impl Write trait for the streaming SeaHasher

.gitlab-ci.yml

@@ -21,4 +21,4 @@ image: "rust:latest"
 test:cargo:
   script:
     - rustc --version && cargo --version  # Print version info for debugging
-    - cargo test --all --verbose
+    - cargo test --all --verbose --all-features

Cargo.toml

@@ -6,8 +6,12 @@ description = "A blazingly fast, portable hash function with proven statistical
 repository = "https://gitlab.redox-os.org/redox-os/seahash"
 documentation = "https://docs.rs/seahash"
 license = "MIT"
-keywords = ["hash", "hashing", "checksum", "checsumming", "portable"]
+keywords = ["hash", "hashing", "checksum", "checksumming", "portable"]
 exclude = ["target", "Cargo.lock"]
 
 [dev-dependencies]
 quickcheck = "0.9.2"
+
+[features]
+default = []
+use_std = []

src/buffer.rs

 //! A highly optimized version of SeaHash.
 
-use core::slice;
+use std::slice;
 
 use helper;
 

src/impl_std.rs

+use crate::SeaHasher;
+use std::hash::Hasher;
+use std::io;
+
+impl io::Write for SeaHasher {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        Hasher::write(self, buf);
+        Ok(buf.len())
+    }
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn hash_write_trait() {
+        let reader: &[u8] = &[0xFF, 0xFF, 0xFF, 0xFF,
+                        0xFF, 0xFF, 0xFF, 0xFF,
+                        0x00, 0x00, 0x00, 0x00,
+                        0x00, 0x00, 0x00, 0x00];
+        let mut hasher = SeaHasher::new();
+        // io::copy consumes the mutable reader -> cloning the buffer
+        let _ = io::copy(&mut reader.clone(), &mut hasher).unwrap();
+        let hash = hasher.finish();
+        let control = crate::hash(&reader);
+        assert_eq!(control, hash);
+    }
+}

src/lib.rs

@@ -151,8 +151,10 @@
 //! Joshua Landau suggested using the [PCG family of diffusions](http://www.pcg-random.org/),
 //! created by Melissa E. O'Neill. Sokolov Yura spotted multiple bugs in SeaHash.
 
-#![no_std]
 #![warn(missing_docs)]
+#![cfg_attr(all(not(test), not(feature = "use_std")), no_std)]
+#[cfg(all(not(test), not(feature = "use_std")))]
+extern crate core as std;
 
 pub use buffer::{hash, hash_seeded, State};
 pub use stream::SeaHasher;
@@ -161,3 +163,6 @@ pub mod reference;
 mod buffer;
 mod helper;
 mod stream;
+
+#[cfg(feature = "use_std")]
+mod impl_std;

src/stream.rs

-use core::hash::Hasher;
-use core::slice;
+use std::hash::Hasher;
+use std::slice;
 
 use helper;
 
@@ -213,7 +213,7 @@ impl Hasher for SeaHasher {
 mod tests {
     use super::*;
     use crate::hash_seeded;
-    use core::hash::Hasher;
+    use std::hash::Hasher;
 
     #[test]
     fn chunked_equiv() {