[plain_hasher] Remove dep on ethereum-types and make no_std compatible

kvdb/src/lib.rs

@@ -17,7 +17,7 @@
 //! Key-Value store abstraction with `RocksDB` backend.
 
 extern crate elastic_array;
-extern crate parity_bytes as bytes; // TODO: name changed; update upstream when `parity-common` is available
+extern crate parity_bytes as bytes;
 
 use std::io;
 use std::path::Path;

plain_hasher/Cargo.toml

@@ -1,13 +1,16 @@
 [package]
 name = "plain_hasher"
 description = "Hasher for 32-bit keys."
-version = "0.1.0"
+version = "0.2.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 license = "MIT"
 keywords = ["hash", "hasher"]
-homepage = "https://github.com/paritytech/plain_hasher"
+homepage = "https://github.com/paritytech/parity-common"
+categories = [ "no-std"]
 
 [dependencies]
 crunchy = "0.1.6"
-ethereum-types = "0.3"
-hashdb = { path = "../hashdb" }
+
+[features]
+default = ["std"]
+std = []

plain_hasher/README.md

@@ -0,0 +1,5 @@
+# Specialized Hasher for 32-bit keys
+
+Provides `PlainHasher`, a specialized `core::hash::Hasher` that takes just 8 bytes of the provided value and may only be used for keys which are 32 bytes.
+
+The crate is `no_std`-compatible.

plain_hasher/src/lib.rs

@@ -14,20 +14,15 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
+#![cfg_attr(not(feature = "std"), no_std)]
+
 #[macro_use]
 extern crate crunchy;
-extern crate ethereum_types;
-extern crate hashdb;
 
-use ethereum_types::H256;
-// use hashdb::Hasher;
-use std::hash;
-use std::collections::{HashMap, HashSet};
-/// Specialized version of `HashMap` with H256 keys and fast hashing function.
-pub type H256FastMap<T> = HashMap<H256, T, hash::BuildHasherDefault<PlainHasher>>;
-/// Specialized version of `HashSet` with H256 keys and fast hashing function.
-pub type H256FastSet = HashSet<H256, hash::BuildHasherDefault<PlainHasher>>;
+#[cfg(feature = "std")]
+extern crate core;
 
+use core::hash;
 /// Hasher that just takes 8 bytes of the provided value.
 /// May only be used for keys which are 32 bytes.
 #[derive(Default)]
@@ -50,7 +45,7 @@ impl hash::Hasher for PlainHasher {
 
 		unroll! {
 			for _i in 0..8 {
-				unsafe { 
+				unsafe {
 					*prefix_ptr ^= (*bytes_ptr ^ *bytes_ptr.offset(8)) ^ (*bytes_ptr.offset(16) ^ *bytes_ptr.offset(24));
 					bytes_ptr = bytes_ptr.offset(1);
 					prefix_ptr = prefix_ptr.offset(1);

test-support/keccak-hasher/Cargo.toml

@@ -10,4 +10,4 @@ license = "GPL-3.0"
 ethereum-types = "0.3"
 tiny-keccak = "1.4.2"
 hashdb = { version = "0.2.0", path = "../../hashdb" }
-plain_hasher = {  version = "0.1.0", path = "../../plain_hasher" }
+plain_hasher = {  path = "../../plain_hasher" }

triehash/Cargo.toml

@@ -8,7 +8,6 @@ license = "GPL-3.0"
 
 [dependencies]
 elastic-array = "0.10"
-ethereum-types = "0.3"
 hashdb = { version = "0.2", path = "../hashdb" }
 rlp = { version = "0.2.1", path = "../rlp" }
 

triehash/src/lib.rs

@@ -19,7 +19,6 @@
 //! This module should be used to generate trie root hash.
 
 extern crate elastic_array;
-extern crate ethereum_types;
 extern crate hashdb;
 extern crate rlp;
 #[cfg(test)] extern crate keccak_hasher;