writer.go

   1 package main
   2
   3 import (
   4         "encoding/binary"
   5         "io"
   6         "log"
   7 )
   8
   9 func mustWrite(w io.Writer, buf []byte) {
  10         if _, err := w.Write(buf); err != nil {
  11                 log.Fatalln(err)
  12         }
  13 }
  14
  15 func writer(w io.Writer, sink chan Ent) {
  16         num := make([]byte, 8)
  17         var name string
  18         for ent := range sink {
  19                 name = ent.name[len(ent.name)-1]
  20                 if len(ent.name) >= 1<<16 {
  21                         panic("too long")
  22                 }
  23                 binary.BigEndian.PutUint16(num[:2], uint16(len(name)))
  24                 mustWrite(w, num[:2])
  25                 mustWrite(w, []byte(name))
  26                 if len(ent.name) >= 1<<8 {
  27                         panic("too deep")
  28                 }
  29                 mustWrite(w, []byte{byte(len(ent.name) - 1)})
  30                 binary.BigEndian.PutUint64(num, uint64(ent.mtime))
  31                 mustWrite(w, num)
  32                 binary.BigEndian.PutUint64(num, uint64(ent.size))
  33                 mustWrite(w, num)
  34         }
  35 }