| // Copyright (C) 2020, Cloudflare, Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright notice, |
| // this list of conditions and the following disclaimer. |
| // |
| // * Redistributions in binary form must reproduce the above copyright |
| // notice, this list of conditions and the following disclaimer in the |
| // documentation and/or other materials provided with the distribution. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS |
| // IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| // THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| // PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR |
| // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| use crate::Error; |
| use crate::Result; |
| |
| use std::collections::VecDeque; |
| |
| /// Keeps track of DATAGRAM frames. |
| #[derive(Default)] |
| pub struct DatagramQueue { |
| queue: Option<VecDeque<Vec<u8>>>, |
| queue_max_len: usize, |
| queue_bytes_size: usize, |
| } |
| |
| impl DatagramQueue { |
| pub fn new(queue_max_len: usize) -> Self { |
| DatagramQueue { |
| queue: None, |
| queue_bytes_size: 0, |
| queue_max_len, |
| } |
| } |
| |
| pub fn push(&mut self, data: Vec<u8>) -> Result<()> { |
| if self.is_full() { |
| return Err(Error::Done); |
| } |
| |
| self.queue_bytes_size += data.len(); |
| self.queue |
| .get_or_insert_with(Default::default) |
| .push_back(data); |
| |
| Ok(()) |
| } |
| |
| pub fn peek_front_len(&self) -> Option<usize> { |
| self.queue.as_ref().and_then(|q| q.front().map(|d| d.len())) |
| } |
| |
| pub fn peek_front_bytes(&self, buf: &mut [u8], len: usize) -> Result<usize> { |
| match self.queue.as_ref().and_then(|q| q.front()) { |
| Some(d) => { |
| let len = std::cmp::min(len, d.len()); |
| if buf.len() < len { |
| return Err(Error::BufferTooShort); |
| } |
| |
| buf[..len].copy_from_slice(&d[..len]); |
| Ok(len) |
| }, |
| |
| None => Err(Error::Done), |
| } |
| } |
| |
| pub fn pop(&mut self) -> Option<Vec<u8>> { |
| if let Some(d) = self.queue.as_mut().and_then(|q| q.pop_front()) { |
| self.queue_bytes_size = self.queue_bytes_size.saturating_sub(d.len()); |
| return Some(d); |
| } |
| |
| None |
| } |
| |
| pub fn has_pending(&self) -> bool { |
| !self.queue.as_ref().map(|q| q.is_empty()).unwrap_or(true) |
| } |
| |
| pub fn purge<F: Fn(&[u8]) -> bool>(&mut self, f: F) { |
| if let Some(q) = self.queue.as_mut() { |
| q.retain(|d| !f(d)); |
| self.queue_bytes_size = q.iter().fold(0, |total, d| total + d.len()); |
| } |
| } |
| |
| pub fn is_full(&self) -> bool { |
| self.len() == self.queue_max_len |
| } |
| |
| pub fn len(&self) -> usize { |
| self.queue.as_ref().map(|q| q.len()).unwrap_or(0) |
| } |
| |
| pub fn byte_size(&self) -> usize { |
| self.queue_bytes_size |
| } |
| } |