Light provider trait

ethcore/src/light/provider.rs

@@ -0,0 +1,57 @@
+// 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/>.
+
+//! A provider for the LES protocol. This is typically a full node, who can
+//! give as much data as necessary to its peers.
+
+pub use proof_request::{CHTProofRequest, ProofRequest};
+
+use util::Bytes;
+use util::hash::H256;
+
+/// Defines the operations that a provider for `LES` must fulfill.
+///
+/// These are defined at [1], but may be subject to change.
+///
+/// [1]: https://github.com/ethcore/parity/wiki/Light-Ethereum-Subprotocol-(LES)
+pub trait Provider {
+	/// Provide a list of headers starting at the requested block,
+	/// possibly in reverse and skipping `skip` at a time.
+	///
+	/// The returned vector may have any length in the range [0, `max`], but the
+	/// results within must adhere to the `skip` and `reverse` parameters.
+	fn block_headers(&self, block: H256, skip: usize, max: usize, reverse: bool) -> Vec<Bytes>;
+
+	/// Provide as many as possible of the requested blocks (minus the headers) encoded
+	/// in RLP format.
+	fn block_bodies(&self, blocks: Vec<H256>) -> Vec<Bytes>;
+
+	/// Provide the receipts as many as possible of the requested blocks.
+	/// Returns a vector of RLP-encoded lists of receipts.
+	fn receipts(&self, blocks: Vec<H256>) -> Vec<Bytes>;
+
+	/// Provide a set of merkle proofs, as requested. Each request is a
+	/// block hash and request parameters.
+	///
+	/// Returns a vector to RLP-encoded lists satisfying the requests.
+	fn proofs(&self, requests: Vec<(H256, ProofRequest)>) -> Vec<Bytes>;
+
+	/// Provide contract code for the specified (block_hash, account_hash) pairs.
+	fn code(&self, accounts: Vec<(H256, H256)>) -> Vec<Bytes>;
+
+	/// Provide header proofs from the Canonical Hash Tries.
+	fn header_proofs(&self, requests: Vec<CHTProofRequest>) -> Vec<Bytes>;
+}

ethcore/src/types/mod.rs.in

@@ -33,3 +33,4 @@ pub mod transaction_import;
 pub mod block_import_error;
 pub mod restoration_status;
 pub mod snapshot_manifest;
+pub mod proof_request;

ethcore/src/types/proof_request.rs

@@ -0,0 +1,44 @@
+// 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/>.
+
+//! Merkle proof request.
+use util::hash::H256;
+
+/// A request for a state merkle proof.
+#[derive(Debug, Clone, PartialEq, Eq, Binary)]
+pub enum ProofRequest {
+	/// Request a proof of the given account's (denoted by sha3(address))
+	/// node in the state trie. Nodes with depth less than the second item
+	/// may be omitted.
+	Account(H256, usize),
+
+	/// Request a proof for a key in the given account's storage trie.
+	/// Both values are hashes of their actual values. Nodes with depth
+	/// less than the third item may be omitted.
+	Storage(H256, H256, usize),
+}
+
+/// A request for a Canonical Hash Trie proof for the given block number.
+/// Nodes with depth less than the second item may be omitted.
+#[derive(Debug, Clone, PartialEq, Eq, Binary)]
+pub struct CHTProofRequest {
+	/// The number of the block the proof is requested for.
+	/// The CHT's number can be deduced from this (`number` / 4096)
+	pub number: u64,
+
+	/// Nodes with depth less than this can be omitted from the proof.
+	pub depth: usize,
+}