minio/pkg/quick/errorutil.go
Nitish Tiwari 638f01f9e4 Generalize loadConfig method to avoid reading from disk (#5819)
As we move to multiple config backends like local disk and etcd,
config file should not be read from the disk, instead the quick
package should load and verify for duplicate entries.
2018-04-13 15:14:19 -07:00

142 lines
3.6 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"
"errors"
"fmt"
"io"
"github.com/cheggaaa/pb"
"github.com/tidwall/gjson"
)
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, offset int64) (highlight string) {
var readLine bytes.Buffer
var errLine = 1
var readBytes int64
bio := bufio.NewReader(data)
// 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 {
break
}
readBytes++
if readBytes > 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
}
return fmt.Sprintf(errorFmt, errLine, readLine.String()[idx:])
}
// doCheckDupJSONKeys recursively detects duplicate json keys
func doCheckDupJSONKeys(key, value gjson.Result) error {
// Key occurrences map of the current scope to count
// if there is any duplicated json key.
keysOcc := make(map[string]int)
// Holds the found error
var checkErr error
// Iterate over keys in the current json scope
value.ForEach(func(k, v gjson.Result) bool {
// If current key is not null, check if its
// value contains some duplicated keys.
if k.Type != gjson.Null {
keysOcc[k.String()]++
checkErr = doCheckDupJSONKeys(k, v)
}
return checkErr == nil
})
// Check found err
if checkErr != nil {
return errors.New(key.String() + " => " + checkErr.Error())
}
// Check for duplicated keys
for k, v := range keysOcc {
if v > 1 {
return errors.New(key.String() + " => `" + k + "` entry is duplicated")
}
}
return nil
}
// Check recursively if a key is duplicated in the same json scope
// e.g.:
// `{ "key" : { "key" ..` is accepted
// `{ "key" : { "subkey" : "val1", "subkey": "val2" ..` throws subkey duplicated error
func checkDupJSONKeys(json string) error {
// Parse config with gjson library
config := gjson.Parse(json)
// Create a fake rootKey since root json doesn't seem to have representation
// in gjson library.
rootKey := gjson.Result{Type: gjson.String, Str: "config.json"}
// Check if loaded json contains any duplicated keys
return doCheckDupJSONKeys(rootKey, config)
}
// CheckDuplicateKeys - checks for duplicate entries in a JSON file
func CheckDuplicateKeys(json string) error {
return checkDupJSONKeys(json)
}