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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:47:55 +0000 |
commit | 2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4 (patch) | |
tree | 033cc839730fda84ff08db877037977be94e5e3a /vendor/flate2/src/crc.rs | |
parent | Initial commit. (diff) | |
download | cargo-2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4.tar.xz cargo-2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4.zip |
Adding upstream version 0.70.1+ds1.upstream/0.70.1+ds1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/flate2/src/crc.rs')
-rw-r--r-- | vendor/flate2/src/crc.rs | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/vendor/flate2/src/crc.rs b/vendor/flate2/src/crc.rs new file mode 100644 index 0000000..16f5601 --- /dev/null +++ b/vendor/flate2/src/crc.rs @@ -0,0 +1,184 @@ +//! Simple CRC bindings backed by miniz.c + +use std::io; +use std::io::prelude::*; + +use crc32fast::Hasher; + +/// The CRC calculated by a [`CrcReader`]. +/// +/// [`CrcReader`]: struct.CrcReader.html +#[derive(Debug)] +pub struct Crc { + amt: u32, + hasher: Hasher, +} + +/// A wrapper around a [`Read`] that calculates the CRC. +/// +/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html +#[derive(Debug)] +pub struct CrcReader<R> { + inner: R, + crc: Crc, +} + +impl Default for Crc { + fn default() -> Self { + Self::new() + } +} + +impl Crc { + /// Create a new CRC. + pub fn new() -> Crc { + Crc { + amt: 0, + hasher: Hasher::new(), + } + } + + /// Returns the current crc32 checksum. + pub fn sum(&self) -> u32 { + self.hasher.clone().finalize() + } + + /// The number of bytes that have been used to calculate the CRC. + /// This value is only accurate if the amount is lower than 2<sup>32</sup>. + pub fn amount(&self) -> u32 { + self.amt + } + + /// Update the CRC with the bytes in `data`. + pub fn update(&mut self, data: &[u8]) { + self.amt = self.amt.wrapping_add(data.len() as u32); + self.hasher.update(data); + } + + /// Reset the CRC. + pub fn reset(&mut self) { + self.amt = 0; + self.hasher.reset(); + } + + /// Combine the CRC with the CRC for the subsequent block of bytes. + pub fn combine(&mut self, additional_crc: &Crc) { + self.amt = self.amt.wrapping_add(additional_crc.amt); + self.hasher.combine(&additional_crc.hasher); + } +} + +impl<R: Read> CrcReader<R> { + /// Create a new `CrcReader`. + pub fn new(r: R) -> CrcReader<R> { + CrcReader { + inner: r, + crc: Crc::new(), + } + } +} + +impl<R> CrcReader<R> { + /// Get the Crc for this `CrcReader`. + pub fn crc(&self) -> &Crc { + &self.crc + } + + /// Get the reader that is wrapped by this `CrcReader`. + pub fn into_inner(self) -> R { + self.inner + } + + /// Get the reader that is wrapped by this `CrcReader` by reference. + pub fn get_ref(&self) -> &R { + &self.inner + } + + /// Get a mutable reference to the reader that is wrapped by this `CrcReader`. + pub fn get_mut(&mut self) -> &mut R { + &mut self.inner + } + + /// Reset the Crc in this `CrcReader`. + pub fn reset(&mut self) { + self.crc.reset(); + } +} + +impl<R: Read> Read for CrcReader<R> { + fn read(&mut self, into: &mut [u8]) -> io::Result<usize> { + let amt = self.inner.read(into)?; + self.crc.update(&into[..amt]); + Ok(amt) + } +} + +impl<R: BufRead> BufRead for CrcReader<R> { + fn fill_buf(&mut self) -> io::Result<&[u8]> { + self.inner.fill_buf() + } + fn consume(&mut self, amt: usize) { + if let Ok(data) = self.inner.fill_buf() { + self.crc.update(&data[..amt]); + } + self.inner.consume(amt); + } +} + +/// A wrapper around a [`Write`] that calculates the CRC. +/// +/// [`Write`]: https://doc.rust-lang.org/std/io/trait.Write.html +#[derive(Debug)] +pub struct CrcWriter<W> { + inner: W, + crc: Crc, +} + +impl<W> CrcWriter<W> { + /// Get the Crc for this `CrcWriter`. + pub fn crc(&self) -> &Crc { + &self.crc + } + + /// Get the writer that is wrapped by this `CrcWriter`. + pub fn into_inner(self) -> W { + self.inner + } + + /// Get the writer that is wrapped by this `CrcWriter` by reference. + pub fn get_ref(&self) -> &W { + &self.inner + } + + /// Get a mutable reference to the writer that is wrapped by this `CrcWriter`. + pub fn get_mut(&mut self) -> &mut W { + &mut self.inner + } + + /// Reset the Crc in this `CrcWriter`. + pub fn reset(&mut self) { + self.crc.reset(); + } +} + +impl<W: Write> CrcWriter<W> { + /// Create a new `CrcWriter`. + pub fn new(w: W) -> CrcWriter<W> { + CrcWriter { + inner: w, + crc: Crc::new(), + } + } +} + +impl<W: Write> Write for CrcWriter<W> { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + let amt = self.inner.write(buf)?; + self.crc.update(&buf[..amt]); + Ok(amt) + } + + fn flush(&mut self) -> io::Result<()> { + self.inner.flush() + } +} |