615 lines
15 KiB
Go
615 lines
15 KiB
Go
package cbor
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// This file contains code to decode a stream of CBOR Data into JSON.
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import (
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"bufio"
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"bytes"
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"fmt"
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"io"
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"math"
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"net"
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"runtime"
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"strconv"
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"strings"
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"time"
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"unicode/utf8"
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)
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var decodeTimeZone *time.Location
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const hexTable = "0123456789abcdef"
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const isFloat32 = 4
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const isFloat64 = 8
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func readNBytes(src *bufio.Reader, n int) []byte {
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ret := make([]byte, n)
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for i := 0; i < n; i++ {
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ch, e := src.ReadByte()
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if e != nil {
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panic(fmt.Errorf("Tried to Read %d Bytes.. But hit end of file", n))
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}
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ret[i] = ch
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}
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return ret
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}
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func readByte(src *bufio.Reader) byte {
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b, e := src.ReadByte()
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if e != nil {
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panic(fmt.Errorf("Tried to Read 1 Byte.. But hit end of file"))
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}
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return b
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}
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func decodeIntAdditionalType(src *bufio.Reader, minor byte) int64 {
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val := int64(0)
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if minor <= 23 {
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val = int64(minor)
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} else {
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bytesToRead := 0
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switch minor {
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case additionalTypeIntUint8:
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bytesToRead = 1
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case additionalTypeIntUint16:
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bytesToRead = 2
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case additionalTypeIntUint32:
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bytesToRead = 4
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case additionalTypeIntUint64:
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bytesToRead = 8
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default:
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panic(fmt.Errorf("Invalid Additional Type: %d in decodeInteger (expected <28)", minor))
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}
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pb := readNBytes(src, bytesToRead)
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for i := 0; i < bytesToRead; i++ {
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val = val * 256
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val += int64(pb[i])
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}
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}
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return val
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}
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func decodeInteger(src *bufio.Reader) int64 {
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pb := readByte(src)
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major := pb & maskOutAdditionalType
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minor := pb & maskOutMajorType
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if major != majorTypeUnsignedInt && major != majorTypeNegativeInt {
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panic(fmt.Errorf("Major type is: %d in decodeInteger!! (expected 0 or 1)", major))
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}
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val := decodeIntAdditionalType(src, minor)
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if major == 0 {
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return val
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}
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return (-1 - val)
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}
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func decodeFloat(src *bufio.Reader) (float64, int) {
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pb := readByte(src)
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major := pb & maskOutAdditionalType
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minor := pb & maskOutMajorType
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if major != majorTypeSimpleAndFloat {
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panic(fmt.Errorf("Incorrect Major type is: %d in decodeFloat", major))
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}
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switch minor {
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case additionalTypeFloat16:
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panic(fmt.Errorf("float16 is not suppported in decodeFloat"))
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case additionalTypeFloat32:
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pb := readNBytes(src, 4)
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switch string(pb) {
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case float32Nan:
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return math.NaN(), isFloat32
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case float32PosInfinity:
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return math.Inf(0), isFloat32
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case float32NegInfinity:
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return math.Inf(-1), isFloat32
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}
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n := uint32(0)
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for i := 0; i < 4; i++ {
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n = n * 256
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n += uint32(pb[i])
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}
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val := math.Float32frombits(n)
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return float64(val), isFloat32
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case additionalTypeFloat64:
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pb := readNBytes(src, 8)
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switch string(pb) {
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case float64Nan:
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return math.NaN(), isFloat64
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case float64PosInfinity:
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return math.Inf(0), isFloat64
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case float64NegInfinity:
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return math.Inf(-1), isFloat64
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}
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n := uint64(0)
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for i := 0; i < 8; i++ {
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n = n * 256
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n += uint64(pb[i])
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}
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val := math.Float64frombits(n)
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return val, isFloat64
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}
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panic(fmt.Errorf("Invalid Additional Type: %d in decodeFloat", minor))
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}
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func decodeStringComplex(dst []byte, s string, pos uint) []byte {
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i := int(pos)
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start := 0
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for i < len(s) {
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b := s[i]
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if b >= utf8.RuneSelf {
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r, size := utf8.DecodeRuneInString(s[i:])
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if r == utf8.RuneError && size == 1 {
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// In case of error, first append previous simple characters to
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// the byte slice if any and append a replacement character code
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// in place of the invalid sequence.
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if start < i {
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dst = append(dst, s[start:i]...)
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}
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dst = append(dst, `\ufffd`...)
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i += size
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start = i
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continue
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}
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i += size
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continue
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}
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if b >= 0x20 && b <= 0x7e && b != '\\' && b != '"' {
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i++
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continue
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}
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// We encountered a character that needs to be encoded.
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// Let's append the previous simple characters to the byte slice
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// and switch our operation to read and encode the remainder
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// characters byte-by-byte.
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if start < i {
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dst = append(dst, s[start:i]...)
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}
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switch b {
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case '"', '\\':
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dst = append(dst, '\\', b)
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case '\b':
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dst = append(dst, '\\', 'b')
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case '\f':
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dst = append(dst, '\\', 'f')
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case '\n':
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dst = append(dst, '\\', 'n')
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case '\r':
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dst = append(dst, '\\', 'r')
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case '\t':
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dst = append(dst, '\\', 't')
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default:
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dst = append(dst, '\\', 'u', '0', '0', hexTable[b>>4], hexTable[b&0xF])
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}
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i++
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start = i
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}
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if start < len(s) {
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dst = append(dst, s[start:]...)
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}
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return dst
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}
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func decodeString(src *bufio.Reader, noQuotes bool) []byte {
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pb := readByte(src)
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major := pb & maskOutAdditionalType
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minor := pb & maskOutMajorType
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if major != majorTypeByteString {
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panic(fmt.Errorf("Major type is: %d in decodeString", major))
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}
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result := []byte{}
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if !noQuotes {
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result = append(result, '"')
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}
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length := decodeIntAdditionalType(src, minor)
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len := int(length)
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pbs := readNBytes(src, len)
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result = append(result, pbs...)
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if noQuotes {
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return result
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}
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return append(result, '"')
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}
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func decodeUTF8String(src *bufio.Reader) []byte {
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pb := readByte(src)
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major := pb & maskOutAdditionalType
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minor := pb & maskOutMajorType
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if major != majorTypeUtf8String {
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panic(fmt.Errorf("Major type is: %d in decodeUTF8String", major))
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}
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result := []byte{'"'}
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length := decodeIntAdditionalType(src, minor)
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len := int(length)
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pbs := readNBytes(src, len)
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for i := 0; i < len; i++ {
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// Check if the character needs encoding. Control characters, slashes,
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// and the double quote need json encoding. Bytes above the ascii
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// boundary needs utf8 encoding.
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if pbs[i] < 0x20 || pbs[i] > 0x7e || pbs[i] == '\\' || pbs[i] == '"' {
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// We encountered a character that needs to be encoded. Switch
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// to complex version of the algorithm.
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dst := []byte{'"'}
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dst = decodeStringComplex(dst, string(pbs), uint(i))
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return append(dst, '"')
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}
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}
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// The string has no need for encoding and therefore is directly
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// appended to the byte slice.
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result = append(result, pbs...)
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return append(result, '"')
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}
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func array2Json(src *bufio.Reader, dst io.Writer) {
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dst.Write([]byte{'['})
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pb := readByte(src)
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major := pb & maskOutAdditionalType
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minor := pb & maskOutMajorType
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if major != majorTypeArray {
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panic(fmt.Errorf("Major type is: %d in array2Json", major))
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}
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len := 0
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unSpecifiedCount := false
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if minor == additionalTypeInfiniteCount {
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unSpecifiedCount = true
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} else {
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length := decodeIntAdditionalType(src, minor)
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len = int(length)
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}
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for i := 0; unSpecifiedCount || i < len; i++ {
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if unSpecifiedCount {
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pb, e := src.Peek(1)
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if e != nil {
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panic(e)
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}
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if pb[0] == majorTypeSimpleAndFloat|additionalTypeBreak {
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readByte(src)
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break
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}
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}
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cbor2JsonOneObject(src, dst)
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if unSpecifiedCount {
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pb, e := src.Peek(1)
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if e != nil {
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panic(e)
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}
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if pb[0] == majorTypeSimpleAndFloat|additionalTypeBreak {
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readByte(src)
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break
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}
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dst.Write([]byte{','})
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} else if i+1 < len {
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dst.Write([]byte{','})
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}
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}
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dst.Write([]byte{']'})
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}
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func map2Json(src *bufio.Reader, dst io.Writer) {
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pb := readByte(src)
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major := pb & maskOutAdditionalType
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minor := pb & maskOutMajorType
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if major != majorTypeMap {
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panic(fmt.Errorf("Major type is: %d in map2Json", major))
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}
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len := 0
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unSpecifiedCount := false
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if minor == additionalTypeInfiniteCount {
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unSpecifiedCount = true
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} else {
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length := decodeIntAdditionalType(src, minor)
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len = int(length)
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}
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dst.Write([]byte{'{'})
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for i := 0; unSpecifiedCount || i < len; i++ {
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if unSpecifiedCount {
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pb, e := src.Peek(1)
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if e != nil {
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panic(e)
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}
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if pb[0] == majorTypeSimpleAndFloat|additionalTypeBreak {
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readByte(src)
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break
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}
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}
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cbor2JsonOneObject(src, dst)
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if i%2 == 0 {
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// Even position values are keys.
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dst.Write([]byte{':'})
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} else {
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if unSpecifiedCount {
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pb, e := src.Peek(1)
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if e != nil {
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panic(e)
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}
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if pb[0] == majorTypeSimpleAndFloat|additionalTypeBreak {
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readByte(src)
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break
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}
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dst.Write([]byte{','})
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} else if i+1 < len {
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dst.Write([]byte{','})
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}
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}
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}
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dst.Write([]byte{'}'})
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}
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func decodeTagData(src *bufio.Reader) []byte {
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pb := readByte(src)
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major := pb & maskOutAdditionalType
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minor := pb & maskOutMajorType
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if major != majorTypeTags {
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panic(fmt.Errorf("Major type is: %d in decodeTagData", major))
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}
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switch minor {
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case additionalTypeTimestamp:
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return decodeTimeStamp(src)
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// Tag value is larger than 256 (so uint16).
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case additionalTypeIntUint16:
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val := decodeIntAdditionalType(src, minor)
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switch uint16(val) {
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case additionalTypeEmbeddedJSON:
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pb := readByte(src)
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dataMajor := pb & maskOutAdditionalType
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if dataMajor != majorTypeByteString {
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panic(fmt.Errorf("Unsupported embedded Type: %d in decodeEmbeddedJSON", dataMajor))
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}
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src.UnreadByte()
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return decodeString(src, true)
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case additionalTypeTagNetworkAddr:
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octets := decodeString(src, true)
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ss := []byte{'"'}
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switch len(octets) {
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case 6: // MAC address.
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ha := net.HardwareAddr(octets)
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ss = append(append(ss, ha.String()...), '"')
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case 4: // IPv4 address.
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fallthrough
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case 16: // IPv6 address.
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ip := net.IP(octets)
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ss = append(append(ss, ip.String()...), '"')
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default:
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panic(fmt.Errorf("Unexpected Network Address length: %d (expected 4,6,16)", len(octets)))
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}
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return ss
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case additionalTypeTagNetworkPrefix:
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pb := readByte(src)
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if pb != majorTypeMap|0x1 {
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panic(fmt.Errorf("IP Prefix is NOT of MAP of 1 elements as expected"))
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}
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octets := decodeString(src, true)
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val := decodeInteger(src)
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ip := net.IP(octets)
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var mask net.IPMask
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pfxLen := int(val)
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if len(octets) == 4 {
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mask = net.CIDRMask(pfxLen, 32)
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} else {
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mask = net.CIDRMask(pfxLen, 128)
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}
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ipPfx := net.IPNet{IP: ip, Mask: mask}
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ss := []byte{'"'}
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ss = append(append(ss, ipPfx.String()...), '"')
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return ss
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case additionalTypeTagHexString:
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octets := decodeString(src, true)
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ss := []byte{'"'}
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for _, v := range octets {
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ss = append(ss, hexTable[v>>4], hexTable[v&0x0f])
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}
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return append(ss, '"')
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default:
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panic(fmt.Errorf("Unsupported Additional Tag Type: %d in decodeTagData", val))
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}
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}
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panic(fmt.Errorf("Unsupported Additional Type: %d in decodeTagData", minor))
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}
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func decodeTimeStamp(src *bufio.Reader) []byte {
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pb := readByte(src)
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src.UnreadByte()
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tsMajor := pb & maskOutAdditionalType
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if tsMajor == majorTypeUnsignedInt || tsMajor == majorTypeNegativeInt {
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n := decodeInteger(src)
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t := time.Unix(n, 0)
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if decodeTimeZone != nil {
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t = t.In(decodeTimeZone)
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} else {
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t = t.In(time.UTC)
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}
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tsb := []byte{}
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tsb = append(tsb, '"')
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tsb = t.AppendFormat(tsb, IntegerTimeFieldFormat)
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tsb = append(tsb, '"')
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return tsb
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} else if tsMajor == majorTypeSimpleAndFloat {
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n, _ := decodeFloat(src)
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secs := int64(n)
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n -= float64(secs)
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n *= float64(1e9)
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t := time.Unix(secs, int64(n))
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if decodeTimeZone != nil {
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t = t.In(decodeTimeZone)
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} else {
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t = t.In(time.UTC)
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}
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tsb := []byte{}
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tsb = append(tsb, '"')
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tsb = t.AppendFormat(tsb, NanoTimeFieldFormat)
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tsb = append(tsb, '"')
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return tsb
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}
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panic(fmt.Errorf("TS format is neigther int nor float: %d", tsMajor))
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}
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func decodeSimpleFloat(src *bufio.Reader) []byte {
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pb := readByte(src)
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major := pb & maskOutAdditionalType
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minor := pb & maskOutMajorType
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if major != majorTypeSimpleAndFloat {
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panic(fmt.Errorf("Major type is: %d in decodeSimpleFloat", major))
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}
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switch minor {
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case additionalTypeBoolTrue:
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return []byte("true")
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case additionalTypeBoolFalse:
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return []byte("false")
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case additionalTypeNull:
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return []byte("null")
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case additionalTypeFloat16:
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fallthrough
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case additionalTypeFloat32:
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fallthrough
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case additionalTypeFloat64:
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src.UnreadByte()
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v, bc := decodeFloat(src)
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ba := []byte{}
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switch {
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case math.IsNaN(v):
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return []byte("\"NaN\"")
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case math.IsInf(v, 1):
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return []byte("\"+Inf\"")
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case math.IsInf(v, -1):
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return []byte("\"-Inf\"")
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}
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if bc == isFloat32 {
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ba = strconv.AppendFloat(ba, v, 'f', -1, 32)
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} else if bc == isFloat64 {
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ba = strconv.AppendFloat(ba, v, 'f', -1, 64)
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} else {
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panic(fmt.Errorf("Invalid Float precision from decodeFloat: %d", bc))
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}
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return ba
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default:
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panic(fmt.Errorf("Invalid Additional Type: %d in decodeSimpleFloat", minor))
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}
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}
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func cbor2JsonOneObject(src *bufio.Reader, dst io.Writer) {
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pb, e := src.Peek(1)
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if e != nil {
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panic(e)
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}
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major := (pb[0] & maskOutAdditionalType)
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switch major {
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case majorTypeUnsignedInt:
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fallthrough
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case majorTypeNegativeInt:
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n := decodeInteger(src)
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dst.Write([]byte(strconv.Itoa(int(n))))
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case majorTypeByteString:
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s := decodeString(src, false)
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dst.Write(s)
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case majorTypeUtf8String:
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s := decodeUTF8String(src)
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dst.Write(s)
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case majorTypeArray:
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array2Json(src, dst)
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case majorTypeMap:
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map2Json(src, dst)
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case majorTypeTags:
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s := decodeTagData(src)
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dst.Write(s)
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case majorTypeSimpleAndFloat:
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s := decodeSimpleFloat(src)
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dst.Write(s)
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}
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}
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func moreBytesToRead(src *bufio.Reader) bool {
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_, e := src.ReadByte()
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if e == nil {
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src.UnreadByte()
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return true
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}
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return false
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}
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// Cbor2JsonManyObjects decodes all the CBOR Objects read from src
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// reader. It keeps on decoding until reader returns EOF (error when reading).
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// Decoded string is written to the dst. At the end of every CBOR Object
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|
// newline is written to the output stream.
|
|
//
|
|
// Returns error (if any) that was encountered during decode.
|
|
// The child functions will generate a panic when error is encountered and
|
|
// this function will recover non-runtime Errors and return the reason as error.
|
|
func Cbor2JsonManyObjects(src io.Reader, dst io.Writer) (err error) {
|
|
defer func() {
|
|
if r := recover(); r != nil {
|
|
if _, ok := r.(runtime.Error); ok {
|
|
panic(r)
|
|
}
|
|
err = r.(error)
|
|
}
|
|
}()
|
|
bufRdr := bufio.NewReader(src)
|
|
for moreBytesToRead(bufRdr) {
|
|
cbor2JsonOneObject(bufRdr, dst)
|
|
dst.Write([]byte("\n"))
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Detect if the bytes to be printed is Binary or not.
|
|
func binaryFmt(p []byte) bool {
|
|
if len(p) > 0 && p[0] > 0x7F {
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
func getReader(str string) *bufio.Reader {
|
|
return bufio.NewReader(strings.NewReader(str))
|
|
}
|
|
|
|
// DecodeIfBinaryToString converts a binary formatted log msg to a
|
|
// JSON formatted String Log message - suitable for printing to Console/Syslog.
|
|
func DecodeIfBinaryToString(in []byte) string {
|
|
if binaryFmt(in) {
|
|
var b bytes.Buffer
|
|
Cbor2JsonManyObjects(strings.NewReader(string(in)), &b)
|
|
return b.String()
|
|
}
|
|
return string(in)
|
|
}
|
|
|
|
// DecodeObjectToStr checks if the input is a binary format, if so,
|
|
// it will decode a single Object and return the decoded string.
|
|
func DecodeObjectToStr(in []byte) string {
|
|
if binaryFmt(in) {
|
|
var b bytes.Buffer
|
|
cbor2JsonOneObject(getReader(string(in)), &b)
|
|
return b.String()
|
|
}
|
|
return string(in)
|
|
}
|
|
|
|
// DecodeIfBinaryToBytes checks if the input is a binary format, if so,
|
|
// it will decode all Objects and return the decoded string as byte array.
|
|
func DecodeIfBinaryToBytes(in []byte) []byte {
|
|
if binaryFmt(in) {
|
|
var b bytes.Buffer
|
|
Cbor2JsonManyObjects(bytes.NewReader(in), &b)
|
|
return b.Bytes()
|
|
}
|
|
return in
|
|
}
|