kami
60 lines
1.7 KiB
Go
60 lines
1.7 KiB
Go
// voice/frame.go — length-prefixed JSON framing.
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//
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// Same shape as ipc/worker with the 64 MiB cap (see wire.go maxFrame). One
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// frame carries EITHER a Request, Response, or Push — distinguished by the
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// present fields (Request has `id`+`m`; Response has `id`; Push has `kind`).
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// Server-side reads probe all three shallowly; client-side reads expect
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// either Response or Push depending on context.
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package voice
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import (
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"encoding/binary"
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"encoding/json"
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"errors"
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"fmt"
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"io"
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)
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// ErrFrameTooLarge — frame exceeded maxFrame; conn is desynced; caller must close.
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var ErrFrameTooLarge = errors.New("voice: frame too large")
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func writeFrame(w io.Writer, v any) error {
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body, err := json.Marshal(v)
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if err != nil {
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return fmt.Errorf("voice: marshal frame: %w", err)
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}
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if len(body) > maxFrame {
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return fmt.Errorf("%w: %d bytes", ErrFrameTooLarge, len(body))
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}
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var hdr [4]byte
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binary.BigEndian.PutUint32(hdr[:], uint32(len(body)))
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if _, err := w.Write(hdr[:]); err != nil {
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return fmt.Errorf("voice: write frame header: %w", err)
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}
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if _, err := w.Write(body); err != nil {
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return fmt.Errorf("voice: write frame body: %w", err)
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}
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return nil
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}
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func readFrame(r io.Reader, v any) error {
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var hdr [4]byte
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if _, err := io.ReadFull(r, hdr[:]); err != nil {
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if errors.Is(err, io.EOF) {
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return io.EOF
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}
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return fmt.Errorf("voice: read frame header: %w", err)
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}
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n := binary.BigEndian.Uint32(hdr[:])
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if n > maxFrame {
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return fmt.Errorf("%w: %d bytes", ErrFrameTooLarge, n)
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}
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buf := make([]byte, n)
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if _, err := io.ReadFull(r, buf); err != nil {
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return fmt.Errorf("voice: read frame body: %w", err)
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}
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if err := json.Unmarshal(buf, v); err != nil {
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return fmt.Errorf("voice: unmarshal frame: %w", err)
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}
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return nil
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} |