add stream

jsoniter.go

@@ -1,853 +0,0 @@
-package jsoniter
-
-import (
-	"encoding/base64"
-	"fmt"
-	"io"
-	"strconv"
-	"unicode/utf16"
-	"unsafe"
-)
-
-type ValueType int
-
-const (
-	Invalid ValueType = iota
-	String
-	Number
-	Null
-	Bool
-	Array
-	Object
-)
-
-var digits []byte
-var valueTypes []ValueType
-
-func init() {
-	digits = make([]byte, 256)
-	for i := 0; i < len(digits); i++ {
-		digits[i] = 255
-	}
-	for i := '0'; i <= '9'; i++ {
-		digits[i] = byte(i - '0')
-	}
-	for i := 'a'; i <= 'f'; i++ {
-		digits[i] = byte((i - 'a') + 10)
-	}
-	for i := 'A'; i <= 'F'; i++ {
-		digits[i] = byte((i - 'A') + 10)
-	}
-	valueTypes = make([]ValueType, 256)
-	for i := 0; i < len(valueTypes); i++ {
-		valueTypes[i] = Invalid
-	}
-	valueTypes['"'] = String
-	valueTypes['-'] = Number
-	valueTypes['0'] = Number
-	valueTypes['1'] = Number
-	valueTypes['2'] = Number
-	valueTypes['3'] = Number
-	valueTypes['4'] = Number
-	valueTypes['5'] = Number
-	valueTypes['6'] = Number
-	valueTypes['7'] = Number
-	valueTypes['8'] = Number
-	valueTypes['9'] = Number
-	valueTypes['t'] = Bool
-	valueTypes['f'] = Bool
-	valueTypes['n'] = Null
-	valueTypes['['] = Array
-	valueTypes['{'] = Object
-}
-
-// Iterator is a fast and flexible JSON parser
-type Iterator struct {
-	reader io.Reader
-	buf    []byte
-	head   int
-	tail   int
-	Error  error
-}
-
-// Create creates an empty Iterator instance
-func Create() *Iterator {
-	return &Iterator{
-		reader: nil,
-		buf:    nil,
-		head:   0,
-		tail:   0,
-	}
-}
-
-// Parse parses a json buffer in io.Reader into an Iterator instance
-func Parse(reader io.Reader, bufSize int) *Iterator {
-	return &Iterator{
-		reader: reader,
-		buf:    make([]byte, bufSize),
-		head:   0,
-		tail:   0,
-	}
-}
-
-// ParseBytes parses a json byte slice into an Iterator instance
-func ParseBytes(input []byte) *Iterator {
-	return &Iterator{
-		reader: nil,
-		buf:    input,
-		head:   0,
-		tail:   len(input),
-	}
-}
-
-// ParseString parses a json string into an Iterator instance
-func ParseString(input string) *Iterator {
-	return ParseBytes([]byte(input))
-}
-
-// Reset can reset an Iterator instance for another json buffer in io.Reader
-func (iter *Iterator) Reset(reader io.Reader) *Iterator {
-	iter.reader = reader
-	iter.head = 0
-	iter.tail = 0
-	return iter
-}
-
-// ResetBytes can reset an Iterator instance for another json byte slice
-func (iter *Iterator) ResetBytes(input []byte) *Iterator {
-	iter.reader = nil
-	iter.Error = nil
-	iter.buf = input
-	iter.head = 0
-	iter.tail = len(input)
-	return iter
-}
-
-// WhatIsNext gets ValueType of relatively next json object
-func (iter *Iterator) WhatIsNext() ValueType {
-	valueType := valueTypes[iter.nextToken()]
-	iter.unreadByte()
-	return valueType
-}
-
-func (iter *Iterator) skipWhitespacesWithoutLoadMore() bool {
-	for i := iter.head; i < iter.tail; i++ {
-		c := iter.buf[i]
-		switch c {
-		case ' ', '\n', '\t', '\r':
-			continue
-		}
-		iter.head = i
-		return false
-	}
-	return true
-}
-
-func (iter *Iterator) nextToken() byte {
-	// a variation of skip whitespaces, returning the next non-whitespace token
-	for {
-		for i := iter.head; i < iter.tail; i++ {
-			c := iter.buf[i]
-			switch c {
-			case ' ', '\n', '\t', '\r':
-				continue
-			}
-			iter.head = i + 1
-			return c
-		}
-		if !iter.loadMore() {
-			return 0
-		}
-	}
-}
-
-func (iter *Iterator) reportError(operation string, msg string) {
-	if iter.Error != nil {
-		return
-	}
-	peekStart := iter.head - 10
-	if peekStart < 0 {
-		peekStart = 0
-	}
-	iter.Error = fmt.Errorf("%s: %s, parsing %v ...%s... at %s", operation, msg, iter.head,
-		string(iter.buf[peekStart:iter.head]), string(iter.buf[0:iter.tail]))
-}
-
-// CurrentBuffer gets current buffer as string
-func (iter *Iterator) CurrentBuffer() string {
-	peekStart := iter.head - 10
-	if peekStart < 0 {
-		peekStart = 0
-	}
-	return fmt.Sprintf("parsing %v ...|%s|... at %s", iter.head,
-		string(iter.buf[peekStart:iter.head]), string(iter.buf[0:iter.tail]))
-}
-
-func (iter *Iterator) readByte() (ret byte) {
-	if iter.head == iter.tail {
-		if iter.loadMore() {
-			ret = iter.buf[iter.head]
-			iter.head++
-			return ret
-		}
-		return 0
-	}
-	ret = iter.buf[iter.head]
-	iter.head++
-	return ret
-}
-
-func (iter *Iterator) loadMore() bool {
-	if iter.reader == nil {
-		iter.Error = io.EOF
-		return false
-	}
-	for {
-		n, err := iter.reader.Read(iter.buf)
-		if n == 0 {
-			if err != nil {
-				iter.Error = err
-				return false
-			}
-		} else {
-			iter.head = 0
-			iter.tail = n
-			return true
-		}
-	}
-}
-
-func (iter *Iterator) unreadByte() {
-	if iter.head == 0 {
-		iter.reportError("unreadByte", "unread too many bytes")
-		return
-	}
-	iter.head--
-	return
-}
-
-const maxUint64 = (1<<64 - 1)
-const cutoffUint64 = maxUint64/10 + 1
-const maxUint32 = (1<<32 - 1)
-const cutoffUint32 = maxUint32/10 + 1
-
-// ReadUint reads a json object as Uint
-func (iter *Iterator) ReadUint() (ret uint) {
-	val := iter.ReadUint64()
-	converted := uint(val)
-	if uint64(converted) != val {
-		iter.reportError("ReadUint", "int overflow")
-		return
-	}
-	return converted
-}
-
-// ReadUint8 reads a json object as Uint8
-func (iter *Iterator) ReadUint8() (ret uint8) {
-	val := iter.ReadUint64()
-	converted := uint8(val)
-	if uint64(converted) != val {
-		iter.reportError("ReadUint8", "int overflow")
-		return
-	}
-	return converted
-}
-
-// ReadUint16 reads a json object as Uint16
-func (iter *Iterator) ReadUint16() (ret uint16) {
-	val := iter.ReadUint64()
-	converted := uint16(val)
-	if uint64(converted) != val {
-		iter.reportError("ReadUint16", "int overflow")
-		return
-	}
-	return converted
-}
-
-// ReadUint32 reads a json object as Uint32
-func (iter *Iterator) ReadUint32() (ret uint32) {
-	val := iter.ReadUint64()
-	converted := uint32(val)
-	if uint64(converted) != val {
-		iter.reportError("ReadUint32", "int overflow")
-		return
-	}
-	return converted
-}
-
-// ReadUint64 reads a json object as Uint64
-func (iter *Iterator) ReadUint64() (ret uint64) {
-	c := iter.nextToken()
-	v := digits[c]
-	if v == 0 {
-		return 0 // single zero
-	}
-	if v == 255 {
-		iter.reportError("ReadUint64", "unexpected character")
-		return
-	}
-	for {
-		if ret >= cutoffUint64 {
-			iter.reportError("ReadUint64", "overflow")
-			return
-		}
-		ret = ret*10 + uint64(v)
-		c = iter.readByte()
-		v = digits[c]
-		if v == 255 {
-			iter.unreadByte()
-			break
-		}
-	}
-	return ret
-}
-
-// ReadInt reads a json object as Int
-func (iter *Iterator) ReadInt() (ret int) {
-	val := iter.ReadInt64()
-	converted := int(val)
-	if int64(converted) != val {
-		iter.reportError("ReadInt", "int overflow")
-		return
-	}
-	return converted
-}
-
-// ReadInt8 reads a json object as Int8
-func (iter *Iterator) ReadInt8() (ret int8) {
-	val := iter.ReadInt64()
-	converted := int8(val)
-	if int64(converted) != val {
-		iter.reportError("ReadInt8", "int overflow")
-		return
-	}
-	return converted
-}
-
-// ReadInt16 reads a json object as Int16
-func (iter *Iterator) ReadInt16() (ret int16) {
-	val := iter.ReadInt64()
-	converted := int16(val)
-	if int64(converted) != val {
-		iter.reportError("ReadInt16", "int overflow")
-		return
-	}
-	return converted
-}
-
-// ReadInt32 reads a json object as Int32
-func (iter *Iterator) ReadInt32() (ret int32) {
-	val := iter.ReadInt64()
-	converted := int32(val)
-	if int64(converted) != val {
-		iter.reportError("ReadInt32", "int overflow")
-		return
-	}
-	return converted
-}
-
-// ReadInt64 reads a json object as Int64
-func (iter *Iterator) ReadInt64() (ret int64) {
-	c := iter.nextToken()
-	if iter.Error != nil {
-		return
-	}
-
-	/* optional leading minus */
-	if c == '-' {
-		n := iter.ReadUint64()
-		return -int64(n)
-	}
-	iter.unreadByte()
-	n := iter.ReadUint64()
-	return int64(n)
-}
-
-// ReadString reads a json object as String
-func (iter *Iterator) ReadString() (ret string) {
-	return string(iter.readStringAsBytes())
-}
-
-func (iter *Iterator) readStringAsBytes() (ret []byte) {
-	c := iter.nextToken()
-	if c == '"' {
-		end := iter.findStringEndWithoutEscape()
-		if end != -1 {
-			// fast path: reuse the underlying buffer
-			ret = iter.buf[iter.head : end-1]
-			iter.head = end
-			return ret
-		}
-		return iter.readStringAsBytesSlowPath()
-	}
-	if c == 'n' {
-		iter.skipUntilBreak()
-		return
-	}
-	iter.reportError("ReadString", `expects " or n`)
-	return
-}
-
-func (iter *Iterator) readStringAsBytesSlowPath() (ret []byte) {
-	str := make([]byte, 0, 8)
-	var c byte
-	for iter.Error == nil {
-		c = iter.readByte()
-		if c == '"' {
-			return str
-		}
-		if c == '\\' {
-			c = iter.readByte()
-			if iter.Error != nil {
-				return
-			}
-			switch c {
-			case 'u':
-				r := iter.readU4()
-				if iter.Error != nil {
-					return
-				}
-				if utf16.IsSurrogate(r) {
-					c = iter.readByte()
-					if iter.Error != nil {
-						return
-					}
-					if c != '\\' {
-						iter.reportError("ReadString",
-							`expects \u after utf16 surrogate, but \ not found`)
-						return
-					}
-					c = iter.readByte()
-					if iter.Error != nil {
-						return
-					}
-					if c != 'u' {
-						iter.reportError("ReadString",
-							`expects \u after utf16 surrogate, but \u not found`)
-						return
-					}
-					r2 := iter.readU4()
-					if iter.Error != nil {
-						return
-					}
-					combined := utf16.DecodeRune(r, r2)
-					str = appendRune(str, combined)
-				} else {
-					str = appendRune(str, r)
-				}
-			case '"':
-				str = append(str, '"')
-			case '\\':
-				str = append(str, '\\')
-			case '/':
-				str = append(str, '/')
-			case 'b':
-				str = append(str, '\b')
-			case 'f':
-				str = append(str, '\f')
-			case 'n':
-				str = append(str, '\n')
-			case 'r':
-				str = append(str, '\r')
-			case 't':
-				str = append(str, '\t')
-			default:
-				iter.reportError("ReadString",
-					`invalid escape char after \`)
-				return
-			}
-		} else {
-			str = append(str, c)
-		}
-	}
-	return
-}
-
-func (iter *Iterator) readU4() (ret rune) {
-	for i := 0; i < 4; i++ {
-		c := iter.readByte()
-		if iter.Error != nil {
-			return
-		}
-		if c >= '0' && c <= '9' {
-			if ret >= cutoffUint32 {
-				iter.reportError("readU4", "overflow")
-				return
-			}
-			ret = ret*16 + rune(c-'0')
-		} else if c >= 'a' && c <= 'f' {
-			if ret >= cutoffUint32 {
-				iter.reportError("readU4", "overflow")
-				return
-			}
-			ret = ret*16 + rune(c-'a'+10)
-		} else {
-			iter.reportError("readU4", "expects 0~9 or a~f")
-			return
-		}
-	}
-	return ret
-}
-
-const (
-	t1 = 0x00 // 0000 0000
-	tx = 0x80 // 1000 0000
-	t2 = 0xC0 // 1100 0000
-	t3 = 0xE0 // 1110 0000
-	t4 = 0xF0 // 1111 0000
-	t5 = 0xF8 // 1111 1000
-
-	maskx = 0x3F // 0011 1111
-	mask2 = 0x1F // 0001 1111
-	mask3 = 0x0F // 0000 1111
-	mask4 = 0x07 // 0000 0111
-
-	rune1Max = 1<<7 - 1
-	rune2Max = 1<<11 - 1
-	rune3Max = 1<<16 - 1
-
-	surrogateMin = 0xD800
-	surrogateMax = 0xDFFF
-
-	MaxRune   = '\U0010FFFF' // Maximum valid Unicode code point.
-	RuneError = '\uFFFD'     // the "error" Rune or "Unicode replacement character"
-)
-
-func appendRune(p []byte, r rune) []byte {
-	// Negative values are erroneous. Making it unsigned addresses the problem.
-	switch i := uint32(r); {
-	case i <= rune1Max:
-		p = append(p, byte(r))
-		return p
-	case i <= rune2Max:
-		p = append(p, t2|byte(r>>6))
-		p = append(p, tx|byte(r)&maskx)
-		return p
-	case i > MaxRune, surrogateMin <= i && i <= surrogateMax:
-		r = RuneError
-		fallthrough
-	case i <= rune3Max:
-		p = append(p, t3|byte(r>>12))
-		p = append(p, tx|byte(r>>6)&maskx)
-		p = append(p, tx|byte(r)&maskx)
-		return p
-	default:
-		p = append(p, t4|byte(r>>18))
-		p = append(p, tx|byte(r>>12)&maskx)
-		p = append(p, tx|byte(r>>6)&maskx)
-		p = append(p, tx|byte(r)&maskx)
-		return p
-	}
-}
-
-// ReadArray reads a json object as Array
-func (iter *Iterator) ReadArray() (ret bool) {
-	c := iter.nextToken()
-	if iter.Error != nil {
-		return
-	}
-	switch c {
-	case 'n':
-		iter.skipUntilBreak()
-		return false // null
-	case '[':
-		c = iter.nextToken()
-		if iter.Error != nil {
-			return
-		}
-		if c == ']' {
-			return false
-		}
-		iter.unreadByte()
-		return true
-	case ']':
-		return false
-	case ',':
-		return true
-	default:
-		iter.reportError("ReadArray", "expect [ or , or ] or n, but found: "+string([]byte{c}))
-		return
-	}
-}
-
-// ReadFloat32 reads a json object as Float32
-func (iter *Iterator) ReadFloat32() (ret float32) {
-	strBuf := [8]byte{}
-	str := strBuf[0:0]
-	hasMore := true
-	for hasMore {
-		for i := iter.head; i < iter.tail; i++ {
-			c := iter.buf[i]
-			switch c {
-			case '-', '+', '.', 'e', 'E', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
-				str = append(str, c)
-				continue
-			default:
-				hasMore = false
-				break
-			}
-		}
-		if hasMore {
-			if !iter.loadMore() {
-				break
-			}
-		}
-	}
-	if iter.Error != nil && iter.Error != io.EOF {
-		return
-	}
-	val, err := strconv.ParseFloat(*(*string)(unsafe.Pointer(&str)), 32)
-	if err != nil {
-		iter.Error = err
-		return
-	}
-	return float32(val)
-}
-
-// ReadFloat64 reads a json object as Float64
-func (iter *Iterator) ReadFloat64() (ret float64) {
-	strBuf := [8]byte{}
-	str := strBuf[0:0]
-	hasMore := true
-	for hasMore {
-		for i := iter.head; i < iter.tail; i++ {
-			c := iter.buf[i]
-			switch c {
-			case '-', '+', '.', 'e', 'E', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
-				str = append(str, c)
-				continue
-			default:
-				hasMore = false
-				break
-			}
-		}
-		if hasMore {
-			if !iter.loadMore() {
-				break
-			}
-		}
-	}
-	if iter.Error != nil && iter.Error != io.EOF {
-		return
-	}
-	val, err := strconv.ParseFloat(*(*string)(unsafe.Pointer(&str)), 64)
-	if err != nil {
-		iter.Error = err
-		return
-	}
-	return val
-}
-
-// ReadBool reads a json object as Bool
-func (iter *Iterator) ReadBool() (ret bool) {
-	c := iter.nextToken()
-	if iter.Error != nil {
-		return
-	}
-	switch c {
-	case 't':
-		iter.skipUntilBreak()
-		return true
-	case 'f':
-		iter.skipUntilBreak()
-		return false
-	default:
-		iter.reportError("ReadBool", "expect t or f")
-		return
-	}
-}
-
-// ReadBase64 reads a json object as Base64 in byte slice
-func (iter *Iterator) ReadBase64() (ret []byte) {
-	src := iter.readStringAsBytes()
-	if iter.Error != nil {
-		return
-	}
-	b64 := base64.StdEncoding
-	ret = make([]byte, b64.DecodedLen(len(src)))
-	n, err := b64.Decode(ret, src)
-	if err != nil {
-		iter.Error = err
-		return
-	}
-	return ret[:n]
-}
-
-// ReadNil reads a json object as nil and
-// returns whether it's a nil or not
-func (iter *Iterator) ReadNil() (ret bool) {
-	c := iter.nextToken()
-	if c == 'n' {
-		iter.skipUntilBreak()
-		return true
-	}
-	iter.unreadByte()
-	return false
-}
-
-// Skip skips a json object and positions to relatively the next json object
-func (iter *Iterator) Skip() {
-	c := iter.nextToken()
-	switch c {
-	case '"':
-		iter.skipString()
-	case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 't', 'f', 'n':
-		iter.skipUntilBreak()
-	case '[':
-		iter.skipArray()
-	case '{':
-		iter.skipObject()
-	default:
-		iter.reportError("Skip", fmt.Sprintf("do not know how to skip: %v", c))
-		return
-	}
-}
-
-func (iter *Iterator) skipString() {
-	for {
-		end, escaped := iter.findStringEnd()
-		if end == -1 {
-			if !iter.loadMore() {
-				return
-			}
-			if escaped {
-				iter.head = 1 // skip the first char as last char read is \
-			}
-		} else {
-			iter.head = end
-			return
-		}
-	}
-}
-
-// adapted from: https://github.com/buger/jsonparser/blob/master/parser.go
-// Tries to find the end of string
-// Support if string contains escaped quote symbols.
-func (iter *Iterator) findStringEnd() (int, bool) {
-	escaped := false
-	for i := iter.head; i < iter.tail; i++ {
-		c := iter.buf[i]
-		if c == '"' {
-			if !escaped {
-				return i + 1, false
-			}
-			j := i - 1
-			for {
-				if j < iter.head || iter.buf[j] != '\\' {
-					// even number of backslashes
-					// either end of buffer, or " found
-					return i + 1, true
-				}
-				j--
-				if j < iter.head || iter.buf[j] != '\\' {
-					// odd number of backslashes
-					// it is \" or \\\"
-					break
-				}
-				j--
-			}
-		} else if c == '\\' {
-			escaped = true
-		}
-	}
-	j := iter.tail - 1
-	for {
-		if j < iter.head || iter.buf[j] != '\\' {
-			// even number of backslashes
-			// either end of buffer, or " found
-			return -1, false // do not end with \
-		}
-		j--
-		if j < iter.head || iter.buf[j] != '\\' {
-			// odd number of backslashes
-			// it is \" or \\\"
-			break
-		}
-		j--
-
-	}
-	return -1, true // end with \
-}
-
-func (iter *Iterator) findStringEndWithoutEscape() int {
-	for i := iter.head; i < iter.tail; i++ {
-		c := iter.buf[i]
-		if c == '"' {
-			return i + 1
-		} else if c == '\\' {
-			return -1
-		}
-	}
-	return -1
-}
-
-func (iter *Iterator) skipArray() {
-	level := 1
-	for {
-		for i := iter.head; i < iter.tail; i++ {
-			switch iter.buf[i] {
-			case '"': // If inside string, skip it
-				iter.head = i + 1
-				iter.skipString()
-				i = iter.head - 1 // it will be i++ soon
-			case '[': // If open symbol, increase level
-				level++
-			case ']': // If close symbol, increase level
-				level--
-
-				// If we have returned to the original level, we're done
-				if level == 0 {
-					iter.head = i + 1
-					return
-				}
-			}
-		}
-		if !iter.loadMore() {
-			return
-		}
-	}
-}
-
-func (iter *Iterator) skipObject() {
-	level := 1
-	for {
-		for i := iter.head; i < iter.tail; i++ {
-			switch iter.buf[i] {
-			case '"': // If inside string, skip it
-				iter.head = i + 1
-				iter.skipString()
-				i = iter.head - 1 // it will be i++ soon
-			case '{': // If open symbol, increase level
-				level++
-			case '}': // If close symbol, increase level
-				level--
-
-				// If we have returned to the original level, we're done
-				if level == 0 {
-					iter.head = i + 1
-					return
-				}
-			}
-		}
-		if !iter.loadMore() {
-			return
-		}
-	}
-}
-
-func (iter *Iterator) skipUntilBreak() {
-	// true, false, null, number
-	for {
-		for i := iter.head; i < iter.tail; i++ {
-			c := iter.buf[i]
-			switch c {
-			case ' ', '\n', '\r', '\t', ',', '}', ']':
-				iter.head = i
-				return
-			}
-		}
-		if !iter.loadMore() {
-			return
-		}
-	}
-}