mirror of
https://github.com/MontFerret/ferret.git
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64 lines
924 B
Go
64 lines
924 B
Go
package common
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import (
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"github.com/MontFerret/ferret/pkg/runtime/core"
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"github.com/MontFerret/ferret/pkg/runtime/values"
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"sync"
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)
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type (
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LazyFactory func() (core.Value, error)
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LazyValue struct {
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sync.Mutex
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factory LazyFactory
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ready bool
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value core.Value
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err error
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}
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)
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func NewLazyValue(factory LazyFactory) *LazyValue {
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lz := new(LazyValue)
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lz.ready = false
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lz.factory = factory
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lz.value = values.None
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return lz
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}
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func (lv *LazyValue) Ready() bool {
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lv.Lock()
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defer lv.Unlock()
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return lv.ready
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}
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func (lv *LazyValue) Value() (core.Value, error) {
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lv.Lock()
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defer lv.Unlock()
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if !lv.ready {
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val, err := lv.factory()
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if err == nil {
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lv.value = val
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lv.err = nil
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} else {
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lv.value = values.None
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lv.err = err
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}
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}
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return lv.value, lv.err
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}
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func (lv *LazyValue) Reset() {
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lv.Lock()
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defer lv.Unlock()
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lv.ready = false
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lv.value = values.None
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lv.err = nil
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}
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