frostfs-s3-gw/pkg/madmin/parse-kv.go

204 lines
4.7 KiB
Go

/*
* MinIO Cloud Storage, (C) 2019 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 madmin
import (
"bufio"
"bytes"
"fmt"
"sort"
"strings"
"unicode"
)
// KV - is a shorthand of each key value.
type KV struct {
Key string `json:"key"`
Value string `json:"value"`
}
// KVS - is a shorthand for some wrapper functions
// to operate on list of key values.
type KVS []KV
// Empty - return if kv is empty
func (kvs KVS) Empty() bool {
return len(kvs) == 0
}
// Set sets a value, if not sets a default value.
func (kvs *KVS) Set(key, value string) {
for i, kv := range *kvs {
if kv.Key == key {
(*kvs)[i] = KV{
Key: key,
Value: value,
}
return
}
}
*kvs = append(*kvs, KV{
Key: key,
Value: value,
})
}
// Get - returns the value of a key, if not found returns empty.
func (kvs KVS) Get(key string) string {
v, ok := kvs.Lookup(key)
if ok {
return v
}
return ""
}
// Lookup - lookup a key in a list of KVS
func (kvs KVS) Lookup(key string) (string, bool) {
for _, kv := range kvs {
if kv.Key == key {
return kv.Value, true
}
}
return "", false
}
// Target signifies an individual target
type Target struct {
SubSystem string `json:"subSys"`
KVS KVS `json:"kvs"`
}
// Standard config keys and values.
const (
EnableKey = "enable"
CommentKey = "comment"
// Enable values
EnableOn = "on"
EnableOff = "off"
)
// HasSpace - returns if given string has space.
func HasSpace(s string) bool {
for _, r := range s {
if unicode.IsSpace(r) {
return true
}
}
return false
}
// Constant separators
const (
SubSystemSeparator = `:`
KvSeparator = `=`
KvComment = `#`
KvSpaceSeparator = ` `
KvNewline = "\n"
KvDoubleQuote = `"`
KvSingleQuote = `'`
Default = `_`
)
// SanitizeValue - this function is needed, to trim off single or double quotes, creeping into the values.
func SanitizeValue(v string) string {
v = strings.TrimSuffix(strings.TrimPrefix(strings.TrimSpace(v), KvDoubleQuote), KvDoubleQuote)
return strings.TrimSuffix(strings.TrimPrefix(v, KvSingleQuote), KvSingleQuote)
}
// KvFields - converts an input string of form "k1=v1 k2=v2" into
// fields of ["k1=v1", "k2=v2"], the tokenization of each `k=v`
// happens with the right number of input keys, if keys
// input is empty returned value is empty slice as well.
func KvFields(input string, keys []string) []string {
var valueIndexes []int
for _, key := range keys {
i := strings.Index(input, key+KvSeparator)
if i == -1 {
continue
}
valueIndexes = append(valueIndexes, i)
}
sort.Ints(valueIndexes)
var fields = make([]string, len(valueIndexes))
for i := range valueIndexes {
j := i + 1
if j < len(valueIndexes) {
fields[i] = strings.TrimSpace(input[valueIndexes[i]:valueIndexes[j]])
} else {
fields[i] = strings.TrimSpace(input[valueIndexes[i]:])
}
}
return fields
}
// ParseTarget - adds new targets, by parsing the input string s.
func ParseTarget(s string, help Help) (*Target, error) {
inputs := strings.SplitN(s, KvSpaceSeparator, 2)
if len(inputs) <= 1 {
return nil, fmt.Errorf("invalid number of arguments '%s'", s)
}
subSystemValue := strings.SplitN(inputs[0], SubSystemSeparator, 2)
if len(subSystemValue) == 0 {
return nil, fmt.Errorf("invalid number of arguments %s", s)
}
if help.SubSys != subSystemValue[0] {
return nil, fmt.Errorf("unknown sub-system %s", subSystemValue[0])
}
var kvs = KVS{}
var prevK string
for _, v := range KvFields(inputs[1], help.Keys()) {
kv := strings.SplitN(v, KvSeparator, 2)
if len(kv) == 0 {
continue
}
if len(kv) == 1 && prevK != "" {
value := strings.Join([]string{
kvs.Get(prevK),
SanitizeValue(kv[0]),
}, KvSpaceSeparator)
kvs.Set(prevK, value)
continue
}
if len(kv) == 2 {
prevK = kv[0]
kvs.Set(prevK, SanitizeValue(kv[1]))
continue
}
return nil, fmt.Errorf("value for key '%s' cannot be empty", kv[0])
}
return &Target{
SubSystem: inputs[0],
KVS: kvs,
}, nil
}
// ParseSubSysTarget - parse a sub-system target
func ParseSubSysTarget(buf []byte, help Help) (target *Target, err error) {
bio := bufio.NewScanner(bytes.NewReader(buf))
if bio.Scan() {
return ParseTarget(bio.Text(), help)
}
return nil, bio.Err()
}