102 lines
2.8 KiB
Go
102 lines
2.8 KiB
Go
// Package cbor provides primitives for storing different data
|
|
// in the CBOR (binary) format. CBOR is defined in RFC7049.
|
|
package cbor
|
|
|
|
import "time"
|
|
|
|
const (
|
|
majorOffset = 5
|
|
additionalMax = 23
|
|
|
|
// Non Values.
|
|
additionalTypeBoolFalse byte = 20
|
|
additionalTypeBoolTrue byte = 21
|
|
additionalTypeNull byte = 22
|
|
|
|
// Integer (+ve and -ve) Sub-types.
|
|
additionalTypeIntUint8 byte = 24
|
|
additionalTypeIntUint16 byte = 25
|
|
additionalTypeIntUint32 byte = 26
|
|
additionalTypeIntUint64 byte = 27
|
|
|
|
// Float Sub-types.
|
|
additionalTypeFloat16 byte = 25
|
|
additionalTypeFloat32 byte = 26
|
|
additionalTypeFloat64 byte = 27
|
|
additionalTypeBreak byte = 31
|
|
|
|
// Tag Sub-types.
|
|
additionalTypeTimestamp byte = 01
|
|
|
|
// Extended Tags - from https://www.iana.org/assignments/cbor-tags/cbor-tags.xhtml
|
|
additionalTypeTagNetworkAddr uint16 = 260
|
|
additionalTypeTagNetworkPrefix uint16 = 261
|
|
additionalTypeEmbeddedJSON uint16 = 262
|
|
additionalTypeTagHexString uint16 = 263
|
|
|
|
// Unspecified number of elements.
|
|
additionalTypeInfiniteCount byte = 31
|
|
)
|
|
const (
|
|
majorTypeUnsignedInt byte = iota << majorOffset // Major type 0
|
|
majorTypeNegativeInt // Major type 1
|
|
majorTypeByteString // Major type 2
|
|
majorTypeUtf8String // Major type 3
|
|
majorTypeArray // Major type 4
|
|
majorTypeMap // Major type 5
|
|
majorTypeTags // Major type 6
|
|
majorTypeSimpleAndFloat // Major type 7
|
|
)
|
|
|
|
const (
|
|
maskOutAdditionalType byte = (7 << majorOffset)
|
|
maskOutMajorType byte = 31
|
|
)
|
|
|
|
const (
|
|
float32Nan = "\xfa\x7f\xc0\x00\x00"
|
|
float32PosInfinity = "\xfa\x7f\x80\x00\x00"
|
|
float32NegInfinity = "\xfa\xff\x80\x00\x00"
|
|
float64Nan = "\xfb\x7f\xf8\x00\x00\x00\x00\x00\x00"
|
|
float64PosInfinity = "\xfb\x7f\xf0\x00\x00\x00\x00\x00\x00"
|
|
float64NegInfinity = "\xfb\xff\xf0\x00\x00\x00\x00\x00\x00"
|
|
)
|
|
|
|
// IntegerTimeFieldFormat indicates the format of timestamp decoded
|
|
// from an integer (time in seconds).
|
|
var IntegerTimeFieldFormat = time.RFC3339
|
|
|
|
// NanoTimeFieldFormat indicates the format of timestamp decoded
|
|
// from a float value (time in seconds and nanoseconds).
|
|
var NanoTimeFieldFormat = time.RFC3339Nano
|
|
|
|
func appendCborTypePrefix(dst []byte, major byte, number uint64) []byte {
|
|
byteCount := 8
|
|
var minor byte
|
|
switch {
|
|
case number < 256:
|
|
byteCount = 1
|
|
minor = additionalTypeIntUint8
|
|
|
|
case number < 65536:
|
|
byteCount = 2
|
|
minor = additionalTypeIntUint16
|
|
|
|
case number < 4294967296:
|
|
byteCount = 4
|
|
minor = additionalTypeIntUint32
|
|
|
|
default:
|
|
byteCount = 8
|
|
minor = additionalTypeIntUint64
|
|
|
|
}
|
|
|
|
dst = append(dst, major|minor)
|
|
byteCount--
|
|
for ; byteCount >= 0; byteCount-- {
|
|
dst = append(dst, byte(number>>(uint(byteCount)*8)))
|
|
}
|
|
return dst
|
|
}
|