bp3d_proto/message/util/
common.rs

1// Copyright (c) 2024, BlockProject 3D
2//
3// All rights reserved.
4//
5// Redistribution and use in source and binary forms, with or without modification,
6// are permitted provided that the following conditions are met:
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8//     * Redistributions of source code must retain the above copyright notice,
9//       this list of conditions and the following disclaimer.
10//     * Redistributions in binary form must reproduce the above copyright notice,
11//       this list of conditions and the following disclaimer in the documentation
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14//       may be used to endorse or promote products derived from this software
15//       without specific prior written permission.
16//
17// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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21// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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26// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
29use crate::message::{Error, FromBytes, FromBytesWithOffsets, Message, WriteTo};
30use bytesutil::ReadBytes;
31use std::io::Write;
32use std::marker::PhantomData;
33
34pub struct Optional<T>(PhantomData<T>);
35
36impl<'a, T: FromBytes<'a>> FromBytes<'a> for Optional<T> {
37    type Output = Option<T::Output>;
38
39    fn from_bytes(slice: &'a [u8]) -> Result<Message<Option<T::Output>>, Error> {
40        if slice.is_empty() {
41            Err(Error::Truncated)
42        } else {
43            let b = slice[0] > 0;
44            if b {
45                let msg = T::from_bytes(&slice[1..])?;
46                Ok(Message::new(msg.size() + 1, Some(msg.into_inner())))
47            } else {
48                Ok(Message::new(1, None))
49            }
50        }
51    }
52}
53
54impl<'a, T: FromBytes<'a> + FromBytesWithOffsets<'a>> FromBytesWithOffsets<'a> for Optional<T> {
55    type Offsets = Option<T::Offsets>;
56
57    fn from_bytes_with_offsets(slice: &'a [u8]) -> crate::message::Result<Message<(Self::Output, Self::Offsets)>> {
58        if slice.is_empty() {
59            Err(Error::Truncated)
60        } else {
61            let b = slice[0] > 0;
62            if b {
63                let msg = T::from_bytes_with_offsets(&slice[1..])?;
64                let size = msg.size();
65                let (msg, offsets) = msg.into_inner();
66                Ok(Message::new(size + 1, (Some(msg), Some(offsets))))
67            } else {
68                Ok(Message::new(1, (None, None)))
69            }
70        }
71    }
72}
73
74impl<T: WriteTo> WriteTo for Optional<T> {
75    type Input<'a> = Option<T::Input<'a>>;
76
77    fn write_to<W: Write>(input: &Self::Input<'_>, mut out: W) -> Result<(), Error> {
78        match input {
79            None => out.write_all(&[0x0])?,
80            Some(v) => {
81                out.write_all(&[0x1])?;
82                T::write_to(v, out)?;
83            }
84        }
85        Ok(())
86    }
87}
88
89#[cfg(feature = "tokio")]
90impl<T: crate::message::WriteToAsync> crate::message::WriteToAsync for Optional<T> {
91    async fn write_to_async<W: tokio::io::AsyncWriteExt + Unpin>(
92        input: &Self::Input<'_>,
93        mut out: W,
94    ) -> crate::message::Result<()> {
95        match input {
96            None => out.write_all(&[0x0]).await?,
97            Some(v) => {
98                out.write_all(&[0x1]).await?;
99                T::write_to_async(v, out).await?;
100            }
101        }
102        Ok(())
103    }
104}
105
106#[derive(Debug, Copy, Clone)]
107pub struct ValueLE<T>(PhantomData<T>);
108#[derive(Debug, Copy, Clone)]
109pub struct ValueBE<T>(PhantomData<T>);
110
111impl<'a, T: ReadBytes> FromBytes<'a> for ValueLE<T> {
112    type Output = T;
113
114    fn from_bytes(slice: &'a [u8]) -> Result<Message<Self::Output>, Error> {
115        let size = size_of::<T>();
116        if slice.len() < size {
117            Err(Error::Truncated)
118        } else {
119            let value = T::read_bytes_le(slice);
120            Ok(Message::new(size, value))
121        }
122    }
123}
124
125impl<T: bytesutil::WriteTo> WriteTo for ValueLE<T> {
126    type Input<'a> = T;
127
128    fn write_to<W: Write>(input: &Self::Input<'_>, out: W) -> Result<(), Error> {
129        input.write_to_le(out)?;
130        Ok(())
131    }
132}
133
134#[cfg(feature = "tokio")]
135impl<T: bytesutil::WriteTo + bytesutil::WriteBytes> crate::message::WriteToAsync for ValueLE<T> {
136    async fn write_to_async<W: tokio::io::AsyncWriteExt + Unpin>(
137        input: &Self::Input<'_>,
138        mut out: W,
139    ) -> crate::message::Result<()> {
140        let mut buffer = [0; 8];
141        T::write_bytes_le(input, &mut buffer);
142        out.write_all(&buffer[..size_of::<T>()]).await?;
143        Ok(())
144    }
145}
146
147impl<'a, T: ReadBytes> FromBytes<'a> for ValueBE<T> {
148    type Output = T;
149
150    fn from_bytes(slice: &'a [u8]) -> Result<Message<Self::Output>, Error> {
151        let size = size_of::<T>();
152        if slice.len() < size {
153            Err(Error::Truncated)
154        } else {
155            let value = T::read_bytes_be(slice);
156            Ok(Message::new(size, value))
157        }
158    }
159}
160
161impl<T: bytesutil::WriteTo> WriteTo for ValueBE<T> {
162    type Input<'a> = T;
163
164    fn write_to<W: Write>(input: &Self::Input<'_>, out: W) -> Result<(), Error> {
165        input.write_to_be(out)?;
166        Ok(())
167    }
168}
169
170#[cfg(feature = "tokio")]
171impl<T: bytesutil::WriteTo + bytesutil::WriteBytes> crate::message::WriteToAsync for ValueBE<T> {
172    async fn write_to_async<W: tokio::io::AsyncWriteExt + Unpin>(
173        input: &Self::Input<'_>,
174        mut out: W,
175    ) -> crate::message::Result<()> {
176        let mut buffer = [0; 8];
177        T::write_bytes_be(input, &mut buffer);
178        out.write_all(&buffer[..size_of::<T>()]).await?;
179        Ok(())
180    }
181}
bp3d_proto/message/util/common.rs

bp3d_proto/message/util/
common.rs
