42 lines
1 KiB
Go
42 lines
1 KiB
Go
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package protocol
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import (
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"encoding/binary"
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"encoding/json"
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"fmt"
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"io"
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)
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// encode is a helper function that encodes any message with the given message type
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func encode(w io.Writer, msgType MessageType, payload interface{}) error {
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var payloadBytes []byte
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var err error
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// Only marshal if payload is not nil
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if payload != nil {
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payloadBytes, err = json.Marshal(payload)
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if err != nil {
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return fmt.Errorf("failed to encode payload: %w", err)
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}
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}
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// Write message type (1 byte)
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if err := binary.Write(w, binary.BigEndian, msgType); err != nil {
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return fmt.Errorf("failed to write message type: %w", err)
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}
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// Write payload length (4 bytes, big-endian)
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if err := binary.Write(w, binary.BigEndian, uint32(len(payloadBytes))); err != nil {
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return fmt.Errorf("failed to write payload length: %w", err)
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}
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// Write JSON payload if we have one
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if len(payloadBytes) > 0 {
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if _, err := w.Write(payloadBytes); err != nil {
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return fmt.Errorf("failed to write payload: %w", err)
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}
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}
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return nil
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}
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