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mirror of https://github.com/duke-git/lancet.git synced 2026-02-23 13:52:26 +08:00

修改promise内存布局,提高了安全性,减少了内存占用

This commit is contained in:
lee
2023-11-17 19:24:55 +08:00
parent 31c618c187
commit 731be48b30

View File

@@ -8,6 +8,7 @@ import (
"errors"
"fmt"
"sync"
"sync/atomic"
"github.com/duke-git/lancet/v2/internal"
)
@@ -16,14 +17,15 @@ import (
// ref : chebyrash/promise (https://github.com/chebyrash/promise)
// see js promise: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise
type Promise[T any] struct {
*p_[T]
}
type p_[T any] struct {
runnable func(resolve func(T), reject func(error))
result T
err error
pending bool
mu *sync.Mutex
wg *sync.WaitGroup
wait sync.WaitGroup
pending atomic.Bool
}
// New create a new promise instance.
@@ -32,12 +34,13 @@ func New[T any](runnable func(resolve func(T), reject func(error))) *Promise[T]
panic("runnable function should not be nil")
}
p := &Promise[T]{
p := &Promise[T]{&p_[T]{
runnable: runnable,
pending: true,
mu: &sync.Mutex{},
wg: &sync.WaitGroup{},
}
wait: sync.WaitGroup{},
pending: atomic.Bool{},
}}
p.pending.Store(true)
defer p.run()
@@ -45,11 +48,11 @@ func New[T any](runnable func(resolve func(T), reject func(error))) *Promise[T]
}
func (p *Promise[T]) run() {
p.wg.Add(1)
p.p_.wait.Add(1)
go func() {
defer func() {
if !p.pending {
if !p.pending.Load() {
return
}
@@ -64,50 +67,42 @@ func (p *Promise[T]) run() {
// Resolve returns a Promise that has been resolved with a given value.
func Resolve[T any](resolution T) *Promise[T] {
return &Promise[T]{
return &Promise[T]{&p_[T]{
result: resolution,
pending: false,
mu: &sync.Mutex{},
wg: &sync.WaitGroup{},
}
wait: sync.WaitGroup{},
pending: atomic.Bool{},
}}
}
func (p *Promise[T]) resolve(value T) {
p.mu.Lock()
defer p.mu.Unlock()
if !p.pending {
if !p.pending.Load() {
return
}
p.result = value
p.pending = false
p.pending.Store(false)
p.wg.Done()
p.wait.Done()
}
// Reject returns a Promise that has been rejected with a given error.
func Reject[T any](err error) *Promise[T] {
return &Promise[T]{
return &Promise[T]{&p_[T]{
err: err,
pending: false,
mu: &sync.Mutex{},
wg: &sync.WaitGroup{},
}
wait: sync.WaitGroup{},
pending: atomic.Bool{},
}}
}
func (p *Promise[T]) reject(err error) {
p.mu.Lock()
defer p.mu.Unlock()
if !p.pending {
if !p.pending.Load() {
return
}
p.err = err
p.pending = false
p.pending.Store(false)
p.wg.Done()
p.wait.Done()
}
// Then allows chain calls to other promise methods.
@@ -149,18 +144,18 @@ func Catch[T any](promise *Promise[T], rejection func(err error) error) *Promise
// Catch chain an existing promise with an intermediate reject function.
func (p *Promise[T]) Catch(reject func(error) error) *Promise[T] {
return New(func(resolve func(T), rej func(error)) {
resutl, err := p.Await()
result, err := p.Await()
if err != nil {
rej(reject(err))
return
}
resolve(resutl)
resolve(result)
})
}
// Await blocks until the 'runable' to finish execution.
func (p *Promise[T]) Await() (T, error) {
p.wg.Wait()
p.wait.Wait()
return p.result, p.err
}