130 lines
2.4 KiB
Go
130 lines
2.4 KiB
Go
package mg
|
|
|
|
import (
|
|
"fmt"
|
|
"reflect"
|
|
"runtime"
|
|
"strings"
|
|
"sync"
|
|
)
|
|
|
|
type onceMap struct {
|
|
mu *sync.Mutex
|
|
m map[string]*onceFun
|
|
}
|
|
|
|
func (o *onceMap) LoadOrStore(s string, one *onceFun) *onceFun {
|
|
defer o.mu.Unlock()
|
|
o.mu.Lock()
|
|
|
|
existing, ok := o.m[s]
|
|
if ok {
|
|
return existing
|
|
}
|
|
o.m[s] = one
|
|
return one
|
|
}
|
|
|
|
var onces = &onceMap{
|
|
mu: &sync.Mutex{},
|
|
m: map[string]*onceFun{},
|
|
}
|
|
|
|
// Deps runs the given functions as dependencies of the calling function.
|
|
// Dependencies must only be func() or func() error. The function calling Deps
|
|
// is guaranteed that all dependent functions will be run exactly once when Deps
|
|
// returns. Dependent functions may in turn declare their own dependencies
|
|
// using Deps. Each dependency is run in their own goroutines.
|
|
func Deps(fns ...interface{}) {
|
|
for _, f := range fns {
|
|
switch f.(type) {
|
|
case func(), func() error:
|
|
// ok
|
|
default:
|
|
panic(fmt.Errorf("Invalid type for dependent function: %T. Dependencies must be func() or func() error", f))
|
|
}
|
|
}
|
|
mu := &sync.Mutex{}
|
|
var errs []string
|
|
var exit int
|
|
wg := &sync.WaitGroup{}
|
|
for _, f := range fns {
|
|
fn := addDep(f)
|
|
wg.Add(1)
|
|
go func() {
|
|
defer func() {
|
|
if v := recover(); v != nil {
|
|
mu.Lock()
|
|
if err, ok := v.(error); ok {
|
|
exit = changeExit(exit, ExitStatus(err))
|
|
} else {
|
|
exit = changeExit(exit, 1)
|
|
}
|
|
errs = append(errs, fmt.Sprint(v))
|
|
mu.Unlock()
|
|
}
|
|
wg.Done()
|
|
}()
|
|
if err := fn.run(); err != nil {
|
|
mu.Lock()
|
|
errs = append(errs, fmt.Sprint(err))
|
|
exit = changeExit(exit, ExitStatus(err))
|
|
mu.Unlock()
|
|
}
|
|
}()
|
|
}
|
|
|
|
wg.Wait()
|
|
if len(errs) > 0 {
|
|
panic(Fatal(exit, strings.Join(errs, "\n")))
|
|
}
|
|
}
|
|
|
|
func changeExit(old, new int) int {
|
|
if new == 0 {
|
|
return old
|
|
}
|
|
if old == 0 {
|
|
return new
|
|
}
|
|
if old == new {
|
|
return old
|
|
}
|
|
// both different and both non-zero, just set
|
|
// exit to 1. Nothing more we can do.
|
|
return 1
|
|
}
|
|
|
|
func addDep(f interface{}) *onceFun {
|
|
var fn func() error
|
|
switch f := f.(type) {
|
|
case func():
|
|
fn = func() error { f(); return nil }
|
|
case func() error:
|
|
fn = f
|
|
}
|
|
|
|
n := name(f)
|
|
of := onces.LoadOrStore(n, &onceFun{
|
|
fn: fn,
|
|
})
|
|
return of
|
|
}
|
|
|
|
func name(i interface{}) string {
|
|
return runtime.FuncForPC(reflect.ValueOf(i).Pointer()).Name()
|
|
}
|
|
|
|
type onceFun struct {
|
|
once sync.Once
|
|
fn func() error
|
|
}
|
|
|
|
func (o *onceFun) run() error {
|
|
var err error
|
|
o.once.Do(func() {
|
|
err = o.fn()
|
|
})
|
|
return err
|
|
}
|