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// Copyright (c) 2012-2020 Ugorji Nwoke. All rights reserved.
// Use of this source code is governed by a MIT license found in the LICENSE file.
package codec
import (
"reflect"
)
// major
const (
cborMajorUint byte = iota
cborMajorNegInt
cborMajorBytes
cborMajorString
cborMajorArray
cborMajorMap
cborMajorTag
cborMajorSimpleOrFloat
)
// simple
const (
cborBdFalse byte = 0xf4 + iota
cborBdTrue
cborBdNil
cborBdUndefined
cborBdExt
cborBdFloat16
cborBdFloat32
cborBdFloat64
)
// indefinite
const (
cborBdIndefiniteBytes byte = 0x5f
cborBdIndefiniteString byte = 0x7f
cborBdIndefiniteArray byte = 0x9f
cborBdIndefiniteMap byte = 0xbf
cborBdBreak byte = 0xff
)
// These define some in-stream descriptors for
// manual encoding e.g. when doing explicit indefinite-length
const (
CborStreamBytes byte = 0x5f
CborStreamString byte = 0x7f
CborStreamArray byte = 0x9f
CborStreamMap byte = 0xbf
CborStreamBreak byte = 0xff
)
// base values
const (
cborBaseUint byte = 0x00
cborBaseNegInt byte = 0x20
cborBaseBytes byte = 0x40
cborBaseString byte = 0x60
cborBaseArray byte = 0x80
cborBaseMap byte = 0xa0
cborBaseTag byte = 0xc0
cborBaseSimple byte = 0xe0
)
// const (
// cborSelfDesrTag byte = 0xd9
// cborSelfDesrTag2 byte = 0xd9
// cborSelfDesrTag3 byte = 0xf7
// )
var (
cbordescSimpleNames = map[byte]string{
cborBdNil: "nil",
cborBdFalse: "false",
cborBdTrue: "true",
cborBdFloat16: "float",
cborBdFloat32: "float",
cborBdFloat64: "float",
cborBdBreak: "break",
}
cbordescIndefNames = map[byte]string{
cborBdIndefiniteBytes: "bytes*",
cborBdIndefiniteString: "string*",
cborBdIndefiniteArray: "array*",
cborBdIndefiniteMap: "map*",
}
cbordescMajorNames = map[byte]string{
cborMajorUint: "(u)int",
cborMajorNegInt: "int",
cborMajorBytes: "bytes",
cborMajorString: "string",
cborMajorArray: "array",
cborMajorMap: "map",
cborMajorTag: "tag",
cborMajorSimpleOrFloat: "simple",
}
)
func cbordesc(bd byte) (s string) {
bm := bd >> 5
if bm == cborMajorSimpleOrFloat {
s = cbordescSimpleNames[bd]
} else {
s = cbordescMajorNames[bm]
if s == "" {
s = cbordescIndefNames[bd]
}
}
if s == "" {
s = "unknown"
}
return
}
// -------------------------
// CborHandle is a Handle for the CBOR encoding format,
// defined at http://tools.ietf.org/html/rfc7049 and documented further at http://cbor.io .
//
// CBOR is comprehensively supported, including support for:
// - indefinite-length arrays/maps/bytes/strings
// - (extension) tags in range 0..0xffff (0 .. 65535)
// - half, single and double-precision floats
// - all numbers (1, 2, 4 and 8-byte signed and unsigned integers)
// - nil, true, false, ...
// - arrays and maps, bytes and text strings
//
// None of the optional extensions (with tags) defined in the spec are supported out-of-the-box.
// Users can implement them as needed (using SetExt), including spec-documented ones:
// - timestamp, BigNum, BigFloat, Decimals,
// - Encoded Text (e.g. URL, regexp, base64, MIME Message), etc.
type CborHandle struct {
binaryEncodingType
notJsonType
// noElemSeparators
BasicHandle
// IndefiniteLength=true, means that we encode using indefinitelength
IndefiniteLength bool
// TimeRFC3339 says to encode time.Time using RFC3339 format.
// If unset, we encode time.Time using seconds past epoch.
TimeRFC3339 bool
// SkipUnexpectedTags says to skip over any tags for which extensions are
// not defined. This is in keeping with the cbor spec on "Optional Tagging of Items".
//
// Furthermore, this allows the skipping over of the Self Describing Tag 0xd9d9f7.
SkipUnexpectedTags bool
}
// Name returns the name of the handle: cbor
func (h *CborHandle) Name() string { return "cbor" }
func (h *CborHandle) desc(bd byte) string { return cbordesc(bd) }
// SetInterfaceExt sets an extension
func (h *CborHandle) SetInterfaceExt(rt reflect.Type, tag uint64, ext InterfaceExt) (err error) {
return h.SetExt(rt, tag, makeExt(ext))
}
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