Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/util.go


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// Copyright (c) 2013, Suryandaru Triandana <syndtr@gmail.com>
// All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Package util provides utilities used throughout leveldb.
package util

import (
    "errors"
)

var (
    ErrNotFound = errors.New("leveldb: not found")
)

// Releaser is the interface that wraps the basic Release method.
type Releaser interface {
    // Release releases associated resources. Release should always success
    // and can be called multipe times without causing error.
    Release()
}

// ReleaseSetter is the interface that wraps the basic SetReleaser method.
type ReleaseSetter interface {
    // SetReleaser associates the given releaser to the resources. The
    // releaser will be called once coresponding resources released.
    // Calling SetReleaser with nil will clear the releaser.
    SetReleaser(releaser Releaser)
}

// BasicReleaser provides basic implementation of Releaser and ReleaseSetter.
type BasicReleaser struct {
    releaser Releaser
}

// Release implements Releaser.Release.
func (r *BasicReleaser) Release() {
    if r.releaser != nil {
        r.releaser.Release()
        r.releaser = nil
    }
}

// SetReleaser implements ReleaseSetter.SetReleaser.
func (r *BasicReleaser) SetReleaser(releaser Releaser) {
    r.releaser = releaser
}