61 lines
1017 B
Go
61 lines
1017 B
Go
// Copyright 2020 lesismal. All rights reserved.
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// Use of this source code is governed by an MIT-style
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// license that can be found in the LICENSE file.
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package concurrent
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import (
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"sync"
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)
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var (
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_defaultBatch = NewBatch()
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)
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type call struct {
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mux sync.RWMutex
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ret interface{}
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err error
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}
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// Batch .
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type Batch struct {
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_mux sync.Mutex
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_callings map[interface{}]*call
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}
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// Do .
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func (o *Batch) Do(key interface{}, f func() (interface{}, error)) (interface{}, error) {
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o._mux.Lock()
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c, ok := o._callings[key]
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if ok {
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o._mux.Unlock()
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c.mux.RLock()
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c.mux.RUnlock()
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return c.ret, c.err
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}
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c = &call{}
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c.mux.Lock()
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o._callings[key] = c
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o._mux.Unlock()
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c.ret, c.err = f()
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c.mux.Unlock()
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o._mux.Lock()
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delete(o._callings, key)
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o._mux.Unlock()
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return c.ret, c.err
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}
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// NewBatch .
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func NewBatch() *Batch {
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return &Batch{_callings: map[interface{}]*call{}}
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}
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// Do .
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func Do(key interface{}, f func() (interface{}, error)) (interface{}, error) {
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return _defaultBatch.Do(key, f)
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}
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