1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130

//! Provide progress callbacks for types which implement `io::Read` or `io::Write`.
//! 
//! ## Examples
//! 
//! ### Reader
//! 
//! ```rust,no_run
//! extern crate progress_streams;
//! 
//! use progress_streams::ProgressReader;
//! use std::fs::File;
//! use std::io::Read;
//! use std::sync::Arc;
//! use std::sync::atomic::{AtomicUsize, Ordering};
//! use std::thread;
//! use std::time::Duration;
//! 
//! fn main() {
//!     let total = Arc::new(AtomicUsize::new(0));
//!     let mut file = File::open("/dev/urandom").unwrap();
//!     let mut reader = ProgressReader::new(&mut file, |progress: usize| {
//!         total.fetch_add(progress, Ordering::SeqCst);
//!     });
//! 
//!     {
//!         let total = total.clone();
//!         thread::spawn(move || {
//!             loop {
//!                 println!("Read {} KiB", total.load(Ordering::SeqCst) / 1024);
//!                 thread::sleep(Duration::from_millis(16));
//!             }
//!         });
//!     }
//! 
//!     let mut buffer = [0u8; 8192];
//!     while total.load(Ordering::SeqCst) < 100 * 1024 * 1024 {
//!         reader.read(&mut buffer).unwrap();
//!     }
//! }
//! ```
//! 
//! ### Writer
//! 
//! ```rust,no_run
//! extern crate progress_streams;
//! 
//! use progress_streams::ProgressWriter;
//! use std::io::{Cursor, Write};
//! use std::sync::Arc;
//! use std::sync::atomic::{AtomicUsize, Ordering};
//! use std::thread;
//! use std::time::Duration;
//! 
//! fn main() {
//!     let total = Arc::new(AtomicUsize::new(0));
//!     let mut file = Cursor::new(Vec::new());
//!     let mut writer = ProgressWriter::new(&mut file, |progress: usize| {
//!         total.fetch_add(progress, Ordering::SeqCst);
//!     });
//! 
//!     {
//!         let total = total.clone();
//!         thread::spawn(move || {
//!             loop {
//!                 println!("Written {} Kib", total.load(Ordering::SeqCst) / 1024);
//!                 thread::sleep(Duration::from_millis(16));
//!             }
//!         });
//!     }
//! 
//!     let buffer = [0u8; 8192];
//!     while total.load(Ordering::SeqCst) < 1000 * 1024 * 1024 {
//!         writer.write(&buffer).unwrap();
//!     }
//! }
//! ```

use std::io::{self, Read, Write};

/// Callback-based progress-monitoring writer.
pub struct ProgressWriter<W: Write, C: FnMut(usize)> {
    writer: W,
    callback: C
}

impl<W: Write, C: FnMut(usize)> ProgressWriter<W, C> {
    pub fn new(writer: W, callback: C) -> Self {
        Self { writer, callback }
    }

    pub fn into_inner(self) -> W {
        self.writer
    }
}

impl<W: Write, C: FnMut(usize)> Write for ProgressWriter<W, C> {
    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        let written = self.writer.write(buf)?;
        (self.callback)(written);
        Ok(written)
    }

    fn flush(&mut self) -> io::Result<()> {
        self.writer.flush()
    }
}

/// Callback-based progress-monitoring reader.
pub struct ProgressReader<R: Read, C: FnMut(usize)> {
    reader: R,
    callback: C
}

impl<R: Read, C: FnMut(usize)> ProgressReader<R, C> {
    pub fn new(reader: R, callback: C) -> Self {
        Self { reader, callback }
    }

    pub fn into_inner(self) -> R {
        self.reader
    }
}

impl<R: Read, C: FnMut(usize)> Read for ProgressReader<R, C> {
    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
        let read = self.reader.read(buf)?;
        (self.callback)(read);
        Ok(read)
    }
}