use fs wrapper

Author: v1rtl

pkg/fs/fs.go

@@ -0,0 +1,89 @@
+// Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com>
+// All rights reservefs.
+//
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package fs
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+)
+
+// osFile is an interface for interacting with a file. In Go, the underlying
+// type of osFile is always simply *os.File. In JavaScript/Wasm, the underlying
+// type is a wrapper type which mimics the functionality of os.File.
+type OsFile interface {
+	// Stat returns the FileInfo structure describing file. If there is an error,
+	// it will be of type *PathError.
+	Stat() (os.FileInfo, error)
+	// Read reads up to len(b) bytes from the File. It returns the number of bytes
+	// read and any error encountered. At end of file, Read returns 0, io.EOF.
+	Read(b []byte) (n int, err error)
+	// ReadAt reads len(b) bytes from the File starting at byte offset off. It
+	// returns the number of bytes read and the error, if any. ReadAt always
+	// returns a non-nil error when n < len(b). At end of file, that error is
+	// io.EOF.
+	ReadAt(b []byte, off int64) (n int, err error)
+	// Write writes len(b) bytes to the File. It returns the number of bytes
+	// written and an error, if any. Write returns a non-nil error when n !=
+	// len(b).
+	Write(b []byte) (n int, err error)
+	// Seek sets the offset for the next Read or Write on file to offset,
+	// interpreted according to whence: 0 means relative to the origin of the
+	// file, 1 means relative to the current offset, and 2 means relative to the
+	// end. It returns the new offset and an error, if any. The behavior of Seek
+	// on a file opened with O_APPEND is not specified.
+	Seek(offset int64, whence int) (ret int64, err error)
+	// Sync commits the current contents of the file to stable storage. Typically,
+	// this means flushing the file system's in-memory copy of recently written
+	// data to disk.
+	Sync() error
+	// Close closes the File, rendering it unusable for I/O. On files that support
+	// SetDeadline, any pending I/O operations will be canceled and return
+	// immediately with an error.
+	Close() error
+
+	WriteAt([]byte, int64) (int, error)
+	Truncate(size int64) error
+	WriteString(s string) (n int, err error)
+}
+
+func ReadFile(filename string) ([]byte, error) {
+	f, err := osOpen(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return io.ReadAll(f)
+}
+
+func MkdirAll(path string, perm os.FileMode) error {
+	return osMkdirAll(path, perm)
+}
+
+func Open(name string) (OsFile, error) {
+	return osOpen(name)
+}
+
+func OpenFile(name string, flag int, perm os.FileMode) (OsFile, error) {
+	return osOpenFile(name, flag, perm)
+}
+
+func WriteFile(filename string, data []byte, perm os.FileMode) error {
+	if err := MkdirAll(filepath.Dir(filename), 0o755); err != nil {
+		return err
+	}
+	return writeFile(filename, data, perm)
+}
+
+func Stat(name string) (os.FileInfo, error) {
+	return fsStat(name)
+}
+
+func Remove(name string) error {
+	return osRemove(name)
+}