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use std::sync::Arc;
use ethereum_types::U256;
use jsonrpc_core::{
futures::{Async, Future, IntoFuture, Poll},
Error, Result,
};
use types::transaction::SignedTransaction;
use super::{Accounts, PostSign, SignWith, WithToken};
use v1::helpers::{errors, nonce, FilledTransactionRequest};
#[derive(Debug, Clone, Copy)]
enum ProspectiveSignerState {
TryProspectiveSign,
WaitForPostSign,
WaitForNonce,
}
pub struct ProspectiveSigner<P: PostSign> {
signer: Arc<dyn Accounts>,
filled: FilledTransactionRequest,
chain_id: Option<u64>,
reserved: nonce::Reserved,
password: SignWith,
state: ProspectiveSignerState,
prospective: Option<WithToken<SignedTransaction>>,
ready: Option<nonce::Ready>,
post_sign: Option<P>,
post_sign_future: Option<<P::Out as IntoFuture>::Future>,
}
impl<P: PostSign> ProspectiveSigner<P> {
pub fn new(
signer: Arc<dyn Accounts>,
filled: FilledTransactionRequest,
chain_id: Option<u64>,
reserved: nonce::Reserved,
password: SignWith,
post_sign: P,
) -> Self {
let supports_prospective = signer.supports_prospective_signing(&filled.from, &password);
ProspectiveSigner {
signer,
filled,
chain_id,
reserved,
password,
state: if supports_prospective {
ProspectiveSignerState::TryProspectiveSign
} else {
ProspectiveSignerState::WaitForNonce
},
prospective: None,
ready: None,
post_sign: Some(post_sign),
post_sign_future: None,
}
}
fn sign(&self, nonce: &U256) -> Result<WithToken<SignedTransaction>> {
self.signer.sign_transaction(
self.filled.clone(),
self.chain_id,
*nonce,
self.password.clone(),
)
}
fn poll_reserved(&mut self) -> Poll<nonce::Ready, Error> {
self.reserved
.poll()
.map_err(|_| errors::internal("Nonce reservation failure", ""))
}
}
impl<P: PostSign> Future for ProspectiveSigner<P> {
type Item = P::Item;
type Error = Error;
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
use self::ProspectiveSignerState::*;
loop {
match self.state {
TryProspectiveSign => {
match self.poll_reserved()? {
Async::NotReady => {
self.state = WaitForNonce;
self.prospective = Some(self.sign(self.reserved.prospective_value())?);
}
Async::Ready(nonce) => {
self.state = WaitForPostSign;
self.post_sign_future = Some(
self.post_sign
.take()
.expect("post_sign is set on creation; qed")
.execute(self.sign(nonce.value())?)
.into_future(),
);
self.ready = Some(nonce);
}
}
}
WaitForNonce => {
let nonce = try_ready!(self.poll_reserved());
let prospective = match (self.prospective.take(), nonce.matches_prospective()) {
(Some(prospective), true) => prospective,
_ => self.sign(nonce.value())?,
};
self.ready = Some(nonce);
self.state = WaitForPostSign;
self.post_sign_future = Some(
self.post_sign
.take()
.expect("post_sign is set on creation; qed")
.execute(prospective)
.into_future(),
);
}
WaitForPostSign => {
if let Some(fut) = self.post_sign_future.as_mut() {
match fut.poll()? {
Async::Ready(item) => {
let nonce = self.ready.take().expect(
"nonce is set before state transitions to WaitForPostSign; qed",
);
nonce.mark_used();
return Ok(Async::Ready(item));
}
Async::NotReady => return Ok(Async::NotReady),
}
} else {
panic!("Poll after ready.");
}
}
}
}
}
}
