55 lines
1.6 KiB
Go
55 lines
1.6 KiB
Go
// Copyright 2018 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Package vecnet provides access to recvmsg syscalls on net.Conns.
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package vecnet
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import (
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"io"
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"net"
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"syscall"
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)
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// Buffers points to zero or more buffers to read into.
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//
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// On connections that support it, ReadFrom is optimized into the batch read
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// operation recvmsg.
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type Buffers net.Buffers
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// ReadFrom reads into the pre-allocated bufs. Returns bytes read.
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//
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// ReadFrom keeps reading until all bufs are filled or EOF is received.
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//
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// The pre-allocatted space used by ReadFrom is based upon slice lengths.
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func (bufs Buffers) ReadFrom(r io.Reader) (int64, error) {
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if conn, ok := r.(syscall.Conn); ok && readFromBuffers != nil {
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return readFromBuffers(bufs, conn)
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}
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var total int64
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for _, buf := range bufs {
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for filled := 0; filled < len(buf); {
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n, err := r.Read(buf[filled:])
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total += int64(n)
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filled += n
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if (n == 0 && err == nil) || err == io.EOF {
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return total, io.EOF
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} else if err != nil {
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return total, err
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}
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}
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}
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return total, nil
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}
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