tailscale/util/dirwalk/dirwalk.go
Will Norris 71029cea2d all: update copyright and license headers
This updates all source files to use a new standard header for copyright
and license declaration.  Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.

This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.

Updates #6865

Signed-off-by: Will Norris <will@tailscale.com>
2023-01-27 15:36:29 -08:00

54 lines
1.2 KiB
Go

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