return; }
+
+        return knex.schema.createTable('messages', function (table) {
+            table.increments('id');
+            table.string('content');
+            table.string('channel');
+            table.timestamps();
+        });
+    })
+    .then(function () {
+        cb({
+            message: function (channelName, content, cb) {
+                insert(knex, channelName, content, cb);
+            },
+            getMessages: function (channelName, msgHandler, cb) {
+                getMessages(knex, channelName, msgHandler, cb);
+            },
+        });
+    });
+};