minio/pkg/quick/errorutil.go

97 lines
2.2 KiB
Go

/*
* Quick - Quick key value store for config files and persistent state files
*
* Quick (C) 2015 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package quick
import (
"bufio"
"bytes"
"encoding/json"
"errors"
"fmt"
"io"
"github.com/cheggaaa/pb"
)
const errorFmt = "%5d: %s <-- "
// FormatJSONSyntaxError generates a pretty printed json syntax error since
// golang doesn't provide an easy way to report the location of the error
func FormatJSONSyntaxError(data io.Reader, sErr *json.SyntaxError) error {
if sErr == nil {
return nil
}
var readLine bytes.Buffer
bio := bufio.NewReader(data)
errLine := int64(1)
readBytes := int64(0)
// termWidth is set to a default one to use when we are
// not able to calculate terminal width via OS syscalls
termWidth := 25
// errorShift is the length of the minimum needed place for
// error msg accessories, like <--, etc.. We calculate it
// dynamically to avoid an eventual bug after modifying errorFmt
errorShift := len(fmt.Sprintf(errorFmt, 1, ""))
if width, err := pb.GetTerminalWidth(); err == nil {
termWidth = width
}
for {
b, err := bio.ReadByte()
if err != nil {
if err != io.EOF {
return err
}
break
}
readBytes++
if readBytes > sErr.Offset {
break
}
switch b {
case '\n':
readLine.Reset()
errLine++
case '\t':
readLine.WriteByte(' ')
case '\r':
break
default:
readLine.WriteByte(b)
}
}
lineLen := readLine.Len()
idx := lineLen - termWidth + errorShift
if idx < 0 || idx > lineLen-1 {
idx = 0
}
errorStr := fmt.Sprintf("JSON syntax error at line %d, col %d : %s.\n",
errLine, readLine.Len(), sErr)
errorStr += fmt.Sprintf(errorFmt, errLine, readLine.String()[idx:])
return errors.New(errorStr)
}