Phase 1 of repo reorg (#719)

* Remove unneeded script * Rename Substrate Demo -> Substrate * Rename demo -> node * Build wasm from last rename. * Merge ed25519 into substrate-primitives * Minor tweak * Rename substrate -> core * Move substrate-runtime-support to core/runtime/support * Rename/move substrate-runtime-version * Move codec up a level * Rename substrate-codec -> parity-codec * Move environmental up a level * Move pwasm-* up to top, ready for removal * Remove requirement of s-r-support from s-r-primitives * Move core/runtime/primitives into core/runtime-primitives * Remove s-r-support dep from s-r-version * Remove dep of s-r-support from bft * Remove dep of s-r-support from node/consensus * Sever all other core deps from s-r-support * Forgot the no_std directive * Rename non-SRML modules to sr-* to avoid match clashes * Move runtime/* to srml/* * Rename substrate-runtime-* -> srml-* * Move srml to top-level
2026-07-11 05:47:21 +00:00 · 2018-09-12 11:13:31 +02:00
parent 8fe5aa4c81
commit 1e01162505
374 changed files with 2845 additions and 2902 deletions
@@ -0,0 +1,90 @@
+// Copyright 2017 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! An implementation of double map backed by storage.
+//!
+//! This implementation is somewhat specialized to the tracking of the storage of accounts.
+
+use rstd::prelude::*;
+use codec::{Codec, Encode};
+use runtime_support::storage::unhashed;
+use runtime_io::{blake2_256, twox_128};
+
+/// Returns only a first part of the storage key.
+///
+/// Hashed by XX.
+fn first_part_of_key<M: StorageDoubleMap + ?Sized>(k1: M::Key1) -> [u8; 16] {
+	let mut raw_prefix = Vec::new();
+	raw_prefix.extend(M::PREFIX);
+	raw_prefix.extend(Encode::encode(&k1));
+	twox_128(&raw_prefix)
+}
+
+/// Returns a compound key that consist of the two parts: (prefix, `k1`) and `k2`.
+///
+/// The first part is hased by XX and then concatenated with a blake2 hash of `k2`.
+fn full_key<M: StorageDoubleMap + ?Sized>(k1: M::Key1, k2: M::Key2) -> Vec<u8> {
+	let first_part = first_part_of_key::<M>(k1);
+	let second_part = blake2_256(&Encode::encode(&k2));
+
+	let mut k = Vec::new();
+	k.extend(&first_part);
+	k.extend(&second_part);
+	k
+}
+
+/// An implementation of a map with a two keys.
+///
+/// It provides an important ability to efficiently remove all entries
+/// that have a common first key.
+///
+/// # Mapping of keys to a storage path
+///
+/// The storage key (i.e. the key under which the `Value` will be stored) is created from two parts.
+/// The first part is a XX hash of a concatenation of the `PREFIX` and `Key1`. And the second part
+/// is a blake2 hash of a `Key2`.
+///
+/// Blake2 is used for `Key2` is because it will be used as a key for contract's storage and
+/// thus will be susceptible for a untrusted input.
+pub trait StorageDoubleMap {
+	type Key1: Codec;
+	type Key2: Codec;
+	type Value: Codec + Default;
+
+	const PREFIX: &'static [u8];
+
+	/// Insert an entry into this map.
+	fn insert(k1: Self::Key1, k2: Self::Key2, val: Self::Value) {
+		unhashed::put(&full_key::<Self>(k1, k2)[..], &val);
+	}
+
+	/// Remove an entry from this map.
+	fn remove(k1: Self::Key1, k2: Self::Key2) {
+		unhashed::kill(&full_key::<Self>(k1, k2)[..]);
+	}
+
+	/// Get an entry from this map.
+	///
+	/// If there is entry stored under the given keys, returns `None`.
+	fn get(k1: Self::Key1, k2: Self::Key2) -> Option<Self::Value> {
+		unhashed::get(&full_key::<Self>(k1, k2)[..])
+	}
+
+	/// Removes all entries that shares the `k1` as the first key.
+	fn remove_prefix(k1: Self::Key1) {
+		unhashed::kill_prefix(&first_part_of_key::<Self>(k1))
+	}
+}