github.com/aacfactory/fns@v1.2.86-0.20240310083819-80d667fc0a17/barriers/barrier.go (about)

     1  /*
     2   * Copyright 2023 Wang Min Xiang
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   * 	http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   *
    16   */
    17  
    18  package barriers
    19  
    20  import (
    21  	"github.com/aacfactory/configures"
    22  	"github.com/aacfactory/errors"
    23  	"github.com/aacfactory/fns/commons/bytex"
    24  	"github.com/aacfactory/fns/commons/objects"
    25  	"github.com/aacfactory/fns/context"
    26  	"golang.org/x/sync/singleflight"
    27  )
    28  
    29  type Result interface {
    30  	objects.Object
    31  }
    32  
    33  type Barrier interface {
    34  	Do(ctx context.Context, key []byte, fn func() (result interface{}, err error)) (result Result, err error)
    35  }
    36  
    37  type BarrierBuilder interface {
    38  	Build(ctx context.Context, config configures.Config) (barrier Barrier, err error)
    39  }
    40  
    41  func New() (b Barrier) {
    42  	b = &barrier{
    43  		group: new(singleflight.Group),
    44  	}
    45  	return
    46  }
    47  
    48  // Barrier
    49  // @barrier
    50  // 当@authorization 存在时，则key为 services.HashRequest(r, services.HashRequestWithToken())
    51  type barrier struct {
    52  	group *singleflight.Group
    53  }
    54  
    55  func (b *barrier) Do(_ context.Context, key []byte, fn func() (result interface{}, err error)) (r Result, err error) {
    56  	if len(key) == 0 {
    57  		key = []byte{'-'}
    58  	}
    59  	groupKey := bytex.ToString(key)
    60  	v, doErr, _ := b.group.Do(bytex.ToString(key), func() (v interface{}, err error) {
    61  		v, err = fn()
    62  		return
    63  	})
    64  	b.group.Forget(groupKey)
    65  	if doErr != nil {
    66  		err = errors.Wrap(doErr)
    67  		return
    68  	}
    69  	r = objects.New(v)
    70  	return
    71  }