Newer
Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
// Copyright 2017 Parity Technologies (UK) Ltd.
// This file is part of Polkadot.
// Polkadot 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.
// Polkadot 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 Polkadot. If not, see <http://www.gnu.org/licenses/>.
//! Polkadot Client
#![warn(missing_docs)]
extern crate polkadot_primitives as primitives;
extern crate polkadot_state_machine as state_machine;
#[macro_use]
extern crate error_chain;
pub mod error;
use primitives::{block, Address, H256};
use primitives::contract::{CallData, OutData, StorageData};
use state_machine::backend::Backend;
use self::error::ResultExt;
/// Blockchain access
pub trait Blockchain {
/// Error Type
type Error;
/// Returns the hash of latest block.
fn latest_hash(&self) -> Result<block::HeaderHash, Self::Error>;
/// Given a hash return a header
fn header(&self, hash: &block::HeaderHash) -> Result<Option<block::Header>, Self::Error>;
}
/// Polkadot Client
#[derive(Debug)]
pub struct Client<B, E> {
blockchain: B,
executor: E,
}
impl<B, E> Client<B, E> {
/// Creates new Polkadot Client with given blockchain and code executor.
pub fn new(blockchain: B, executor: E) -> Self {
Client {
blockchain,
executor,
}
}
}
impl<B, E> Client<B, E> where
B: Blockchain,
E: state_machine::CodeExecutor,
{
fn state_at(&self, _hash: &block::HeaderHash) -> error::Result<state_machine::backend::InMemory> {
// TODO [ToDr] Actually retrieve the state.
Ok(state_machine::backend::InMemory::default())
}
/// Return single storage entry of contract under given address in state in a block of given hash.
pub fn storage(&self, hash: &block::HeaderHash, address: &Address, key: &H256) -> error::Result<StorageData> {
self.state_at(hash)?
.storage(address, key)
.map(|x| StorageData(x.to_vec()))
.chain_err(|| error::ErrorKind::Backend)
}
/// Execute a call to a contract on top of state in a block of given hash.
pub fn call(&self, hash: &block::HeaderHash, address: &Address, method: &str, call_data: &CallData) -> error::Result<OutData> {
let state = self.state_at(hash)?;
let mut changes = state_machine::OverlayedChanges::default();
Ok(state_machine::execute(
&state,
&mut changes,
&self.executor,
address,
method,
call_data,
)?)
}
}