go-ethereum/cmd/swarm/mimegen/generator.go

125 lines
3.1 KiB
Go

// Copyright 2018 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package main
// Standard "mime" package rely on system-settings, see mime.osInitMime
// Swarm will run on many OS/Platform/Docker and must behave similar
// This command generates code to add common mime types based on mime.types file
//
// mime.types file provided by mailcap, which follow https://www.iana.org/assignments/media-types/media-types.xhtml
//
// Get last version of mime.types file by:
// docker run --rm -v $(pwd):/tmp alpine:edge /bin/sh -c "apk add -U mailcap; mv /etc/mime.types /tmp"
import (
"bufio"
"bytes"
"flag"
"html/template"
"io/ioutil"
"strings"
"log"
)
var (
typesFlag = flag.String("types", "", "Input mime.types file")
packageFlag = flag.String("package", "", "Golang package in output file")
outFlag = flag.String("out", "", "Output file name for the generated mime types")
)
type mime struct {
Name string
Exts []string
}
type templateParams struct {
PackageName string
Mimes []mime
}
func main() {
// Parse and ensure all needed inputs are specified
flag.Parse()
if *typesFlag == "" {
log.Fatalf("--types is required")
}
if *packageFlag == "" {
log.Fatalf("--types is required")
}
if *outFlag == "" {
log.Fatalf("--out is required")
}
params := templateParams{
PackageName: *packageFlag,
}
types, err := ioutil.ReadFile(*typesFlag)
if err != nil {
log.Fatal(err)
}
scanner := bufio.NewScanner(bytes.NewReader(types))
for scanner.Scan() {
txt := scanner.Text()
if strings.HasPrefix(txt, "#") || len(txt) == 0 {
continue
}
parts := strings.Fields(txt)
if len(parts) == 1 {
continue
}
params.Mimes = append(params.Mimes, mime{parts[0], parts[1:]})
}
if err = scanner.Err(); err != nil {
log.Fatal(err)
}
result := bytes.NewBuffer([]byte{})
if err := template.Must(template.New("_").Parse(tpl)).Execute(result, params); err != nil {
log.Fatal(err)
}
if err := ioutil.WriteFile(*outFlag, result.Bytes(), 0600); err != nil {
log.Fatal(err)
}
}
var tpl = `// Code generated by github.com/ethereum/go-ethereum/cmd/swarm/mimegen. DO NOT EDIT.
package {{ .PackageName }}
import "mime"
func init() {
var mimeTypes = map[string]string{
{{- range .Mimes -}}
{{ $name := .Name -}}
{{- range .Exts }}
".{{ . }}": "{{ $name | html }}",
{{- end }}
{{- end }}
}
for ext, name := range mimeTypes {
if err := mime.AddExtensionType(ext, name); err != nil {
panic(err)
}
}
}
`