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

substrate/core/client/src/blockchain.rs

@@ -0,0 +1,92 @@
+// 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/>.
+
+//! Polkadot blockchain trait
+
+use primitives::AuthorityId;
+use runtime_primitives::traits::{Block as BlockT, Header as HeaderT, NumberFor};
+use runtime_primitives::generic::BlockId;
+use runtime_primitives::bft::Justification;
+
+use error::{ErrorKind, Result};
+
+/// Blockchain database header backend. Does not perform any validation.
+pub trait HeaderBackend<Block: BlockT>: Send + Sync {
+	/// Get block header. Returns `None` if block is not found.
+	fn header(&self, id: BlockId<Block>) -> Result<Option<Block::Header>>;
+	/// Get blockchain info.
+	fn info(&self) -> Result<Info<Block>>;
+	/// Get block status.
+	fn status(&self, id: BlockId<Block>) -> Result<BlockStatus>;
+	/// Get block number by hash. Returns `None` if the header is not in the chain.
+	fn number(&self, hash: Block::Hash) -> Result<Option<<<Block as BlockT>::Header as HeaderT>::Number>>;
+	/// Get block hash by number. Returns `None` if the header is not in the chain.
+	fn hash(&self, number: NumberFor<Block>) -> Result<Option<Block::Hash>>;
+
+	/// Get block header. Returns `UnknownBlock` error if block is not found.
+	fn expect_header(&self, id: BlockId<Block>) -> Result<Block::Header> {
+		self.header(id)?.ok_or_else(|| ErrorKind::UnknownBlock(format!("{}", id)).into())
+	}
+}
+
+/// Blockchain database backend. Does not perform any validation.
+pub trait Backend<Block: BlockT>: HeaderBackend<Block> {
+	/// Get block body. Returns `None` if block is not found.
+	fn body(&self, id: BlockId<Block>) -> Result<Option<Vec<<Block as BlockT>::Extrinsic>>>;
+	/// Get block justification. Returns `None` if justification does not exist.
+	fn justification(&self, id: BlockId<Block>) -> Result<Option<Justification<Block::Hash>>>;
+
+	/// Returns data cache reference, if it is enabled on this backend.
+	fn cache(&self) -> Option<&Cache<Block>>;
+}
+
+/// Blockchain optional data cache.
+pub trait Cache<Block: BlockT>: Send + Sync {
+	/// Returns the set of authorities, that was active at given block or None if there's no entry in the cache.
+	fn authorities_at(&self, block: BlockId<Block>) -> Option<Vec<AuthorityId>>;
+}
+
+/// Block import outcome
+pub enum ImportResult<E> {
+	/// Imported successfully.
+	Imported,
+	/// Block already exists, skippped.
+	AlreadyInChain,
+	/// Unknown parent.
+	UnknownParent,
+	/// Other errror.
+	Err(E),
+}
+
+/// Blockchain info
+#[derive(Debug)]
+pub struct Info<Block: BlockT> {
+	/// Best block hash.
+	pub best_hash: <<Block as BlockT>::Header as HeaderT>::Hash,
+	/// Best block number.
+	pub best_number: <<Block as BlockT>::Header as HeaderT>::Number,
+	/// Genesis block hash.
+	pub genesis_hash: <<Block as BlockT>::Header as HeaderT>::Hash,
+}
+
+/// Block status.
+#[derive(Debug, PartialEq, Eq)]
+pub enum BlockStatus {
+	/// Already in the blockchain.
+	InChain,
+	/// Not in the queue or the blockchain.
+	Unknown,
+}