Files
kata-containers/src/tools/log-parser/hexbytes.go
Fabiano Fidêncio 16b8375095 golang: Stop using io/ioutils
The package has been deprecated as part of 1.16 and the same
functionality is now provided by either the io or the os package.

Signed-off-by: Fabiano Fidêncio <fabiano.fidencio@intel.com>
2022-11-17 13:43:25 +01:00

106 lines
1.7 KiB
Go

//
// Copyright (c) 2017-2018 Intel Corporation
//
// SPDX-License-Identifier: Apache-2.0
//
package main
import (
"errors"
"io"
"os"
"strings"
)
// HexByteReader is an I/O Reader type.
type HexByteReader struct {
file string
f *os.File
data []byte
// total length of "data"
len int
// how much of "data" has been sent back to the caller
offset int
}
// NewHexByteReader returns a new hex byte reader that escapes all
// hex-encoded characters.
func NewHexByteReader(file string) *HexByteReader {
var f *os.File
// treat dash as an alias for standard input
if file == stdinFile {
f = os.Stdin
}
return &HexByteReader{
file: file,
f: f,
}
}
// Read is a Reader that converts "\x" to "\\x"
func (r *HexByteReader) Read(p []byte) (n int, err error) {
size := len(p)
if r.data == nil {
if r.f == nil {
r.f, err = os.Open(r.file)
if err != nil {
return 0, err
}
}
// read the entire file
bytes, err := io.ReadAll(r.f)
if err != nil {
return 0, err
}
// although logfmt is happy to parse an empty file, this is
// surprising to users, so make it an error.
if len(bytes) == 0 {
return 0, errors.New("file is empty")
}
// perform the conversion
s := string(bytes)
result := strings.Replace(s, `\x`, `\\x`, -1)
// store the data
r.data = []byte(result)
r.len = len(r.data)
r.offset = 0
}
// calculate how much data is left to copy
remaining := r.len - r.offset
if remaining == 0 {
return 0, io.EOF
}
// see how much data can be copied on this call
limit := size
if remaining < limit {
limit = remaining
}
for i := 0; i < limit; i++ {
// index into the stored data
src := r.offset
// copy
p[i] = r.data[src]
// update
r.offset++
}
return limit, nil
}