libp2prs_traits/
copy.rs

1// Copyright 2020 Netwarps Ltd.
2//
3// Permission is hereby granted, free of charge, to any person obtaining a
4// copy of this software and associated documentation files (the "Software"),
5// to deal in the Software without restriction, including without limitation
6// the rights to use, copy, modify, merge, publish, distribute, sublicense,
7// and/or sell copies of the Software, and to permit persons to whom the
8// Software is furnished to do so, subject to the following conditions:
9//
10// The above copyright notice and this permission notice shall be included in
11// all copies or substantial portions of the Software.
12//
13// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
14// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
19// DEALINGS IN THE SOFTWARE.
20
21use crate::{ReadEx, WriteEx};
22/// Copies the entire contents of a reader into a writer.
23///
24/// This function will read data from `reader` and write it into `writer` in a streaming fashion
25/// until `reader` returns EOF.
26///
27/// On success, returns the total number of bytes copied.
28///
29pub async fn copy<R, W>(mut reader: R, mut writer: W) -> std::io::Result<usize>
30where
31    R: ReadEx + Unpin,
32    W: WriteEx + Unpin,
33{
34    let mut copyed = 0_usize;
35
36    let mut buf = [0u8; 1024];
37    loop {
38        let n = reader.read2(&mut buf).await?;
39        if n == 0 {
40            return Ok(copyed);
41        }
42        copyed += n;
43        writer.write_all2(&buf[..n]).await?;
44    }
45}
libp2prs_traits/copy.rs

libp2prs_traits/
copy.rs
