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// Smoldot
// Copyright (C) 2019-2022 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 <http://www.gnu.org/licenses/>.
//! All JSON-RPC method handlers that relate to transactions.
use super::{Background, Platform, SubscriptionTy};
use crate::transactions_service;
use alloc::{borrow::ToOwned as _, boxed::Box, str, string::ToString as _, sync::Arc, vec::Vec};
use core::sync::atomic;
use futures::prelude::*;
use smoldot::json_rpc::{self, methods, requests_subscriptions};
impl<TPlat: Platform> Background<TPlat> {
/// Handles a call to [`methods::MethodCall::author_pendingExtrinsics`].
pub(super) async fn author_pending_extrinsics(
self: &Arc<Self>,
request_id: &str,
state_machine_request_id: &requests_subscriptions::RequestId,
) {
// Because multiple different chains ("chain" in the context of the public API of smoldot)
// might share the same transactions service, it could be possible for chain A to submit
// a transaction and then for chain B to read it by calling `author_pendingExtrinsics`.
// This would make it possible for the API user of chain A to be able to communicate with
// the API user of chain B. While the implications of permitting this are unclear, it is
// not a bad idea to prevent this communication from happening. Consequently, we always
// return an empty list of pending extrinsics.
self.requests_subscriptions
.respond(
state_machine_request_id,
methods::Response::author_pendingExtrinsics(Vec::new())
.to_json_response(request_id),
)
.await;
}
/// Handles a call to [`methods::MethodCall::author_submitExtrinsic`].
pub(super) async fn author_submit_extrinsic(
self: &Arc<Self>,
request_id: &str,
state_machine_request_id: &requests_subscriptions::RequestId,
transaction: methods::HexString,
) {
// Note that this function is misnamed. It should really be called
// "author_submitTransaction".
// In Substrate, `author_submitExtrinsic` returns the hash of the transaction. It
// is unclear whether it has to actually be the hash of the transaction or if it
// could be any opaque value. Additionally, there isn't any other JSON-RPC method
// that accepts as parameter the value returned here. When in doubt, we return
// the hash as well.
let mut hash_context = blake2_rfc::blake2b::Blake2b::new(32);
hash_context.update(&transaction.0);
let mut transaction_hash: [u8; 32] = Default::default();
transaction_hash.copy_from_slice(hash_context.finalize().as_bytes());
self.transactions_service
.submit_transaction(transaction.0)
.await;
self.requests_subscriptions
.respond(
state_machine_request_id,
methods::Response::author_submitExtrinsic(methods::HashHexString(transaction_hash))
.to_json_response(request_id),
)
.await;
}
/// Handles a call to [`methods::MethodCall::author_unwatchExtrinsic`].
pub(super) async fn author_unwatch_extrinsic(
self: &Arc<Self>,
request_id: &str,
state_machine_request_id: &requests_subscriptions::RequestId,
subscription: &str,
) {
let state_machine_subscription = if let Some((abort_handle, state_machine_subscription)) =
self.subscriptions
.lock()
.await
.misc
.remove(&(subscription.to_owned(), SubscriptionTy::TransactionLegacy))
{
abort_handle.abort();
Some(state_machine_subscription)
} else {
None
};
if let Some(state_machine_subscription) = &state_machine_subscription {
self.requests_subscriptions
.stop_subscription(state_machine_subscription)
.await;
}
self.requests_subscriptions
.respond(
state_machine_request_id,
methods::Response::author_unwatchExtrinsic(state_machine_subscription.is_some())
.to_json_response(request_id),
)
.await;
}
/// Handles a call to [`methods::MethodCall::author_submitAndWatchExtrinsic`] (if `is_legacy`
/// is `true`) or to [`methods::MethodCall::transaction_unstable_submitAndWatch`] (if
/// `is_legacy` is `false`).
pub(super) async fn submit_and_watch_transaction(
self: &Arc<Self>,
request_id: &str,
state_machine_request_id: &requests_subscriptions::RequestId,
transaction: methods::HexString,
is_legacy: bool,
) {
let state_machine_subscription = match self
.requests_subscriptions
.start_subscription(state_machine_request_id, 16)
.await
{
Ok(v) => v,
Err(requests_subscriptions::StartSubscriptionError::LimitReached) => {
self.requests_subscriptions
.respond(
state_machine_request_id,
json_rpc::parse::build_error_response(
request_id,
json_rpc::parse::ErrorResponse::ServerError(
-32000,
"Too many active subscriptions",
),
None,
),
)
.await;
return;
}
};
let subscription_id = self
.next_subscription_id
.fetch_add(1, atomic::Ordering::Relaxed)
.to_string();
let abort_registration = {
let (abort_handle, abort_registration) = future::AbortHandle::new_pair();
let mut subscriptions_list = self.subscriptions.lock().await;
let ty = if is_legacy {
SubscriptionTy::TransactionLegacy
} else {
SubscriptionTy::Transaction
};
subscriptions_list.misc.insert(
(subscription_id.clone(), ty),
(abort_handle, state_machine_subscription.clone()),
);
abort_registration
};
self.requests_subscriptions
.respond(
&state_machine_request_id,
if is_legacy {
methods::Response::author_submitAndWatchExtrinsic((&subscription_id).into())
.to_json_response(request_id)
} else {
methods::Response::transaction_unstable_submitAndWatch(
(&subscription_id).into(),
)
.to_json_response(request_id)
},
)
.await;
// Spawn a separate task for the transaction updates.
let task = {
let mut transaction_updates = self
.transactions_service
.submit_and_watch_transaction(transaction.0, 16)
.await;
let me = self.clone();
async move {
let mut included_block = None;
let mut num_broadcasted_peers = 0;
// TODO: doesn't reported `validated` events
loop {
match transaction_updates.next().await {
Some(update) => {
let update = match (update, is_legacy) {
(transactions_service::TransactionStatus::Broadcast(peers), false) => {
methods::ServerToClient::author_extrinsicUpdate {
subscription: (&subscription_id).into(),
result: methods::TransactionStatus::Broadcast(
peers.into_iter().map(|peer| peer.to_base58()).collect(),
)
}
.to_json_call_object_parameters(None)
}
(transactions_service::TransactionStatus::Broadcast(peers), true) => {
num_broadcasted_peers += peers.len();
methods::ServerToClient::transaction_unstable_watchEvent {
subscription: (&subscription_id).into(),
result: methods::TransactionWatchEvent::Broadcasted {
num_peers: u32::try_from(num_broadcasted_peers).unwrap_or(u32::max_value()),
}
}
.to_json_call_object_parameters(None)
}
(transactions_service::TransactionStatus::IncludedBlockUpdate {
block_hash: Some((block_hash, _)),
}, true) => {
included_block = Some(block_hash);
methods::ServerToClient::author_extrinsicUpdate {
subscription: (&subscription_id).into(),
result: methods::TransactionStatus::InBlock(methods::HashHexString(
block_hash,
))
}
.to_json_call_object_parameters(None)
}
(transactions_service::TransactionStatus::IncludedBlockUpdate {
block_hash: None,
}, true) => {
if let Some(block_hash) = included_block.take() {
methods::ServerToClient::author_extrinsicUpdate {
subscription: (&subscription_id).into(),
result: methods::TransactionStatus::Retracted(
methods::HashHexString(block_hash),
)
}
.to_json_call_object_parameters(None)
} else {
continue;
}
}
(transactions_service::TransactionStatus::IncludedBlockUpdate {
block_hash: Some((block_hash, index)),
}, false) => {
included_block = Some(block_hash);
methods::ServerToClient::transaction_unstable_watchEvent {
subscription: (&subscription_id).into(),
result: methods::TransactionWatchEvent::BestChainBlockIncluded {
block: Some(methods::TransactionWatchEventBlock {
hash: methods::HashHexString(block_hash),
index: methods::NumberAsString(index),
})
}
}
.to_json_call_object_parameters(None)
}
(transactions_service::TransactionStatus::IncludedBlockUpdate {
block_hash: None,
}, false) => {
methods::ServerToClient::transaction_unstable_watchEvent {
subscription: (&subscription_id).into(),
result: methods::TransactionWatchEvent::BestChainBlockIncluded {
block: None,
}
}
.to_json_call_object_parameters(None)
}
(transactions_service::TransactionStatus::Dropped(
transactions_service::DropReason::GapInChain,
), true)
| (transactions_service::TransactionStatus::Dropped(
transactions_service::DropReason::MaxPendingTransactionsReached,
), true)
| (transactions_service::TransactionStatus::Dropped(
transactions_service::DropReason::Invalid(_),
), true)
| (transactions_service::TransactionStatus::Dropped(
transactions_service::DropReason::ValidateError(_),
), true) => {
methods::ServerToClient::author_extrinsicUpdate {
subscription: (&subscription_id).into(),
result: methods::TransactionStatus::Dropped,
}
.to_json_call_object_parameters(None)
},
(transactions_service::TransactionStatus::Dropped(
transactions_service::DropReason::GapInChain,
), false) => {
methods::ServerToClient::transaction_unstable_watchEvent {
subscription: (&subscription_id).into(),
result: methods::TransactionWatchEvent::Dropped {
error: "gap in chain of blocks".into(),
broadcasted: num_broadcasted_peers != 0,
}
}
.to_json_call_object_parameters(None)
},
(transactions_service::TransactionStatus::Dropped(
transactions_service::DropReason::MaxPendingTransactionsReached,
), false) => {
methods::ServerToClient::transaction_unstable_watchEvent {
subscription: (&subscription_id).into(),
result: methods::TransactionWatchEvent::Dropped {
error: "transactions pool full".into(),
broadcasted: num_broadcasted_peers != 0,
}
}
.to_json_call_object_parameters(None)
},
(transactions_service::TransactionStatus::Dropped(
transactions_service::DropReason::Invalid(error),
), false) => {
methods::ServerToClient::transaction_unstable_watchEvent {
subscription: (&subscription_id).into(),
result: methods::TransactionWatchEvent::Invalid {
error: error.to_string().into(),
}
}
.to_json_call_object_parameters(None)
},
(transactions_service::TransactionStatus::Dropped(
transactions_service::DropReason::ValidateError(error),
), false) => {
methods::ServerToClient::transaction_unstable_watchEvent {
subscription: (&subscription_id).into(),
result: methods::TransactionWatchEvent::Error {
error: error.to_string().into(),
}
}
.to_json_call_object_parameters(None)
},
(transactions_service::TransactionStatus::Dropped(
transactions_service::DropReason::Finalized { block_hash, .. },
), true) => {
methods::ServerToClient::author_extrinsicUpdate {
subscription: (&subscription_id).into(),
result: methods::TransactionStatus::Finalized(methods::HashHexString(
block_hash,
))
}
.to_json_call_object_parameters(None)
}
(transactions_service::TransactionStatus::Dropped(
transactions_service::DropReason::Finalized { block_hash, index },
), false) => {
methods::ServerToClient::transaction_unstable_watchEvent {
subscription: (&subscription_id).into(),
result: methods::TransactionWatchEvent::Finalized {
block: methods::TransactionWatchEventBlock {
hash: methods::HashHexString(block_hash),
index: methods::NumberAsString(index),
},
}
}
.to_json_call_object_parameters(None)
}
};
// TODO: handle situation where buffer is full
let _ = me
.requests_subscriptions
.try_push_notification(&state_machine_subscription, update)
.await;
}
None => {
// Channel from the transactions service has been closed.
// Stop the task.
// There is nothing more that can be done except hope that the
// client understands that no new notification is expected and
// unsubscribes.
break;
}
}
}
}
};
self.new_child_tasks_tx
.lock()
.await
.unbounded_send(Box::pin(
future::Abortable::new(task, abort_registration).map(|_| ()),
))
.unwrap();
}
/// Handles a call to [`methods::MethodCall::transaction_unstable_unwatch`].
pub(super) async fn transaction_unstable_unwatch(
self: &Arc<Self>,
request_id: &str,
state_machine_request_id: &requests_subscriptions::RequestId,
subscription: &str,
) {
let state_machine_subscription = if let Some((abort_handle, state_machine_subscription)) =
self.subscriptions
.lock()
.await
.misc
.remove(&(subscription.to_owned(), SubscriptionTy::Transaction))
{
abort_handle.abort();
Some(state_machine_subscription)
} else {
None
};
if let Some(state_machine_subscription) = &state_machine_subscription {
self.requests_subscriptions
.stop_subscription(state_machine_subscription)
.await;
}
self.requests_subscriptions
.respond(
state_machine_request_id,
methods::Response::transaction_unstable_unwatch(()).to_json_response(request_id),
)
.await;
}
}