github.com/ubuntu-core/snappy@v0.0.0-20210827154228-9e584df982bb/snap/internal/file.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2020 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     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 General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package internal
    21  
    22  import (
    23  	"os"
    24  )
    25  
    26  // SizedFile holds an os.File plus its (initial) size.
    27  type SizedFile struct {
    28  	*os.File
    29  	size int64
    30  }
    31  
    32  func NewSizedFile(f *os.File) (*SizedFile, error) {
    33  	fi, err := f.Stat()
    34  	if err != nil {
    35  		return nil, err
    36  	}
    37  	return &SizedFile{File: f, size: fi.Size()}, nil
    38  }
    39  
    40  func (f *SizedFile) Size() int64 {
    41  	return f.size
    42  }