nuts_tool/
format.rs

1// MIT License
2//
3// Copyright (c) 2023 Robin Doer
4//
5// Permission is hereby granted, free of charge, to any person obtaining a copy
6// of this software and associated documentation files (the "Software"), to
7// deal in the Software without restriction, including without limitation the
8// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
9// sell copies of the Software, and to permit persons to whom the Software is
10// furnished to do so, subject to the following conditions:
11//
12// The above copyright notice and this permission notice shall be included in
13// all copies or substantial portions of the Software.
14//
15// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21// IN THE SOFTWARE.
22
23use anyhow::Result;
24use clap::ValueEnum;
25use log::{trace, warn};
26use std::cmp;
27use std::io::{self, Write};
28
29const WIDTH: usize = 16;
30
31#[derive(Clone, Copy, Debug, ValueEnum)]
32pub enum Format {
33    Raw,
34    Hex,
35}
36
37impl Format {
38    pub fn create_writer(&self) -> Writer {
39        match self {
40            Self::Raw => Writer(None),
41            Self::Hex => Writer(Some(Hex::new())),
42        }
43    }
44}
45
46pub struct Writer(Option<Hex>);
47
48impl Writer {
49    pub fn print(&mut self, buf: &[u8]) -> Result<()> {
50        match self.0.as_mut() {
51            Some(hex) => {
52                hex.fill(buf);
53                hex.print();
54            }
55            None => io::stdout().write_all(buf)?,
56        }
57
58        Ok(())
59    }
60
61    pub fn flush(&mut self) -> Result<()> {
62        match self.0.as_mut() {
63            Some(hex) => hex.flush(),
64            None => io::stdout().flush()?,
65        }
66
67        Ok(())
68    }
69}
70
71#[derive(Debug)]
72struct Hex {
73    buf: Vec<u8>,
74    offset: usize,
75}
76
77impl Hex {
78    fn new() -> Hex {
79        Hex {
80            buf: vec![],
81            offset: 0,
82        }
83    }
84
85    fn fill<T: AsRef<[u8]>>(&mut self, buf: T) {
86        self.buf.extend_from_slice(buf.as_ref());
87    }
88
89    fn print(&mut self) {
90        while self.buf.len() >= WIDTH {
91            self.print_line(false);
92        }
93    }
94
95    fn flush(&mut self) {
96        self.print();
97        self.print_line(true);
98    }
99
100    fn print_line(&mut self, force: bool) {
101        if self.buf.is_empty() {
102            return;
103        }
104
105        let width = if force {
106            cmp::min(self.buf.len(), WIDTH)
107        } else {
108            WIDTH
109        };
110
111        trace!(
112            "print_line: width = {}, avail = {}, force = {}",
113            width,
114            self.buf.len(),
115            force
116        );
117
118        if self.buf.len() < width {
119            warn!(
120                "insufficient data available, need {}, got {} (force: {})",
121                width,
122                self.buf.len(),
123                force
124            );
125            return;
126        }
127
128        let (hex, ascii) = self.buf.drain(..width).enumerate().fold(
129            (String::new(), String::new()),
130            |(mut hex, mut ascii), (idx, n)| {
131                hex += &format!("{:02x} ", n);
132
133                if idx % 4 == 3 {
134                    hex.push(' ');
135                }
136
137                if n.is_ascii() && !n.is_ascii_control() {
138                    ascii.push(n.into());
139                } else {
140                    ascii.push('.');
141                }
142
143                (hex, ascii)
144            },
145        );
146
147        println!("{:>04x}:   {:<52} {}", self.offset, hex, ascii);
148
149        self.offset += WIDTH;
150    }
151}
nuts_tool/format.rs

nuts_tool/
format.rs
