maelstromMongo.go

package main

import (
	"google.golang.org/cloud/compute/metadata"
	"gopkg.in/mgo.v2"
	"gopkg.in/mgo.v2/bson"
)

var mongoUrl string = "localhost:27017"
var dbName string = "test"

type MongoDatastore struct{}

func (db *MongoDatastore) Ping() bool {
	if gce {
		mongoUrl, _ = metadata.InstanceAttributeValue("mongoUrl")
		if Debug {
			InfoLog.Println("Mongo URL pulled from GCE Metadata: " + mongoUrl)
		}
	}
	session, err := mgo.Dial(mongoUrl)
	if err != nil {
		return false
	}
	session.Close()
	return true
}

func (db *MongoDatastore) StoreContact(contact Contact) Contact {
	session, err := mgo.Dial(mongoUrl)
	check(err)
	defer session.Close()

	contact.Id = bson.NewObjectId()
	c := session.DB(dbName).C("contact")
	err = c.Insert(&contact)
	if err != nil {
		ErrorLog.Println("Error storing Contact: " + contact.Name)
		return Contact{}
	}

	return contact
}

func (db *MongoDatastore) UpdateContact(contact Contact) Contact {
	session, err := mgo.Dial(mongoUrl)
	check(err)
	defer session.Close()

	c := session.DB(dbName).C("contact")
	err = c.UpdateId(contact.Id, &contact)
	if err != nil {
		return Contact{}
	}

	return contact
}

func (db *MongoDatastore) RetrieveContactsBy(param string, value string) []Contact {
	session, err := mgo.Dial(mongoUrl)
	check(err)
	defer session.Close()

	c := session.DB(dbName).C("contact")

	result := []Contact{}

	if param == "id" {
		contact := Contact{}
		oid := bson.ObjectIdHex(value)
		err = c.FindId(oid).One(&contact)
		if err != nil {
			if Debug {
				InfoLog.Printf("Cannot retrieve contact where %s = %s \n", param, value)
			}
		}
		result = make([]Contact, 1, 1)
		result[0] = contact
	} else {
		err = c.Find(bson.M{param: value}).All(&result)
		if err != nil {
			if Debug {
				InfoLog.Printf("Cannot retrieve contact where %s = %s \n", param, value)
			}
			return []Contact{}
		}
	}
	return result
}

func (db *MongoDatastore) DeleteContact(id string) bool {
	session, err := mgo.Dial(mongoUrl)
	check(err)
	defer session.Close()

	objectId := bson.ObjectIdHex(id)
	c := session.DB(dbName).C("contact")
	err = c.RemoveId(objectId)
	if err != nil {
		return false
	}

	return true
}

func (db *MongoDatastore) Status() bool {
	return true
}