mirror of https://github.com/k3s-io/k3s
71 lines
1.9 KiB
Go
71 lines
1.9 KiB
Go
/*
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Copyright 2016 The Kubernetes Authors.
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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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http://www.apache.org/licenses/LICENSE-2.0
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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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*/
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package ioutils
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import "io"
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// writeCloserWrapper represents a WriteCloser whose closer operation is noop.
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type writeCloserWrapper struct {
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Writer io.Writer
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}
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func (w *writeCloserWrapper) Write(buf []byte) (int, error) {
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return w.Writer.Write(buf)
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}
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func (w *writeCloserWrapper) Close() error {
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return nil
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}
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// WriteCloserWrapper returns a writeCloserWrapper.
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func WriteCloserWrapper(w io.Writer) io.WriteCloser {
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return &writeCloserWrapper{w}
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}
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// LimitWriter is a copy of the standard library ioutils.LimitReader,
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// applied to the writer interface.
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// LimitWriter returns a Writer that writes to w
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// but stops with EOF after n bytes.
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// The underlying implementation is a *LimitedWriter.
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func LimitWriter(w io.Writer, n int64) io.Writer { return &LimitedWriter{w, n} }
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// A LimitedWriter writes to W but limits the amount of
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// data returned to just N bytes. Each call to Write
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// updates N to reflect the new amount remaining.
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// Write returns EOF when N <= 0 or when the underlying W returns EOF.
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type LimitedWriter struct {
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W io.Writer // underlying writer
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N int64 // max bytes remaining
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}
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func (l *LimitedWriter) Write(p []byte) (n int, err error) {
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if l.N <= 0 {
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return 0, io.ErrShortWrite
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}
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truncated := false
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if int64(len(p)) > l.N {
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p = p[0:l.N]
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truncated = true
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}
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n, err = l.W.Write(p)
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l.N -= int64(n)
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if err == nil && truncated {
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err = io.ErrShortWrite
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}
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return
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}
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