partial implementation of provider for client types

ethcore/light/src/provider.rs

@@ -17,8 +17,11 @@
 //! A provider for the LES protocol. This is typically a full node, who can
 //! give as much data as necessary to its peers.
 
+use ethcore::client::BlockChainClient;
 use ethcore::transaction::SignedTransaction;
 use ethcore::blockchain_info::BlockChainInfo;
+
+use rlp::EMPTY_LIST_RLP;
 use util::{Bytes, H256};
 
 use request;
@@ -36,8 +39,9 @@ pub trait Provider: Send + Sync {
 	/// Find the depth of a common ancestor between two blocks.
 	fn reorg_depth(&self, a: &H256, b: &H256) -> Option<u64>;
 
-	/// Earliest state.
+	/// Earliest block where state queries are available.
-	fn earliest_state(&self) -> Option<u64>;
+	/// All states between this value and
+	fn earliest_state(&self) -> u64;
 
 	/// Provide a list of headers starting at the requested block,
 	/// possibly in reverse and skipping `skip` at a time.
@@ -69,3 +73,51 @@ pub trait Provider: Send + Sync {
 	/// Provide pending transactions.
 	fn pending_transactions(&self) -> Vec<SignedTransaction>;
 }
+
+// TODO [rob] move into trait definition file after ethcore crate
+// is split up. ideally `ethcore-light` will be between `ethcore-blockchain`
+// and `ethcore-client`
+impl<T: BlockChainClient + ?Sized> Provider for T {
+	fn chain_info(&self) -> BlockChainInfo {
+		BlockChainClient::chain_info(self)
+	}
+
+	fn reorg_depth(&self, a: &H256, b: &H256) -> Option<u64> {
+		self.tree_route.map(|route| route.index as u64)
+	}
+
+	fn earliest_state(&self) -> u64 {
+		self.pruning_info().earliest_state
+	}
+
+	fn block_headers(&self, req: request::Headers) -> Vec<Bytes> {
+		unimplemented!()
+	}
+
+	fn block_bodies(&self, req: request::Bodies) -> Vec<Bytes> {
+		req.block_hashes.into_iter()
+			.map(|hash| self.block_body(hash.into()))
+			.map(|body| body.unwrap_or_else(|| EMPTY_LIST_RLP.into()))
+			.collect()
+	}
+
+	fn receipts(&self, req: request::Receipts) -> Vec<Bytes> {
+		req.block_hashes.into_iter()
+			.map(|hash| self.block_receipts(&hash)
+			.map(|receipts| receips.unwrap_or_else(|| EMPTY_LIST_RLP.into()))
+			.collect()
+	}
+
+	fn proofs(&self, req: request::StateProofs) -> Vec<Bytes> {
+		unimplemented!()
+	}
+
+	fn code(&self, req: request::ContractCodes) -> Vec<Bytes>;
+
+	fn header_proofs(&self, req: request::HeaderProofs) -> Vec<Bytes> {
+		// TODO: [rob] implement CHT stuff on `ethcore` side.
+		req.requests.into_iter().map(|_| EMPTY_LIST_RLP.into()).collect()
+	}
+
+	fn pending_transactions(&self) -> Vec<SignedTransaction>;
+}

ethcore/src/client/client.rs

@@ -52,7 +52,7 @@ use blockchain::{BlockChain, BlockProvider, TreeRoute, ImportRoute};
 use client::{
 	BlockID, TransactionID, UncleID, TraceId, ClientConfig, BlockChainClient,
 	MiningBlockChainClient, TraceFilter, CallAnalytics, BlockImportError, Mode,
-	ChainNotify,
+	ChainNotify, PruningInfo,
 };
 use client::Error as ClientError;
 use env_info::EnvInfo;
@@ -1226,6 +1226,13 @@ impl BlockChainClient for Client {
 		self.uncle(id)
 			.map(|header| self.engine.extra_info(&decode(&header)))
 	}
+
+	fn pruning_info(&self) -> PruningInfo {
+		PruningInfo {
+			earliest_chain: self.chain.read().first_block().unwrap_or(1),
+			earliest_state: self.state_db.lock().journal_db().earliest_era().unwrap_or(0),
+		}
+	}
 }
 
 impl MiningBlockChainClient for Client {

ethcore/src/client/mod.rs

@@ -25,18 +25,21 @@ mod client;
 pub use self::client::*;
 pub use self::config::{Mode, ClientConfig, DatabaseCompactionProfile, BlockChainConfig, VMType};
 pub use self::error::Error;
-pub use types::ids::*;
 pub use self::test_client::{TestBlockChainClient, EachBlockWith};
+pub use self::chain_notify::ChainNotify;
+pub use self::traits::{BlockChainClient, MiningBlockChainClient};
+
+pub use types::ids::*;
 pub use types::trace_filter::Filter as TraceFilter;
+pub use types::pruning_info::PruningInfo;
+pub use types::call_analytics::CallAnalytics;
+
 pub use executive::{Executed, Executive, TransactOptions};
 pub use env_info::{LastHashes, EnvInfo};
-pub use self::chain_notify::ChainNotify;
 
-pub use types::call_analytics::CallAnalytics;
 pub use block_import_error::BlockImportError;
 pub use transaction_import::TransactionImportResult;
 pub use transaction_import::TransactionImportError;
-pub use self::traits::{BlockChainClient, MiningBlockChainClient};
 pub use verification::VerifierType;
 
 /// IPC interfaces

ethcore/src/client/test_client.rs

@@ -38,6 +38,7 @@ use evm::{Factory as EvmFactory, VMType, Schedule};
 use miner::{Miner, MinerService, TransactionImportResult};
 use spec::Spec;
 use types::mode::Mode;
+use types::pruning_info::PruningInfo;
 use views::BlockView;
 
 use verification::queue::QueueInfo;
@@ -650,4 +651,11 @@ impl BlockChainClient for TestBlockChainClient {
 	fn mode(&self) -> Mode { Mode::Active }
 
 	fn set_mode(&self, _: Mode) { unimplemented!(); }
+
+	fn pruning_info(&self) -> PruningInfo {
+		PruningInfo {
+			earliest_chain: 1,
+			earlest_state: 1,
+		}
+	}
 }

ethcore/src/client/traits.rs

@@ -39,6 +39,7 @@ use types::call_analytics::CallAnalytics;
 use types::blockchain_info::BlockChainInfo;
 use types::block_status::BlockStatus;
 use types::mode::Mode;
+use types::pruning_info::PruningInfo;
 
 #[ipc(client_ident="RemoteClient")]
 /// Blockchain database client. Owns and manages a blockchain and a block queue.
@@ -241,6 +242,9 @@ pub trait BlockChainClient : Sync + Send {
 
 	/// Returns engine-related extra info for `UncleID`.
 	fn uncle_extra_info(&self, id: UncleID) -> Option<BTreeMap<String, String>>;
+
+	/// Returns information about pruning/data availability.
+	fn pruning_info(&self) -> PruningInfo;
 }
 
 /// Extended client interface used for mining

ethcore/src/types/pruning_info.rs

@@ -0,0 +1,30 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity 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.
+
+// Parity 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 Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Information about portions of the state and chain which the client may serve.
+//!
+//! Currently assumes that a client will store everything past a certain point
+//! or everything. Will be extended in the future to support a definition
+//! of which portions of the ancient chain and current state trie are stored as well.
+
+/// Client pruning info. See module-level docs for more details.
+#[derive(Debug, Clone, Binary)]
+pub struct PruningInfo {
+	/// The first block which everything can be served after.
+	pub earliest_chain: u64
+	/// The first block where state requests may be served.
+	pub earliest_state: u64
+}