aboutsummaryrefslogtreecommitdiff
path: root/vendor/flate2/src/crc.rs
diff options
context:
space:
mode:
authorValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
committerValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
commit1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch)
tree7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/flate2/src/crc.rs
parent5ecd8cf2cba827454317368b68571df0d13d7842 (diff)
downloadfparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz
fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/flate2/src/crc.rs')
-rw-r--r--vendor/flate2/src/crc.rs184
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()
+ }
+}