github.com/code-reading/golang@v0.0.0-20220303082512-ba5bc0e589a3/go/src/time/tzdata/generate_zipdata.go (about)

     1  // Copyright 2020 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build ignore
     6  // +build ignore
     7  
     8  // This program generates zipdata.go from $GOROOT/lib/time/zoneinfo.zip.
     9  package main
    10  
    11  import (
    12  	"bufio"
    13  	"fmt"
    14  	"os"
    15  	"strconv"
    16  )
    17  
    18  // header is put at the start of the generated file.
    19  // The string addition avoids this file (generate_zipdata.go) from
    20  // matching the "generated file" regexp.
    21  const header = `// Copyright 2020 The Go Authors. All rights reserved.
    22  // Use of this source code is governed by a BSD-style
    23  // license that can be found in the LICENSE file.
    24  
    25  ` + `// Code generated by generate_zipdata. DO NOT EDIT.
    26  
    27  // This file contains an embedded zip archive that contains time zone
    28  // files compiled using the code and data maintained as part of the
    29  // IANA Time Zone Database.
    30  // The IANA asserts that the data is in the public domain.
    31  
    32  // For more information, see
    33  // https://www.iana.org/time-zones
    34  // ftp://ftp.iana.org/tz/code/tz-link.htm
    35  // http://tools.ietf.org/html/rfc6557
    36  
    37  package tzdata
    38  
    39  const zipdata = `
    40  
    41  func main() {
    42  	// We should be run in the $GOROOT/src/time/tzdata directory.
    43  	data, err := os.ReadFile("../../../lib/time/zoneinfo.zip")
    44  	if err != nil {
    45  		die("cannot find zoneinfo.zip file: %v", err)
    46  	}
    47  
    48  	of, err := os.Create("zipdata.go")
    49  	if err != nil {
    50  		die("%v", err)
    51  	}
    52  
    53  	buf := bufio.NewWriter(of)
    54  	buf.WriteString(header)
    55  
    56  	ds := string(data)
    57  	i := 0
    58  	const chunk = 60
    59  	for ; i+chunk < len(data); i += chunk {
    60  		if i > 0 {
    61  			buf.WriteRune('\t')
    62  		}
    63  		fmt.Fprintf(buf, "%s +\n", strconv.Quote(ds[i:i+chunk]))
    64  	}
    65  	fmt.Fprintf(buf, "\t%s\n", strconv.Quote(ds[i:]))
    66  
    67  	if err := buf.Flush(); err != nil {
    68  		die("error writing to zipdata.go: %v", err)
    69  	}
    70  	if err := of.Close(); err != nil {
    71  		die("error closing zipdata.go: %v", err)
    72  	}
    73  }
    74  
    75  func die(format string, args ...interface{}) {
    76  	fmt.Fprintf(os.Stderr, format+"\n", args...)
    77  	os.Exit(1)
    78  }