Initial project import

tools/v/vlib/io/fs/fs.v

@@ -0,0 +1,163 @@
+module fs
+
+import io
+import os
+
+// FileInfo describes a file or directory entry.
+pub interface FileInfo {
+	name() string
+	size() u64
+	mode() os.FileMode
+	mod_time() i64
+	is_dir() bool
+}
+
+// DirEntry describes a single directory entry.
+pub interface DirEntry {
+	name() string
+	is_dir() bool
+	typ() os.FileType
+	info() !FileInfo
+}
+
+// File is the minimum interface required to read from a filesystem entry.
+pub interface File {
+	io.Reader
+	stat() !FileInfo
+mut:
+	close()
+}
+
+// FS opens slash-separated paths that pass `valid_path`.
+pub interface FS {
+	open(name string) !File
+}
+
+// ReadDirFile can read directory entries directly from an opened file.
+pub interface ReadDirFile {
+	File
+mut:
+	read_dir(n int) ![]DirEntry
+}
+
+// ReadDirFS can read a directory without first opening it as a `File`.
+pub interface ReadDirFS {
+	read_dir(name string) ![]DirEntry
+}
+
+// ReadFileFS can read a whole file without first opening it as a `File`.
+pub interface ReadFileFS {
+	read_file(name string) ![]u8
+}
+
+// StatFS can stat a path without first opening it as a `File`.
+pub interface StatFS {
+	stat(name string) !FileInfo
+}
+
+// GlobFS can expand glob patterns within a filesystem.
+pub interface GlobFS {
+	glob(pattern string) ![]string
+}
+
+// SubFS can return a filesystem rooted at a subdirectory.
+pub interface SubFS {
+	sub(dir string) !FS
+}
+
+struct FileInfoDirEntry {
+	source FileInfo
+}
+
+fn (entry FileInfoDirEntry) name() string {
+	return entry.source.name()
+}
+
+fn (entry FileInfoDirEntry) is_dir() bool {
+	return entry.source.is_dir()
+}
+
+fn (entry FileInfoDirEntry) typ() os.FileType {
+	return entry.source.mode().typ
+}
+
+fn (entry FileInfoDirEntry) info() !FileInfo {
+	return entry.source
+}
+
+fn sort_dir_entries(mut entries []DirEntry) {
+	entries.sort(a.name() < b.name())
+}
+
+// valid_path reports whether `name` is a valid slash-separated path for `FS.open`.
+pub fn valid_path(name string) bool {
+	if name == '.' {
+		return true
+	}
+	if name.len == 0 {
+		return false
+	}
+	for elem in name.split('/') {
+		if elem.len == 0 || elem == '.' || elem == '..' {
+			return false
+		}
+	}
+	return true
+}
+
+// file_info_to_dir_entry wraps a `FileInfo` in a `DirEntry`.
+pub fn file_info_to_dir_entry(info FileInfo) DirEntry {
+	return FileInfoDirEntry{
+		source: info
+	}
+}
+
+// read_file reads the named file from `filesystem`.
+pub fn read_file(filesystem FS, name string) ![]u8 {
+	if filesystem is ReadFileFS {
+		reader := filesystem as ReadFileFS
+		return reader.read_file(name)
+	}
+	mut file := filesystem.open(name)!
+	defer {
+		file.close()
+	}
+	reader := file as io.Reader
+	return io.read_all(
+		reader:                reader
+		read_to_end_of_stream: true
+	)
+}
+
+// read_dir reads and sorts the named directory from `filesystem`.
+pub fn read_dir(filesystem FS, name string) ![]DirEntry {
+	if filesystem is ReadDirFS {
+		reader := filesystem as ReadDirFS
+		mut entries := reader.read_dir(name)!
+		sort_dir_entries(mut entries)
+		return entries
+	}
+	mut file := filesystem.open(name)!
+	defer {
+		file.close()
+	}
+	if mut file is ReadDirFile {
+		mut entries := file.read_dir(-1)!
+		sort_dir_entries(mut entries)
+		return entries
+	}
+	return error('fs: `${name}` does not support read_dir')
+}
+
+// stat returns file information for the named path from `filesystem`.
+pub fn stat(filesystem FS, name string) !FileInfo {
+	if filesystem is StatFS {
+		stats := filesystem as StatFS
+		return stats.stat(name)
+	}
+	mut file := filesystem.open(name)!
+	defer {
+		file.close()
+	}
+	return file.stat()
+}