minio/vendor/github.com/tidwall/sjson/sjson.go

483 lines
11 KiB
Go

// Package sjson provides setting json values.
package sjson
import (
jsongo "encoding/json"
"strconv"
"github.com/tidwall/gjson"
)
type errorType struct {
msg string
}
func (err *errorType) Error() string {
return err.msg
}
// Options represents additional options for the Set and Delete functions.
type Options struct {
// Optimistic is a hint that the value likely exists which
// allows for the sjson to perform a fast-track search and replace.
Optimistic bool
// ReplaceInPlace is a hint to replace the input json rather than
// allocate a new json byte slice. When this field is specified
// the input json will not longer be valid and it should not be used
// In the case when the destination slice doesn't have enough free
// bytes to replace the data in place, a new bytes slice will be
// created under the hood.
// The Optimistic flag must be set to true and the input must be a
// byte slice in order to use this field.
ReplaceInPlace bool
}
type pathResult struct {
part string // current key part
gpart string // gjson get part
path string // remaining path
force bool // force a string key
more bool // there is more path to parse
}
func parsePath(path string) (pathResult, error) {
var r pathResult
if len(path) > 0 && path[0] == ':' {
r.force = true
path = path[1:]
}
for i := 0; i < len(path); i++ {
if path[i] == '.' {
r.part = path[:i]
r.gpart = path[:i]
r.path = path[i+1:]
r.more = true
return r, nil
}
if path[i] == '*' || path[i] == '?' {
return r, &errorType{"wildcard characters not allowed in path"}
} else if path[i] == '#' {
return r, &errorType{"array access character not allowed in path"}
}
if path[i] == '\\' {
// go into escape mode. this is a slower path that
// strips off the escape character from the part.
epart := []byte(path[:i])
gpart := []byte(path[:i+1])
i++
if i < len(path) {
epart = append(epart, path[i])
gpart = append(gpart, path[i])
i++
for ; i < len(path); i++ {
if path[i] == '\\' {
gpart = append(gpart, '\\')
i++
if i < len(path) {
epart = append(epart, path[i])
gpart = append(gpart, path[i])
}
continue
} else if path[i] == '.' {
r.part = string(epart)
r.gpart = string(gpart)
r.path = path[i+1:]
r.more = true
return r, nil
} else if path[i] == '*' || path[i] == '?' {
return r, &errorType{
"wildcard characters not allowed in path"}
} else if path[i] == '#' {
return r, &errorType{
"array access character not allowed in path"}
}
epart = append(epart, path[i])
gpart = append(gpart, path[i])
}
}
// append the last part
r.part = string(epart)
r.gpart = string(gpart)
return r, nil
}
}
r.part = path
r.gpart = path
return r, nil
}
func mustMarshalString(s string) bool {
for i := 0; i < len(s); i++ {
if s[i] < ' ' || s[i] > 0x7f || s[i] == '"' || s[i] == '\\' {
return true
}
}
return false
}
// appendStringify makes a json string and appends to buf.
func appendStringify(buf []byte, s string) []byte {
if mustMarshalString(s) {
b, _ := jsongo.Marshal(s)
return append(buf, b...)
}
buf = append(buf, '"')
buf = append(buf, s...)
buf = append(buf, '"')
return buf
}
// appendBuild builds a json block from a json path.
func appendBuild(buf []byte, array bool, paths []pathResult, raw string,
stringify bool) []byte {
if !array {
buf = appendStringify(buf, paths[0].part)
buf = append(buf, ':')
}
if len(paths) > 1 {
n, numeric := atoui(paths[1])
if numeric || (!paths[1].force && paths[1].part == "-1") {
buf = append(buf, '[')
buf = appendRepeat(buf, "null,", n)
buf = appendBuild(buf, true, paths[1:], raw, stringify)
buf = append(buf, ']')
} else {
buf = append(buf, '{')
buf = appendBuild(buf, false, paths[1:], raw, stringify)
buf = append(buf, '}')
}
} else {
if stringify {
buf = appendStringify(buf, raw)
} else {
buf = append(buf, raw...)
}
}
return buf
}
// atoui does a rip conversion of string -> unigned int.
func atoui(r pathResult) (n int, ok bool) {
if r.force {
return 0, false
}
for i := 0; i < len(r.part); i++ {
if r.part[i] < '0' || r.part[i] > '9' {
return 0, false
}
n = n*10 + int(r.part[i]-'0')
}
return n, true
}
// appendRepeat repeats string "n" times and appends to buf.
func appendRepeat(buf []byte, s string, n int) []byte {
for i := 0; i < n; i++ {
buf = append(buf, s...)
}
return buf
}
// trim does a rip trim
func trim(s string) string {
for len(s) > 0 {
if s[0] <= ' ' {
s = s[1:]
continue
}
break
}
for len(s) > 0 {
if s[len(s)-1] <= ' ' {
s = s[:len(s)-1]
continue
}
break
}
return s
}
// deleteTailItem deletes the previous key or comma.
func deleteTailItem(buf []byte) ([]byte, bool) {
loop:
for i := len(buf) - 1; i >= 0; i-- {
// look for either a ',',':','['
switch buf[i] {
case '[':
return buf, true
case ',':
return buf[:i], false
case ':':
// delete tail string
i--
for ; i >= 0; i-- {
if buf[i] == '"' {
i--
for ; i >= 0; i-- {
if buf[i] == '"' {
i--
if i >= 0 && buf[i] == '\\' {
i--
continue
}
for ; i >= 0; i-- {
// look for either a ',','{'
switch buf[i] {
case '{':
return buf[:i+1], true
case ',':
return buf[:i], false
}
}
}
}
break
}
}
break loop
}
}
return buf, false
}
var errNoChange = &errorType{"no change"}
func appendRawPaths(buf []byte, jstr string, paths []pathResult, raw string,
stringify, del bool) ([]byte, error) {
var err error
var res gjson.Result
var found bool
if del {
if paths[0].part == "-1" && !paths[0].force {
res = gjson.Get(jstr, "#")
if res.Int() > 0 {
res = gjson.Get(jstr, strconv.FormatInt(int64(res.Int()-1), 10))
found = true
}
}
}
if !found {
res = gjson.Get(jstr, paths[0].gpart)
}
if res.Index > 0 {
if len(paths) > 1 {
buf = append(buf, jstr[:res.Index]...)
buf, err = appendRawPaths(buf, res.Raw, paths[1:], raw,
stringify, del)
if err != nil {
return nil, err
}
buf = append(buf, jstr[res.Index+len(res.Raw):]...)
return buf, nil
}
buf = append(buf, jstr[:res.Index]...)
var exidx int // additional forward stripping
if del {
var delNextComma bool
buf, delNextComma = deleteTailItem(buf)
if delNextComma {
i, j := res.Index+len(res.Raw), 0
for ; i < len(jstr); i, j = i+1, j+1 {
if jstr[i] <= ' ' {
continue
}
if jstr[i] == ',' {
exidx = j + 1
}
break
}
}
} else {
if stringify {
buf = appendStringify(buf, raw)
} else {
buf = append(buf, raw...)
}
}
buf = append(buf, jstr[res.Index+len(res.Raw)+exidx:]...)
return buf, nil
}
if del {
return nil, errNoChange
}
n, numeric := atoui(paths[0])
isempty := true
for i := 0; i < len(jstr); i++ {
if jstr[i] > ' ' {
isempty = false
break
}
}
if isempty {
if numeric {
jstr = "[]"
} else {
jstr = "{}"
}
}
jsres := gjson.Parse(jstr)
if jsres.Type != gjson.JSON {
if numeric {
jstr = "[]"
} else {
jstr = "{}"
}
jsres = gjson.Parse(jstr)
}
var comma bool
for i := 1; i < len(jsres.Raw); i++ {
if jsres.Raw[i] <= ' ' {
continue
}
if jsres.Raw[i] == '}' || jsres.Raw[i] == ']' {
break
}
comma = true
break
}
switch jsres.Raw[0] {
default:
return nil, &errorType{"json must be an object or array"}
case '{':
buf = append(buf, '{')
buf = appendBuild(buf, false, paths, raw, stringify)
if comma {
buf = append(buf, ',')
}
buf = append(buf, jsres.Raw[1:]...)
return buf, nil
case '[':
var appendit bool
if !numeric {
if paths[0].part == "-1" && !paths[0].force {
appendit = true
} else {
return nil, &errorType{
"cannot set array element for non-numeric key '" +
paths[0].part + "'"}
}
}
if appendit {
njson := trim(jsres.Raw)
if njson[len(njson)-1] == ']' {
njson = njson[:len(njson)-1]
}
buf = append(buf, njson...)
if comma {
buf = append(buf, ',')
}
buf = appendBuild(buf, true, paths, raw, stringify)
buf = append(buf, ']')
return buf, nil
}
buf = append(buf, '[')
ress := jsres.Array()
for i := 0; i < len(ress); i++ {
if i > 0 {
buf = append(buf, ',')
}
buf = append(buf, ress[i].Raw...)
}
if len(ress) == 0 {
buf = appendRepeat(buf, "null,", n-len(ress))
} else {
buf = appendRepeat(buf, ",null", n-len(ress))
if comma {
buf = append(buf, ',')
}
}
buf = appendBuild(buf, true, paths, raw, stringify)
buf = append(buf, ']')
return buf, nil
}
}
func isOptimisticPath(path string) bool {
for i := 0; i < len(path); i++ {
if path[i] < '.' || path[i] > 'z' {
return false
}
if path[i] > '9' && path[i] < 'A' {
return false
}
if path[i] > 'z' {
return false
}
}
return true
}
// Set sets a json value for the specified path.
// A path is in dot syntax, such as "name.last" or "age".
// This function expects that the json is well-formed, and does not validate.
// Invalid json will not panic, but it may return back unexpected results.
// An error is returned if the path is not valid.
//
// A path is a series of keys separated by a dot.
//
// {
// "name": {"first": "Tom", "last": "Anderson"},
// "age":37,
// "children": ["Sara","Alex","Jack"],
// "friends": [
// {"first": "James", "last": "Murphy"},
// {"first": "Roger", "last": "Craig"}
// ]
// }
// "name.last" >> "Anderson"
// "age" >> 37
// "children.1" >> "Alex"
//
func Set(json, path string, value interface{}) (string, error) {
return SetOptions(json, path, value, nil)
}
// SetBytes sets a json value for the specified path.
// If working with bytes, this method preferred over
// Set(string(data), path, value)
func SetBytes(json []byte, path string, value interface{}) ([]byte, error) {
return SetBytesOptions(json, path, value, nil)
}
// SetRaw sets a raw json value for the specified path.
// This function works the same as Set except that the value is set as a
// raw block of json. This allows for setting premarshalled json objects.
func SetRaw(json, path, value string) (string, error) {
return SetRawOptions(json, path, value, nil)
}
// SetRawOptions sets a raw json value for the specified path with options.
// This furnction works the same as SetOptions except that the value is set
// as a raw block of json. This allows for setting premarshalled json objects.
func SetRawOptions(json, path, value string, opts *Options) (string, error) {
var optimistic bool
if opts != nil {
optimistic = opts.Optimistic
}
res, err := set(json, path, value, false, false, optimistic, false)
if err == errNoChange {
return json, nil
}
return string(res), err
}
// SetRawBytes sets a raw json value for the specified path.
// If working with bytes, this method preferred over
// SetRaw(string(data), path, value)
func SetRawBytes(json []byte, path string, value []byte) ([]byte, error) {
return SetRawBytesOptions(json, path, value, nil)
}
type dtype struct{}
// Delete deletes a value from json for the specified path.
func Delete(json, path string) (string, error) {
return Set(json, path, dtype{})
}
// DeleteBytes deletes a value from json for the specified path.
func DeleteBytes(json []byte, path string) ([]byte, error) {
return SetBytes(json, path, dtype{})
}