github.com/minio/minio@v0.0.0-20240328213742-3f72439b8a27/internal/ioutil/read_file.go (about)

     1  // Copyright (c) 2015-2021 MinIO, Inc.
     2  //
     3  // This file is part of MinIO Object Storage stack
     4  //
     5  // This program is free software: you can redistribute it and/or modify
     6  // it under the terms of the GNU Affero General Public License as published by
     7  // the Free Software Foundation, either version 3 of the License, or
     8  // (at your option) any later version.
     9  //
    10  // This program is distributed in the hope that it will be useful
    11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13  // GNU Affero General Public License for more details.
    14  //
    15  // You should have received a copy of the GNU Affero General Public License
    16  // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17  
    18  package ioutil
    19  
    20  import (
    21  	"io"
    22  	"io/fs"
    23  	"os"
    24  
    25  	"github.com/minio/minio/internal/disk"
    26  )
    27  
    28  var (
    29  	// OpenFileDirectIO allows overriding default function.
    30  	OpenFileDirectIO = disk.OpenFileDirectIO
    31  	// OsOpen allows overriding default function.
    32  	OsOpen = os.Open
    33  	// OsOpenFile allows overriding default function.
    34  	OsOpenFile = os.OpenFile
    35  )
    36  
    37  // ReadFileWithFileInfo reads the named file and returns the contents.
    38  // A successful call returns err == nil, not err == EOF.
    39  // Because ReadFile reads the whole file, it does not treat an EOF from Read
    40  // as an error to be reported.
    41  func ReadFileWithFileInfo(name string) ([]byte, fs.FileInfo, error) {
    42  	f, err := OsOpenFile(name, readMode, 0o666)
    43  	if err != nil {
    44  		return nil, nil, err
    45  	}
    46  	defer f.Close()
    47  
    48  	st, err := f.Stat()
    49  	if err != nil {
    50  		return nil, nil, err
    51  	}
    52  
    53  	dst := make([]byte, st.Size())
    54  	_, err = io.ReadFull(f, dst)
    55  	return dst, st, err
    56  }
    57  
    58  // ReadFile reads the named file and returns the contents.
    59  // A successful call returns err == nil, not err == EOF.
    60  // Because ReadFile reads the whole file, it does not treat an EOF from Read
    61  // as an error to be reported.
    62  //
    63  // passes NOATIME flag for reads on Unix systems to avoid atime updates.
    64  func ReadFile(name string) ([]byte, error) {
    65  	// Don't wrap with un-needed buffer.
    66  	// Don't use os.ReadFile, since it doesn't pass NO_ATIME when present.
    67  	f, err := OsOpenFile(name, readMode, 0o666)
    68  	if err != nil {
    69  		return nil, err
    70  	}
    71  	defer f.Close()
    72  	st, err := f.Stat()
    73  	if err != nil {
    74  		return io.ReadAll(f)
    75  	}
    76  	dst := make([]byte, st.Size())
    77  	_, err = io.ReadFull(f, dst)
    78  	return dst, err
    79  }