45 lines
1.4 KiB
Rust
45 lines
1.4 KiB
Rust
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use std::io::{Read, Write};
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use anyhow::Result;
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pub(crate) const MAX_FRAME_SIZE: usize = 64 * 1024 * 1024;
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pub fn write_frame<W: Write>(writer: &mut W, data: &[u8]) -> Result<()> {
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let len = data.len();
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if len > MAX_FRAME_SIZE {
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anyhow::bail!("frame too large: {} bytes exceeds 64 MiB limit", len);
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}
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let len_bytes = (len as u32).to_be_bytes();
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writer.write_all(&len_bytes)?;
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writer.write_all(data)?;
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writer.flush()?;
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Ok(())
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}
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pub fn read_frame<R: Read>(reader: &mut R) -> Result<Option<Vec<u8>>> {
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let mut len_buf = [0u8; 4];
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match reader.read_exact(&mut len_buf) {
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Ok(()) => {}
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Err(e) if e.kind() == std::io::ErrorKind::UnexpectedEof => return Ok(None),
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Err(e) => return Err(e.into()),
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}
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let len = u32::from_be_bytes(len_buf) as usize;
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if len > MAX_FRAME_SIZE {
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anyhow::bail!("frame too large: {} bytes exceeds 64 MiB limit", len);
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}
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let mut buf = vec![0u8; len];
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reader.read_exact(&mut buf)?;
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Ok(Some(buf))
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}
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pub fn serialize_frame<T: serde::Serialize>(value: &T) -> Result<Vec<u8>> {
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let json = serde_json::to_vec(value)?;
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if json.len() > MAX_FRAME_SIZE {
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anyhow::bail!("serialized frame too large: {} bytes", json.len());
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}
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Ok(json)
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}
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pub fn deserialize_frame<'a, T: serde::Deserialize<'a>>(data: &'a [u8]) -> Result<T> {
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Ok(serde_json::from_slice(data)?)
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}
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