54 lines
1.2 KiB
Go
54 lines
1.2 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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// Package dirwalk contains code to walk a directory.
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package dirwalk
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import (
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"io"
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"io/fs"
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"os"
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"go4.org/mem"
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)
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var osWalkShallow func(name mem.RO, fn WalkFunc) error
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// WalkFunc is the callback type used with WalkShallow.
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//
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// The name and de are only valid for the duration of func's call
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// and should not be retained.
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type WalkFunc func(name mem.RO, de fs.DirEntry) error
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// WalkShallow reads the entries in the named directory and calls fn for each.
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// It does not recurse into subdirectories.
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//
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// If fn returns an error, iteration stops and WalkShallow returns that value.
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//
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// On Linux, WalkShallow does not allocate, so long as certain methods on the
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// WalkFunc's DirEntry are not called which necessarily allocate.
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func WalkShallow(dirName mem.RO, fn WalkFunc) error {
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if f := osWalkShallow; f != nil {
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return f(dirName, fn)
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}
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of, err := os.Open(dirName.StringCopy())
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if err != nil {
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return err
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}
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defer of.Close()
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for {
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fis, err := of.ReadDir(100)
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for _, de := range fis {
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if err := fn(mem.S(de.Name()), de); err != nil {
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return err
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}
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}
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if err != nil {
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if err == io.EOF {
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return nil
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}
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return err
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}
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}
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}
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