Book Image

Go: Design Patterns for Real-World Projects

By : Vladimir Vivien, Mario Castro Contreras, Mat Ryer
Book Image

Go: Design Patterns for Real-World Projects

By: Vladimir Vivien, Mario Castro Contreras, Mat Ryer

Overview of this book

The Go programming language has firmly established itself as a favorite for building complex and scalable system applications. Go offers a direct and practical approach to programming that lets programmers write correct and predictable code using concurrency idioms and a full-featured standard library. This practical guide is full of real-world examples to help you get started with Go in no time at all. You’ll start by understanding the fundamentals of Go, then get a detailed description of the Go data types, program structures, and Maps. After that, you’ll learn how to use Go concurrency idioms to avoid pitfalls and create programs that are exact in expected behavior. Next, you will get familiar with the tools and libraries that are available in Go to write and exercise tests, benchmarking, and code coverage. After that, you will be able to utilize some of the most important features of GO such as Network Programming and OS integration to build efficient applications. Then you’ll start applying your skills to build some amazing projects in Go. You will learn to develop high-quality command-line tools that utilize the powerful shell capabilities and perform well using Go’s built-in concurrency mechanisms. Scale, performance, and high availability lie at the heart of our projects, and the lessons learned throughout the sections will arm you with everything you need to build world-class solutions. You will get a feel for app deployment using Docker and Google App Engine. Each project could form the basis of a start-up, which means they are directly applicable to modern software markets. With these skills in hand, you will be able to conquer all your fears of application development and go on to build large, robust and succinct apps in Go. This Learning Path combines some of the best that Packt has to offer in one complete, curated package. It includes content from the following Packt products: 1. Learning Go Programming 2. Go Design Patterns 3. Go Programming Blueprints, Second Edition
Table of Contents (38 chapters)
Go: Design Patterns for Real-World Projects
Credits
Preface
Bibliography

Votes


Now that we have modeled questions and answers in our application, it's time to think about how voting might work.

Let's design it a little:

  • Users vote answers up and down based on their opinion of them

  • Answers are ordered by their score so the best ones appear first

  • Each person is allowed one vote per answer

  • If a user votes again, they should replace their previous vote

We will make use of a few things we have learned so far in this chapter; transactions will help us ensure the correct score is calculated for answers, and we'll use predictable keys again to ensure that each person gets only one vote per answer.

We will first build a structure to represent each vote and use field tags to be a little more specific about how we want the data store to index our data.

Indexing

Reads from Google Cloud Datastore are extremely fast due to the extensive use of indexes. By default, every field in our structure is indexed. Queries that attempt to filter on fields that aren't indexed will fail (the method...