72 lines
1.7 KiB
Go
72 lines
1.7 KiB
Go
// Copyright (C) 2018 Storj Labs, Inc.
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// See LICENSE for copying information.
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package readcloser
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import (
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"io"
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"storj.io/storj/pkg/utils"
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)
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type eofReadCloser struct{}
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func (eofReadCloser) Read([]byte) (int, error) {
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return 0, io.EOF
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}
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func (eofReadCloser) Close() error {
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return nil
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}
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type multiReadCloser struct {
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readers []io.ReadCloser
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}
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// MultiReadCloser is a MultiReader extension that returns a ReaderCloser
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// that's the logical concatenation of the provided input readers.
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// They're read sequentially. Once all inputs have returned EOF,
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// Read will return EOF. If any of the readers return a non-nil,
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// non-EOF error, Read will return that error.
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func MultiReadCloser(readers ...io.ReadCloser) io.ReadCloser {
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r := make([]io.ReadCloser, len(readers))
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copy(r, readers)
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return &multiReadCloser{r}
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}
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func (mr *multiReadCloser) Read(p []byte) (n int, err error) {
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for len(mr.readers) > 0 {
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// Optimization to flatten nested multiReaders.
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if len(mr.readers) == 1 {
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if r, ok := mr.readers[0].(*multiReadCloser); ok {
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mr.readers = r.readers
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continue
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}
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}
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n, err = mr.readers[0].Read(p)
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if err == io.EOF {
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utils.LogClose(mr.readers[0])
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// Use eofReader instead of nil to avoid nil panic
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// after performing flatten (Issue 18232).
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mr.readers[0] = eofReadCloser{} // permit earlier GC
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mr.readers = mr.readers[1:]
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}
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if n > 0 || err != io.EOF {
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if err == io.EOF && len(mr.readers) > 0 {
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// Don't return EOF yet. More readers remain.
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err = nil
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}
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return
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}
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}
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return 0, io.EOF
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}
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func (mr *multiReadCloser) Close() error {
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errs := make([]error, len(mr.readers))
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for i, r := range mr.readers {
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errs[i] = r.Close()
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}
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return utils.CombineErrors(errs...)
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}
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