storj/cmd/uplinkng/ulfs/local.go

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// Copyright (C) 2021 Storj Labs, Inc.
// See LICENSE for copying information.
package ulfs
import (
"context"
"io/ioutil"
"os"
"path/filepath"
"strings"
"github.com/zeebo/errs"
"storj.io/storj/cmd/uplinkng/ulloc"
)
// Local implements something close to a filesystem but backed by the local disk.
type Local struct{}
// NewLocal constructs a Local filesystem.
func NewLocal() *Local {
return &Local{}
}
func (l *Local) abs(path string) (string, error) {
abs, err := filepath.Abs(path)
if err != nil {
return "", errs.Wrap(err)
}
if strings.HasSuffix(path, string(filepath.Separator)) &&
!strings.HasSuffix(abs, string(filepath.Separator)) {
abs += string(filepath.Separator)
}
return abs, nil
}
// Open returns a read ReadHandle for the given local path.
func (l *Local) Open(ctx context.Context, path string) (ReadHandle, error) {
path, err := l.abs(path)
if err != nil {
return nil, err
}
fh, err := os.Open(path)
if err != nil {
return nil, errs.Wrap(err)
}
return newOSReadHandle(fh)
}
// Create makes any directories necessary to create a file at path and returns a WriteHandle.
func (l *Local) Create(ctx context.Context, path string) (WriteHandle, error) {
path, err := l.abs(path)
if err != nil {
return nil, err
}
fi, err := os.Stat(path)
if err != nil && !os.IsNotExist(err) {
return nil, errs.Wrap(err)
} else if err == nil && fi.IsDir() {
return nil, errs.New("path exists as a directory already")
}
if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
return nil, errs.Wrap(err)
}
// TODO: atomic rename
fh, err := os.Create(path)
if err != nil {
return nil, errs.Wrap(err)
}
return newOSWriteHandle(fh), nil
}
// Remove unlinks the file at the path. It is not an error if the file does not exist.
func (l *Local) Remove(ctx context.Context, path string) error {
path, err := l.abs(path)
if err != nil {
return err
}
if err := os.Remove(path); os.IsNotExist(err) {
return nil
} else if err != nil {
return err
}
return nil
}
// ListObjects returns an ObjectIterator listing files and directories that have string prefix
// with the provided path.
func (l *Local) ListObjects(ctx context.Context, path string, recursive bool) (ObjectIterator, error) {
path, err := l.abs(path)
if err != nil {
return nil, err
}
prefix := path
if idx := strings.LastIndexByte(path, filepath.Separator); idx >= 0 {
prefix = path[:idx+1]
}
var files []os.FileInfo
if recursive {
err = filepath.Walk(prefix, func(path string, info os.FileInfo, err error) error {
if err == nil && !info.IsDir() {
files = append(files, &namedFileInfo{
FileInfo: info,
name: path[len(prefix):],
})
}
return nil
})
} else {
files, err = ioutil.ReadDir(prefix)
}
if err != nil {
return nil, err
}
trim := prefix
if recursive {
trim = ""
}
return &filteredObjectIterator{
trim: trim,
filter: path,
iter: &fileinfoObjectIterator{
base: prefix,
files: files,
},
}, nil
}
// IsLocalDir returns true if the path is a directory.
func (l *Local) IsLocalDir(ctx context.Context, path string) bool {
fi, err := os.Stat(path)
if err != nil {
return false
}
return fi.IsDir()
}
type namedFileInfo struct {
os.FileInfo
name string
}
func (n *namedFileInfo) Name() string { return n.name }
type fileinfoObjectIterator struct {
base string
files []os.FileInfo
current os.FileInfo
}
func (fi *fileinfoObjectIterator) Next() bool {
if len(fi.files) == 0 {
return false
}
fi.current, fi.files = fi.files[0], fi.files[1:]
return true
}
func (fi *fileinfoObjectIterator) Err() error { return nil }
func (fi *fileinfoObjectIterator) Item() ObjectInfo {
name := filepath.Join(fi.base, fi.current.Name())
isDir := fi.current.IsDir()
if isDir {
name += string(filepath.Separator)
}
// TODO(jeff): is this the right thing to do on windows? is there more to do?
// convert the paths to be forward slash based because keys are supposed to always be remote
if filepath.Separator != '/' {
name = strings.ReplaceAll(name, string(filepath.Separator), "/")
}
return ObjectInfo{
Loc: ulloc.NewLocal(name),
IsPrefix: isDir,
Created: fi.current.ModTime(), // TODO: use real crtime
ContentLength: fi.current.Size(),
}
}