PG basis

lib/document_stores/postgres.js

@@ -0,0 +1,74 @@
+/*global require,module,process*/
+
+var postgres = require('pg');
+var winston = require('winston');
+
+(function () {
+
+  'use strict';
+
+  // A postgres document store
+  var PostgresDocumentStore = function (options) {
+    this.expireJS = options.expire * 1000;
+    this.connectionString = process.env.DATABASE_URL;
+  };
+
+  PostgresDocumentStore.prototype = {
+
+    // Set a given key
+    set: function (key, data, callback, skipExpire) {
+      var now = new Date().getTime() / 1000;
+      var that = this;
+      this.safeConnect(function (err, client, done) {
+        if (err) { return callback(false); }
+        client.query('INSERT INTO entries (key, value, expiration) VALUES ($1, $2, $3)', [
+          key,
+          data,
+          that.expireJS && !skipExpire ? now + that.expireJS : null
+        ], function (err, result) {
+          if (err) {
+            winston.error('error persisting value to postgres', { error: err });
+            return callback(false);
+          }
+          callback(true);
+          done();
+        });
+      });
+    },
+
+    // Get a given key's data
+    get: function (key, callback, skipExpire) {
+      var now = new Date().getTime() / 1000;
+      var that = this;
+      this.safeConnect(function (err, client, done) {
+        if (err) { return callback(false); }
+        client.query('SELECT value from entries where KEY = $1 AND (expiration IS NULL or expiration < $2)', [
+          key,
+          that.expireJS ? now - that.expireJS : 0
+        ], function (err, result) {
+          if (err) {
+            winston.error('error retrieving value from postgres', { error: err });
+            return callback(false);
+          }
+          callback(result.rows.length ? result.rows[0].value : false);
+        });
+      });
+    },
+
+    // A connection wrapper
+    safeConnect: function (callback) {
+      postgres.connect(this.connectionString, function (err, client, done) {
+        if (err) {
+          winston.error('error connecting to postgres', { error: err });
+          callback(err);
+        } else {
+          callback(undefined, client, done);
+        }
+      });
+    }
+
+  };
+
+  module.export = PostgresDocumentStore;
+
+}());