GH #9 - Replace MD5 checksum on blob with a safe hasher

- Replace MD5 with Blake2b with 32 bytes (256 bits) digest output.
- To be more scalable on multi-core processor, move checksum
  calculation from the WAL thread to client threads.
- Update examples/simple to store larger values (8KB).

Cargo.toml

@@ -7,11 +7,10 @@ build = "build.rs"
 [build-dependencies]
 
 [dependencies]
+blake2-rfc = "0.2.17"
 byteorder = "1.0.0"
 data-encoding = "2.0.0-rc.1"
-generic-array = "0.7.2"
 lazy_static = "0.2.2"
-md-5 = "0.4.3"
 promising-future = "0.2.4"
 rmp-serde = "0.13.1"
 rocksdb = "0.6.0"

examples/simple.rs

@@ -30,13 +30,15 @@ fn main() {
     let brick_id = brick::add_brick(brick_name);
 
     let put_op = |brick_id: brick::BrickId, key_str: &str, key: &[u8], value: &[u8]| {
-        brick::put(brick_id, key.to_vec(), value.to_vec())
+        let mut large_value = vec![0; 8 * 1024];
+        large_value[..value.len()].copy_from_slice(value);
+        brick::put(brick_id, key.to_vec(), large_value)
             .expect(&format!("Failed to put a key {}", key_str));
     };
 
     let get_op = |brick_id: brick::BrickId, key_str: &str, key: &[u8], value: &[u8]| {
         let val = brick::get(brick_id, key).expect(&format!("Failed to get a key {}", key_str));
-        assert_eq!(value.to_vec(), val.unwrap());
+        assert_eq!(value, &val.unwrap()[..value.len()]);
     };
 
     do_ops(brick_id, NUM_THREADS, NUM_KEYS_PER_THREAD, "put", put_op);