Why go ?
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The document discusses the Go programming language, highlighting its design goals of simplicity and developer productivity by addressing issues found in C++ and other languages. It emphasizes Go's key features such as concurrency, first-class functions, and implicit interfaces, along with its strengths in tooling and standard libraries. Additionally, it addresses both true and perceived weaknesses of Go, as well as its adoption by major companies and use cases in infrastructure and distributed systems.
![What is Go ?
● first-class functions (a function is a value like any other)
type ReadFn func(buffer []byte) (int, error) // function type
func doSomething(fn ReadFn) {...} // function parameter
fn := func(buffer []byte) (int, error) {...} // anonymous functions
● methods on types
type FileReader struct {...}
func (rw *FileReader) Read(buffer []byte) (int, error) {...}
rw := NewFileReader()
rw.Read(...)](https://image.slidesharecdn.com/whygo-151203154515-lva1-app6892/85/Why-go-6-320.jpg)
![What is Go ?
● implicit interfaces (duck typing)
package io
type Reader interface {
Read(buffer []byte) (int, error)
}
package os
type File struct {...}
// os.File implements io.Reader
func (f *File) Read(buffer []byte) (int, error) {...}](https://image.slidesharecdn.com/whygo-151203154515-lva1-app6892/85/Why-go-7-320.jpg)
Why go ?
- 1. Go ? Go. Go ! Jean-François Bustarret - 1/12/2015
- 2. Why Go ? Where : Google Who : Rob Pike, Ken Thompson et Robert Griesemer Why : C++ has a few problems ● maintenance problems as the codebase grows/ages ● productivity problems ● in a lot of cases, performance gains do not justify the time spent
- 3. Go vs competitor languages C/C++ Java Go Python Performance Developer Productivity
- 4. Goal #1: simplicity ● start with C ● remove every difficult to use feature (e.g. pointer arithmetics) ● add a couple of new features (GC, concurrency, maps, …) ● clean the syntax ● standardize coding style Goal ● easy to learn ● easy to read/maintain existing code ● easy to parse
- 5. What is Go ? ● a compiled language, statically typed, with GC ● opinionated ● sequential and not event-driven ● concurrency ○ goroutines (collaborative multiplexing) - small CPU overhead, 2Ko RAM used, all CPU cores available ○ channels (communication rather than sharing of state with mutexes) ● not object-oriented - composition prefered to inheritance type Reader struct {...} type Writer struct {...} type ReadWriter struct { // has all methods and properties from both Reader Writer }
- 6. What is Go ? ● first-class functions (a function is a value like any other) type ReadFn func(buffer []byte) (int, error) // function type func doSomething(fn ReadFn) {...} // function parameter fn := func(buffer []byte) (int, error) {...} // anonymous functions ● methods on types type FileReader struct {...} func (rw *FileReader) Read(buffer []byte) (int, error) {...} rw := NewFileReader() rw.Read(...)
- 7. What is Go ? ● implicit interfaces (duck typing) package io type Reader interface { Read(buffer []byte) (int, error) } package os type File struct {...} // os.File implements io.Reader func (f *File) Read(buffer []byte) (int, error) {...}
- 8. What is Go ? ● reading a JSON document from a file // Open a file fd, err := os.Open(filename) // Decode json data (takes a io.Reader as a parameter) json.NewDecoder(fd).Decode(...) ● compressed data ? fd, err := os.Open(filename) bz := bzip2.NewReader(fd) json.NewDecoder(bz).Decode(...)
- 9. What is Go ? ● HTTP ? resp, err := http.Get("http://example.com/data.json.bz2") // resp.Body implements io.Reader bz := bzip2.NewReader(resp.Body) json.NewDecoder(bz).Decode(...) ● Also works with ○ transports : FTP, ... ○ encodings : Base64, XML, ... ○ archives : tar, zip, ... ○ other : pipes
- 10. Strengths Tooling ● formatting (go fmt) ● coding style analysis (go vet, go lint) and code analysis (oracle) ● refactoring (gorename) ● documentation (go doc) ● downloading packages from git, mercurial, ... (go get) ● code generation (go generate) ● debugging (gdb) Community contributions: debuggers (delve (coreos), godebug (mailgun))
- 11. Strengths (cont.) Standard library ● network, encoding, compression, crypto, … ● written in Go Concurrency Compiles to a (near) static binary, little to no dependency on 3rd party libs Language stability (very good forward compatibility)
- 12. Weaknesses True weaknesses ● Templating web vs Python/Ruby/PHP ● No generics ○ no implementation identified with acceptable impact on language simplicity ● Vendoring ○ work in progress False weaknesses ● Verbose error management ● Hiring Go developers is difficult ● Performances
- 13. Can Go be used for high performance ? Cloudflare (CDN) : log analysis, alerting, statistics ● 4 million log lines/s - 400 TB/day (after compression) ● https://www.youtube.com/watch?v=LA-gNoxSLCE Youtube : vitess (MySQL proxy // PgBouncer on steroids) ● > 1 million MySQL queries/s ● https://github.com/youtube/vitess Google : dl.google.com (all Google downloads - Chrome, Earth, SDK Android, …) ● replaces C++ with Go, < ½ code, better performance ● http://talks.golang.org/2013/oscon-dl.slide
- 14. Who uses Go ? What for ? Infrastructure : containers, distributed or service oriented platforms ● Docker, Packer, Kubernetes, etcd, Consul, CoreOS ● NoSQL : InfluxDB, CockroachDB ● Supervision : Prometheus ● Message queues : NSQd, NATS Startups heavily using Go ● Youtube, Bitly, Hailo, SoundCloud, Iron.io, Digital Ocean, twitch, Heroku, ...
- 15. References Go philosophy : ● http://jmoiron.net/blog/for-better-or-for-worse/ ● http://talks.golang.org/2012/splash.slide ● http://dave.cheney.net/2015/03/08/simplicity-and-collaboration Documentation : https://golang.org/doc/effective_go.html Learn Go : https://tour.golang.org