1 files changed, 215 insertions, 0 deletions
diff --git a/vendor/adler-0.2.3/src/lib.rs b/vendor/adler-0.2.3/src/lib.rs
new file mode 100644
index 000000000..ac29ea23f
--- /dev/null
+++ b/vendor/adler-0.2.3/src/lib.rs
@@ -0,0 +1,215 @@
+//! Adler-32 checksum implementation.
+//!
+//! This implementation features:
+//!
+//! - Permissively licensed (0BSD) clean-room implementation.
+//! - Zero dependencies.
+//! - Decent performance (3-4 GB/s).
+//! - `#![no_std]` support (with `default-features = false`).
+
+#![doc(html_root_url = "https://docs.rs/adler/0.2.3")]
+// Deny a few warnings in doctests, since rustdoc `allow`s many warnings by default
+#![doc(test(attr(deny(unused_imports, unused_must_use))))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![warn(missing_debug_implementations)]
+#![forbid(unsafe_code)]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg(not(feature = "std"))]
+extern crate core as std;
+
+mod algo;
+
+use std::hash::Hasher;
+
+#[cfg(feature = "std")]
+use std::io::{self, BufRead};
+
+/// Adler-32 checksum calculator.
+///
+/// An instance of this type is equivalent to an Adler-32 checksum: It can be created in the default
+/// state via [`new`] (or the provided `Default` impl), or from a precalculated checksum via
+/// [`from_checksum`], and the currently stored checksum can be fetched via [`checksum`].
+///
+/// This type also implements `Hasher`, which makes it easy to calculate Adler-32 checksums of any
+/// type that implements or derives `Hash`. This also allows using Adler-32 in a `HashMap`, although
+/// that is not recommended (while every checksum is a hash, they are not necessarily good at being
+/// one).
+///
+/// [`new`]: #method.new
+/// [`from_checksum`]: #method.from_checksum
+/// [`checksum`]: #method.checksum
+#[derive(Debug, Copy, Clone)]
+pub struct Adler32 {
+    a: u16,
+    b: u16,
+}
+
+impl Adler32 {
+    /// Creates a new Adler-32 instance with default state.
+    #[inline]
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Creates an `Adler32` instance from a precomputed Adler-32 checksum.
+    ///
+    /// This allows resuming checksum calculation without having to keep the `Adler32` instance
+    /// around.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use adler::Adler32;
+    /// let parts = [
+    ///     "rust",
+    ///     "acean",
+    /// ];
+    /// let whole = adler::adler32_slice(b"rustacean");
+    ///
+    /// let mut sum = Adler32::new();
+    /// sum.write_slice(parts[0].as_bytes());
+    /// let partial = sum.checksum();
+    ///
+    /// // ...later
+    ///
+    /// let mut sum = Adler32::from_checksum(partial);
+    /// sum.write_slice(parts[1].as_bytes());
+    /// assert_eq!(sum.checksum(), whole);
+    /// ```
+    #[inline]
+    pub fn from_checksum(sum: u32) -> Self {
+        Adler32 {
+            a: sum as u16,
+            b: (sum >> 16) as u16,
+        }
+    }
+
+    /// Returns the calculated checksum at this point in time.
+    #[inline]
+    pub fn checksum(&self) -> u32 {
+        (u32::from(self.b) << 16) | u32::from(self.a)
+    }
+
+    /// Adds `bytes` to the checksum calculation.
+    ///
+    /// If efficiency matters, this should be called with Byte slices that contain at least a few
+    /// thousand Bytes.
+    pub fn write_slice(&mut self, bytes: &[u8]) {
+        self.compute(bytes);
+    }
+}
+
+impl Default for Adler32 {
+    #[inline]
+    fn default() -> Self {
+        Adler32 { a: 1, b: 0 }
+    }
+}
+
+impl Hasher for Adler32 {
+    #[inline]
+    fn finish(&self) -> u64 {
+        u64::from(self.checksum())
+    }
+
+    fn write(&mut self, bytes: &[u8]) {
+        self.write_slice(bytes);
+    }
+}
+
+/// Calculates the Adler-32 checksum of a byte slice.
+pub fn adler32_slice(data: &[u8]) -> u32 {
+    let mut h = Adler32::new();
+    h.write_slice(data);
+    h.checksum()
+}
+
+/// Calculates the Adler-32 checksum of a `BufRead`'s contents.
+///
+/// The passed `BufRead` implementor will be read until it reaches EOF.
+///
+/// If you only have a `Read` implementor, wrap it in `std::io::BufReader`.
+#[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+pub fn adler32_reader<R: BufRead>(reader: &mut R) -> io::Result<u32> {
+    let mut h = Adler32::new();
+    loop {
+        let len = {
+            let buf = reader.fill_buf()?;
+            if buf.is_empty() {
+                return Ok(h.checksum());
+            }
+
+            h.write_slice(buf);
+            buf.len()
+        };
+        reader.consume(len);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::io::BufReader;
+
+    #[test]
+    fn zeroes() {
+        assert_eq!(adler32_slice(&[]), 1);
+        assert_eq!(adler32_slice(&[0]), 1 | 1 << 16);
+        assert_eq!(adler32_slice(&[0, 0]), 1 | 2 << 16);
+        assert_eq!(adler32_slice(&[0; 100]), 0x00640001);
+        assert_eq!(adler32_slice(&[0; 1024]), 0x04000001);
+        assert_eq!(adler32_slice(&[0; 1024 * 1024]), 0x00f00001);
+    }
+
+    #[test]
+    fn ones() {
+        assert_eq!(adler32_slice(&[0xff; 1024]), 0x79a6fc2e);
+        assert_eq!(adler32_slice(&[0xff; 1024 * 1024]), 0x8e88ef11);
+    }
+
+    #[test]
+    fn mixed() {
+        assert_eq!(adler32_slice(&[1]), 2 | 2 << 16);
+        assert_eq!(adler32_slice(&[40]), 41 | 41 << 16);
+
+        assert_eq!(adler32_slice(&[0xA5; 1024 * 1024]), 0xd5009ab1);
+    }
+
+    /// Example calculation from https://en.wikipedia.org/wiki/Adler-32.
+    #[test]
+    fn wiki() {
+        assert_eq!(adler32_slice(b"Wikipedia"), 0x11E60398);
+    }
+
+    #[test]
+    fn resume() {
+        let mut adler = Adler32::new();
+        adler.write_slice(&[0xff; 1024]);
+        let partial = adler.checksum();
+        assert_eq!(partial, 0x79a6fc2e); // from above
+        adler.write_slice(&[0xff; 1024 * 1024 - 1024]);
+        assert_eq!(adler.checksum(), 0x8e88ef11); // from above
+
+        // Make sure that we can resume computing from the partial checksum via `from_checksum`.
+        let mut adler = Adler32::from_checksum(partial);
+        adler.write_slice(&[0xff; 1024 * 1024 - 1024]);
+        assert_eq!(adler.checksum(), 0x8e88ef11); // from above
+    }
+
+    #[test]
+    fn bufread() {
+        fn test(data: &[u8], checksum: u32) {
+            // `BufReader` uses an 8 KB buffer, so this will test buffer refilling.
+            let mut buf = BufReader::new(data);
+            let real_sum = adler32_reader(&mut buf).unwrap();
+            assert_eq!(checksum, real_sum);
+        }
+
+        test(&[], 1);
+        test(&[0; 1024], 0x04000001);
+        test(&[0; 1024 * 1024], 0x00f00001);
+        test(&[0xA5; 1024 * 1024], 0xd5009ab1);
+    }
+}