constellation/cli/file/file.go
Leonard Cohnen 2d8fcd9bf4 monorepo
Co-authored-by: Malte Poll <mp@edgeless.systems>
Co-authored-by: katexochen <katexochen@users.noreply.github.com>
Co-authored-by: Daniel Weiße <dw@edgeless.systems>
Co-authored-by: Thomas Tendyck <tt@edgeless.systems>
Co-authored-by: Benedict Schlueter <bs@edgeless.systems>
Co-authored-by: leongross <leon.gross@rub.de>
Co-authored-by: Moritz Eckert <m1gh7ym0@gmail.com>
2022-03-22 16:09:39 +01:00

87 lines
2.3 KiB
Go

/*
Package file provides functions that combine file handling, JSON marshaling
and file system abstraction.
*/
package file
import (
"encoding/json"
"io"
"io/fs"
"os"
"github.com/spf13/afero"
)
// Handler handles file interaction.
type Handler struct {
fs *afero.Afero
}
// NewHandler returns a new file handler.
func NewHandler(fs afero.Fs) Handler {
afs := &afero.Afero{Fs: fs}
return Handler{fs: afs}
}
// Read reads the file given name and returns the bytes read.
func (h *Handler) Read(name string) ([]byte, error) {
file, err := h.fs.OpenFile(name, os.O_RDONLY, 0o644)
if err != nil {
return nil, err
}
defer file.Close()
return io.ReadAll(file)
}
// Write writes the data bytes into the file with the given name.
// If a file already exists at path and overwrite is true, the file will be
// overwritten. Otherwise, an error is returned.
func (h *Handler) Write(name string, data []byte, overwrite bool) error {
flags := os.O_WRONLY | os.O_CREATE | os.O_EXCL
if overwrite {
flags = os.O_WRONLY | os.O_CREATE | os.O_TRUNC
}
file, err := h.fs.OpenFile(name, flags, 0o644)
if err != nil {
return err
}
_, err = file.Write(data)
if errTmp := file.Close(); errTmp != nil && err == nil {
err = errTmp
}
return err
}
// ReadJSON reads a JSON file from name and unmarshals it into the content interface.
// The interface content must be a pointer to a JSON marchalable object.
func (h *Handler) ReadJSON(name string, content interface{}) error {
data, err := h.Read(name)
if err != nil {
return err
}
return json.Unmarshal(data, content)
}
// WriteJSON marshals the content interface to JSON and writes it to the path with the given name.
// If a file already exists and overwrite is true, the file will be
// overwritten. Otherwise, an error is returned.
func (h *Handler) WriteJSON(name string, content interface{}, overwrite bool) error {
jsonData, err := json.MarshalIndent(content, "", "\t")
if err != nil {
return err
}
return h.Write(name, jsonData, overwrite)
}
// Remove deletes the file with the given name.
func (h *Handler) Remove(name string) error {
return h.fs.Remove(name)
}
// Stat returns a FileInfo describing the named file, or an error, if any
// happens.
func (h *Handler) Stat(name string) (fs.FileInfo, error) {
return h.fs.Stat(name)
}