github.com/goshafaq/sonic@v0.0.0-20231026082336-871835fb94c6/decoder/decoder_compat.go

//go:build !amd64 || !go1.16 || go1.22
// +build !amd64 !go1.16 go1.22

/*
* Copyright 2023 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 (
	"bytes"
	"encoding/json"
	"io"
	"reflect"
	"unsafe"

	"github.com/goshafaq/sonic/internal/native/types"
	"github.com/goshafaq/sonic/option"
)

func init() {
	println("WARNING: sonic only supports Go1.16~1.20 && CPU amd64, but your environment is not suitable")
}

const (
	_F_use_int64       = 0
	_F_disable_urc     = 2
	_F_disable_unknown = 3
	_F_copy_string     = 4

	_F_use_number      = types.B_USE_NUMBER
	_F_validate_string = types.B_VALIDATE_STRING
	_F_allow_control   = types.B_ALLOW_CONTROL
)

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
}

// NOTE: api fallback do nothing
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 nil
}

// 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 {
	r := bytes.NewBufferString(self.s)
	dec := json.NewDecoder(r)
	if (self.f & uint64(OptionUseNumber)) != 0 {
		dec.UseNumber()
	}
	if (self.f & uint64(OptionDisableUnknown)) != 0 {
		dec.DisallowUnknownFields()
	}
	return dec.Decode(val)
}

// 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 {
	return nil
}

type StreamDecoder = json.Decoder

// NewStreamDecoder adapts to encoding/json.NewDecoder API.
//
// NewStreamDecoder returns a new decoder that reads from r.
func NewStreamDecoder(r io.Reader) *StreamDecoder {
	return json.NewDecoder(r)
}

// SyntaxError represents json syntax error
type SyntaxError json.SyntaxError

// Description
func (s SyntaxError) Description() string {
	return (*json.SyntaxError)(unsafe.Pointer(&s)).Error()
}

// Error
func (s SyntaxError) Error() string {
	return (*json.SyntaxError)(unsafe.Pointer(&s)).Error()
}

// MismatchTypeError represents dismatching between json and object
type MismatchTypeError json.UnmarshalTypeError