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提交 ee667a09 编写于 作者: martianzhang's avatar martianzhang
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tiast-json marshal unexported type 

  change encoding/json -> github.com/CorgiMan/json2
上级 d891be61
隐藏空白更改
内联 并排
Showing with 3220 addition and 2 deletion
ast/tidb.go
浏览文件 @ ee667a09
......@@ -17,14 +17,14 @@
package ast
import (
"encoding/json"
"github.com/XiaoMi/soar/common"
"github.com/kr/pretty"
"github.com/pingcap/parser"
"github.com/pingcap/parser/ast"
json "github.com/CorgiMan/json2"
// for pingcap parser
_ "github.com/pingcap/tidb/types/parser_driver"
)
......
vendor/github.com/CorgiMan/json2/decode.go 0 → 100644
浏览文件 @ ee667a09
// I stole this from golang, only changed package name
// and commented out line 1018-1020 of encode.go
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Represents JSON data structure using native Go types: booleans, floats,
// strings, arrays, and maps.
package json2
import (
"encoding"
"encoding/base64"
"errors"
"fmt"
"reflect"
"runtime"
"strconv"
"strings"
"unicode"
"unicode/utf16"
"unicode/utf8"
)
// Unmarshal parses the JSON-encoded data and stores the result
// in the value pointed to by v.
//
// Unmarshal uses the inverse of the encodings that
// Marshal uses, allocating maps, slices, and pointers as necessary,
// with the following additional rules:
//
// To unmarshal JSON into a pointer, Unmarshal first handles the case of
// the JSON being the JSON literal null. In that case, Unmarshal sets
// the pointer to nil. Otherwise, Unmarshal unmarshals the JSON into
// the value pointed at by the pointer. If the pointer is nil, Unmarshal
// allocates a new value for it to point to.
//
// To unmarshal JSON into a struct, Unmarshal matches incoming object
// keys to the keys used by Marshal (either the struct field name or its tag),
// preferring an exact match but also accepting a case-insensitive match.
//
// To unmarshal JSON into an interface value,
// Unmarshal stores one of these in the interface value:
//
// bool, for JSON booleans
// float64, for JSON numbers
// string, for JSON strings
// []interface{}, for JSON arrays
// map[string]interface{}, for JSON objects
// nil for JSON null
//
// If a JSON value is not appropriate for a given target type,
// or if a JSON number overflows the target type, Unmarshal
// skips that field and completes the unmarshalling as best it can.
// If no more serious errors are encountered, Unmarshal returns
// an UnmarshalTypeError describing the earliest such error.
//
// When unmarshaling quoted strings, invalid UTF-8 or
// invalid UTF-16 surrogate pairs are not treated as an error.
// Instead, they are replaced by the Unicode replacement
// character U+FFFD.
//
func Unmarshal(data []byte, v interface{}) error {
// Check for well-formedness.
// Avoids filling out half a data structure
// before discovering a JSON syntax error.
var d decodeState
err := checkValid(data, &d.scan)
if err != nil {
return err
}
d.init(data)
return d.unmarshal(v)
}
// Unmarshaler is the interface implemented by objects
// that can unmarshal a JSON description of themselves.
// The input can be assumed to be a valid encoding of
// a JSON value. UnmarshalJSON must copy the JSON data
// if it wishes to retain the data after returning.
type Unmarshaler interface {
UnmarshalJSON([]byte) error
}
// An UnmarshalTypeError describes a JSON value that was
// not appropriate for a value of a specific Go type.
type UnmarshalTypeError struct {
Value string // description of JSON value - "bool", "array", "number -5"
Type reflect.Type // type of Go value it could not be assigned to
}
func (e *UnmarshalTypeError) Error() string {
return "json: cannot unmarshal " + e.Value + " into Go value of type " + e.Type.String()
}
// An UnmarshalFieldError describes a JSON object key that
// led to an unexported (and therefore unwritable) struct field.
// (No longer used; kept for compatibility.)
type UnmarshalFieldError struct {
Key string
Type reflect.Type
Field reflect.StructField
}
func (e *UnmarshalFieldError) Error() string {
return "json: cannot unmarshal object key " + strconv.Quote(e.Key) + " into unexported field " + e.Field.Name + " of type " + e.Type.String()
}
// An InvalidUnmarshalError describes an invalid argument passed to Unmarshal.
// (The argument to Unmarshal must be a non-nil pointer.)
type InvalidUnmarshalError struct {
Type reflect.Type
}
func (e *InvalidUnmarshalError) Error() string {
if e.Type == nil {
return "json: Unmarshal(nil)"
}
if e.Type.Kind() != reflect.Ptr {
return "json: Unmarshal(non-pointer " + e.Type.String() + ")"
}
return "json: Unmarshal(nil " + e.Type.String() + ")"
}
func (d *decodeState) unmarshal(v interface{}) (err error) {
defer func() {
if r := recover(); r != nil {
if _, ok := r.(runtime.Error); ok {
panic(r)
}
err = r.(error)
}
}()
rv := reflect.ValueOf(v)
if rv.Kind() != reflect.Ptr || rv.IsNil() {
return &InvalidUnmarshalError{reflect.TypeOf(v)}
}
d.scan.reset()
// We decode rv not rv.Elem because the Unmarshaler interface
// test must be applied at the top level of the value.
d.value(rv)
return d.savedError
}
// A Number represents a JSON number literal.
type Number string
// String returns the literal text of the number.
func (n Number) String() string { return string(n) }
// Float64 returns the number as a float64.
func (n Number) Float64() (float64, error) {
return strconv.ParseFloat(string(n), 64)
}
// Int64 returns the number as an int64.
func (n Number) Int64() (int64, error) {
return strconv.ParseInt(string(n), 10, 64)
}
// decodeState represents the state while decoding a JSON value.
type decodeState struct {
data []byte
off int // read offset in data
scan scanner
nextscan scanner // for calls to nextValue
savedError error
tempstr string // scratch space to avoid some allocations
useNumber bool
}
// errPhase is used for errors that should not happen unless
// there is a bug in the JSON decoder or something is editing
// the data slice while the decoder executes.
var errPhase = errors.New("JSON decoder out of sync - data changing underfoot?")
func (d *decodeState) init(data []byte) *decodeState {
d.data = data
d.off = 0
d.savedError = nil
return d
}
// error aborts the decoding by panicking with err.
func (d *decodeState) error(err error) {
panic(err)
}
// saveError saves the first err it is called with,
// for reporting at the end of the unmarshal.
func (d *decodeState) saveError(err error) {
if d.savedError == nil {
d.savedError = err
}
}
// next cuts off and returns the next full JSON value in d.data[d.off:].
// The next value is known to be an object or array, not a literal.
func (d *decodeState) next() []byte {
c := d.data[d.off]
item, rest, err := nextValue(d.data[d.off:], &d.nextscan)
if err != nil {
d.error(err)
}
d.off = len(d.data) - len(rest)
// Our scanner has seen the opening brace/bracket
// and thinks we're still in the middle of the object.
// invent a closing brace/bracket to get it out.
if c == '{' {
d.scan.step(&d.scan, '}')
} else {
d.scan.step(&d.scan, ']')
}
return item
}
// scanWhile processes bytes in d.data[d.off:] until it
// receives a scan code not equal to op.
// It updates d.off and returns the new scan code.
func (d *decodeState) scanWhile(op int) int {
var newOp int
for {
if d.off >= len(d.data) {
newOp = d.scan.eof()
d.off = len(d.data) + 1 // mark processed EOF with len+1
} else {
c := int(d.data[d.off])
d.off++
newOp = d.scan.step(&d.scan, c)
}
if newOp != op {
break
}
}
return newOp
}
// value decodes a JSON value from d.data[d.off:] into the value.
// it updates d.off to point past the decoded value.
func (d *decodeState) value(v reflect.Value) {
if !v.IsValid() {
_, rest, err := nextValue(d.data[d.off:], &d.nextscan)
if err != nil {
d.error(err)
}
d.off = len(d.data) - len(rest)
// d.scan thinks we're still at the beginning of the item.
// Feed in an empty string - the shortest, simplest value -
// so that it knows we got to the end of the value.
if d.scan.redo {
// rewind.
d.scan.redo = false
d.scan.step = stateBeginValue
}
d.scan.step(&d.scan, '"')
d.scan.step(&d.scan, '"')
n := len(d.scan.parseState)
if n > 0 && d.scan.parseState[n-1] == parseObjectKey {
// d.scan thinks we just read an object key; finish the object
d.scan.step(&d.scan, ':')
d.scan.step(&d.scan, '"')
d.scan.step(&d.scan, '"')
d.scan.step(&d.scan, '}')
}
return
}
switch op := d.scanWhile(scanSkipSpace); op {
default:
d.error(errPhase)
case scanBeginArray:
d.array(v)
case scanBeginObject:
d.object(v)
case scanBeginLiteral:
d.literal(v)
}
}
// indirect walks down v allocating pointers as needed,
// until it gets to a non-pointer.
// if it encounters an Unmarshaler, indirect stops and returns that.
// if decodingNull is true, indirect stops at the last pointer so it can be set to nil.
func (d *decodeState) indirect(v reflect.Value, decodingNull bool) (Unmarshaler, encoding.TextUnmarshaler, reflect.Value) {
// If v is a named type and is addressable,
// start with its address, so that if the type has pointer methods,
// we find them.
if v.Kind() != reflect.Ptr && v.Type().Name() != "" && v.CanAddr() {
v = v.Addr()
}
for {
// Load value from interface, but only if the result will be
// usefully addressable.
if v.Kind() == reflect.Interface && !v.IsNil() {
e := v.Elem()
if e.Kind() == reflect.Ptr && !e.IsNil() && (!decodingNull || e.Elem().Kind() == reflect.Ptr) {
v = e
continue
}
}
if v.Kind() != reflect.Ptr {
break
}
if v.Elem().Kind() != reflect.Ptr && decodingNull && v.CanSet() {
break
}
if v.IsNil() {
v.Set(reflect.New(v.Type().Elem()))
}
if v.Type().NumMethod() > 0 {
if u, ok := v.Interface().(Unmarshaler); ok {
return u, nil, reflect.Value{}
}
if u, ok := v.Interface().(encoding.TextUnmarshaler); ok {
return nil, u, reflect.Value{}
}
}
v = v.Elem()
}
return nil, nil, v
}
// array consumes an array from d.data[d.off-1:], decoding into the value v.
// the first byte of the array ('[') has been read already.
func (d *decodeState) array(v reflect.Value) {
// Check for unmarshaler.
u, ut, pv := d.indirect(v, false)
if u != nil {
d.off--
err := u.UnmarshalJSON(d.next())
if err != nil {
d.error(err)
}
return
}
if ut != nil {
d.saveError(&UnmarshalTypeError{"array", v.Type()})
d.off--
d.next()
return
}
v = pv
// Check type of target.
switch v.Kind() {
case reflect.Interface:
if v.NumMethod() == 0 {
// Decoding into nil interface? Switch to non-reflect code.
v.Set(reflect.ValueOf(d.arrayInterface()))
return
}
// Otherwise it's invalid.
fallthrough
default:
d.saveError(&UnmarshalTypeError{"array", v.Type()})
d.off--
d.next()
return
case reflect.Array:
case reflect.Slice:
break
}
i := 0
for {
// Look ahead for ] - can only happen on first iteration.
op := d.scanWhile(scanSkipSpace)
if op == scanEndArray {
break
}
// Back up so d.value can have the byte we just read.
d.off--
d.scan.undo(op)
// Get element of array, growing if necessary.
if v.Kind() == reflect.Slice {
// Grow slice if necessary
if i >= v.Cap() {
newcap := v.Cap() + v.Cap()/2
if newcap < 4 {
newcap = 4
}
newv := reflect.MakeSlice(v.Type(), v.Len(), newcap)
reflect.Copy(newv, v)
v.Set(newv)
}
if i >= v.Len() {
v.SetLen(i + 1)
}
}
if i < v.Len() {
// Decode into element.
d.value(v.Index(i))
} else {
// Ran out of fixed array: skip.
d.value(reflect.Value{})
}
i++
// Next token must be , or ].
op = d.scanWhile(scanSkipSpace)
if op == scanEndArray {
break
}
if op != scanArrayValue {
d.error(errPhase)
}
}
if i < v.Len() {
if v.Kind() == reflect.Array {
// Array. Zero the rest.
z := reflect.Zero(v.Type().Elem())
for ; i < v.Len(); i++ {
v.Index(i).Set(z)
}
} else {
v.SetLen(i)
}
}
if i == 0 && v.Kind() == reflect.Slice {
v.Set(reflect.MakeSlice(v.Type(), 0, 0))
}
}
// object consumes an object from d.data[d.off-1:], decoding into the value v.
// the first byte of the object ('{') has been read already.
func (d *decodeState) object(v reflect.Value) {
// Check for unmarshaler.
u, ut, pv := d.indirect(v, false)
if u != nil {
d.off--
err := u.UnmarshalJSON(d.next())
if err != nil {
d.error(err)
}
return
}
if ut != nil {
d.saveError(&UnmarshalTypeError{"object", v.Type()})
d.off--
d.next() // skip over { } in input
return
}
v = pv
// Decoding into nil interface? Switch to non-reflect code.
if v.Kind() == reflect.Interface && v.NumMethod() == 0 {
v.Set(reflect.ValueOf(d.objectInterface()))
return
}
// Check type of target: struct or map[string]T
switch v.Kind() {
case reflect.Map:
// map must have string kind
t := v.Type()
if t.Key().Kind() != reflect.String {
d.saveError(&UnmarshalTypeError{"object", v.Type()})
break
}
if v.IsNil() {
v.Set(reflect.MakeMap(t))
}
case reflect.Struct:
default:
d.saveError(&UnmarshalTypeError{"object", v.Type()})
d.off--
d.next() // skip over { } in input
return
}
var mapElem reflect.Value
for {
// Read opening " of string key or closing }.
op := d.scanWhile(scanSkipSpace)
if op == scanEndObject {
// closing } - can only happen on first iteration.
break
}
if op != scanBeginLiteral {
d.error(errPhase)
}
// Read string key.
start := d.off - 1
op = d.scanWhile(scanContinue)
item := d.data[start : d.off-1]
key, ok := unquote(item)
if !ok {
d.error(errPhase)
}
// Figure out field corresponding to key.
var subv reflect.Value
destring := false // whether the value is wrapped in a string to be decoded first
if v.Kind() == reflect.Map {
elemType := v.Type().Elem()
if !mapElem.IsValid() {
mapElem = reflect.New(elemType).Elem()
} else {
mapElem.Set(reflect.Zero(elemType))
}
subv = mapElem
} else {
var f *field
fields := cachedTypeFields(v.Type())
for i := range fields {
ff := &fields[i]
if ff.name == key {
f = ff
break
}
if f == nil && strings.EqualFold(ff.name, key) {
f = ff
}
}
if f != nil {
subv = v
destring = f.quoted
for _, i := range f.index {
if subv.Kind() == reflect.Ptr {
if subv.IsNil() {
subv.Set(reflect.New(subv.Type().Elem()))
}
subv = subv.Elem()
}
subv = subv.Field(i)
}
}
}
// Read : before value.
if op == scanSkipSpace {
op = d.scanWhile(scanSkipSpace)
}
if op != scanObjectKey {
d.error(errPhase)
}
// Read value.
if destring {
d.value(reflect.ValueOf(&d.tempstr))
d.literalStore([]byte(d.tempstr), subv, true)
} else {
d.value(subv)
}
// Write value back to map;
// if using struct, subv points into struct already.
if v.Kind() == reflect.Map {
kv := reflect.ValueOf(key).Convert(v.Type().Key())
v.SetMapIndex(kv, subv)
}
// Next token must be , or }.
op = d.scanWhile(scanSkipSpace)
if op == scanEndObject {
break
}
if op != scanObjectValue {
d.error(errPhase)
}
}
}
// literal consumes a literal from d.data[d.off-1:], decoding into the value v.
// The first byte of the literal has been read already
// (that's how the caller knows it's a literal).
func (d *decodeState) literal(v reflect.Value) {
// All bytes inside literal return scanContinue op code.
start := d.off - 1
op := d.scanWhile(scanContinue)
// Scan read one byte too far; back up.
d.off--
d.scan.undo(op)
d.literalStore(d.data[start:d.off], v, false)
}
// convertNumber converts the number literal s to a float64 or a Number
// depending on the setting of d.useNumber.
func (d *decodeState) convertNumber(s string) (interface{}, error) {
if d.useNumber {
return Number(s), nil
}
f, err := strconv.ParseFloat(s, 64)
if err != nil {
return nil, &UnmarshalTypeError{"number " + s, reflect.TypeOf(0.0)}
}
return f, nil
}
var numberType = reflect.TypeOf(Number(""))
// literalStore decodes a literal stored in item into v.
//
// fromQuoted indicates whether this literal came from unwrapping a
// string from the ",string" struct tag option. this is used only to
// produce more helpful error messages.
func (d *decodeState) literalStore(item []byte, v reflect.Value, fromQuoted bool) {
// Check for unmarshaler.
if len(item) == 0 {
//Empty string given
d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
return
}
wantptr := item[0] == 'n' // null
u, ut, pv := d.indirect(v, wantptr)
if u != nil {
err := u.UnmarshalJSON(item)
if err != nil {
d.error(err)
}
return
}
if ut != nil {
if item[0] != '"' {
if fromQuoted {
d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
} else {
d.saveError(&UnmarshalTypeError{"string", v.Type()})
}
}
s, ok := unquoteBytes(item)
if !ok {
if fromQuoted {
d.error(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
} else {
d.error(errPhase)
}
}
err := ut.UnmarshalText(s)
if err != nil {
d.error(err)
}
return
}
v = pv
switch c := item[0]; c {
case 'n': // null
switch v.Kind() {
case reflect.Interface, reflect.Ptr, reflect.Map, reflect.Slice:
v.Set(reflect.Zero(v.Type()))
// otherwise, ignore null for primitives/string
}
case 't', 'f': // true, false
value := c == 't'
switch v.Kind() {
default:
if fromQuoted {
d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
} else {
d.saveError(&UnmarshalTypeError{"bool", v.Type()})
}
case reflect.Bool:
v.SetBool(value)
case reflect.Interface:
if v.NumMethod() == 0 {
v.Set(reflect.ValueOf(value))
} else {
d.saveError(&UnmarshalTypeError{"bool", v.Type()})
}
}
case '"': // string
s, ok := unquoteBytes(item)
if !ok {
if fromQuoted {
d.error(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
} else {
d.error(errPhase)
}
}
switch v.Kind() {
default:
d.saveError(&UnmarshalTypeError{"string", v.Type()})
case reflect.Slice:
if v.Type() != byteSliceType {
d.saveError(&UnmarshalTypeError{"string", v.Type()})
break
}
b := make([]byte, base64.StdEncoding.DecodedLen(len(s)))
n, err := base64.StdEncoding.Decode(b, s)
if err != nil {
d.saveError(err)
break
}
v.Set(reflect.ValueOf(b[0:n]))
case reflect.String:
v.SetString(string(s))
case reflect.Interface:
if v.NumMethod() == 0 {
v.Set(reflect.ValueOf(string(s)))
} else {
d.saveError(&UnmarshalTypeError{"string", v.Type()})
}
}
default: // number
if c != '-' && (c < '0' || c > '9') {
if fromQuoted {
d.error(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
} else {
d.error(errPhase)
}
}
s := string(item)
switch v.Kind() {
default:
if v.Kind() == reflect.String && v.Type() == numberType {
v.SetString(s)
break
}
if fromQuoted {
d.error(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
} else {
d.error(&UnmarshalTypeError{"number", v.Type()})
}
case reflect.Interface:
n, err := d.convertNumber(s)
if err != nil {
d.saveError(err)
break
}
if v.NumMethod() != 0 {
d.saveError(&UnmarshalTypeError{"number", v.Type()})
break
}
v.Set(reflect.ValueOf(n))
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
n, err := strconv.ParseInt(s, 10, 64)
if err != nil || v.OverflowInt(n) {
d.saveError(&UnmarshalTypeError{"number " + s, v.Type()})
break
}
v.SetInt(n)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
n, err := strconv.ParseUint(s, 10, 64)
if err != nil || v.OverflowUint(n) {
d.saveError(&UnmarshalTypeError{"number " + s, v.Type()})
break
}
v.SetUint(n)
case reflect.Float32, reflect.Float64:
n, err := strconv.ParseFloat(s, v.Type().Bits())
if err != nil || v.OverflowFloat(n) {
d.saveError(&UnmarshalTypeError{"number " + s, v.Type()})
break
}
v.SetFloat(n)
}
}
}
// The xxxInterface routines build up a value to be stored
// in an empty interface. They are not strictly necessary,
// but they avoid the weight of reflection in this common case.
// valueInterface is like value but returns interface{}
func (d *decodeState) valueInterface() interface{} {
switch d.scanWhile(scanSkipSpace) {
default:
d.error(errPhase)
panic("unreachable")
case scanBeginArray:
return d.arrayInterface()
case scanBeginObject:
return d.objectInterface()
case scanBeginLiteral:
return d.literalInterface()
}
}
// arrayInterface is like array but returns []interface{}.
func (d *decodeState) arrayInterface() []interface{} {
var v = make([]interface{}, 0)
for {
// Look ahead for ] - can only happen on first iteration.
op := d.scanWhile(scanSkipSpace)
if op == scanEndArray {
break
}
// Back up so d.value can have the byte we just read.
d.off--
d.scan.undo(op)
v = append(v, d.valueInterface())
// Next token must be , or ].
op = d.scanWhile(scanSkipSpace)
if op == scanEndArray {
break
}
if op != scanArrayValue {
d.error(errPhase)
}
}
return v
}
// objectInterface is like object but returns map[string]interface{}.
func (d *decodeState) objectInterface() map[string]interface{} {
m := make(map[string]interface{})
for {
// Read opening " of string key or closing }.
op := d.scanWhile(scanSkipSpace)
if op == scanEndObject {
// closing } - can only happen on first iteration.
break
}
if op != scanBeginLiteral {
d.error(errPhase)
}
// Read string key.
start := d.off - 1
op = d.scanWhile(scanContinue)
item := d.data[start : d.off-1]
key, ok := unquote(item)
if !ok {
d.error(errPhase)
}
// Read : before value.
if op == scanSkipSpace {
op = d.scanWhile(scanSkipSpace)
}
if op != scanObjectKey {
d.error(errPhase)
}
// Read value.
m[key] = d.valueInterface()
// Next token must be , or }.
op = d.scanWhile(scanSkipSpace)
if op == scanEndObject {
break
}
if op != scanObjectValue {
d.error(errPhase)
}
}
return m
}
// literalInterface is like literal but returns an interface value.
func (d *decodeState) literalInterface() interface{} {
// All bytes inside literal return scanContinue op code.
start := d.off - 1
op := d.scanWhile(scanContinue)
// Scan read one byte too far; back up.
d.off--
d.scan.undo(op)
item := d.data[start:d.off]
switch c := item[0]; c {
case 'n': // null
return nil
case 't', 'f': // true, false
return c == 't'
case '"': // string
s, ok := unquote(item)
if !ok {
d.error(errPhase)
}
return s
default: // number
if c != '-' && (c < '0' || c > '9') {
d.error(errPhase)
}
n, err := d.convertNumber(string(item))
if err != nil {
d.saveError(err)
}
return n
}
}
// getu4 decodes \uXXXX from the beginning of s, returning the hex value,
// or it returns -1.
func getu4(s []byte) rune {
if len(s) < 6 || s[0] != '\\' || s[1] != 'u' {
return -1
}
r, err := strconv.ParseUint(string(s[2:6]), 16, 64)
if err != nil {
return -1
}
return rune(r)
}
// unquote converts a quoted JSON string literal s into an actual string t.
// The rules are different than for Go, so cannot use strconv.Unquote.
func unquote(s []byte) (t string, ok bool) {
s, ok = unquoteBytes(s)
t = string(s)
return
}
func unquoteBytes(s []byte) (t []byte, ok bool) {
if len(s) < 2 || s[0] != '"' || s[len(s)-1] != '"' {
return
}
s = s[1 : len(s)-1]
// Check for unusual characters. If there are none,
// then no unquoting is needed, so return a slice of the
// original bytes.
r := 0
for r < len(s) {
c := s[r]
if c == '\\' || c == '"' || c < ' ' {
break
}
if c < utf8.RuneSelf {
r++
continue
}
rr, size := utf8.DecodeRune(s[r:])
if rr == utf8.RuneError && size == 1 {
break
}
r += size
}
if r == len(s) {
return s, true
}
b := make([]byte, len(s)+2*utf8.UTFMax)
w := copy(b, s[0:r])
for r < len(s) {
// Out of room? Can only happen if s is full of
// malformed UTF-8 and we're replacing each
// byte with RuneError.
if w >= len(b)-2*utf8.UTFMax {
nb := make([]byte, (len(b)+utf8.UTFMax)*2)
copy(nb, b[0:w])
b = nb
}
switch c := s[r]; {
case c == '\\':
r++
if r >= len(s) {
return
}
switch s[r] {
default:
return
case '"', '\\', '/', '\'':
b[w] = s[r]
r++
w++
case 'b':
b[w] = '\b'
r++
w++
case 'f':
b[w] = '\f'
r++
w++
case 'n':
b[w] = '\n'
r++
w++
case 'r':
b[w] = '\r'
r++
w++
case 't':
b[w] = '\t'
r++
w++
case 'u':
r--
rr := getu4(s[r:])
if rr < 0 {
return
}
r += 6
if utf16.IsSurrogate(rr) {
rr1 := getu4(s[r:])
if dec := utf16.DecodeRune(rr, rr1); dec != unicode.ReplacementChar {
// A valid pair; consume.
r += 6
w += utf8.EncodeRune(b[w:], dec)
break
}
// Invalid surrogate; fall back to replacement rune.
rr = unicode.ReplacementChar
}
w += utf8.EncodeRune(b[w:], rr)
}
// Quote, control characters are invalid.
case c == '"', c < ' ':
return
// ASCII
case c < utf8.RuneSelf:
b[w] = c
r++
w++
// Coerce to well-formed UTF-8.
default:
rr, size := utf8.DecodeRune(s[r:])
r += size
w += utf8.EncodeRune(b[w:], rr)
}
}
return b[0:w], true
}
vendor/github.com/CorgiMan/json2/encode.go 0 → 100644
浏览文件 @ ee667a09
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package json implements encoding and decoding of JSON objects as defined in
// RFC 4627. The mapping between JSON objects and Go values is described
// in the documentation for the Marshal and Unmarshal functions.
//
// See "JSON and Go" for an introduction to this package:
// http://golang.org/doc/articles/json_and_go.html
package json2
import (
"bytes"
"encoding"
"encoding/base64"
"math"
"reflect"
"runtime"
"sort"
"strconv"
"strings"
"sync"
"unicode"
"unicode/utf8"
)
// Marshal returns the JSON encoding of v.
//
// Marshal traverses the value v recursively.
// If an encountered value implements the Marshaler interface
// and is not a nil pointer, Marshal calls its MarshalJSON method
// to produce JSON. The nil pointer exception is not strictly necessary
// but mimics a similar, necessary exception in the behavior of
// UnmarshalJSON.
//
// Otherwise, Marshal uses the following type-dependent default encodings:
//
// Boolean values encode as JSON booleans.
//
// Floating point, integer, and Number values encode as JSON numbers.
//
// String values encode as JSON strings. InvalidUTF8Error will be returned
// if an invalid UTF-8 sequence is encountered.
// The angle brackets "<" and ">" are escaped to "\u003c" and "\u003e"
// to keep some browsers from misinterpreting JSON output as HTML.
//
// Array and slice values encode as JSON arrays, except that
// []byte encodes as a base64-encoded string, and a nil slice
// encodes as the null JSON object.
//
// Struct values encode as JSON objects. Each exported struct field
// becomes a member of the object unless
// - the field's tag is "-", or
// - the field is empty and its tag specifies the "omitempty" option.
// The empty values are false, 0, any
// nil pointer or interface value, and any array, slice, map, or string of
// length zero. The object's default key string is the struct field name
// but can be specified in the struct field's tag value. The "json" key in
// the struct field's tag value is the key name, followed by an optional comma
// and options. Examples:
//
// // Field is ignored by this package.
// Field int `json:"-"`
//
// // Field appears in JSON as key "myName".
// Field int `json:"myName"`
//
// // Field appears in JSON as key "myName" and
// // the field is omitted from the object if its value is empty,
// // as defined above.
// Field int `json:"myName,omitempty"`
//
// // Field appears in JSON as key "Field" (the default), but
// // the field is skipped if empty.
// // Note the leading comma.
// Field int `json:",omitempty"`
//
// The "string" option signals that a field is stored as JSON inside a
// JSON-encoded string. It applies only to fields of string, floating point,
// or integer types. This extra level of encoding is sometimes used when
// communicating with JavaScript programs:
//
// Int64String int64 `json:",string"`
//
// The key name will be used if it's a non-empty string consisting of
// only Unicode letters, digits, dollar signs, percent signs, hyphens,
// underscores and slashes.
//
// Anonymous struct fields are usually marshaled as if their inner exported fields
// were fields in the outer struct, subject to the usual Go visibility rules amended
// as described in the next paragraph.
// An anonymous struct field with a name given in its JSON tag is treated as
// having that name, rather than being anonymous.
//
// The Go visibility rules for struct fields are amended for JSON when
// deciding which field to marshal or unmarshal. If there are
// multiple fields at the same level, and that level is the least
// nested (and would therefore be the nesting level selected by the
// usual Go rules), the following extra rules apply:
//
// 1) Of those fields, if any are JSON-tagged, only tagged fields are considered,
// even if there are multiple untagged fields that would otherwise conflict.
// 2) If there is exactly one field (tagged or not according to the first rule), that is selected.
// 3) Otherwise there are multiple fields, and all are ignored; no error occurs.
//
// Handling of anonymous struct fields is new in Go 1.1.
// Prior to Go 1.1, anonymous struct fields were ignored. To force ignoring of
// an anonymous struct field in both current and earlier versions, give the field
// a JSON tag of "-".
//
// Map values encode as JSON objects.
// The map's key type must be string; the object keys are used directly
// as map keys.
//
// Pointer values encode as the value pointed to.
// A nil pointer encodes as the null JSON object.
//
// Interface values encode as the value contained in the interface.
// A nil interface value encodes as the null JSON object.
//
// Channel, complex, and function values cannot be encoded in JSON.
// Attempting to encode such a value causes Marshal to return
// an UnsupportedTypeError.
//
// JSON cannot represent cyclic data structures and Marshal does not
// handle them. Passing cyclic structures to Marshal will result in
// an infinite recursion.
//
func Marshal(v interface{}) ([]byte, error) {
e := &encodeState{}
err := e.marshal(v)
if err != nil {
return nil, err
}
return e.Bytes(), nil
}
// MarshalIndent is like Marshal but applies Indent to format the output.
func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error) {
b, err := Marshal(v)
if err != nil {
return nil, err
}
var buf bytes.Buffer
err = Indent(&buf, b, prefix, indent)
if err != nil {
return nil, err
}
return buf.Bytes(), nil
}
// HTMLEscape appends to dst the JSON-encoded src with <, >, &, U+2028 and U+2029
// characters inside string literals changed to \u003c, \u003e, \u0026, \u2028, \u2029
// so that the JSON will be safe to embed inside HTML <script> tags.
// For historical reasons, web browsers don't honor standard HTML
// escaping within <script> tags, so an alternative JSON encoding must
// be used.
func HTMLEscape(dst *bytes.Buffer, src []byte) {
// The characters can only appear in string literals,
// so just scan the string one byte at a time.
start := 0
for i, c := range src {
if c == '<' || c == '>' || c == '&' {
if start < i {
dst.Write(src[start:i])
}
dst.WriteString(`\u00`)
dst.WriteByte(hex[c>>4])
dst.WriteByte(hex[c&0xF])
start = i + 1
}
// Convert U+2028 and U+2029 (E2 80 A8 and E2 80 A9).
if c == 0xE2 && i+2 < len(src) && src[i+1] == 0x80 && src[i+2]&^1 == 0xA8 {
if start < i {
dst.Write(src[start:i])
}
dst.WriteString(`\u202`)
dst.WriteByte(hex[src[i+2]&0xF])
start = i + 3
}
}
if start < len(src) {
dst.Write(src[start:])
}
}
// Marshaler is the interface implemented by objects that
// can marshal themselves into valid JSON.
type Marshaler interface {
MarshalJSON() ([]byte, error)
}
// An UnsupportedTypeError is returned by Marshal when attempting
// to encode an unsupported value type.
type UnsupportedTypeError struct {
Type reflect.Type
}
func (e *UnsupportedTypeError) Error() string {
return "json: unsupported type: " + e.Type.String()
}
type UnsupportedValueError struct {
Value reflect.Value
Str string
}
func (e *UnsupportedValueError) Error() string {
return "json: unsupported value: " + e.Str
}
// Before Go 1.2, an InvalidUTF8Error was returned by Marshal when
// attempting to encode a string value with invalid UTF-8 sequences.
// As of Go 1.2, Marshal instead coerces the string to valid UTF-8 by
// replacing invalid bytes with the Unicode replacement rune U+FFFD.
// This error is no longer generated but is kept for backwards compatibility
// with programs that might mention it.
type InvalidUTF8Error struct {
S string // the whole string value that caused the error
}
func (e *InvalidUTF8Error) Error() string {
return "json: invalid UTF-8 in string: " + strconv.Quote(e.S)
}
type MarshalerError struct {
Type reflect.Type
Err error
}
func (e *MarshalerError) Error() string {
return "json: error calling MarshalJSON for type " + e.Type.String() + ": " + e.Err.Error()
}
var hex = "0123456789abcdef"
// An encodeState encodes JSON into a bytes.Buffer.
type encodeState struct {
bytes.Buffer // accumulated output
scratch [64]byte
}
// TODO(bradfitz): use a sync.Cache here
var encodeStatePool = make(chan *encodeState, 8)
func newEncodeState() *encodeState {
select {
case e := <-encodeStatePool:
e.Reset()
return e
default:
return new(encodeState)
}
}
func putEncodeState(e *encodeState) {
select {
case encodeStatePool <- e:
default:
}
}
func (e *encodeState) marshal(v interface{}) (err error) {
defer func() {
if r := recover(); r != nil {
if _, ok := r.(runtime.Error); ok {
panic(r)
}
if s, ok := r.(string); ok {
panic(s)
}
err = r.(error)
}
}()
e.reflectValue(reflect.ValueOf(v))
return nil
}
func (e *encodeState) error(err error) {
panic(err)
}
var byteSliceType = reflect.TypeOf([]byte(nil))
func isEmptyValue(v reflect.Value) bool {
switch v.Kind() {
case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
return v.Len() == 0
case reflect.Bool:
return !v.Bool()
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return v.Int() == 0
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return v.Uint() == 0
case reflect.Float32, reflect.Float64:
return v.Float() == 0
case reflect.Interface, reflect.Ptr:
return v.IsNil()
}
return false
}
func (e *encodeState) reflectValue(v reflect.Value) {
valueEncoder(v)(e, v, false)
}
type encoderFunc func(e *encodeState, v reflect.Value, quoted bool)
var encoderCache struct {
sync.RWMutex
m map[reflect.Type]encoderFunc
}
func valueEncoder(v reflect.Value) encoderFunc {
if !v.IsValid() {
return invalidValueEncoder
}
return typeEncoder(v.Type())
}
func typeEncoder(t reflect.Type) encoderFunc {
encoderCache.RLock()
f := encoderCache.m[t]
encoderCache.RUnlock()
if f != nil {
return f
}
// To deal with recursive types, populate the map with an
// indirect func before we build it. This type waits on the
// real func (f) to be ready and then calls it. This indirect
// func is only used for recursive types.
encoderCache.Lock()
if encoderCache.m == nil {
encoderCache.m = make(map[reflect.Type]encoderFunc)
}
var wg sync.WaitGroup
wg.Add(1)
encoderCache.m[t] = func(e *encodeState, v reflect.Value, quoted bool) {
wg.Wait()
f(e, v, quoted)
}
encoderCache.Unlock()
// Compute fields without lock.
// Might duplicate effort but won't hold other computations back.
f = newTypeEncoder(t, true)
wg.Done()
encoderCache.Lock()
encoderCache.m[t] = f
encoderCache.Unlock()
return f
}
var (
marshalerType = reflect.TypeOf(new(Marshaler)).Elem()
textMarshalerType = reflect.TypeOf(new(encoding.TextMarshaler)).Elem()
)
// newTypeEncoder constructs an encoderFunc for a type.
// The returned encoder only checks CanAddr when allowAddr is true.
func newTypeEncoder(t reflect.Type, allowAddr bool) encoderFunc {
if t.Implements(marshalerType) {
return marshalerEncoder
}
if t.Kind() != reflect.Ptr && allowAddr {
if reflect.PtrTo(t).Implements(marshalerType) {
return newCondAddrEncoder(addrMarshalerEncoder, newTypeEncoder(t, false))
}
}
if t.Implements(textMarshalerType) {
return textMarshalerEncoder
}
if t.Kind() != reflect.Ptr && allowAddr {
if reflect.PtrTo(t).Implements(textMarshalerType) {
return newCondAddrEncoder(addrTextMarshalerEncoder, newTypeEncoder(t, false))
}
}
switch t.Kind() {
case reflect.Bool:
return boolEncoder
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return intEncoder
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return uintEncoder
case reflect.Float32:
return float32Encoder
case reflect.Float64:
return float64Encoder
case reflect.String:
return stringEncoder
case reflect.Interface:
return interfaceEncoder
case reflect.Struct:
return newStructEncoder(t)
case reflect.Map:
return newMapEncoder(t)
case reflect.Slice:
return newSliceEncoder(t)
case reflect.Array:
return newArrayEncoder(t)
case reflect.Ptr:
return newPtrEncoder(t)
default:
return unsupportedTypeEncoder
}
}
func invalidValueEncoder(e *encodeState, v reflect.Value, quoted bool) {
e.WriteString("null")
}
func marshalerEncoder(e *encodeState, v reflect.Value, quoted bool) {
if v.Kind() == reflect.Ptr && v.IsNil() {
e.WriteString("null")
return
}
m := v.Interface().(Marshaler)
b, err := m.MarshalJSON()
if err == nil {
// copy JSON into buffer, checking validity.
err = compact(&e.Buffer, b, true)
}
if err != nil {
e.error(&MarshalerError{v.Type(), err})
}
}
func addrMarshalerEncoder(e *encodeState, v reflect.Value, quoted bool) {
va := v.Addr()
if va.IsNil() {
e.WriteString("null")
return
}
m := va.Interface().(Marshaler)
b, err := m.MarshalJSON()
if err == nil {
// copy JSON into buffer, checking validity.
err = compact(&e.Buffer, b, true)
}
if err != nil {
e.error(&MarshalerError{v.Type(), err})
}
}
func textMarshalerEncoder(e *encodeState, v reflect.Value, quoted bool) {
if v.Kind() == reflect.Ptr && v.IsNil() {
e.WriteString("null")
return
}
m := v.Interface().(encoding.TextMarshaler)
b, err := m.MarshalText()
if err == nil {
_, err = e.stringBytes(b)
}
if err != nil {
e.error(&MarshalerError{v.Type(), err})
}
}
func addrTextMarshalerEncoder(e *encodeState, v reflect.Value, quoted bool) {
va := v.Addr()
if va.IsNil() {
e.WriteString("null")
return
}
m := va.Interface().(encoding.TextMarshaler)
b, err := m.MarshalText()
if err == nil {
_, err = e.stringBytes(b)
}
if err != nil {
e.error(&MarshalerError{v.Type(), err})
}
}
func boolEncoder(e *encodeState, v reflect.Value, quoted bool) {
if quoted {
e.WriteByte('"')
}
if v.Bool() {
e.WriteString("true")
} else {
e.WriteString("false")
}
if quoted {
e.WriteByte('"')
}
}
func intEncoder(e *encodeState, v reflect.Value, quoted bool) {
b := strconv.AppendInt(e.scratch[:0], v.Int(), 10)
if quoted {
e.WriteByte('"')
}
e.Write(b)
if quoted {
e.WriteByte('"')
}
}
func uintEncoder(e *encodeState, v reflect.Value, quoted bool) {
b := strconv.AppendUint(e.scratch[:0], v.Uint(), 10)
if quoted {
e.WriteByte('"')
}
e.Write(b)
if quoted {
e.WriteByte('"')
}
}
type floatEncoder int // number of bits
func (bits floatEncoder) encode(e *encodeState, v reflect.Value, quoted bool) {
f := v.Float()
if math.IsInf(f, 0) || math.IsNaN(f) {
e.error(&UnsupportedValueError{v, strconv.FormatFloat(f, 'g', -1, int(bits))})
}
b := strconv.AppendFloat(e.scratch[:0], f, 'g', -1, int(bits))
if quoted {
e.WriteByte('"')
}
e.Write(b)
if quoted {
e.WriteByte('"')
}
}
var (
float32Encoder = (floatEncoder(32)).encode
float64Encoder = (floatEncoder(64)).encode
)
func stringEncoder(e *encodeState, v reflect.Value, quoted bool) {
if v.Type() == numberType {
numStr := v.String()
if numStr == "" {
numStr = "0" // Number's zero-val
}
e.WriteString(numStr)
return
}
if quoted {
sb, err := Marshal(v.String())
if err != nil {
e.error(err)
}
e.string(string(sb))
} else {
e.string(v.String())
}
}
func interfaceEncoder(e *encodeState, v reflect.Value, quoted bool) {
if v.IsNil() {
e.WriteString("null")
return
}
e.reflectValue(v.Elem())
}
func unsupportedTypeEncoder(e *encodeState, v reflect.Value, quoted bool) {
e.error(&UnsupportedTypeError{v.Type()})
}
type structEncoder struct {
fields []field
fieldEncs []encoderFunc
}
func (se *structEncoder) encode(e *encodeState, v reflect.Value, quoted bool) {
e.WriteByte('{')
first := true
for i, f := range se.fields {
fv := fieldByIndex(v, f.index)
if !fv.IsValid() || f.omitEmpty && isEmptyValue(fv) {
continue
}
if first {
first = false
} else {
e.WriteByte(',')
}
e.string(f.name)
e.WriteByte(':')
se.fieldEncs[i](e, fv, f.quoted)
}
e.WriteByte('}')
}
func newStructEncoder(t reflect.Type) encoderFunc {
fields := cachedTypeFields(t)
se := &structEncoder{
fields: fields,
fieldEncs: make([]encoderFunc, len(fields)),
}
for i, f := range fields {
se.fieldEncs[i] = typeEncoder(typeByIndex(t, f.index))
}
return se.encode
}
type mapEncoder struct {
elemEnc encoderFunc
}
func (me *mapEncoder) encode(e *encodeState, v reflect.Value, _ bool) {
if v.IsNil() {
e.WriteString("null")
return
}
e.WriteByte('{')
var sv stringValues = v.MapKeys()
sort.Sort(sv)
for i, k := range sv {
if i > 0 {
e.WriteByte(',')
}
e.string(k.String())
e.WriteByte(':')
me.elemEnc(e, v.MapIndex(k), false)
}
e.WriteByte('}')
}
func newMapEncoder(t reflect.Type) encoderFunc {
if t.Key().Kind() != reflect.String {
return unsupportedTypeEncoder
}
me := &mapEncoder{typeEncoder(t.Elem())}
return me.encode
}
func encodeByteSlice(e *encodeState, v reflect.Value, _ bool) {
if v.IsNil() {
e.WriteString("null")
return
}
s := v.Bytes()
e.WriteByte('"')
if len(s) < 1024 {
// for small buffers, using Encode directly is much faster.
dst := make([]byte, base64.StdEncoding.EncodedLen(len(s)))
base64.StdEncoding.Encode(dst, s)
e.Write(dst)
} else {
// for large buffers, avoid unnecessary extra temporary
// buffer space.
enc := base64.NewEncoder(base64.StdEncoding, e)
enc.Write(s)
enc.Close()
}
e.WriteByte('"')
}
// sliceEncoder just wraps an arrayEncoder, checking to make sure the value isn't nil.
type sliceEncoder struct {
arrayEnc encoderFunc
}
func (se *sliceEncoder) encode(e *encodeState, v reflect.Value, _ bool) {
if v.IsNil() {
e.WriteString("null")
return
}
se.arrayEnc(e, v, false)
}
func newSliceEncoder(t reflect.Type) encoderFunc {
// Byte slices get special treatment; arrays don't.
if t.Elem().Kind() == reflect.Uint8 {
return encodeByteSlice
}
enc := &sliceEncoder{newArrayEncoder(t)}
return enc.encode
}
type arrayEncoder struct {
elemEnc encoderFunc
}
func (ae *arrayEncoder) encode(e *encodeState, v reflect.Value, _ bool) {
e.WriteByte('[')
n := v.Len()
for i := 0; i < n; i++ {
if i > 0 {
e.WriteByte(',')
}
ae.elemEnc(e, v.Index(i), false)
}
e.WriteByte(']')
}
func newArrayEncoder(t reflect.Type) encoderFunc {
enc := &arrayEncoder{typeEncoder(t.Elem())}
return enc.encode
}
type ptrEncoder struct {
elemEnc encoderFunc
}
func (pe *ptrEncoder) encode(e *encodeState, v reflect.Value, _ bool) {
if v.IsNil() {
e.WriteString("null")
return
}
pe.elemEnc(e, v.Elem(), false)
}
func newPtrEncoder(t reflect.Type) encoderFunc {
enc := &ptrEncoder{typeEncoder(t.Elem())}
return enc.encode
}
type condAddrEncoder struct {
canAddrEnc, elseEnc encoderFunc
}
func (ce *condAddrEncoder) encode(e *encodeState, v reflect.Value, quoted bool) {
if v.CanAddr() {
ce.canAddrEnc(e, v, quoted)
} else {
ce.elseEnc(e, v, quoted)
}
}
// newCondAddrEncoder returns an encoder that checks whether its value
// CanAddr and delegates to canAddrEnc if so, else to elseEnc.
func newCondAddrEncoder(canAddrEnc, elseEnc encoderFunc) encoderFunc {
enc := &condAddrEncoder{canAddrEnc: canAddrEnc, elseEnc: elseEnc}
return enc.encode
}
func isValidTag(s string) bool {
if s == "" {
return false
}
for _, c := range s {
switch {
case strings.ContainsRune("!#$%&()*+-./:<=>?@[]^_{|}~ ", c):
// Backslash and quote chars are reserved, but
// otherwise any punctuation chars are allowed
// in a tag name.
default:
if !unicode.IsLetter(c) && !unicode.IsDigit(c) {
return false
}
}
}
return true
}
func fieldByIndex(v reflect.Value, index []int) reflect.Value {
for _, i := range index {
if v.Kind() == reflect.Ptr {
if v.IsNil() {
return reflect.Value{}
}
v = v.Elem()
}
v = v.Field(i)
}
return v
}
func typeByIndex(t reflect.Type, index []int) reflect.Type {
for _, i := range index {
if t.Kind() == reflect.Ptr {
t = t.Elem()
}
t = t.Field(i).Type
}
return t
}
// stringValues is a slice of reflect.Value holding *reflect.StringValue.
// It implements the methods to sort by string.
type stringValues []reflect.Value
func (sv stringValues) Len() int { return len(sv) }
func (sv stringValues) Swap(i, j int) { sv[i], sv[j] = sv[j], sv[i] }
func (sv stringValues) Less(i, j int) bool { return sv.get(i) < sv.get(j) }
func (sv stringValues) get(i int) string { return sv[i].String() }
// NOTE: keep in sync with stringBytes below.
func (e *encodeState) string(s string) (int, error) {
len0 := e.Len()
e.WriteByte('"')
start := 0
for i := 0; i < len(s); {
if b := s[i]; b < utf8.RuneSelf {
if 0x20 <= b && b != '\\' && b != '"' && b != '<' && b != '>' && b != '&' {
i++
continue
}
if start < i {
e.WriteString(s[start:i])
}
switch b {
case '\\', '"':
e.WriteByte('\\')
e.WriteByte(b)
case '\n':
e.WriteByte('\\')
e.WriteByte('n')
case '\r':
e.WriteByte('\\')
e.WriteByte('r')
default:
// This encodes bytes < 0x20 except for \n and \r,
// as well as < and >. The latter are escaped because they
// can lead to security holes when user-controlled strings
// are rendered into JSON and served to some browsers.
e.WriteString(`\u00`)
e.WriteByte(hex[b>>4])
e.WriteByte(hex[b&0xF])
}
i++
start = i
continue
}
c, size := utf8.DecodeRuneInString(s[i:])
if c == utf8.RuneError && size == 1 {
if start < i {
e.WriteString(s[start:i])
}
e.WriteString(`\ufffd`)
i += size
start = i
continue
}
// U+2028 is LINE SEPARATOR.
// U+2029 is PARAGRAPH SEPARATOR.
// They are both technically valid characters in JSON strings,
// but don't work in JSONP, which has to be evaluated as JavaScript,
// and can lead to security holes there. It is valid JSON to
// escape them, so we do so unconditionally.
// See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
if c == '\u2028' || c == '\u2029' {
if start < i {
e.WriteString(s[start:i])
}
e.WriteString(`\u202`)
e.WriteByte(hex[c&0xF])
i += size
start = i
continue
}
i += size
}
if start < len(s) {
e.WriteString(s[start:])
}
e.WriteByte('"')
return e.Len() - len0, nil
}
// NOTE: keep in sync with string above.
func (e *encodeState) stringBytes(s []byte) (int, error) {
len0 := e.Len()
e.WriteByte('"')
start := 0
for i := 0; i < len(s); {
if b := s[i]; b < utf8.RuneSelf {
if 0x20 <= b && b != '\\' && b != '"' && b != '<' && b != '>' && b != '&' {
i++
continue
}
if start < i {
e.Write(s[start:i])
}
switch b {
case '\\', '"':
e.WriteByte('\\')
e.WriteByte(b)
case '\n':
e.WriteByte('\\')
e.WriteByte('n')
case '\r':
e.WriteByte('\\')
e.WriteByte('r')
default:
// This encodes bytes < 0x20 except for \n and \r,
// as well as < and >. The latter are escaped because they
// can lead to security holes when user-controlled strings
// are rendered into JSON and served to some browsers.
e.WriteString(`\u00`)
e.WriteByte(hex[b>>4])
e.WriteByte(hex[b&0xF])
}
i++
start = i
continue
}
c, size := utf8.DecodeRune(s[i:])
if c == utf8.RuneError && size == 1 {
if start < i {
e.Write(s[start:i])
}
e.WriteString(`\ufffd`)
i += size
start = i
continue
}
// U+2028 is LINE SEPARATOR.
// U+2029 is PARAGRAPH SEPARATOR.
// They are both technically valid characters in JSON strings,
// but don't work in JSONP, which has to be evaluated as JavaScript,
// and can lead to security holes there. It is valid JSON to
// escape them, so we do so unconditionally.
// See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
if c == '\u2028' || c == '\u2029' {
if start < i {
e.Write(s[start:i])
}
e.WriteString(`\u202`)
e.WriteByte(hex[c&0xF])
i += size
start = i
continue
}
i += size
}
if start < len(s) {
e.Write(s[start:])
}
e.WriteByte('"')
return e.Len() - len0, nil
}
// A field represents a single field found in a struct.
type field struct {
name string
tag bool
index []int
typ reflect.Type
omitEmpty bool
quoted bool
}
// byName sorts field by name, breaking ties with depth,
// then breaking ties with "name came from json tag", then
// breaking ties with index sequence.
type byName []field
func (x byName) Len() int { return len(x) }
func (x byName) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x byName) Less(i, j int) bool {
if x[i].name != x[j].name {
return x[i].name < x[j].name
}
if len(x[i].index) != len(x[j].index) {
return len(x[i].index) < len(x[j].index)
}
if x[i].tag != x[j].tag {
return x[i].tag
}
return byIndex(x).Less(i, j)
}
// byIndex sorts field by index sequence.
type byIndex []field
func (x byIndex) Len() int { return len(x) }
func (x byIndex) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x byIndex) Less(i, j int) bool {
for k, xik := range x[i].index {
if k >= len(x[j].index) {
return false
}
if xik != x[j].index[k] {
return xik < x[j].index[k]
}
}
return len(x[i].index) < len(x[j].index)
}
// typeFields returns a list of fields that JSON should recognize for the given type.
// The algorithm is breadth-first search over the set of structs to include - the top struct
// and then any reachable anonymous structs.
func typeFields(t reflect.Type) []field {
// Anonymous fields to explore at the current level and the next.
current := []field{}
next := []field{{typ: t}}
// Count of queued names for current level and the next.
count := map[reflect.Type]int{}
nextCount := map[reflect.Type]int{}
// Types already visited at an earlier level.
visited := map[reflect.Type]bool{}
// Fields found.
var fields []field
for len(next) > 0 {
current, next = next, current[:0]
count, nextCount = nextCount, map[reflect.Type]int{}
for _, f := range current {
if visited[f.typ] {
continue
}
visited[f.typ] = true
// Scan f.typ for fields to include.
for i := 0; i < f.typ.NumField(); i++ {
sf := f.typ.Field(i)
// if sf.PkgPath != "" { // unexported
// continue
// }
tag := sf.Tag.Get("json")
if tag == "-" {
continue
}
name, opts := parseTag(tag)
if !isValidTag(name) {
name = ""
}
index := make([]int, len(f.index)+1)
copy(index, f.index)
index[len(f.index)] = i
ft := sf.Type
if ft.Name() == "" && ft.Kind() == reflect.Ptr {
// Follow pointer.
ft = ft.Elem()
}
// Record found field and index sequence.
if name != "" || !sf.Anonymous || ft.Kind() != reflect.Struct {
tagged := name != ""
if name == "" {
name = sf.Name
}
fields = append(fields, field{name, tagged, index, ft,
opts.Contains("omitempty"), opts.Contains("string")})
if count[f.typ] > 1 {
// If there were multiple instances, add a second,
// so that the annihilation code will see a duplicate.
// It only cares about the distinction between 1 or 2,
// so don't bother generating any more copies.
fields = append(fields, fields[len(fields)-1])
}
continue
}
// Record new anonymous struct to explore in next round.
nextCount[ft]++
if nextCount[ft] == 1 {
next = append(next, field{name: ft.Name(), index: index, typ: ft})
}
}
}
}
sort.Sort(byName(fields))
// Delete all fields that are hidden by the Go rules for embedded fields,
// except that fields with JSON tags are promoted.
// The fields are sorted in primary order of name, secondary order
// of field index length. Loop over names; for each name, delete
// hidden fields by choosing the one dominant field that survives.
out := fields[:0]
for advance, i := 0, 0; i < len(fields); i += advance {
// One iteration per name.
// Find the sequence of fields with the name of this first field.
fi := fields[i]
name := fi.name
for advance = 1; i+advance < len(fields); advance++ {
fj := fields[i+advance]
if fj.name != name {
break
}
}
if advance == 1 { // Only one field with this name
out = append(out, fi)
continue
}
dominant, ok := dominantField(fields[i : i+advance])
if ok {
out = append(out, dominant)
}
}
fields = out
sort.Sort(byIndex(fields))
return fields
}
// dominantField looks through the fields, all of which are known to
// have the same name, to find the single field that dominates the
// others using Go's embedding rules, modified by the presence of
// JSON tags. If there are multiple top-level fields, the boolean
// will be false: This condition is an error in Go and we skip all
// the fields.
func dominantField(fields []field) (field, bool) {
// The fields are sorted in increasing index-length order. The winner
// must therefore be one with the shortest index length. Drop all
// longer entries, which is easy: just truncate the slice.
length := len(fields[0].index)
tagged := -1 // Index of first tagged field.
for i, f := range fields {
if len(f.index) > length {
fields = fields[:i]
break
}
if f.tag {
if tagged >= 0 {
// Multiple tagged fields at the same level: conflict.
// Return no field.
return field{}, false
}
tagged = i
}
}
if tagged >= 0 {
return fields[tagged], true
}
// All remaining fields have the same length. If there's more than one,
// we have a conflict (two fields named "X" at the same level) and we
// return no field.
if len(fields) > 1 {
return field{}, false
}
return fields[0], true
}
var fieldCache struct {
sync.RWMutex
m map[reflect.Type][]field
}
// cachedTypeFields is like typeFields but uses a cache to avoid repeated work.
func cachedTypeFields(t reflect.Type) []field {
fieldCache.RLock()
f := fieldCache.m[t]
fieldCache.RUnlock()
if f != nil {
return f
}
// Compute fields without lock.
// Might duplicate effort but won't hold other computations back.
f = typeFields(t)
if f == nil {
f = []field{}
}
fieldCache.Lock()
if fieldCache.m == nil {
fieldCache.m = map[reflect.Type][]field{}
}
fieldCache.m[t] = f
fieldCache.Unlock()
return f
}
vendor/github.com/CorgiMan/json2/indent.go 0 → 100644
浏览文件 @ ee667a09
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package json2
import "bytes"
// Compact appends to dst the JSON-encoded src with
// insignificant space characters elided.
func Compact(dst *bytes.Buffer, src []byte) error {
return compact(dst, src, false)
}
func compact(dst *bytes.Buffer, src []byte, escape bool) error {
origLen := dst.Len()
var scan scanner
scan.reset()
start := 0
for i, c := range src {
if escape && (c == '<' || c == '>' || c == '&') {
if start < i {
dst.Write(src[start:i])
}
dst.WriteString(`\u00`)
dst.WriteByte(hex[c>>4])
dst.WriteByte(hex[c&0xF])
start = i + 1
}
// Convert U+2028 and U+2029 (E2 80 A8 and E2 80 A9).
if c == 0xE2 && i+2 < len(src) && src[i+1] == 0x80 && src[i+2]&^1 == 0xA8 {
if start < i {
dst.Write(src[start:i])
}
dst.WriteString(`\u202`)
dst.WriteByte(hex[src[i+2]&0xF])
start = i + 3
}
v := scan.step(&scan, int(c))
if v >= scanSkipSpace {
if v == scanError {
break
}
if start < i {
dst.Write(src[start:i])
}
start = i + 1
}
}
if scan.eof() == scanError {
dst.Truncate(origLen)
return scan.err
}
if start < len(src) {
dst.Write(src[start:])
}
return nil
}
func newline(dst *bytes.Buffer, prefix, indent string, depth int) {
dst.WriteByte('\n')
dst.WriteString(prefix)
for i := 0; i < depth; i++ {
dst.WriteString(indent)
}
}
// Indent appends to dst an indented form of the JSON-encoded src.
// Each element in a JSON object or array begins on a new,
// indented line beginning with prefix followed by one or more
// copies of indent according to the indentation nesting.
// The data appended to dst has no trailing newline, to make it easier
// to embed inside other formatted JSON data.
func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error {
origLen := dst.Len()
var scan scanner
scan.reset()
needIndent := false
depth := 0
for _, c := range src {
scan.bytes++
v := scan.step(&scan, int(c))
if v == scanSkipSpace {
continue
}
if v == scanError {
break
}
if needIndent && v != scanEndObject && v != scanEndArray {
needIndent = false
depth++
newline(dst, prefix, indent, depth)
}
// Emit semantically uninteresting bytes
// (in particular, punctuation in strings) unmodified.
if v == scanContinue {
dst.WriteByte(c)
continue
}
// Add spacing around real punctuation.
switch c {
case '{', '[':
// delay indent so that empty object and array are formatted as {} and [].
needIndent = true
dst.WriteByte(c)
case ',':
dst.WriteByte(c)
newline(dst, prefix, indent, depth)
case ':':
dst.WriteByte(c)
dst.WriteByte(' ')
case '}', ']':
if needIndent {
// suppress indent in empty object/array
needIndent = false
} else {
depth--
newline(dst, prefix, indent, depth)
}
dst.WriteByte(c)
default:
dst.WriteByte(c)
}
}
if scan.eof() == scanError {
dst.Truncate(origLen)
return scan.err
}
return nil
}
vendor/github.com/CorgiMan/json2/scanner.go 0 → 100644
浏览文件 @ ee667a09
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package json2
// JSON value parser state machine.
// Just about at the limit of what is reasonable to write by hand.
// Some parts are a bit tedious, but overall it nicely factors out the
// otherwise common code from the multiple scanning functions
// in this package (Compact, Indent, checkValid, nextValue, etc).
//
// This file starts with two simple examples using the scanner
// before diving into the scanner itself.
import "strconv"
// checkValid verifies that data is valid JSON-encoded data.
// scan is passed in for use by checkValid to avoid an allocation.
func checkValid(data []byte, scan *scanner) error {
scan.reset()
for _, c := range data {
scan.bytes++
if scan.step(scan, int(c)) == scanError {
return scan.err
}
}
if scan.eof() == scanError {
return scan.err
}
return nil
}
// nextValue splits data after the next whole JSON value,
// returning that value and the bytes that follow it as separate slices.
// scan is passed in for use by nextValue to avoid an allocation.
func nextValue(data []byte, scan *scanner) (value, rest []byte, err error) {
scan.reset()
for i, c := range data {
v := scan.step(scan, int(c))
if v >= scanEnd {
switch v {
case scanError:
return nil, nil, scan.err
case scanEnd:
return data[0:i], data[i:], nil
}
}
}
if scan.eof() == scanError {
return nil, nil, scan.err
}
return data, nil, nil
}
// A SyntaxError is a description of a JSON syntax error.
type SyntaxError struct {
msg string // description of error
Offset int64 // error occurred after reading Offset bytes
}
func (e *SyntaxError) Error() string { return e.msg }
// A scanner is a JSON scanning state machine.
// Callers call scan.reset() and then pass bytes in one at a time
// by calling scan.step(&scan, c) for each byte.
// The return value, referred to as an opcode, tells the
// caller about significant parsing events like beginning
// and ending literals, objects, and arrays, so that the
// caller can follow along if it wishes.
// The return value scanEnd indicates that a single top-level
// JSON value has been completed, *before* the byte that
// just got passed in. (The indication must be delayed in order
// to recognize the end of numbers: is 123 a whole value or
// the beginning of 12345e+6?).
type scanner struct {
// The step is a func to be called to execute the next transition.
// Also tried using an integer constant and a single func
// with a switch, but using the func directly was 10% faster
// on a 64-bit Mac Mini, and it's nicer to read.
step func(*scanner, int) int
// Reached end of top-level value.
endTop bool
// Stack of what we're in the middle of - array values, object keys, object values.
parseState []int
// Error that happened, if any.
err error
// 1-byte redo (see undo method)
redo bool
redoCode int
redoState func(*scanner, int) int
// total bytes consumed, updated by decoder.Decode
bytes int64
}
// These values are returned by the state transition functions
// assigned to scanner.state and the method scanner.eof.
// They give details about the current state of the scan that
// callers might be interested to know about.
// It is okay to ignore the return value of any particular
// call to scanner.state: if one call returns scanError,
// every subsequent call will return scanError too.
const (
// Continue.
scanContinue = iota // uninteresting byte
scanBeginLiteral // end implied by next result != scanContinue
scanBeginObject // begin object
scanObjectKey // just finished object key (string)
scanObjectValue // just finished non-last object value
scanEndObject // end object (implies scanObjectValue if possible)
scanBeginArray // begin array
scanArrayValue // just finished array value
scanEndArray // end array (implies scanArrayValue if possible)
scanSkipSpace // space byte; can skip; known to be last "continue" result
// Stop.
scanEnd // top-level value ended *before* this byte; known to be first "stop" result
scanError // hit an error, scanner.err.
)
// These values are stored in the parseState stack.
// They give the current state of a composite value
// being scanned. If the parser is inside a nested value
// the parseState describes the nested state, outermost at entry 0.
const (
parseObjectKey = iota // parsing object key (before colon)
parseObjectValue // parsing object value (after colon)
parseArrayValue // parsing array value
)
// reset prepares the scanner for use.
// It must be called before calling s.step.
func (s *scanner) reset() {
s.step = stateBeginValue
s.parseState = s.parseState[0:0]
s.err = nil
s.redo = false
s.endTop = false
}
// eof tells the scanner that the end of input has been reached.
// It returns a scan status just as s.step does.
func (s *scanner) eof() int {
if s.err != nil {
return scanError
}
if s.endTop {
return scanEnd
}
s.step(s, ' ')
if s.endTop {
return scanEnd
}
if s.err == nil {
s.err = &SyntaxError{"unexpected end of JSON input", s.bytes}
}
return scanError
}
// pushParseState pushes a new parse state p onto the parse stack.
func (s *scanner) pushParseState(p int) {
s.parseState = append(s.parseState, p)
}
// popParseState pops a parse state (already obtained) off the stack
// and updates s.step accordingly.
func (s *scanner) popParseState() {
n := len(s.parseState) - 1
s.parseState = s.parseState[0:n]
s.redo = false
if n == 0 {
s.step = stateEndTop
s.endTop = true
} else {
s.step = stateEndValue
}
}
func isSpace(c rune) bool {
return c == ' ' || c == '\t' || c == '\r' || c == '\n'
}
// stateBeginValueOrEmpty is the state after reading `[`.
func stateBeginValueOrEmpty(s *scanner, c int) int {
if c <= ' ' && isSpace(rune(c)) {
return scanSkipSpace
}
if c == ']' {
return stateEndValue(s, c)
}
return stateBeginValue(s, c)
}
// stateBeginValue is the state at the beginning of the input.
func stateBeginValue(s *scanner, c int) int {
if c <= ' ' && isSpace(rune(c)) {
return scanSkipSpace
}
switch c {
case '{':
s.step = stateBeginStringOrEmpty
s.pushParseState(parseObjectKey)
return scanBeginObject
case '[':
s.step = stateBeginValueOrEmpty
s.pushParseState(parseArrayValue)
return scanBeginArray
case '"':
s.step = stateInString
return scanBeginLiteral
case '-':
s.step = stateNeg
return scanBeginLiteral
case '0': // beginning of 0.123
s.step = state0
return scanBeginLiteral
case 't': // beginning of true
s.step = stateT
return scanBeginLiteral
case 'f': // beginning of false
s.step = stateF
return scanBeginLiteral
case 'n': // beginning of null
s.step = stateN
return scanBeginLiteral
}
if '1' <= c && c <= '9' { // beginning of 1234.5
s.step = state1
return scanBeginLiteral
}
return s.error(c, "looking for beginning of value")
}
// stateBeginStringOrEmpty is the state after reading `{`.
func stateBeginStringOrEmpty(s *scanner, c int) int {
if c <= ' ' && isSpace(rune(c)) {
return scanSkipSpace
}
if c == '}' {
n := len(s.parseState)
s.parseState[n-1] = parseObjectValue
return stateEndValue(s, c)
}
return stateBeginString(s, c)
}
// stateBeginString is the state after reading `{"key": value,`.
func stateBeginString(s *scanner, c int) int {
if c <= ' ' && isSpace(rune(c)) {
return scanSkipSpace
}
if c == '"' {
s.step = stateInString
return scanBeginLiteral
}
return s.error(c, "looking for beginning of object key string")
}
// stateEndValue is the state after completing a value,
// such as after reading `{}` or `true` or `["x"`.
func stateEndValue(s *scanner, c int) int {
n := len(s.parseState)
if n == 0 {
// Completed top-level before the current byte.
s.step = stateEndTop
s.endTop = true
return stateEndTop(s, c)
}
if c <= ' ' && isSpace(rune(c)) {
s.step = stateEndValue
return scanSkipSpace
}
ps := s.parseState[n-1]
switch ps {
case parseObjectKey:
if c == ':' {
s.parseState[n-1] = parseObjectValue
s.step = stateBeginValue
return scanObjectKey
}
return s.error(c, "after object key")
case parseObjectValue:
if c == ',' {
s.parseState[n-1] = parseObjectKey
s.step = stateBeginString
return scanObjectValue
}
if c == '}' {
s.popParseState()
return scanEndObject
}
return s.error(c, "after object key:value pair")
case parseArrayValue:
if c == ',' {
s.step = stateBeginValue
return scanArrayValue
}
if c == ']' {
s.popParseState()
return scanEndArray
}
return s.error(c, "after array element")
}
return s.error(c, "")
}
// stateEndTop is the state after finishing the top-level value,
// such as after reading `{}` or `[1,2,3]`.
// Only space characters should be seen now.
func stateEndTop(s *scanner, c int) int {
if c != ' ' && c != '\t' && c != '\r' && c != '\n' {
// Complain about non-space byte on next call.
s.error(c, "after top-level value")
}
return scanEnd
}
// stateInString is the state after reading `"`.
func stateInString(s *scanner, c int) int {
if c == '"' {
s.step = stateEndValue
return scanContinue
}
if c == '\\' {
s.step = stateInStringEsc
return scanContinue
}
if c < 0x20 {
return s.error(c, "in string literal")
}
return scanContinue
}
// stateInStringEsc is the state after reading `"\` during a quoted string.
func stateInStringEsc(s *scanner, c int) int {
switch c {
case 'b', 'f', 'n', 'r', 't', '\\', '/', '"':
s.step = stateInString
return scanContinue
}
if c == 'u' {
s.step = stateInStringEscU
return scanContinue
}
return s.error(c, "in string escape code")
}
// stateInStringEscU is the state after reading `"\u` during a quoted string.
func stateInStringEscU(s *scanner, c int) int {
if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
s.step = stateInStringEscU1
return scanContinue
}
// numbers
return s.error(c, "in \\u hexadecimal character escape")
}
// stateInStringEscU1 is the state after reading `"\u1` during a quoted string.
func stateInStringEscU1(s *scanner, c int) int {
if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
s.step = stateInStringEscU12
return scanContinue
}
// numbers
return s.error(c, "in \\u hexadecimal character escape")
}
// stateInStringEscU12 is the state after reading `"\u12` during a quoted string.
func stateInStringEscU12(s *scanner, c int) int {
if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
s.step = stateInStringEscU123
return scanContinue
}
// numbers
return s.error(c, "in \\u hexadecimal character escape")
}
// stateInStringEscU123 is the state after reading `"\u123` during a quoted string.
func stateInStringEscU123(s *scanner, c int) int {
if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
s.step = stateInString
return scanContinue
}
// numbers
return s.error(c, "in \\u hexadecimal character escape")
}
// stateNeg is the state after reading `-` during a number.
func stateNeg(s *scanner, c int) int {
if c == '0' {
s.step = state0
return scanContinue
}
if '1' <= c && c <= '9' {
s.step = state1
return scanContinue
}
return s.error(c, "in numeric literal")
}
// state1 is the state after reading a non-zero integer during a number,
// such as after reading `1` or `100` but not `0`.
func state1(s *scanner, c int) int {
if '0' <= c && c <= '9' {
s.step = state1
return scanContinue
}
return state0(s, c)
}
// state0 is the state after reading `0` during a number.
func state0(s *scanner, c int) int {
if c == '.' {
s.step = stateDot
return scanContinue
}
if c == 'e' || c == 'E' {
s.step = stateE
return scanContinue
}
return stateEndValue(s, c)
}
// stateDot is the state after reading the integer and decimal point in a number,
// such as after reading `1.`.
func stateDot(s *scanner, c int) int {
if '0' <= c && c <= '9' {
s.step = stateDot0
return scanContinue
}
return s.error(c, "after decimal point in numeric literal")
}
// stateDot0 is the state after reading the integer, decimal point, and subsequent
// digits of a number, such as after reading `3.14`.
func stateDot0(s *scanner, c int) int {
if '0' <= c && c <= '9' {
s.step = stateDot0
return scanContinue
}
if c == 'e' || c == 'E' {
s.step = stateE
return scanContinue
}
return stateEndValue(s, c)
}
// stateE is the state after reading the mantissa and e in a number,
// such as after reading `314e` or `0.314e`.
func stateE(s *scanner, c int) int {
if c == '+' {
s.step = stateESign
return scanContinue
}
if c == '-' {
s.step = stateESign
return scanContinue
}
return stateESign(s, c)
}
// stateESign is the state after reading the mantissa, e, and sign in a number,
// such as after reading `314e-` or `0.314e+`.
func stateESign(s *scanner, c int) int {
if '0' <= c && c <= '9' {
s.step = stateE0
return scanContinue
}
return s.error(c, "in exponent of numeric literal")
}
// stateE0 is the state after reading the mantissa, e, optional sign,
// and at least one digit of the exponent in a number,
// such as after reading `314e-2` or `0.314e+1` or `3.14e0`.
func stateE0(s *scanner, c int) int {
if '0' <= c && c <= '9' {
s.step = stateE0
return scanContinue
}
return stateEndValue(s, c)
}
// stateT is the state after reading `t`.
func stateT(s *scanner, c int) int {
if c == 'r' {
s.step = stateTr
return scanContinue
}
return s.error(c, "in literal true (expecting 'r')")
}
// stateTr is the state after reading `tr`.
func stateTr(s *scanner, c int) int {
if c == 'u' {
s.step = stateTru
return scanContinue
}
return s.error(c, "in literal true (expecting 'u')")
}
// stateTru is the state after reading `tru`.
func stateTru(s *scanner, c int) int {
if c == 'e' {
s.step = stateEndValue
return scanContinue
}
return s.error(c, "in literal true (expecting 'e')")
}
// stateF is the state after reading `f`.
func stateF(s *scanner, c int) int {
if c == 'a' {
s.step = stateFa
return scanContinue
}
return s.error(c, "in literal false (expecting 'a')")
}
// stateFa is the state after reading `fa`.
func stateFa(s *scanner, c int) int {
if c == 'l' {
s.step = stateFal
return scanContinue
}
return s.error(c, "in literal false (expecting 'l')")
}
// stateFal is the state after reading `fal`.
func stateFal(s *scanner, c int) int {
if c == 's' {
s.step = stateFals
return scanContinue
}
return s.error(c, "in literal false (expecting 's')")
}
// stateFals is the state after reading `fals`.
func stateFals(s *scanner, c int) int {
if c == 'e' {
s.step = stateEndValue
return scanContinue
}
return s.error(c, "in literal false (expecting 'e')")
}
// stateN is the state after reading `n`.
func stateN(s *scanner, c int) int {
if c == 'u' {
s.step = stateNu
return scanContinue
}
return s.error(c, "in literal null (expecting 'u')")
}
// stateNu is the state after reading `nu`.
func stateNu(s *scanner, c int) int {
if c == 'l' {
s.step = stateNul
return scanContinue
}
return s.error(c, "in literal null (expecting 'l')")
}
// stateNul is the state after reading `nul`.
func stateNul(s *scanner, c int) int {
if c == 'l' {
s.step = stateEndValue
return scanContinue
}
return s.error(c, "in literal null (expecting 'l')")
}
// stateError is the state after reaching a syntax error,
// such as after reading `[1}` or `5.1.2`.
func stateError(s *scanner, c int) int {
return scanError
}
// error records an error and switches to the error state.
func (s *scanner) error(c int, context string) int {
s.step = stateError
s.err = &SyntaxError{"invalid character " + quoteChar(c) + " " + context, s.bytes}
return scanError
}
// quoteChar formats c as a quoted character literal
func quoteChar(c int) string {
// special cases - different from quoted strings
if c == '\'' {
return `'\''`
}
if c == '"' {
return `'"'`
}
// use quoted string with different quotation marks
s := strconv.Quote(string(c))
return "'" + s[1:len(s)-1] + "'"
}
// undo causes the scanner to return scanCode from the next state transition.
// This gives callers a simple 1-byte undo mechanism.
func (s *scanner) undo(scanCode int) {
if s.redo {
panic("json: invalid use of scanner")
}
s.redoCode = scanCode
s.redoState = s.step
s.step = stateRedo
s.redo = true
}
// stateRedo helps implement the scanner's 1-byte undo.
func stateRedo(s *scanner, c int) int {
s.redo = false
s.step = s.redoState
return s.redoCode
}
vendor/github.com/CorgiMan/json2/stream.go 0 → 100644
浏览文件 @ ee667a09
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package json2
import (
"bytes"
"errors"
"io"
)
// A Decoder reads and decodes JSON objects from an input stream.
type Decoder struct {
r io.Reader
buf []byte
d decodeState
scan scanner
err error
}
// NewDecoder returns a new decoder that reads from r.
//
// The decoder introduces its own buffering and may
// read data from r beyond the JSON values requested.
func NewDecoder(r io.Reader) *Decoder {
return &Decoder{r: r}
}
// UseNumber causes the Decoder to unmarshal a number into an interface{} as a
// Number instead of as a float64.
func (dec *Decoder) UseNumber() { dec.d.useNumber = true }
// Decode reads the next JSON-encoded value from its
// input and stores it in the value pointed to by v.
//
// See the documentation for Unmarshal for details about
// the conversion of JSON into a Go value.
func (dec *Decoder) Decode(v interface{}) error {
if dec.err != nil {
return dec.err
}
n, err := dec.readValue()
if err != nil {
return err
}
// Don't save err from unmarshal into dec.err:
// the connection is still usable since we read a complete JSON
// object from it before the error happened.
dec.d.init(dec.buf[0:n])
err = dec.d.unmarshal(v)
// Slide rest of data down.
rest := copy(dec.buf, dec.buf[n:])
dec.buf = dec.buf[0:rest]
return err
}
// Buffered returns a reader of the data remaining in the Decoder's
// buffer. The reader is valid until the next call to Decode.
func (dec *Decoder) Buffered() io.Reader {
return bytes.NewReader(dec.buf)
}
// readValue reads a JSON value into dec.buf.
// It returns the length of the encoding.
func (dec *Decoder) readValue() (int, error) {
dec.scan.reset()
scanp := 0
var err error
Input:
for {
// Look in the buffer for a new value.
for i, c := range dec.buf[scanp:] {
dec.scan.bytes++
v := dec.scan.step(&dec.scan, int(c))
if v == scanEnd {
scanp += i
break Input
}
// scanEnd is delayed one byte.
// We might block trying to get that byte from src,
// so instead invent a space byte.
if (v == scanEndObject || v == scanEndArray) && dec.scan.step(&dec.scan, ' ') == scanEnd {
scanp += i + 1
break Input
}
if v == scanError {
dec.err = dec.scan.err
return 0, dec.scan.err
}
}
scanp = len(dec.buf)
// Did the last read have an error?
// Delayed until now to allow buffer scan.
if err != nil {
if err == io.EOF {
if dec.scan.step(&dec.scan, ' ') == scanEnd {
break Input
}
if nonSpace(dec.buf) {
err = io.ErrUnexpectedEOF
}
}
dec.err = err
return 0, err
}
// Make room to read more into the buffer.
const minRead = 512
if cap(dec.buf)-len(dec.buf) < minRead {
newBuf := make([]byte, len(dec.buf), 2*cap(dec.buf)+minRead)
copy(newBuf, dec.buf)
dec.buf = newBuf
}
// Read. Delay error for next iteration (after scan).
var n int
n, err = dec.r.Read(dec.buf[len(dec.buf):cap(dec.buf)])
dec.buf = dec.buf[0 : len(dec.buf)+n]
}
return scanp, nil
}
func nonSpace(b []byte) bool {
for _, c := range b {
if !isSpace(rune(c)) {
return true
}
}
return false
}
// An Encoder writes JSON objects to an output stream.
type Encoder struct {
w io.Writer
e encodeState
err error
}
// NewEncoder returns a new encoder that writes to w.
func NewEncoder(w io.Writer) *Encoder {
return &Encoder{w: w}
}
// Encode writes the JSON encoding of v to the stream.
//
// See the documentation for Marshal for details about the
// conversion of Go values to JSON.
func (enc *Encoder) Encode(v interface{}) error {
if enc.err != nil {
return enc.err
}
e := newEncodeState()
err := e.marshal(v)
if err != nil {
return err
}
// Terminate each value with a newline.
// This makes the output look a little nicer
// when debugging, and some kind of space
// is required if the encoded value was a number,
// so that the reader knows there aren't more
// digits coming.
e.WriteByte('\n')
if _, err = enc.w.Write(e.Bytes()); err != nil {
enc.err = err
}
putEncodeState(e)
return err
}
// RawMessage is a raw encoded JSON object.
// It implements Marshaler and Unmarshaler and can
// be used to delay JSON decoding or precompute a JSON encoding.
type RawMessage []byte
// MarshalJSON returns *m as the JSON encoding of m.
func (m *RawMessage) MarshalJSON() ([]byte, error) {
return *m, nil
}
// UnmarshalJSON sets *m to a copy of data.
func (m *RawMessage) UnmarshalJSON(data []byte) error {
if m == nil {
return errors.New("json.RawMessage: UnmarshalJSON on nil pointer")
}
*m = append((*m)[0:0], data...)
return nil
}
var _ Marshaler = (*RawMessage)(nil)
var _ Unmarshaler = (*RawMessage)(nil)
vendor/github.com/CorgiMan/json2/tags.go 0 → 100644
浏览文件 @ ee667a09
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package json2
import (
"strings"
)
// tagOptions is the string following a comma in a struct field's "json"
// tag, or the empty string. It does not include the leading comma.
type tagOptions string
// parseTag splits a struct field's json tag into its name and
// comma-separated options.
func parseTag(tag string) (string, tagOptions) {
if idx := strings.Index(tag, ","); idx != -1 {
return tag[:idx], tagOptions(tag[idx+1:])
}
return tag, tagOptions("")
}
// Contains reports whether a comma-separated list of options
// contains a particular substr flag. substr must be surrounded by a
// string boundary or commas.
func (o tagOptions) Contains(optionName string) bool {
if len(o) == 0 {
return false
}
s := string(o)
for s != "" {
var next string
i := strings.Index(s, ",")
if i >= 0 {
s, next = s[:i], s[i+1:]
}
if s == optionName {
return true
}
s = next
}
return false
}
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