async_compression/codec/zstd/
encoder.rs

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1use crate::{codec::Encode, unshared::Unshared, util::PartialBuffer};
2use libzstd::stream::raw::{CParameter, Encoder, Operation};
3use std::io;
4use std::io::Result;
5
6#[derive(Debug)]
7pub struct ZstdEncoder {
8    encoder: Unshared<Encoder<'static>>,
9}
10
11impl ZstdEncoder {
12    pub(crate) fn new(level: i32) -> Self {
13        Self {
14            encoder: Unshared::new(Encoder::new(level).unwrap()),
15        }
16    }
17
18    pub(crate) fn new_with_params(level: i32, params: &[crate::zstd::CParameter]) -> Self {
19        let mut encoder = Encoder::new(level).unwrap();
20        for param in params {
21            encoder.set_parameter(param.as_zstd()).unwrap();
22        }
23        Self {
24            encoder: Unshared::new(encoder),
25        }
26    }
27
28    pub(crate) fn new_with_dict(level: i32, dictionary: &[u8]) -> io::Result<Self> {
29        let mut encoder = Encoder::with_dictionary(level, dictionary)?;
30        Ok(Self {
31            encoder: Unshared::new(encoder),
32        })
33    }
34}
35
36impl Encode for ZstdEncoder {
37    fn encode(
38        &mut self,
39        input: &mut PartialBuffer<impl AsRef<[u8]>>,
40        output: &mut PartialBuffer<impl AsRef<[u8]> + AsMut<[u8]>>,
41    ) -> Result<()> {
42        let status = self
43            .encoder
44            .get_mut()
45            .run_on_buffers(input.unwritten(), output.unwritten_mut())?;
46        input.advance(status.bytes_read);
47        output.advance(status.bytes_written);
48        Ok(())
49    }
50
51    fn flush(
52        &mut self,
53        output: &mut PartialBuffer<impl AsRef<[u8]> + AsMut<[u8]>>,
54    ) -> Result<bool> {
55        let mut out_buf = zstd_safe::OutBuffer::around(output.unwritten_mut());
56        let bytes_left = self.encoder.get_mut().flush(&mut out_buf)?;
57        let len = out_buf.as_slice().len();
58        output.advance(len);
59        Ok(bytes_left == 0)
60    }
61
62    fn finish(
63        &mut self,
64        output: &mut PartialBuffer<impl AsRef<[u8]> + AsMut<[u8]>>,
65    ) -> Result<bool> {
66        let mut out_buf = zstd_safe::OutBuffer::around(output.unwritten_mut());
67        let bytes_left = self.encoder.get_mut().finish(&mut out_buf, true)?;
68        let len = out_buf.as_slice().len();
69        output.advance(len);
70        Ok(bytes_left == 0)
71    }
72}
async_compression/codec/zstd/encoder.rs

async_compression/codec/zstd/
encoder.rs
