35 lines
637 B
Go
35 lines
637 B
Go
package msgio
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import (
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"encoding/binary"
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"io"
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)
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// NBO is NetworkByteOrder
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var NBO = binary.BigEndian
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// WriteLen writes a length to the given writer.
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func WriteLen(w io.Writer, l int) error {
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ul := uint32(l)
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return binary.Write(w, NBO, &ul)
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}
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// ReadLen reads a length from the given reader.
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// if buf is non-nil, it reuses the buffer. Ex:
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//
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// l, err := ReadLen(r, nil)
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// _, err := ReadLen(r, buf)
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func ReadLen(r io.Reader, buf []byte) (int, error) {
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if len(buf) < 4 {
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buf = make([]byte, 4)
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}
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buf = buf[:4]
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if _, err := io.ReadFull(r, buf); err != nil {
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return 0, err
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}
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n := int(NBO.Uint32(buf))
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return n, nil
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}
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