mirror of https://github.com/docker/cli.git
68 lines
1.3 KiB
Go
68 lines
1.3 KiB
Go
package sysx
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import (
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"bytes"
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"fmt"
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"syscall"
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)
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const defaultXattrBufferSize = 5
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var ErrNotSupported = fmt.Errorf("not supported")
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type listxattrFunc func(path string, dest []byte) (int, error)
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func listxattrAll(path string, listFunc listxattrFunc) ([]string, error) {
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var p []byte // nil on first execution
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for {
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n, err := listFunc(path, p) // first call gets buffer size.
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if err != nil {
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return nil, err
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}
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if n > len(p) {
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p = make([]byte, n)
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continue
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}
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p = p[:n]
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ps := bytes.Split(bytes.TrimSuffix(p, []byte{0}), []byte{0})
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var entries []string
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for _, p := range ps {
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s := string(p)
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if s != "" {
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entries = append(entries, s)
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}
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}
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return entries, nil
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}
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}
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type getxattrFunc func(string, string, []byte) (int, error)
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func getxattrAll(path, attr string, getFunc getxattrFunc) ([]byte, error) {
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p := make([]byte, defaultXattrBufferSize)
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for {
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n, err := getFunc(path, attr, p)
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if err != nil {
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if errno, ok := err.(syscall.Errno); ok && errno == syscall.ERANGE {
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p = make([]byte, len(p)*2) // this can't be ideal.
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continue // try again!
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}
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return nil, err
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}
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// realloc to correct size and repeat
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if n > len(p) {
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p = make([]byte, n)
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continue
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}
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return p[:n], nil
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}
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}
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