github.com/Blockdaemon/celo-blockchain@v0.0.0-20200129231733-e667f6b08419/cmd/swarm/mimegen/generator.go (about)

     1  // Copyright 2018 The go-ethereum Authors
     2  // This file is part of go-ethereum.
     3  //
     4  // go-ethereum is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // go-ethereum is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU General Public License
    15  // along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
    16  package main
    17  
    18  // Standard "mime" package rely on system-settings, see mime.osInitMime
    19  // Swarm will run on many OS/Platform/Docker and must behave similar
    20  // This command generates code to add common mime types based on mime.types file
    21  //
    22  // mime.types file provided by mailcap, which follow https://www.iana.org/assignments/media-types/media-types.xhtml
    23  //
    24  // Get last version of mime.types file by:
    25  // docker run --rm -v $(pwd):/tmp alpine:edge /bin/sh -c "apk add -U mailcap; mv /etc/mime.types /tmp"
    26  
    27  import (
    28  	"bufio"
    29  	"bytes"
    30  	"flag"
    31  	"html/template"
    32  	"io/ioutil"
    33  	"log"
    34  	"strings"
    35  )
    36  
    37  var (
    38  	typesFlag   = flag.String("types", "", "Input mime.types file")
    39  	packageFlag = flag.String("package", "", "Golang package in output file")
    40  	outFlag     = flag.String("out", "", "Output file name for the generated mime types")
    41  )
    42  
    43  type mime struct {
    44  	Name string
    45  	Exts []string
    46  }
    47  
    48  type templateParams struct {
    49  	PackageName string
    50  	Mimes       []mime
    51  }
    52  
    53  func main() {
    54  	// Parse and ensure all needed inputs are specified
    55  	flag.Parse()
    56  	if *typesFlag == "" {
    57  		log.Fatalf("--types is required")
    58  	}
    59  	if *packageFlag == "" {
    60  		log.Fatalf("--types is required")
    61  	}
    62  	if *outFlag == "" {
    63  		log.Fatalf("--out is required")
    64  	}
    65  
    66  	params := templateParams{
    67  		PackageName: *packageFlag,
    68  	}
    69  
    70  	types, err := ioutil.ReadFile(*typesFlag)
    71  	if err != nil {
    72  		log.Fatal(err)
    73  	}
    74  
    75  	scanner := bufio.NewScanner(bytes.NewReader(types))
    76  	for scanner.Scan() {
    77  		txt := scanner.Text()
    78  		if strings.HasPrefix(txt, "#") || len(txt) == 0 {
    79  			continue
    80  		}
    81  		parts := strings.Fields(txt)
    82  		if len(parts) == 1 {
    83  			continue
    84  		}
    85  		params.Mimes = append(params.Mimes, mime{parts[0], parts[1:]})
    86  	}
    87  
    88  	if err = scanner.Err(); err != nil {
    89  		log.Fatal(err)
    90  	}
    91  
    92  	result := bytes.NewBuffer([]byte{})
    93  
    94  	if err := template.Must(template.New("_").Parse(tpl)).Execute(result, params); err != nil {
    95  		log.Fatal(err)
    96  	}
    97  
    98  	if err := ioutil.WriteFile(*outFlag, result.Bytes(), 0600); err != nil {
    99  		log.Fatal(err)
   100  	}
   101  }
   102  
   103  var tpl = `// Code generated by github.com/ethereum/go-ethereum/cmd/swarm/mimegen. DO NOT EDIT.
   104  
   105  package {{ .PackageName }}
   106  
   107  import "mime"
   108  func init() {
   109  	var mimeTypes = map[string]string{
   110  {{- range .Mimes -}}
   111  	{{ $name := .Name -}}
   112  	{{- range .Exts }}
   113  		".{{ . }}": "{{ $name | html }}",
   114  	{{- end }}
   115  {{- end }}
   116  	}
   117  	for ext, name := range mimeTypes {
   118  		if err := mime.AddExtensionType(ext, name); err != nil {
   119  			panic(err)
   120  		}
   121  	}
   122  }
   123  `