go-json/internal/decoder/path.go

654 lines
16 KiB
Go

package decoder
import (
"fmt"
"reflect"
"strconv"
"github.com/goccy/go-json/internal/errors"
"github.com/goccy/go-json/internal/runtime"
)
type PathString string
func (s PathString) Build() (*Path, error) {
builder := new(PathBuilder)
return builder.Build([]rune(s))
}
type PathBuilder struct {
root PathNode
node PathNode
singleQuotePathSelector bool
doubleQuotePathSelector bool
}
func (b *PathBuilder) Build(buf []rune) (*Path, error) {
node, err := b.build(buf)
if err != nil {
return nil, err
}
return &Path{
node: node,
SingleQuotePathSelector: b.singleQuotePathSelector,
DoubleQuotePathSelector: b.doubleQuotePathSelector,
}, nil
}
func (b *PathBuilder) build(buf []rune) (PathNode, error) {
if len(buf) == 0 {
return nil, errors.ErrEmptyPath()
}
if buf[0] != '$' {
return nil, errors.ErrInvalidPath("JSON Path must start with a $ character")
}
if len(buf) == 1 {
return nil, nil
}
buf = buf[1:]
offset, err := b.buildNext(buf)
if err != nil {
return nil, err
}
if len(buf) > offset {
return nil, errors.ErrInvalidPath("remain invalid path %q", buf[offset:])
}
return b.root, nil
}
func (b *PathBuilder) buildNextCharIfExists(buf []rune, cursor int) (int, error) {
if len(buf) > cursor+1 {
offset, err := b.buildNext(buf[cursor+1:])
if err != nil {
return 0, err
}
return cursor + 1 + offset, nil
}
return cursor, nil
}
func (b *PathBuilder) buildNext(buf []rune) (int, error) {
switch buf[0] {
case '.':
if len(buf) == 1 {
return 0, errors.ErrInvalidPath("JSON Path ends with dot character")
}
offset, err := b.buildSelector(buf[1:])
if err != nil {
return 0, err
}
return offset + 1, nil
case '[':
if len(buf) == 1 {
return 0, errors.ErrInvalidPath("JSON Path ends with left bracket character")
}
offset, err := b.buildIndex(buf[1:])
if err != nil {
return 0, err
}
return offset + 1, nil
default:
return 0, errors.ErrInvalidPath("expect dot or left bracket character. but found %c character", buf[0])
}
}
func (b *PathBuilder) buildSelector(buf []rune) (int, error) {
switch buf[0] {
case '.':
if len(buf) == 1 {
return 0, errors.ErrInvalidPath("JSON Path ends with double dot character")
}
offset, err := b.buildPathRecursive(buf[1:])
if err != nil {
return 0, err
}
return 1 + offset, nil
case '[', ']', '$', '*':
return 0, errors.ErrInvalidPath("found invalid path character %c after dot", buf[0])
}
for cursor := 0; cursor < len(buf); cursor++ {
switch buf[cursor] {
case '$', '*', ']':
return 0, errors.ErrInvalidPath("found %c character in field selector context", buf[cursor])
case '.':
if cursor+1 >= len(buf) {
return 0, errors.ErrInvalidPath("JSON Path ends with dot character")
}
selector := buf[:cursor]
b.addSelectorNode(string(selector))
offset, err := b.buildSelector(buf[cursor+1:])
if err != nil {
return 0, err
}
return cursor + 1 + offset, nil
case '[':
if cursor+1 >= len(buf) {
return 0, errors.ErrInvalidPath("JSON Path ends with left bracket character")
}
selector := buf[:cursor]
b.addSelectorNode(string(selector))
offset, err := b.buildIndex(buf[cursor+1:])
if err != nil {
return 0, err
}
return cursor + 1 + offset, nil
case '"':
if cursor+1 >= len(buf) {
return 0, errors.ErrInvalidPath("JSON Path ends with double quote character")
}
offset, err := b.buildQuoteSelector(buf[cursor+1:], DoubleQuotePathSelector)
if err != nil {
return 0, err
}
return cursor + 1 + offset, nil
}
}
b.addSelectorNode(string(buf))
return len(buf), nil
}
func (b *PathBuilder) buildQuoteSelector(buf []rune, sel QuotePathSelector) (int, error) {
switch buf[0] {
case '[', ']', '$', '.', '*', '\'', '"':
return 0, errors.ErrInvalidPath("found invalid path character %c after quote", buf[0])
}
for cursor := 0; cursor < len(buf); cursor++ {
switch buf[cursor] {
case '\'':
if sel != SingleQuotePathSelector {
return 0, errors.ErrInvalidPath("found double quote character in field selector with single quote context")
}
if len(buf) <= cursor+1 {
return 0, errors.ErrInvalidPath("JSON Path ends with single quote character in field selector context")
}
if buf[cursor+1] != ']' {
return 0, errors.ErrInvalidPath("expect right bracket for field selector with single quote but found %c", buf[cursor+1])
}
selector := buf[:cursor]
b.addSelectorNode(string(selector))
return b.buildNextCharIfExists(buf, cursor+1)
case '"':
if sel != DoubleQuotePathSelector {
return 0, errors.ErrInvalidPath("found single quote character in field selector with double quote context")
}
selector := buf[:cursor]
b.addSelectorNode(string(selector))
return b.buildNextCharIfExists(buf, cursor)
}
}
return 0, errors.ErrInvalidPath("couldn't find quote character in selector quote path context")
}
func (b *PathBuilder) buildPathRecursive(buf []rune) (int, error) {
switch buf[0] {
case '.', '[', ']', '$', '*':
return 0, errors.ErrInvalidPath("found invalid path character %c after double dot", buf[0])
}
for cursor := 0; cursor < len(buf); cursor++ {
switch buf[cursor] {
case '$', '*', ']':
return 0, errors.ErrInvalidPath("found %c character in field selector context", buf[cursor])
case '.':
if cursor+1 >= len(buf) {
return 0, errors.ErrInvalidPath("JSON Path ends with dot character")
}
selector := buf[:cursor]
b.addRecursiveNode(string(selector))
offset, err := b.buildSelector(buf[cursor+1:])
if err != nil {
return 0, err
}
return cursor + 1 + offset, nil
case '[':
if cursor+1 >= len(buf) {
return 0, errors.ErrInvalidPath("JSON Path ends with left bracket character")
}
selector := buf[:cursor]
b.addRecursiveNode(string(selector))
offset, err := b.buildIndex(buf[cursor+1:])
if err != nil {
return 0, err
}
return cursor + 1 + offset, nil
}
}
b.addRecursiveNode(string(buf))
return len(buf), nil
}
func (b *PathBuilder) buildIndex(buf []rune) (int, error) {
switch buf[0] {
case '.', '[', ']', '$':
return 0, errors.ErrInvalidPath("found invalid path character %c after left bracket", buf[0])
case '\'':
if len(buf) == 1 {
return 0, errors.ErrInvalidPath("JSON Path ends with single quote character")
}
offset, err := b.buildQuoteSelector(buf[1:], SingleQuotePathSelector)
if err != nil {
return 0, err
}
return 1 + offset, nil
case '*':
if len(buf) == 1 {
return 0, errors.ErrInvalidPath("JSON Path ends with star character")
}
if buf[1] != ']' {
return 0, errors.ErrInvalidPath("expect right bracket character for index all path but found %c character", buf[1])
}
b.addIndexAllNode()
offset := len("*]")
if len(buf) > 2 {
buildOffset, err := b.buildNext(buf[2:])
if err != nil {
return 0, err
}
return offset + buildOffset, nil
}
return offset, nil
}
for cursor := 0; cursor < len(buf); cursor++ {
switch buf[cursor] {
case ']':
index, err := strconv.ParseInt(string(buf[:cursor]), 10, 64)
if err != nil {
return 0, errors.ErrInvalidPath("%q is unexpected index path", buf[:cursor])
}
b.addIndexNode(int(index))
return b.buildNextCharIfExists(buf, cursor)
}
}
return 0, errors.ErrInvalidPath("couldn't find right bracket character in index path context")
}
func (b *PathBuilder) addIndexAllNode() {
node := newPathIndexAllNode()
if b.root == nil {
b.root = node
b.node = node
} else {
b.node = b.node.chain(node)
}
}
func (b *PathBuilder) addRecursiveNode(selector string) {
node := newPathRecursiveNode(selector)
if b.root == nil {
b.root = node
b.node = node
} else {
b.node = b.node.chain(node)
}
}
func (b *PathBuilder) addSelectorNode(name string) {
node := newPathSelectorNode(name)
if b.root == nil {
b.root = node
b.node = node
} else {
b.node = b.node.chain(node)
}
}
func (b *PathBuilder) addIndexNode(idx int) {
node := newPathIndexNode(idx)
if b.root == nil {
b.root = node
b.node = node
} else {
b.node = b.node.chain(node)
}
}
type QuotePathSelector int
const (
SingleQuotePathSelector QuotePathSelector = 1
DoubleQuotePathSelector QuotePathSelector = 2
)
type Path struct {
node PathNode
SingleQuotePathSelector bool
DoubleQuotePathSelector bool
}
func (p *Path) Field(sel string) (PathNode, bool, error) {
return p.node.Field(sel)
}
func (p *Path) Get(src, dst reflect.Value) error {
return p.node.Get(src, dst)
}
type PathNode interface {
fmt.Stringer
Index(idx int) (PathNode, bool, error)
Field(fieldName string) (PathNode, bool, error)
Get(src, dst reflect.Value) error
chain(PathNode) PathNode
target() bool
single() bool
}
type BasePathNode struct {
child PathNode
}
func (n *BasePathNode) chain(node PathNode) PathNode {
n.child = node
return node
}
func (n *BasePathNode) target() bool {
return n.child == nil
}
func (n *BasePathNode) single() bool {
return true
}
type PathSelectorNode struct {
*BasePathNode
selector string
}
func newPathSelectorNode(selector string) *PathSelectorNode {
return &PathSelectorNode{
BasePathNode: &BasePathNode{},
selector: selector,
}
}
func (n *PathSelectorNode) Index(idx int) (PathNode, bool, error) {
return nil, false, &errors.PathError{}
}
func (n *PathSelectorNode) Field(fieldName string) (PathNode, bool, error) {
if n.selector == fieldName {
return n.child, true, nil
}
return nil, false, nil
}
func (n *PathSelectorNode) Get(src, dst reflect.Value) error {
switch src.Type().Kind() {
case reflect.Map:
iter := src.MapRange()
for iter.Next() {
key, ok := iter.Key().Interface().(string)
if !ok {
return fmt.Errorf("invalid map key type %T", src.Type().Key())
}
child, found, err := n.Field(key)
if err != nil {
return err
}
if found {
if child != nil {
return child.Get(iter.Value(), dst)
}
return AssignValue(iter.Value(), dst)
}
}
case reflect.Struct:
typ := src.Type()
for i := 0; i < typ.Len(); i++ {
tag := runtime.StructTagFromField(typ.Field(i))
child, found, err := n.Field(tag.Key)
if err != nil {
return err
}
if found {
if child != nil {
return child.Get(src.Field(i), dst)
}
return AssignValue(src.Field(i), dst)
}
}
case reflect.Ptr:
return n.Get(src.Elem(), dst)
case reflect.Interface:
return n.Get(reflect.ValueOf(src.Interface()), dst)
case reflect.Float64, reflect.String, reflect.Bool:
return AssignValue(src, dst)
}
return fmt.Errorf("failed to get %s value from %s", n.selector, src.Type())
}
func (n *PathSelectorNode) String() string {
s := fmt.Sprintf(".%s", n.selector)
if n.child != nil {
s += n.child.String()
}
return s
}
type PathIndexNode struct {
*BasePathNode
selector int
}
func newPathIndexNode(selector int) *PathIndexNode {
return &PathIndexNode{
BasePathNode: &BasePathNode{},
selector: selector,
}
}
func (n *PathIndexNode) Index(idx int) (PathNode, bool, error) {
if n.selector == idx {
return n.child, true, nil
}
return nil, false, nil
}
func (n *PathIndexNode) Field(fieldName string) (PathNode, bool, error) {
return nil, false, &errors.PathError{}
}
func (n *PathIndexNode) Get(src, dst reflect.Value) error {
switch src.Type().Kind() {
case reflect.Array, reflect.Slice:
if src.Len() > n.selector {
if n.child != nil {
return n.child.Get(src.Index(n.selector), dst)
}
return AssignValue(src.Index(n.selector), dst)
}
case reflect.Ptr:
return n.Get(src.Elem(), dst)
case reflect.Interface:
return n.Get(reflect.ValueOf(src.Interface()), dst)
}
return fmt.Errorf("failed to get [%d] value from %s", n.selector, src.Type())
}
func (n *PathIndexNode) String() string {
s := fmt.Sprintf("[%d]", n.selector)
if n.child != nil {
s += n.child.String()
}
return s
}
type PathIndexAllNode struct {
*BasePathNode
}
func newPathIndexAllNode() *PathIndexAllNode {
return &PathIndexAllNode{
BasePathNode: &BasePathNode{},
}
}
func (n *PathIndexAllNode) Index(idx int) (PathNode, bool, error) {
return n.child, true, nil
}
func (n *PathIndexAllNode) Field(fieldName string) (PathNode, bool, error) {
return nil, false, &errors.PathError{}
}
func (n *PathIndexAllNode) Get(src, dst reflect.Value) error {
switch src.Type().Kind() {
case reflect.Array, reflect.Slice:
var arr []interface{}
for i := 0; i < src.Len(); i++ {
var v interface{}
rv := reflect.ValueOf(&v)
if n.child != nil {
if err := n.child.Get(src.Index(i), rv); err != nil {
return err
}
} else {
if err := AssignValue(src.Index(i), rv); err != nil {
return err
}
}
arr = append(arr, v)
}
if err := AssignValue(reflect.ValueOf(arr), dst); err != nil {
return err
}
return nil
case reflect.Ptr:
return n.Get(src.Elem(), dst)
case reflect.Interface:
return n.Get(reflect.ValueOf(src.Interface()), dst)
}
return fmt.Errorf("failed to get all value from %s", src.Type())
}
func (n *PathIndexAllNode) String() string {
s := "[*]"
if n.child != nil {
s += n.child.String()
}
return s
}
type PathRecursiveNode struct {
*BasePathNode
selector string
}
func newPathRecursiveNode(selector string) *PathRecursiveNode {
node := newPathSelectorNode(selector)
return &PathRecursiveNode{
BasePathNode: &BasePathNode{
child: node,
},
selector: selector,
}
}
func (n *PathRecursiveNode) Field(fieldName string) (PathNode, bool, error) {
if n.selector == fieldName {
return n.child, true, nil
}
return nil, false, nil
}
func (n *PathRecursiveNode) Index(_ int) (PathNode, bool, error) {
return n, true, nil
}
func valueToSliceValue(v interface{}) []interface{} {
rv := reflect.ValueOf(v)
ret := []interface{}{}
if rv.Type().Kind() == reflect.Slice || rv.Type().Kind() == reflect.Array {
for i := 0; i < rv.Len(); i++ {
ret = append(ret, rv.Index(i).Interface())
}
return ret
}
return []interface{}{v}
}
func (n *PathRecursiveNode) Get(src, dst reflect.Value) error {
if n.child == nil {
return fmt.Errorf("failed to get by recursive path ..%s", n.selector)
}
var arr []interface{}
switch src.Type().Kind() {
case reflect.Map:
iter := src.MapRange()
for iter.Next() {
key, ok := iter.Key().Interface().(string)
if !ok {
return fmt.Errorf("invalid map key type %T", src.Type().Key())
}
child, found, err := n.Field(key)
if err != nil {
return err
}
if found {
var v interface{}
rv := reflect.ValueOf(&v)
_ = child.Get(iter.Value(), rv)
arr = append(arr, valueToSliceValue(v)...)
} else {
var v interface{}
rv := reflect.ValueOf(&v)
_ = n.Get(iter.Value(), rv)
if v != nil {
arr = append(arr, valueToSliceValue(v)...)
}
}
}
_ = AssignValue(reflect.ValueOf(arr), dst)
return nil
case reflect.Struct:
typ := src.Type()
for i := 0; i < typ.Len(); i++ {
tag := runtime.StructTagFromField(typ.Field(i))
child, found, err := n.Field(tag.Key)
if err != nil {
return err
}
if found {
var v interface{}
rv := reflect.ValueOf(&v)
_ = child.Get(src.Field(i), rv)
arr = append(arr, valueToSliceValue(v)...)
} else {
var v interface{}
rv := reflect.ValueOf(&v)
_ = n.Get(src.Field(i), rv)
if v != nil {
arr = append(arr, valueToSliceValue(v)...)
}
}
}
_ = AssignValue(reflect.ValueOf(arr), dst)
return nil
case reflect.Array, reflect.Slice:
for i := 0; i < src.Len(); i++ {
var v interface{}
rv := reflect.ValueOf(&v)
_ = n.Get(src.Index(i), rv)
if v != nil {
arr = append(arr, valueToSliceValue(v)...)
}
}
_ = AssignValue(reflect.ValueOf(arr), dst)
return nil
case reflect.Ptr:
return n.Get(src.Elem(), dst)
case reflect.Interface:
return n.Get(reflect.ValueOf(src.Interface()), dst)
}
return fmt.Errorf("failed to get %s value from %s", n.selector, src.Type())
}
func (n *PathRecursiveNode) String() string {
s := fmt.Sprintf("..%s", n.selector)
if n.child != nil {
s += n.child.String()
}
return s
}