| // 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 }} |
| } |
| `)) |