web3-proxy/web3_proxy/src/app.rs
2022-09-06 20:50:37 +00:00

892 lines
35 KiB
Rust

// TODO: this file is way too big now. move things into other modules
use crate::block_number::block_needed;
use crate::config::{AppConfig, TopConfig};
use crate::jsonrpc::JsonRpcForwardedResponse;
use crate::jsonrpc::JsonRpcForwardedResponseEnum;
use crate::jsonrpc::JsonRpcRequest;
use crate::jsonrpc::JsonRpcRequestEnum;
use crate::rpcs::blockchain::{ArcBlock, BlockHashesMap};
use crate::rpcs::connections::Web3Connections;
use crate::rpcs::transactions::TxStatus;
use crate::stats::AppStats;
use anyhow::Context;
use axum::extract::ws::Message;
use derive_more::From;
use ethers::core::utils::keccak256;
use ethers::prelude::{Address, Block, Bytes, TxHash, H256, U64};
use futures::future::Abortable;
use futures::future::{join_all, AbortHandle};
use futures::stream::FuturesUnordered;
use futures::stream::StreamExt;
use futures::Future;
use migration::{Migrator, MigratorTrait};
use moka::future::Cache;
use redis_rate_limit::bb8::PooledConnection;
use redis_rate_limit::{
bb8::{self, ErrorSink},
RedisConnectionManager, RedisErrorSink, RedisPool, RedisRateLimit,
};
use sea_orm::DatabaseConnection;
use serde_json::json;
use std::fmt;
use std::pin::Pin;
use std::str::FromStr;
use std::sync::atomic::{self, AtomicUsize};
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::{broadcast, watch};
use tokio::task::JoinHandle;
use tokio::time::{timeout, Instant};
use tokio_stream::wrappers::{BroadcastStream, WatchStream};
use tracing::{info, info_span, instrument, trace, warn, Instrument};
use uuid::Uuid;
// TODO: make this customizable?
static APP_USER_AGENT: &str = concat!(
"satoshiandkin/",
env!("CARGO_PKG_NAME"),
"/",
env!("CARGO_PKG_VERSION"),
);
/// block hash, method, params
// TODO: better name
type ResponseCacheKey = (H256, String, Option<String>);
type ResponseCache = Cache<ResponseCacheKey, JsonRpcForwardedResponse>;
pub type AnyhowJoinHandle<T> = JoinHandle<anyhow::Result<T>>;
#[derive(Clone, Copy, From)]
pub struct UserCacheValue {
pub expires_at: Instant,
pub user_id: u64,
pub user_count_per_period: u64,
}
/// The application
// TODO: this debug impl is way too verbose. make something smaller
// TODO: i'm sure this is more arcs than necessary, but spawning futures makes references hard
pub struct Web3ProxyApp {
/// Send requests to the best server available
pub balanced_rpcs: Arc<Web3Connections>,
/// Send private requests (like eth_sendRawTransaction) to all these servers
pub private_rpcs: Arc<Web3Connections>,
response_cache: ResponseCache,
// don't drop this or the sender will stop working
// TODO: broadcast channel instead?
head_block_receiver: watch::Receiver<ArcBlock>,
pending_tx_sender: broadcast::Sender<TxStatus>,
pub config: AppConfig,
pub db_conn: Option<sea_orm::DatabaseConnection>,
/// store pending transactions that we've seen so that we don't send duplicates to subscribers
pub pending_transactions: Cache<TxHash, TxStatus>,
pub rate_limiter: Option<RedisRateLimit>,
pub redis_pool: Option<RedisPool>,
pub stats: AppStats,
pub user_cache: Cache<Uuid, UserCacheValue>,
}
/// flatten a JoinError into an anyhow error
/// Useful when joining multiple futures.
pub async fn flatten_handle<T>(handle: AnyhowJoinHandle<T>) -> anyhow::Result<T> {
match handle.await {
Ok(Ok(result)) => Ok(result),
Ok(Err(err)) => Err(err),
Err(err) => Err(err.into()),
}
}
/// return the first error or okay if everything worked
pub async fn flatten_handles<T>(
mut handles: FuturesUnordered<AnyhowJoinHandle<T>>,
) -> anyhow::Result<()> {
while let Some(x) = handles.next().await {
match x {
Err(e) => return Err(e.into()),
Ok(Err(e)) => return Err(e),
Ok(Ok(_)) => continue,
}
}
Ok(())
}
/// Connect to the database and run migrations
pub async fn get_migrated_db(
db_url: String,
min_connections: u32,
max_connections: u32,
) -> anyhow::Result<DatabaseConnection> {
let mut db_opt = sea_orm::ConnectOptions::new(db_url);
// TODO: load all these options from the config file. i think mysql default max is 100
// TODO: sqlx logging only in debug. way too verbose for production
db_opt
.min_connections(min_connections)
.max_connections(max_connections)
.connect_timeout(Duration::from_secs(8))
.idle_timeout(Duration::from_secs(8))
.max_lifetime(Duration::from_secs(60))
.sqlx_logging(false);
// .sqlx_logging_level(log::LevelFilter::Info);
let db = sea_orm::Database::connect(db_opt).await?;
// TODO: if error, roll back?
Migrator::up(&db, None).await?;
Ok(db)
}
impl Web3ProxyApp {
pub async fn spawn(
app_stats: AppStats,
top_config: TopConfig,
num_workers: u32,
) -> anyhow::Result<(
Arc<Web3ProxyApp>,
Pin<Box<dyn Future<Output = anyhow::Result<()>>>>,
)> {
// safety checks on the config
assert!(
top_config.app.redirect_user_url.contains("{{user_id}}"),
"redirect user url must contain \"{{user_id}}\""
);
// first, we connect to mysql and make sure the latest migrations have run
let db_conn = if let Some(db_url) = &top_config.app.db_url {
let db_min_connections = top_config.app.db_min_connections.unwrap_or(num_workers);
// TODO: what default multiple?
let redis_max_connections = top_config
.app
.db_max_connections
.unwrap_or(db_min_connections * 2);
let db =
get_migrated_db(db_url.clone(), db_min_connections, redis_max_connections).await?;
Some(db)
} else {
info!("no database");
None
};
let balanced_rpcs = top_config.balanced_rpcs;
let private_rpcs = if let Some(private_rpcs) = top_config.private_rpcs {
private_rpcs
} else {
Default::default()
};
// TODO: try_join_all instead?
let handles = FuturesUnordered::new();
// make a http shared client
// TODO: can we configure the connection pool? should we?
// TODO: 5 minutes is probably long enough. unlimited is a bad idea if something is wrong with the remote server
let http_client = Some(
reqwest::ClientBuilder::new()
.connect_timeout(Duration::from_secs(5))
.timeout(Duration::from_secs(60))
.user_agent(APP_USER_AGENT)
.build()?,
);
let redis_pool = match top_config.app.redis_url.as_ref() {
Some(redis_url) => {
info!("Connecting to redis on {}", redis_url);
let manager = RedisConnectionManager::new(redis_url.as_ref())?;
let redis_min_connections =
top_config.app.redis_min_connections.unwrap_or(num_workers);
let redis_max_connections = top_config
.app
.redis_max_connections
.unwrap_or(redis_min_connections * 2);
// TODO: min_idle?
// TODO: set max_size based on max expected concurrent connections? set based on num_workers?
let builder = bb8::Pool::builder()
.error_sink(RedisErrorSink.boxed_clone())
.min_idle(Some(redis_min_connections))
.max_size(redis_max_connections);
let pool = builder.build(manager).await?;
Some(pool)
}
None => {
warn!("no redis connection");
None
}
};
// TODO: i don't like doing Block::default here! Change this to "None"?
let (head_block_sender, head_block_receiver) = watch::channel(Arc::new(Block::default()));
// TODO: will one receiver lagging be okay? how big should this be?
let (pending_tx_sender, pending_tx_receiver) = broadcast::channel(256);
// TODO: use this? it could listen for confirmed transactions and then clear pending_transactions, but the head_block_sender is doing that
drop(pending_tx_receiver);
// TODO: sized and timed expiration!
// TODO: put some in Redis, too?
let pending_transactions = Cache::new(10000);
// TODO: don't drop the pending_tx_receiver. instead, read it to mark transactions as "seen". once seen, we won't re-send them
// TODO: once a transaction is "Confirmed" we remove it from the map. this should prevent major memory leaks.
// TODO: we should still have some sort of expiration or maximum size limit for the map
// this block map is shared between balanced_rpcs and private_rpcs.
// TODO: what limits should we have for expiration?
let block_map = BlockHashesMap::new(10_000);
let (balanced_rpcs, balanced_handle) = Web3Connections::spawn(
top_config.app.chain_id,
balanced_rpcs,
http_client.clone(),
redis_pool.clone(),
block_map.clone(),
Some(head_block_sender),
top_config.app.min_sum_soft_limit,
top_config.app.min_synced_rpcs,
Some(pending_tx_sender.clone()),
pending_transactions.clone(),
)
.await
.context("balanced rpcs")?;
handles.push(balanced_handle);
let private_rpcs = if private_rpcs.is_empty() {
// TODO: do None instead of clone?
warn!("No private relays configured. Any transactions will be broadcast to the public mempool!");
balanced_rpcs.clone()
} else {
// TODO: attach context to this error
let (private_rpcs, private_handle) = Web3Connections::spawn(
top_config.app.chain_id,
private_rpcs,
http_client.clone(),
redis_pool.clone(),
block_map,
// subscribing to new heads here won't work well. if they are fast, they might be ahead of balanced_rpcs
None,
// minimum doesn't really matter on private rpcs
1,
1,
// TODO: subscribe to pending transactions on the private rpcs? they seem to have low rate limits
None,
pending_transactions.clone(),
)
.await
.context("private_rpcs")?;
handles.push(private_handle);
private_rpcs
};
let frontend_rate_limiter = redis_pool.as_ref().map(|redis_pool| {
RedisRateLimit::new(
redis_pool.clone(),
"web3_proxy",
"frontend",
top_config.app.public_rate_limit_per_minute,
60.0,
)
});
// TODO: change this to a sized cache
let response_cache = Cache::new(10_000);
let user_cache = Cache::new(10_000);
let app = Self {
config: top_config.app,
balanced_rpcs,
private_rpcs,
response_cache,
head_block_receiver,
pending_tx_sender,
pending_transactions,
rate_limiter: frontend_rate_limiter,
db_conn,
redis_pool,
stats: app_stats,
user_cache,
};
let app = Arc::new(app);
// create a handle that returns on the first error
// TODO: move this to a helper. i think Web3Connections needs it too
let handle = Box::pin(flatten_handles(handles));
Ok((app, handle))
}
pub async fn eth_subscribe(
self: Arc<Self>,
payload: JsonRpcRequest,
subscription_count: &AtomicUsize,
// TODO: taking a sender for Message instead of the exact json we are planning to send feels wrong, but its easier for now
response_sender: flume::Sender<Message>,
) -> anyhow::Result<(AbortHandle, JsonRpcForwardedResponse)> {
let (subscription_abort_handle, subscription_registration) = AbortHandle::new_pair();
// TODO: this only needs to be unique per connection. we don't need it globably unique
let subscription_id = subscription_count.fetch_add(1, atomic::Ordering::SeqCst);
let subscription_id = U64::from(subscription_id);
// save the id so we can use it in the response
let id = payload.id.clone();
// TODO: calling json! on every request is probably not fast. but we can only match against
// TODO: i think we need a stricter EthSubscribeRequest type that JsonRpcRequest can turn into
match payload.params {
Some(x) if x == json!(["newHeads"]) => {
let head_block_receiver = self.head_block_receiver.clone();
trace!(?subscription_id, "new heads subscription");
tokio::spawn(async move {
let mut head_block_receiver = Abortable::new(
WatchStream::new(head_block_receiver),
subscription_registration,
);
while let Some(new_head) = head_block_receiver.next().await {
// TODO: make a struct for this? using our JsonRpcForwardedResponse won't work because it needs an id
let msg = json!({
"jsonrpc": "2.0",
"method":"eth_subscription",
"params": {
"subscription": subscription_id,
// TODO: option to include full transaction objects instead of just the hashes?
"result": new_head.as_ref(),
},
});
// TODO: do clients support binary messages?
let msg = Message::Text(
serde_json::to_string(&msg).expect("this should always be valid json"),
);
if response_sender.send_async(msg).await.is_err() {
// TODO: cancel this subscription earlier? select on head_block_receiver.next() and an abort handle?
break;
};
}
trace!(?subscription_id, "closed new heads subscription");
});
}
Some(x) if x == json!(["newPendingTransactions"]) => {
let pending_tx_receiver = self.pending_tx_sender.subscribe();
let mut pending_tx_receiver = Abortable::new(
BroadcastStream::new(pending_tx_receiver),
subscription_registration,
);
trace!(?subscription_id, "pending transactions subscription");
tokio::spawn(async move {
while let Some(Ok(new_tx_state)) = pending_tx_receiver.next().await {
let new_tx = match new_tx_state {
TxStatus::Pending(tx) => tx,
TxStatus::Confirmed(..) => continue,
TxStatus::Orphaned(tx) => tx,
};
// TODO: make a struct for this? using our JsonRpcForwardedResponse won't work because it needs an id
let msg = json!({
"jsonrpc": "2.0",
"method": "eth_subscription",
"params": {
"subscription": subscription_id,
"result": new_tx.hash,
},
});
let msg = Message::Text(serde_json::to_string(&msg).unwrap());
if response_sender.send_async(msg).await.is_err() {
// TODO: cancel this subscription earlier? select on head_block_receiver.next() and an abort handle?
break;
};
}
trace!(?subscription_id, "closed new heads subscription");
});
}
Some(x) if x == json!(["newPendingFullTransactions"]) => {
// TODO: too much copy/pasta with newPendingTransactions
let pending_tx_receiver = self.pending_tx_sender.subscribe();
let mut pending_tx_receiver = Abortable::new(
BroadcastStream::new(pending_tx_receiver),
subscription_registration,
);
trace!(?subscription_id, "pending transactions subscription");
// TODO: do something with this handle?
tokio::spawn(async move {
while let Some(Ok(new_tx_state)) = pending_tx_receiver.next().await {
let new_tx = match new_tx_state {
TxStatus::Pending(tx) => tx,
TxStatus::Confirmed(..) => continue,
TxStatus::Orphaned(tx) => tx,
};
// TODO: make a struct for this? using our JsonRpcForwardedResponse won't work because it needs an id
let msg = json!({
"jsonrpc": "2.0",
"method": "eth_subscription",
"params": {
"subscription": subscription_id,
// upstream just sends the txid, but we want to send the whole transaction
"result": new_tx,
},
});
let msg = Message::Text(serde_json::to_string(&msg).unwrap());
if response_sender.send_async(msg).await.is_err() {
// TODO: cancel this subscription earlier? select on head_block_receiver.next() and an abort handle?
break;
};
}
trace!(?subscription_id, "closed new heads subscription");
});
}
Some(x) if x == json!(["newPendingRawTransactions"]) => {
// TODO: too much copy/pasta with newPendingTransactions
let pending_tx_receiver = self.pending_tx_sender.subscribe();
let mut pending_tx_receiver = Abortable::new(
BroadcastStream::new(pending_tx_receiver),
subscription_registration,
);
trace!(?subscription_id, "pending transactions subscription");
// TODO: do something with this handle?
tokio::spawn(async move {
while let Some(Ok(new_tx_state)) = pending_tx_receiver.next().await {
let new_tx = match new_tx_state {
TxStatus::Pending(tx) => tx,
TxStatus::Confirmed(..) => continue,
TxStatus::Orphaned(tx) => tx,
};
// TODO: make a struct for this? using our JsonRpcForwardedResponse won't work because it needs an id
let msg = json!({
"jsonrpc": "2.0",
"method": "eth_subscription",
"params": {
"subscription": subscription_id,
// upstream just sends the txid, but we want to send the raw transaction
"result": new_tx.rlp(),
},
});
let msg = Message::Text(serde_json::to_string(&msg).unwrap());
if response_sender.send_async(msg).await.is_err() {
// TODO: cancel this subscription earlier? select on head_block_receiver.next() and an abort handle?
break;
};
}
trace!(?subscription_id, "closed new heads subscription");
});
}
_ => return Err(anyhow::anyhow!("unimplemented")),
}
// TODO: do something with subscription_join_handle?
let response = JsonRpcForwardedResponse::from_value(json!(subscription_id), id);
// TODO: make a `SubscriptonHandle(AbortHandle, JoinHandle)` struct?
Ok((subscription_abort_handle, response))
}
/// send the request or batch of requests to the approriate RPCs
#[instrument(skip_all)]
pub async fn proxy_web3_rpc(
&self,
request: JsonRpcRequestEnum,
) -> anyhow::Result<JsonRpcForwardedResponseEnum> {
// TODO: this should probably be trace level
trace!(?request, "proxy_web3_rpc");
// even though we have timeouts on the requests to our backend providers,
// we need a timeout for the incoming request so that retries don't run forever
// TODO: take this as an optional argument. per user max? expiration time instead of duration?
let max_time = Duration::from_secs(120);
let response = match request {
JsonRpcRequestEnum::Single(request) => JsonRpcForwardedResponseEnum::Single(
timeout(max_time, self.proxy_web3_rpc_request(request)).await??,
),
JsonRpcRequestEnum::Batch(requests) => JsonRpcForwardedResponseEnum::Batch(
timeout(max_time, self.proxy_web3_rpc_requests(requests)).await??,
),
};
// TODO: this should probably be trace level
trace!(?response, "Forwarding");
Ok(response)
}
async fn proxy_web3_rpc_requests(
&self,
requests: Vec<JsonRpcRequest>,
) -> anyhow::Result<Vec<JsonRpcForwardedResponse>> {
// TODO: we should probably change ethers-rs to support this directly
// we cut up the request and send to potentually different servers. this could be a problem.
// if the client needs consistent blocks, they should specify instead of assume batches work on the same
// TODO: is spawning here actually slower?
let num_requests = requests.len();
let responses = join_all(
requests
.into_iter()
.map(|request| self.proxy_web3_rpc_request(request))
.collect::<Vec<_>>(),
)
.await;
// TODO: i'm sure this could be done better with iterators
let mut collected: Vec<JsonRpcForwardedResponse> = Vec::with_capacity(num_requests);
for response in responses {
collected.push(response?);
}
Ok(collected)
}
pub async fn redis_conn(&self) -> anyhow::Result<PooledConnection<RedisConnectionManager>> {
match self.redis_pool.as_ref() {
None => Err(anyhow::anyhow!("no redis server configured")),
Some(redis_pool) => {
let redis_conn = redis_pool.get().await?;
Ok(redis_conn)
}
}
}
async fn cached_response_or_key(
&self,
// TODO: accept a block hash here also?
min_block_needed: Option<&U64>,
request: &JsonRpcRequest,
) -> anyhow::Result<Result<JsonRpcForwardedResponse, ResponseCacheKey>> {
// TODO: inspect the request to pick the right cache
// TODO: https://github.com/ethereum/web3.py/blob/master/web3/middleware/cache.py
let request_block_hash = if let Some(min_block_needed) = min_block_needed {
// TODO: maybe this should be on the app and not on balanced_rpcs
self.balanced_rpcs.block_hash(min_block_needed).await?
} else {
// TODO: maybe this should be on the app and not on balanced_rpcs
self.balanced_rpcs
.head_block_hash()
.context("no servers in sync")?
};
// TODO: better key? benchmark this
let key = (
request_block_hash,
request.method.clone(),
request.params.clone().map(|x| x.to_string()),
);
if let Some(response) = self.response_cache.get(&key) {
// TODO: emit a stat
trace!(?request.method, "cache hit!");
// TODO: can we make references work? maybe put them in an Arc?
return Ok(Ok(response));
}
// TODO: another lock here so that we don't send the same request to a backend more than onces xzs
// TODO: emit a stat
trace!(?request.method, "cache miss!");
Ok(Err(key))
}
async fn proxy_web3_rpc_request(
&self,
mut request: JsonRpcRequest,
) -> anyhow::Result<JsonRpcForwardedResponse> {
trace!("Received request: {:?}", request);
// save the id so we can attach it to the response
let id = request.id.clone();
// TODO: if eth_chainId or net_version, serve those without querying the backend
// TODO: how much should we retry? probably with a timeout and not with a count like this
// TODO: think more about this loop.
// // TODO: add more to this span such as
let span = info_span!("rpc_request");
// let _enter = span.enter(); // DO NOT ENTER! we can't use enter across awaits! (clippy lint soon)
// TODO: don't clone
let partial_response: serde_json::Value = match request.method.clone().as_ref() {
// lots of commands are blocked
"admin_addPeer"
| "admin_datadir"
| "admin_startRPC"
| "admin_startWS"
| "admin_stopRPC"
| "admin_stopWS"
| "db_getHex"
| "db_getString"
| "db_putHex"
| "db_putString"
| "debug_chaindbCompact"
| "debug_freezeClient"
| "debug_goTrace"
| "debug_mutexProfile"
| "debug_setBlockProfileRate"
| "debug_setGCPercent"
| "debug_setHead"
| "debug_setMutexProfileFraction"
| "debug_standardTraceBlockToFile"
| "debug_standardTraceBadBlockToFile"
| "debug_startCPUProfile"
| "debug_startGoTrace"
| "debug_stopCPUProfile"
| "debug_stopGoTrace"
| "debug_writeBlockProfile"
| "debug_writeMemProfile"
| "debug_writeMutexProfile"
| "eth_compileLLL"
| "eth_compileSerpent"
| "eth_compileSolidity"
| "eth_getCompilers"
| "eth_sendTransaction"
| "eth_sign"
| "eth_signTransaction"
| "eth_submitHashrate"
| "eth_submitWork"
| "les_addBalance"
| "les_setClientParams"
| "les_setDefaultParams"
| "miner_setExtra"
| "miner_setGasPrice"
| "miner_start"
| "miner_stop"
| "miner_setEtherbase"
| "miner_setGasLimit"
| "personal_importRawKey"
| "personal_listAccounts"
| "personal_lockAccount"
| "personal_newAccount"
| "personal_unlockAccount"
| "personal_sendTransaction"
| "personal_sign"
| "personal_ecRecover"
| "shh_addToGroup"
| "shh_getFilterChanges"
| "shh_getMessages"
| "shh_hasIdentity"
| "shh_newFilter"
| "shh_newGroup"
| "shh_newIdentity"
| "shh_post"
| "shh_uninstallFilter"
| "shh_version" => {
// TODO: client error stat
// TODO: proper error code
return Err(anyhow::anyhow!("unsupported"));
}
// TODO: implement these commands
"eth_getFilterChanges"
| "eth_getFilterLogs"
| "eth_newBlockFilter"
| "eth_newFilter"
| "eth_newPendingTransactionFilter"
| "eth_uninstallFilter" => {
// TODO: unsupported command stat
return Err(anyhow::anyhow!("not yet implemented"));
}
// some commands can use local data or caches
"eth_accounts" => {
// no stats on this. its cheap
serde_json::Value::Array(vec![])
}
"eth_blockNumber" => {
match self.balanced_rpcs.head_block_num() {
Some(head_block_num) => {
json!(head_block_num)
}
None => {
// TODO: what does geth do if this happens?
return Err(anyhow::anyhow!("no servers synced"));
}
}
}
// TODO: eth_callBundle (https://docs.flashbots.net/flashbots-auction/searchers/advanced/rpc-endpoint#eth_callbundle)
// TODO: eth_cancelPrivateTransaction (https://docs.flashbots.net/flashbots-auction/searchers/advanced/rpc-endpoint#eth_cancelprivatetransaction, but maybe just reject)
// TODO: eth_sendPrivateTransaction (https://docs.flashbots.net/flashbots-auction/searchers/advanced/rpc-endpoint#eth_sendprivatetransaction)
"eth_coinbase" => {
// no need for serving coinbase
// we could return a per-user payment address here, but then we might leak that to dapps
// no stats on this. its cheap
json!(Address::zero())
}
// TODO: eth_estimateGas using anvil?
// TODO: eth_gasPrice that does awesome magic to predict the future
"eth_hashrate" => {
// no stats on this. its cheap
json!(U64::zero())
}
"eth_mining" => {
// no stats on this. its cheap
json!(false)
}
// TODO: eth_sendBundle (flashbots command)
// broadcast transactions to all private rpcs at once
"eth_sendRawTransaction" => {
// emit stats
return self
.private_rpcs
.try_send_all_upstream_servers(request, None)
.instrument(span)
.await;
}
"eth_syncing" => {
// no stats on this. its cheap
// TODO: return a real response if all backends are syncing or if no servers in sync
json!(false)
}
"net_listening" => {
// no stats on this. its cheap
// TODO: only if there are some backends on balanced_rpcs?
json!(true)
}
"net_peerCount" => {
// emit stats
self.balanced_rpcs.num_synced_rpcs().into()
}
"web3_clientVersion" => {
// no stats on this. its cheap
serde_json::Value::String(APP_USER_AGENT.to_string())
}
"web3_sha3" => {
// emit stats
// returns Keccak-256 (not the standardized SHA3-256) of the given data.
match &request.params {
Some(serde_json::Value::Array(params)) => {
// TODO: make a struct and use serde conversion to clean this up
if params.len() != 1 || !params[0].is_string() {
return Err(anyhow::anyhow!("invalid request"));
}
let param = Bytes::from_str(params[0].as_str().unwrap())?;
let hash = H256::from(keccak256(param));
json!(hash)
}
_ => return Err(anyhow::anyhow!("invalid request")),
}
}
// TODO: web3_sha3?
// anything else gets sent to backend rpcs and cached
method => {
// emit stats
let head_block_number = self
.balanced_rpcs
.head_block_num()
.context("no servers synced")?;
// we do this check before checking caches because it might modify the request params
// TODO: add a stat for archive vs full since they should probably cost different
let min_block_needed =
block_needed(method, request.params.as_mut(), head_block_number);
let min_block_needed = min_block_needed.as_ref();
trace!(?min_block_needed, ?method);
// TODO: emit a stat on error. maybe with .map_err?
let cache_key = match self
.cached_response_or_key(min_block_needed, &request)
.await?
{
Ok(mut cache_result) => {
// we got a cache hit! no need to do any backend requests.
// put our request id on the cached response
// TODO: maybe only cache the inner result? then have a JsonRpcForwardedResponse::from_cache
cache_result.id = request.id;
// emit a stat
return Ok(cache_result);
}
Err(cache_key) => cache_key,
};
// TODO: move this caching outside this match and cache some of the other responses?
// TODO: cache the warp::reply to save us serializing every time?
let mut response = self
.response_cache
.try_get_with(cache_key, async move {
match method {
"temporarily disabled" => {
// "eth_getTransactionByHash" | "eth_getTransactionReceipt" => {
// TODO: try_send_all serially with retries instead of parallel
self.private_rpcs
.try_send_all_upstream_servers(request, min_block_needed)
.await
}
_ => {
// TODO: retries?
self.balanced_rpcs
.try_send_best_upstream_server(request, min_block_needed)
.await
}
}
})
.await
.unwrap();
// this is fragile and i no longer like it
response.id = id;
return Ok(response);
}
};
let response = JsonRpcForwardedResponse::from_value(partial_response, id);
Ok(response)
}
}
impl fmt::Debug for Web3ProxyApp {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// TODO: the default formatter takes forever to write. this is too quiet though
f.debug_struct("Web3ProxyApp").finish_non_exhaustive()
}
}