73 lines
1.8 KiB
Go
73 lines
1.8 KiB
Go
/*
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* Copyright (c) 2021 IBM Corp and others.
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*
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* All rights reserved. This program and the accompanying materials
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* are made available under the terms of the Eclipse Public License v2.0
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* and Eclipse Distribution License v1.0 which accompany this distribution.
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*
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* The Eclipse Public License is available at
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* https://www.eclipse.org/legal/epl-2.0/
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* and the Eclipse Distribution License is available at
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* http://www.eclipse.org/org/documents/edl-v10.php.
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*
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* Contributors:
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* Allan Stockdill-Mander
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*/
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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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)
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// UnsubscribePacket is an internal representation of the fields of the
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// Unsubscribe MQTT packet
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type UnsubscribePacket struct {
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FixedHeader
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MessageID uint16
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Topics []string
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}
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func (u *UnsubscribePacket) String() string {
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return fmt.Sprintf("%s MessageID: %d", u.FixedHeader, u.MessageID)
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}
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func (u *UnsubscribePacket) Write(w io.Writer) error {
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var body bytes.Buffer
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var err error
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body.Write(encodeUint16(u.MessageID))
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for _, topic := range u.Topics {
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body.Write(encodeString(topic))
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}
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u.FixedHeader.RemainingLength = body.Len()
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packet := u.FixedHeader.pack()
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packet.Write(body.Bytes())
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_, err = packet.WriteTo(w)
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return err
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}
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// Unpack decodes the details of a ControlPacket after the fixed
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// header has been read
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func (u *UnsubscribePacket) Unpack(b io.Reader) error {
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var err error
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u.MessageID, err = decodeUint16(b)
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if err != nil {
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return err
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}
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for topic, err := decodeString(b); err == nil && topic != ""; topic, err = decodeString(b) {
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u.Topics = append(u.Topics, topic)
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}
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return err
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}
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// Details returns a Details struct containing the Qos and
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// MessageID of this ControlPacket
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func (u *UnsubscribePacket) Details() Details {
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return Details{Qos: 1, MessageID: u.MessageID}
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}
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