84 lines
2.0 KiB
Go
84 lines
2.0 KiB
Go
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package packets
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import (
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"bytes"
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"fmt"
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"io"
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"github.com/winc-link/hummingbird/internal/pkg/codes"
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)
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// Pubrel represents the MQTT Pubrel packet
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type Pubrel struct {
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FixHeader *FixHeader
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PacketID PacketID
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// V5
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Code codes.Code
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Properties *Properties
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}
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func (p *Pubrel) String() string {
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return fmt.Sprintf("Pubrel, Code: %v, Pid: %v, Properties: %s", p.Code, p.PacketID, p.Properties)
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}
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// NewPubrelPacket returns a Pubrel instance by the given FixHeader and io.Reader.
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func NewPubrelPacket(fh *FixHeader, r io.Reader) (*Pubrel, error) {
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p := &Pubrel{FixHeader: fh}
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err := p.Unpack(r)
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if err != nil {
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return nil, err
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}
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return p, nil
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}
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// NewPubcomp returns the Pubcomp struct related to the Pubrel struct in QoS 2.
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func (p *Pubrel) NewPubcomp() *Pubcomp {
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pub := &Pubcomp{FixHeader: &FixHeader{PacketType: PUBCOMP, Flags: FlagReserved, RemainLength: 2}}
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pub.PacketID = p.PacketID
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return pub
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}
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// Pack encodes the packet struct into bytes and writes it into io.Writer.
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func (p *Pubrel) Pack(w io.Writer) error {
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p.FixHeader = &FixHeader{PacketType: PUBREL, Flags: FlagPubrel}
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bufw := &bytes.Buffer{}
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writeUint16(bufw, p.PacketID)
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if p.Code != codes.Success || p.Properties != nil {
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bufw.WriteByte(p.Code)
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p.Properties.Pack(bufw, PUBREL)
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}
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p.FixHeader.RemainLength = bufw.Len()
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err := p.FixHeader.Pack(w)
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if err != nil {
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return err
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}
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_, err = bufw.WriteTo(w)
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return err
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}
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// Unpack read the packet bytes from io.Reader and decodes it into the packet struct.
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func (p *Pubrel) Unpack(r io.Reader) error {
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restBuffer := make([]byte, p.FixHeader.RemainLength)
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_, err := io.ReadFull(r, restBuffer)
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if err != nil {
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return codes.ErrMalformed
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}
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bufr := bytes.NewBuffer(restBuffer)
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p.PacketID, err = readUint16(bufr)
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if err != nil {
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return err
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}
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if p.FixHeader.RemainLength == 2 {
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p.Code = codes.Success
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return nil
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}
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p.Properties = &Properties{}
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if p.Code, err = bufr.ReadByte(); err != nil {
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return err
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}
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if !ValidateCode(PUBREL, p.Code) {
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return codes.ErrProtocol
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}
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return p.Properties.Unpack(bufr, PUBREL)
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}
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