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// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
// gen-atomicint generates an atomic wrapper around an integer type.
//
// gen-atomicint -name Int32 -wrapped int32 -file out.go
//
// The generated wrapper will use the functions in the sync/atomic package
// named after the generated type.
package main
import (
"bytes"
"errors"
"flag"
"fmt"
"go/format"
"io"
"log"
"os"
"text/template"
)
func main() {
log.SetFlags(0)
if err := run(os.Args[1:]); err != nil {
log.Fatalf("%+v", err)
}
}
func run(args []string) error {
var opts struct {
Name string
Wrapped string
File string
Unsigned bool
}
flag := flag.NewFlagSet("gen-atomicint", flag.ContinueOnError)
flag.StringVar(&opts.Name, "name", "", "name of the generated type (e.g. Int32)")
flag.StringVar(&opts.Wrapped, "wrapped", "", "name of the wrapped type (e.g. int32)")
flag.StringVar(&opts.File, "file", "", "output file path (default: stdout)")
flag.BoolVar(&opts.Unsigned, "unsigned", false, "whether the type is unsigned")
if err := flag.Parse(args); err != nil {
return err
}
if len(opts.Name) == 0 || len(opts.Wrapped) == 0 {
return errors.New("flags -name and -wrapped are required")
}
var w io.Writer = os.Stdout
if file := opts.File; len(file) > 0 {
f, err := os.Create(file)
if err != nil {
return fmt.Errorf("create %q: %v", file, err)
}
defer f.Close()
w = f
}
data := struct {
Name string
Wrapped string
Unsigned bool
}{
Name: opts.Name,
Wrapped: opts.Wrapped,
Unsigned: opts.Unsigned,
}
var buff bytes.Buffer
if err := _tmpl.Execute(&buff, data); err != nil {
return fmt.Errorf("render template: %v", err)
}
bs, err := format.Source(buff.Bytes())
if err != nil {
return fmt.Errorf("reformat source: %v", err)
}
_, err = w.Write(bs)
return err
}
var _tmpl = template.Must(template.New("value.go").Parse(`// @generated Code generated by gen-atomicint.
// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package atomic
import (
"encoding/json"
"strconv"
"sync/atomic"
)
// {{ .Name }} is an atomic wrapper around {{ .Wrapped }}.
type {{ .Name }} struct {
_ nocmp // disallow non-atomic comparison
v {{ .Wrapped }}
}
// New{{ .Name }} creates a new {{ .Name }}.
func New{{ .Name }}(i {{ .Wrapped }}) *{{ .Name }} {
return &{{ .Name }}{v: i}
}
// Load atomically loads the wrapped value.
func (i *{{ .Name }}) Load() {{ .Wrapped }} {
return atomic.Load{{ .Name }}(&i.v)
}
// Add atomically adds to the wrapped {{ .Wrapped }} and returns the new value.
func (i *{{ .Name }}) Add(n {{ .Wrapped }}) {{ .Wrapped }} {
return atomic.Add{{ .Name }}(&i.v, n)
}
// Sub atomically subtracts from the wrapped {{ .Wrapped }} and returns the new value.
func (i *{{ .Name }}) Sub(n {{ .Wrapped }}) {{ .Wrapped }} {
return atomic.Add{{ .Name }}(&i.v,
{{- if .Unsigned -}}
^(n - 1)
{{- else -}}
-n
{{- end -}}
)
}
// Inc atomically increments the wrapped {{ .Wrapped }} and returns the new value.
func (i *{{ .Name }}) Inc() {{ .Wrapped }} {
return i.Add(1)
}
// Dec atomically decrements the wrapped {{ .Wrapped }} and returns the new value.
func (i *{{ .Name }}) Dec() {{ .Wrapped }} {
return i.Sub(1)
}
// CAS is an atomic compare-and-swap.
func (i *{{ .Name }}) CAS(old, new {{ .Wrapped }}) bool {
return atomic.CompareAndSwap{{ .Name }}(&i.v, old, new)
}
// Store atomically stores the passed value.
func (i *{{ .Name }}) Store(n {{ .Wrapped }}) {
atomic.Store{{ .Name }}(&i.v, n)
}
// Swap atomically swaps the wrapped {{ .Wrapped }} and returns the old value.
func (i *{{ .Name }}) Swap(n {{ .Wrapped }}) {{ .Wrapped }} {
return atomic.Swap{{ .Name }}(&i.v, n)
}
// MarshalJSON encodes the wrapped {{ .Wrapped }} into JSON.
func (i *{{ .Name }}) MarshalJSON() ([]byte, error) {
return json.Marshal(i.Load())
}
// UnmarshalJSON decodes JSON into the wrapped {{ .Wrapped }}.
func (i *{{ .Name }}) UnmarshalJSON(b []byte) error {
var v {{ .Wrapped }}
if err := json.Unmarshal(b, &v); err != nil {
return err
}
i.Store(v)
return nil
}
// String encodes the wrapped value as a string.
func (i *{{ .Name }}) String() string {
v := i.Load()
{{ if .Unsigned -}}
return strconv.FormatUint(uint64(v), 10)
{{- else -}}
return strconv.FormatInt(int64(v), 10)
{{- end }}
}
`))
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