referrerpolicy=no-referrer-when-downgrade
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
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176

// This file is part of Substrate.

// Copyright (C) Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0

// This program 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.

// This program 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 this program. If not, see <https://www.gnu.org/licenses/>.

//! Substrate blockchain API.

mod chain_full;

#[cfg(test)]
mod tests;

use std::sync::Arc;

use crate::SubscriptionTaskExecutor;

use jsonrpsee::{core::async_trait, PendingSubscriptionSink};
use sc_client_api::BlockchainEvents;
use sp_rpc::{list::ListOrValue, number::NumberOrHex};
use sp_runtime::{
	generic::SignedBlock,
	traits::{Block as BlockT, NumberFor},
};

use self::error::Error;

use sc_client_api::BlockBackend;
pub use sc_rpc_api::chain::*;
use sp_blockchain::HeaderBackend;

/// Blockchain backend API
#[async_trait]
trait ChainBackend<Client, Block: BlockT>: Send + Sync + 'static
where
	Block: BlockT + 'static,
	Block::Header: Unpin,
	Client: HeaderBackend<Block> + BlockchainEvents<Block> + 'static,
{
	/// Get client reference.
	fn client(&self) -> &Arc<Client>;

	/// Tries to unwrap passed block hash, or uses best block hash otherwise.
	fn unwrap_or_best(&self, hash: Option<Block::Hash>) -> Block::Hash {
		match hash {
			None => self.client().info().best_hash,
			Some(hash) => hash,
		}
	}

	/// Get header of a block.
	fn header(&self, hash: Option<Block::Hash>) -> Result<Option<Block::Header>, Error>;

	/// Get header and body of a block.
	fn block(&self, hash: Option<Block::Hash>) -> Result<Option<SignedBlock<Block>>, Error>;

	/// Get hash of the n-th block in the canon chain.
	///
	/// By default returns latest block hash.
	fn block_hash(&self, number: Option<NumberOrHex>) -> Result<Option<Block::Hash>, Error> {
		match number {
			None => Ok(Some(self.client().info().best_hash)),
			Some(num_or_hex) => {
				// FIXME <2329>: Database seems to limit the block number to u32 for no reason
				let block_num: u32 = num_or_hex.try_into().map_err(|_| {
					Error::Other(format!(
						"`{:?}` > u32::MAX, the max block number is u32.",
						num_or_hex
					))
				})?;
				let block_num = <NumberFor<Block>>::from(block_num);
				self.client().hash(block_num).map_err(client_err)
			},
		}
	}

	/// Get hash of the last finalized block in the canon chain.
	fn finalized_head(&self) -> Result<Block::Hash, Error> {
		Ok(self.client().info().finalized_hash)
	}

	/// All new head subscription
	fn subscribe_all_heads(&self, pending: PendingSubscriptionSink);

	/// New best head subscription
	fn subscribe_new_heads(&self, pending: PendingSubscriptionSink);

	/// Finalized head subscription
	fn subscribe_finalized_heads(&self, pending: PendingSubscriptionSink);
}

/// Create new state API that works on full node.
pub fn new_full<Block: BlockT, Client>(
	client: Arc<Client>,
	executor: SubscriptionTaskExecutor,
) -> Chain<Block, Client>
where
	Block: BlockT + 'static,
	Block::Header: Unpin,
	Client: BlockBackend<Block> + HeaderBackend<Block> + BlockchainEvents<Block> + 'static,
{
	Chain { backend: Box::new(self::chain_full::FullChain::new(client, executor)) }
}

/// Chain API with subscriptions support.
pub struct Chain<Block: BlockT, Client> {
	backend: Box<dyn ChainBackend<Client, Block>>,
}

#[async_trait]
impl<Block, Client> ChainApiServer<NumberFor<Block>, Block::Hash, Block::Header, SignedBlock<Block>>
	for Chain<Block, Client>
where
	Block: BlockT + 'static,
	Block::Header: Unpin,
	Client: HeaderBackend<Block> + BlockchainEvents<Block> + 'static,
{
	fn header(&self, hash: Option<Block::Hash>) -> Result<Option<Block::Header>, Error> {
		self.backend.header(hash)
	}

	fn block(&self, hash: Option<Block::Hash>) -> Result<Option<SignedBlock<Block>>, Error> {
		self.backend.block(hash)
	}

	fn block_hash(
		&self,
		number: Option<ListOrValue<NumberOrHex>>,
	) -> Result<ListOrValue<Option<Block::Hash>>, Error> {
		match number {
			None => self.backend.block_hash(None).map(ListOrValue::Value),
			Some(ListOrValue::Value(number)) => self
				.backend
				.block_hash(Some(number))
				.map(ListOrValue::Value)
				.map_err(Into::into),
			Some(ListOrValue::List(list)) => Ok(ListOrValue::List(
				list.into_iter()
					.map(|number| self.backend.block_hash(Some(number)))
					.collect::<Result<_, _>>()?,
			)),
		}
	}

	fn finalized_head(&self) -> Result<Block::Hash, Error> {
		self.backend.finalized_head()
	}

	fn subscribe_all_heads(&self, pending: PendingSubscriptionSink) {
		self.backend.subscribe_all_heads(pending);
	}

	fn subscribe_new_heads(&self, pending: PendingSubscriptionSink) {
		self.backend.subscribe_new_heads(pending)
	}

	fn subscribe_finalized_heads(&self, pending: PendingSubscriptionSink) {
		self.backend.subscribe_finalized_heads(pending)
	}
}

fn client_err(err: sp_blockchain::Error) -> Error {
	Error::Client(Box::new(err))
}