70 lines
1.0 KiB
Go
70 lines
1.0 KiB
Go
package fs
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import (
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"fmt"
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"io"
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"os"
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"path/filepath"
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)
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type FS interface {
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isFS()
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}
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type DirEntry struct {
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Name string
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FS FS
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}
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type Entries interface {
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Get() []DirEntry
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}
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type Dir struct {
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Entries
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}
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func (d Dir) isFS() {}
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type Contents interface {
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Get() io.Reader
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}
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type File struct {
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Contents
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}
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func (f File) isFS() {}
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func Realize(path string, f FS) error {
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if f == nil {
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return fmt.Errorf("cannot realize nil FS at %s", path)
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}
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switch t := f.(type) {
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case File:
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osf, err := os.Create(path)
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if err != nil {
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return fmt.Errorf("cannot create file %s: %w", path, err)
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}
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defer osf.Close()
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_, err = io.Copy(osf, t.Get())
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if err != nil {
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return fmt.Errorf("cannot write file %s: %w", path, err)
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}
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case Dir:
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err := os.Mkdir(path, 0666)
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if err != nil {
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return fmt.Errorf("cannot create dir %s: %w", path, err)
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}
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for _, child := range t.Get() {
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err := Realize(filepath.Join(path, child.Name), child.FS)
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if err != nil {
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return err
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}
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}
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default:
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panic("unknown File type")
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}
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return nil
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}
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