service/vendor/github.com/bytedance/sonic/internal/decoder/decoder.go

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2023-12-21 22:17:40 +08:00
/*
* Copyright 2021 ByteDance 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 decoder
import (
`unsafe`
`encoding/json`
`reflect`
`runtime`
`github.com/bytedance/sonic/internal/native`
`github.com/bytedance/sonic/internal/native/types`
`github.com/bytedance/sonic/internal/rt`
`github.com/bytedance/sonic/option`
`github.com/bytedance/sonic/utf8`
)
const (
_F_use_int64 = iota
_F_use_number
_F_disable_urc
_F_disable_unknown
_F_copy_string
_F_validate_string
_F_allow_control = 31
)
type Options uint64
const (
OptionUseInt64 Options = 1 << _F_use_int64
OptionUseNumber Options = 1 << _F_use_number
OptionUseUnicodeErrors Options = 1 << _F_disable_urc
OptionDisableUnknown Options = 1 << _F_disable_unknown
OptionCopyString Options = 1 << _F_copy_string
OptionValidateString Options = 1 << _F_validate_string
)
func (self *Decoder) SetOptions(opts Options) {
if (opts & OptionUseNumber != 0) && (opts & OptionUseInt64 != 0) {
panic("can't set OptionUseInt64 and OptionUseNumber both!")
}
self.f = uint64(opts)
}
// Decoder is the decoder context object
type Decoder struct {
i int
f uint64
s string
}
// NewDecoder creates a new decoder instance.
func NewDecoder(s string) *Decoder {
return &Decoder{s: s}
}
// Pos returns the current decoding position.
func (self *Decoder) Pos() int {
return self.i
}
func (self *Decoder) Reset(s string) {
self.s = s
self.i = 0
// self.f = 0
}
func (self *Decoder) CheckTrailings() error {
pos := self.i
buf := self.s
/* skip all the trailing spaces */
if pos != len(buf) {
for pos < len(buf) && (types.SPACE_MASK & (1 << buf[pos])) != 0 {
pos++
}
}
/* then it must be at EOF */
if pos == len(buf) {
return nil
}
/* junk after JSON value */
return SyntaxError {
Src : buf,
Pos : pos,
Code : types.ERR_INVALID_CHAR,
}
}
// Decode parses the JSON-encoded data from current position and stores the result
// in the value pointed to by val.
func (self *Decoder) Decode(val interface{}) error {
/* validate json if needed */
if (self.f & (1 << _F_validate_string)) != 0 && !utf8.ValidateString(self.s){
dbuf := utf8.CorrectWith(nil, rt.Str2Mem(self.s), "\ufffd")
self.s = rt.Mem2Str(dbuf)
}
vv := rt.UnpackEface(val)
vp := vv.Value
/* check for nil type */
if vv.Type == nil {
return &json.InvalidUnmarshalError{}
}
/* must be a non-nil pointer */
if vp == nil || vv.Type.Kind() != reflect.Ptr {
return &json.InvalidUnmarshalError{Type: vv.Type.Pack()}
}
etp := rt.PtrElem(vv.Type)
/* check the defined pointer type for issue 379 */
if vv.Type.IsNamed() {
newp := vp
etp = vv.Type
vp = unsafe.Pointer(&newp)
}
/* create a new stack, and call the decoder */
sb := newStack()
nb, err := decodeTypedPointer(self.s, self.i, etp, vp, sb, self.f)
/* return the stack back */
self.i = nb
freeStack(sb)
/* avoid GC ahead */
runtime.KeepAlive(vv)
return err
}
// UseInt64 indicates the Decoder to unmarshal an integer into an interface{} as an
// int64 instead of as a float64.
func (self *Decoder) UseInt64() {
self.f |= 1 << _F_use_int64
self.f &^= 1 << _F_use_number
}
// UseNumber indicates the Decoder to unmarshal a number into an interface{} as a
// json.Number instead of as a float64.
func (self *Decoder) UseNumber() {
self.f &^= 1 << _F_use_int64
self.f |= 1 << _F_use_number
}
// UseUnicodeErrors indicates the Decoder to return an error when encounter invalid
// UTF-8 escape sequences.
func (self *Decoder) UseUnicodeErrors() {
self.f |= 1 << _F_disable_urc
}
// DisallowUnknownFields indicates the Decoder to return an error when the destination
// is a struct and the input contains object keys which do not match any
// non-ignored, exported fields in the destination.
func (self *Decoder) DisallowUnknownFields() {
self.f |= 1 << _F_disable_unknown
}
// CopyString indicates the Decoder to decode string values by copying instead of referring.
func (self *Decoder) CopyString() {
self.f |= 1 << _F_copy_string
}
// ValidateString causes the Decoder to validate string values when decoding string value
// in JSON. Validation is that, returning error when unescaped control chars(0x00-0x1f) or
// invalid UTF-8 chars in the string value of JSON.
func (self *Decoder) ValidateString() {
self.f |= 1 << _F_validate_string
}
// Pretouch compiles vt ahead-of-time to avoid JIT compilation on-the-fly, in
// order to reduce the first-hit latency.
//
// Opts are the compile options, for example, "option.WithCompileRecursiveDepth" is
// a compile option to set the depth of recursive compile for the nested struct type.
func Pretouch(vt reflect.Type, opts ...option.CompileOption) error {
cfg := option.DefaultCompileOptions()
for _, opt := range opts {
opt(&cfg)
}
return pretouchRec(map[reflect.Type]bool{vt:true}, cfg)
}
func pretouchType(_vt reflect.Type, opts option.CompileOptions) (map[reflect.Type]bool, error) {
/* compile function */
compiler := newCompiler().apply(opts)
decoder := func(vt *rt.GoType, _ ...interface{}) (interface{}, error) {
if pp, err := compiler.compile(_vt); err != nil {
return nil, err
} else {
as := newAssembler(pp)
as.name = _vt.String()
return as.Load(), nil
}
}
/* find or compile */
vt := rt.UnpackType(_vt)
if val := programCache.Get(vt); val != nil {
return nil, nil
} else if _, err := programCache.Compute(vt, decoder); err == nil {
return compiler.rec, nil
} else {
return nil, err
}
}
func pretouchRec(vtm map[reflect.Type]bool, opts option.CompileOptions) error {
if opts.RecursiveDepth < 0 || len(vtm) == 0 {
return nil
}
next := make(map[reflect.Type]bool)
for vt := range(vtm) {
sub, err := pretouchType(vt, opts)
if err != nil {
return err
}
for svt := range(sub) {
next[svt] = true
}
}
opts.RecursiveDepth -= 1
return pretouchRec(next, opts)
}
// Skip skips only one json value, and returns first non-blank character position and its ending position if it is valid.
// Otherwise, returns negative error code using start and invalid character position using end
func Skip(data []byte) (start int, end int) {
s := rt.Mem2Str(data)
p := 0
m := types.NewStateMachine()
ret := native.SkipOne(&s, &p, m, uint64(0))
types.FreeStateMachine(m)
return ret, p
}