diff --git a/Cargo.lock b/Cargo.lock index 80c8810fe..43f6c7af2 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -509,6 +509,7 @@ dependencies = [ "ethcore-ipc-codegen 1.5.0", "ethcore-network 1.5.0", "ethcore-util 1.5.0", + "futures 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)", "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)", "rlp 0.1.0", "smallvec 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)", diff --git a/ethcore/light/Cargo.toml b/ethcore/light/Cargo.toml index 67ae166dc..20f5f93bd 100644 --- a/ethcore/light/Cargo.toml +++ b/ethcore/light/Cargo.toml @@ -20,6 +20,7 @@ ethcore-ipc = { path = "../../ipc/rpc", optional = true } rlp = { path = "../../util/rlp" } time = "0.1" smallvec = "0.3.1" +futures = "0.1" [features] default = [] diff --git a/ethcore/light/src/lib.rs b/ethcore/light/src/lib.rs index 5cdc3addc..60984d9c2 100644 --- a/ethcore/light/src/lib.rs +++ b/ethcore/light/src/lib.rs @@ -34,6 +34,7 @@ pub mod client; pub mod net; +pub mod on_demand; #[cfg(not(feature = "ipc"))] pub mod provider; @@ -64,6 +65,7 @@ extern crate ethcore_io as io; extern crate rlp; extern crate smallvec; extern crate time; +extern crate futures; #[cfg(feature = "ipc")] extern crate ethcore_ipc as ipc; diff --git a/ethcore/light/src/on_demand/mod.rs b/ethcore/light/src/on_demand/mod.rs new file mode 100644 index 000000000..0bf25d68b --- /dev/null +++ b/ethcore/light/src/on_demand/mod.rs @@ -0,0 +1,125 @@ +// Copyright 2015, 2016 Parity Technologies (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 . + +//! On-demand chain requests over LES. This is a major building block for RPCs. +//! The request service is implemented using Futures. Higher level request handlers +//! will take the raw data received here and extract meaningful results from it. + +use std::collections::HashMap; + +use ethcore::ids::BlockId; +use ethcore::block::Block; +use ethcore::header::Header; +use ethcore::receipt::Receipt; + +use futures::Future; +use futures::sync::oneshot::{self, Sender, Receiver}; +use network::PeerId; + +use client::Client; +use net::{Handler, Status, Capabilities, Announcement, EventContext, BasicContext, ReqId}; +use util::{Address, H256, RwLock}; + +struct Account; + +// relevant peer info. +struct Peer { + status: Status, + capabilities: Capabilities, +} + +// request info and where to send the result. +enum Request { + HeaderByNumber(u64, H256, Sender
), // num + CHT root + HeaderByHash(H256, Sender
), + Block(Header, Sender), + BlockReceipts(Header, Sender>), + Account(Header, Address, Sender), + Storage(Header, Address, H256, Sender), +} + +/// On demand request service. See module docs for more details. +/// Accumulates info about all peers' capabilities and dispatches +/// requests to them accordingly. +pub struct OnDemand { + peers: RwLock>, + pending_requests: RwLock>, +} + +impl Handler for OnDemand { + fn on_connect(&self, ctx: &EventContext, status: &Status, capabilities: &Capabilities) { + self.peers.write().insert(ctx.peer(), Peer { status: status.clone(), capabilities: capabilities.clone() }) + } + + fn on_disconnect(&self, ctx: &EventContext, unfulfilled: &[ReqId]) { + self.peers.write().remove(&ctx.peer()); + } +} + +impl OnDemand { + /// Request a header by block number and CHT root hash. + pub fn header_by_number(&self, ctx: &BasicContext, num: u64, cht_root: H256) -> Receiver
{ + let (sender, receiver) = oneshot::channel(); + self.dispatch_request(ctx, Request::HeaderByNumber(num, cht_root, sender)); + receiver + } + + /// Request a header by hash. This is less accurate than by-number because we don't know + /// where in the chain this header lies, and therefore can't find a peer who is supposed to have + /// it as easily. + pub fn header_by_hash(&self, ctx: &BasicContext, hash: H256) -> Receiver
{ + let (sender, receiver) = oneshot::channel(); + self.dispatch_request(ctx, Request::HeaderByHash(hash, sender)); + receiver + } + + /// Request a block, given its header. Block bodies are requestable by hash only, + /// and the header is required anyway to verify and complete the block body + /// -- this just doesn't obscure the network query. + pub fn block(&self, ctx: &BasicContext, header: Header) -> Receiver { + let (sender, receiver) = oneshot::channel(); + self.dispatch_request(ctx, Request::Block(header, sender)); + receiver + } + + /// Request the receipts for a block. The header serves two purposes: + /// provide the block hash to fetch receipts for, and for verification of the receipts root. + pub fn block_receipts(&self, ctx: &BasicContext, header: Header) -> Receiver> { + let (sender, receiver) = oneshot::channel(); + self.dispatch_request(ctx, Request::BlockReceipts(header, sender)); + receiver + } + + /// Request an account by address and block header -- which gives a hash to query and a state root + /// to verify against. + pub fn account(&self, ctx: &BasicContext, header: Header, address: Address) -> Receiver { + let (sender, receiver) = oneshot::channel(); + self.dispatch_request(ctx, Request::Account(header, address, sender)); + receiver + } + + /// Request account storage value by block header, address, and key. + pub fn storage(&self, ctx: &BasicContext, header: Header, address: Address, key: H256) -> Receiver { + let (sender, receiver) = oneshot::channel(); + self.dispatch_request(ctx, Request::Storage(header, address, key, sender)); + receiver + } + + // dispatch a request to a suitable peer. + fn dispatch_request(&self, ctx: &BasicContext, request: Request) { + unimplemented!() + } +}