How do you go about instrumenting or debugging a large Go codebase that you've never seen before? Unlike the JVM or a language like ruby it's not so easy to extend third party software in Go. Как вы поступаете, когда инструментируете или дебагите большую кодбазу от Go, которую вы видите впервые? Использовать второстепенный софт в GO не так просто, как с JVM или языком как Ruby.

1. Compile Time Code
Weaving with Go
https://github.com/deferpanic/goweave

2. I like your software
but…

3. What sucks about Go?

4. Do you know about
AspectJ?

5. Really?

6. I’m not a code purist

7. “Which is our full
time job. Write a
program to write
a program”
- rob pike / gopherfest 2015

9. Go is Actually a
Decent Fit

10. Prior Art
go fmt
go fix
go generate

11. go fix

12. No Wrapping
No code residue
Non-trivial amount
of work

13. Regex/Sed Doesn’t Work
scope
many packages
many refs

14. Aspect Oriented
Programming

15. Cross-Cutting Concern
ent in many places but don’t really have anythin

16. ogging is a canonical examp
logging.Error.Println(“got here”)
logging.Error.Println(“got here”)
logging.Error.Println(“got here”)

17. Pointcut
ion that details where to apply yo

18. like a regex but on the ast

19. Advice
fmt.Println("Hello, 世界")

20. Aspect
e combination of a pointcut and advi

21. Sample PointCuts

22. Call
re, after or wrap around calling a func

23. func blah() {
some.stuff()
}
func blah() {
fmt.Println(“before”)
some.stuff()
}
before
after

24. Execute
Before or after inside executing a method.

25. func blah() {
stuff()
}
func stuff() {
}
before
after
func blah() {
stuff()
}
func stuff() {
fmt.Println(“stuff”)
}

26. Within
Every single call within a method.

27. func blah() {
beforeEach()
slowCall()
beforeEach()
fastcall()
}
before
after
func blah() {
slowCall()
fastcall()
}

28. get
Before or After Every Get to a Variable

29. before
after
func blah() {
x := “stuff”
fmt.Println(x)
}
func blah() {
x := “stuff”
fmt.Println(“before getting x”)
fmt.Println(x)
}

30. set
Before or After Every Set to a Variable

31. before
after
func blah() {
x := “stuff”
fmt.Println(x)
}
func blah() {
fmt.Println(“before setting x”)
x := “stuff”
fmt.Println(x)
}

32. declaration
Before or After Every Variable Declaration

33. before
after
func blah() {
ch := make(chan int, 2)
ch <- 1
}
func blah() {
fmt.Println(“before make”)
ch := make(chan int, 2)
ch <- 1
}

34. Logging

35. Monitoring

36. Performance Analysis

37. Debugging &
Tracing

38. Undo Functionality

40. Behavior Mutation

41. Security

42. Transactions

43. Log every call to Itoa

44. Validation

45. Time Database Query
Latencies

46. Ensure we log every panic
in a goroutine

47. the loom
entral repository for storing .weave file

48. https://github.com/deferpanic/goweave
https://github.com/deferpanic/loom