code.vegaprotocol.io/vega@v0.79.0/libs/io/countwriter.go (about)

     1  // Copyright (C) 2023 Gobalsky Labs Limited
     2  //
     3  // This program is free software: you can redistribute it and/or modify
     4  // it under the terms of the GNU Affero General Public License as
     5  // published by the Free Software Foundation, either version 3 of the
     6  // License, or (at your option) any later version.
     7  //
     8  // This program is distributed in the hope that it will be useful,
     9  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    10  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    11  // GNU Affero General Public License for more details.
    12  //
    13  // You should have received a copy of the GNU Affero General Public License
    14  // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    15  
    16  package io
    17  
    18  import "io"
    19  
    20  // CountWriter is an io.Writer that keeps track of the number of bytes written to it.
    21  type CountWriter struct {
    22  	count  int64
    23  	writer io.Writer
    24  }
    25  
    26  func NewCountWriter(w io.Writer) *CountWriter {
    27  	return &CountWriter{
    28  		writer: w,
    29  	}
    30  }
    31  
    32  func (w *CountWriter) Write(p []byte) (int, error) {
    33  	n, err := w.writer.Write(p)
    34  	w.count += int64(n)
    35  	return n, err
    36  }
    37  
    38  // Count returns the total number of bytes written to the writer.
    39  func (w *CountWriter) Count() int64 {
    40  	return w.count
    41  }