1 files changed, 61 insertions, 0 deletions
diff --git a/third_party/rust/murmurhash3/src/hasher.rs b/third_party/rust/murmurhash3/src/hasher.rs
new file mode 100644
index 0000000000..7b7f6c87ca
--- /dev/null
+++ b/third_party/rust/murmurhash3/src/hasher.rs
@@ -0,0 +1,61 @@
+use std::hash::Hasher;
+use std::collections::hash_state::HashState;
+
+use mmh3_32::murmurhash3_x86_32;
+
+pub struct Murmur3Hasher {
+    seed: u32,
+    bytes: Vec<u8>,
+}
+
+#[derive(Clone, Copy)]
+pub struct Murmur3HashState {
+    seed: u32,
+}
+
+impl Murmur3HashState {
+    pub fn new() -> Murmur3HashState {
+        return Murmur3HashState { seed: 0 };
+    }
+
+    pub fn with_seed(seed: u32) -> Murmur3HashState {
+        return Murmur3HashState { seed: seed };
+    }
+}
+
+
+impl Hasher for Murmur3Hasher {
+    fn finish(&self) -> u64 {
+        return murmurhash3_x86_32(&self.bytes, self.seed) as u64;
+    }
+
+    fn write(&mut self, bytes: &[u8]) {
+        self.bytes.push_all(bytes);
+    }
+}
+
+impl HashState for Murmur3HashState {
+    type Hasher = Murmur3Hasher;
+
+    fn hasher(&self) -> Murmur3Hasher {
+        return Murmur3Hasher { seed: self.seed, bytes: vec![] };
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::Murmur3HashState;
+    use std::collections::hash_map::HashMap;
+
+    #[test]
+    fn use_in_hashmap() {
+        let mut hashmap = HashMap::with_hash_state(Murmur3HashState::new());
+        hashmap.insert("one", 1);
+        hashmap.insert("two", 2);
+
+        assert!(hashmap.len() == 2);
+
+        assert!(*hashmap.get("one").unwrap() == 1);
+        assert!(*hashmap.get("two").unwrap() == 2);
+    }
+}