57 lines
1.5 KiB
Go
57 lines
1.5 KiB
Go
// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
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//
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// This program is free software: you can redistribute it and/or modify it
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// under the terms of the GNU General Public License as published by the Free
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// Software Foundation, either version 3 of the License, or (at your option)
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// any later version.
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//
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// This program is distributed in the hope that it will be useful, but WITHOUT
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// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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// more details.
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//
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// You should have received a copy of the GNU General Public License along
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// with this program. If not, see <http://www.gnu.org/licenses/>.
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package protocol
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import "github.com/calmh/xdr"
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type header struct {
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version int
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msgID int
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msgType int
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compression bool
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}
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func (h header) encodeXDR(xw *xdr.Writer) (int, error) {
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u := encodeHeader(h)
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return xw.WriteUint32(u)
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}
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func (h *header) decodeXDR(xr *xdr.Reader) error {
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u := xr.ReadUint32()
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*h = decodeHeader(u)
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return xr.Error()
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}
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func encodeHeader(h header) uint32 {
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var isComp uint32
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if h.compression {
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isComp = 1 << 0 // the zeroth bit is the compression bit
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}
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return uint32(h.version&0xf)<<28 +
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uint32(h.msgID&0xfff)<<16 +
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uint32(h.msgType&0xff)<<8 +
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isComp
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}
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func decodeHeader(u uint32) header {
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return header{
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version: int(u>>28) & 0xf,
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msgID: int(u>>16) & 0xfff,
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msgType: int(u>>8) & 0xff,
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compression: u&1 == 1,
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}
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}
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