quiche/
dgram.rs

1// Copyright (C) 2020, Cloudflare, Inc.
2// All rights reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are
6// met:
7//
8//     * Redistributions of source code must retain the above copyright notice,
9//       this list of conditions and the following disclaimer.
10//
11//     * Redistributions in binary form must reproduce the above copyright
12//       notice, this list of conditions and the following disclaimer in the
13//       documentation and/or other materials provided with the distribution.
14//
15// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
16// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
17// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
19// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
23// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
24// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26
27use crate::Error;
28use crate::Result;
29
30use std::collections::VecDeque;
31
32/// Keeps track of DATAGRAM frames.
33#[derive(Default)]
34pub struct DatagramQueue {
35    queue: Option<VecDeque<Vec<u8>>>,
36    queue_max_len: usize,
37    queue_bytes_size: usize,
38}
39
40impl DatagramQueue {
41    pub fn new(queue_max_len: usize) -> Self {
42        DatagramQueue {
43            queue: None,
44            queue_bytes_size: 0,
45            queue_max_len,
46        }
47    }
48
49    pub fn push(&mut self, data: Vec<u8>) -> Result<()> {
50        if self.is_full() {
51            return Err(Error::Done);
52        }
53
54        self.queue_bytes_size += data.len();
55        self.queue
56            .get_or_insert_with(Default::default)
57            .push_back(data);
58
59        Ok(())
60    }
61
62    pub fn peek_front_len(&self) -> Option<usize> {
63        self.queue.as_ref().and_then(|q| q.front().map(|d| d.len()))
64    }
65
66    pub fn peek_front_bytes(&self, buf: &mut [u8], len: usize) -> Result<usize> {
67        match self.queue.as_ref().and_then(|q| q.front()) {
68            Some(d) => {
69                let len = std::cmp::min(len, d.len());
70                if buf.len() < len {
71                    return Err(Error::BufferTooShort);
72                }
73
74                buf[..len].copy_from_slice(&d[..len]);
75                Ok(len)
76            },
77
78            None => Err(Error::Done),
79        }
80    }
81
82    pub fn pop(&mut self) -> Option<Vec<u8>> {
83        if let Some(d) = self.queue.as_mut().and_then(|q| q.pop_front()) {
84            self.queue_bytes_size = self.queue_bytes_size.saturating_sub(d.len());
85            return Some(d);
86        }
87
88        None
89    }
90
91    pub fn has_pending(&self) -> bool {
92        !self.queue.as_ref().map(|q| q.is_empty()).unwrap_or(true)
93    }
94
95    pub fn purge<F: Fn(&[u8]) -> bool>(&mut self, f: F) {
96        if let Some(q) = self.queue.as_mut() {
97            q.retain(|d| !f(d));
98            self.queue_bytes_size = q.iter().fold(0, |total, d| total + d.len());
99        }
100    }
101
102    pub fn is_full(&self) -> bool {
103        self.len() == self.queue_max_len
104    }
105
106    pub fn is_empty(&self) -> bool {
107        self.len() == 0
108    }
109
110    pub fn len(&self) -> usize {
111        self.queue.as_ref().map(|q| q.len()).unwrap_or(0)
112    }
113
114    pub fn byte_size(&self) -> usize {
115        self.queue_bytes_size
116    }
117}
quiche/dgram.rs

quiche/
dgram.rs
