OP#792 initial commit after fork

internal/ioutil/read_file.go

@@ -0,0 +1,79 @@
+// Copyright (c) 2015-2021 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package ioutil
+
+import (
+	"io"
+	"io/fs"
+	"os"
+
+	"github.com/minio/minio/internal/disk"
+)
+
+var (
+	// OpenFileDirectIO allows overriding default function.
+	OpenFileDirectIO = disk.OpenFileDirectIO
+	// OsOpen allows overriding default function.
+	OsOpen = os.Open
+	// OsOpenFile allows overriding default function.
+	OsOpenFile = os.OpenFile
+)
+
+// ReadFileWithFileInfo reads the named file and returns the contents.
+// A successful call returns err == nil, not err == EOF.
+// Because ReadFile reads the whole file, it does not treat an EOF from Read
+// as an error to be reported.
+func ReadFileWithFileInfo(name string) ([]byte, fs.FileInfo, error) {
+	f, err := OsOpenFile(name, readMode, 0o666)
+	if err != nil {
+		return nil, nil, err
+	}
+	defer f.Close()
+
+	st, err := f.Stat()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	dst := make([]byte, st.Size())
+	_, err = io.ReadFull(f, dst)
+	return dst, st, err
+}
+
+// ReadFile reads the named file and returns the contents.
+// A successful call returns err == nil, not err == EOF.
+// Because ReadFile reads the whole file, it does not treat an EOF from Read
+// as an error to be reported.
+//
+// passes NOATIME flag for reads on Unix systems to avoid atime updates.
+func ReadFile(name string) ([]byte, error) {
+	// Don't wrap with un-needed buffer.
+	// Don't use os.ReadFile, since it doesn't pass NO_ATIME when present.
+	f, err := OsOpenFile(name, readMode, 0o666)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	st, err := f.Stat()
+	if err != nil {
+		return io.ReadAll(f)
+	}
+	dst := make([]byte, st.Size())
+	_, err = io.ReadFull(f, dst)
+	return dst, err
+}