web3-proxy/web3_proxy/src/jsonrpc.rs
2023-04-10 22:29:02 -07:00

385 lines
13 KiB
Rust

use crate::frontend::errors::{Web3ProxyError, Web3ProxyResult};
use derive_more::From;
use ethers::prelude::ProviderError;
use serde::de::{self, Deserializer, MapAccess, SeqAccess, Visitor};
use serde::{Deserialize, Serialize};
use serde_json::json;
use serde_json::value::{to_raw_value, RawValue};
use std::fmt;
fn default_jsonrpc() -> String {
"2.0".to_string()
}
#[derive(Clone, Deserialize, Serialize)]
pub struct JsonRpcRequest {
// TODO: skip jsonrpc entirely? its against spec to drop it, but some servers bad
#[serde(default = "default_jsonrpc")]
pub jsonrpc: String,
/// id could be a stricter type, but many rpcs do things against the spec
pub id: Box<RawValue>,
pub method: String,
pub params: Option<serde_json::Value>,
}
#[derive(From)]
pub enum JsonRpcId {
None,
Number(u64),
String(String),
}
impl JsonRpcId {
pub fn to_raw_value(&self) -> Box<RawValue> {
// TODO: is this a good way to do this? we should probably use references
match self {
Self::None => {
to_raw_value(&json!(None::<Option<()>>)).expect("null id should always work")
}
Self::Number(x) => {
serde_json::from_value(json!(x)).expect("number id should always work")
}
Self::String(x) => serde_json::from_str(x).expect("string id should always work"),
}
}
}
impl JsonRpcRequest {
pub fn new(
id: JsonRpcId,
method: String,
params: Option<serde_json::Value>,
) -> anyhow::Result<Self> {
let x = Self {
jsonrpc: default_jsonrpc(),
id: id.to_raw_value(),
method,
params,
};
Ok(x)
}
}
impl fmt::Debug for JsonRpcRequest {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// TODO: the default formatter takes forever to write. this is too quiet though
// TODO: how should we include params in this? maybe just the length?
f.debug_struct("JsonRpcRequest")
.field("id", &self.id)
.field("method", &self.method)
.field("params", &self.params)
.finish()
}
}
/// Requests can come in multiple formats
#[derive(Debug, From)]
pub enum JsonRpcRequestEnum {
Batch(Vec<JsonRpcRequest>),
Single(JsonRpcRequest),
}
impl<'de> Deserialize<'de> for JsonRpcRequestEnum {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
#[derive(Deserialize)]
#[serde(field_identifier, rename_all = "lowercase")]
enum Field {
JsonRpc,
Id,
Method,
Params,
// TODO: jsonrpc here, too?
}
struct JsonRpcBatchVisitor;
impl<'de> Visitor<'de> for JsonRpcBatchVisitor {
type Value = JsonRpcRequestEnum;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("JsonRpcRequestEnum")
}
fn visit_seq<V>(self, mut seq: V) -> Result<JsonRpcRequestEnum, V::Error>
where
V: SeqAccess<'de>,
{
// TODO: what size should we use as the default?
let mut batch: Vec<JsonRpcRequest> =
Vec::with_capacity(seq.size_hint().unwrap_or(10));
while let Ok(Some(s)) = seq.next_element::<JsonRpcRequest>() {
batch.push(s);
}
Ok(JsonRpcRequestEnum::Batch(batch))
}
fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
where
A: MapAccess<'de>,
{
// TODO: i feel like this should be easier
let mut jsonrpc = None;
let mut id = None;
let mut method = None;
let mut params = None;
while let Some(key) = map.next_key()? {
match key {
Field::JsonRpc => {
// throw away the value
// TODO: should we check that it's 2.0?
// TODO: how do we skip over this value entirely?
jsonrpc = Some(map.next_value()?);
}
Field::Id => {
if id.is_some() {
return Err(de::Error::duplicate_field("id"));
}
id = Some(map.next_value()?);
}
Field::Method => {
if method.is_some() {
return Err(de::Error::duplicate_field("method"));
}
method = Some(map.next_value()?);
}
Field::Params => {
if params.is_some() {
return Err(de::Error::duplicate_field("params"));
}
params = Some(map.next_value()?);
}
}
}
// some providers don't follow the spec and dont include the jsonrpc key
// i think "2.0" should be a fine default to handle these incompatible clones
let jsonrpc = jsonrpc.unwrap_or_else(|| "2.0".to_string());
// TODO: Errors returned by the try operator get shown in an ugly way
let id = id.ok_or_else(|| de::Error::missing_field("id"))?;
let method = method.ok_or_else(|| de::Error::missing_field("method"))?;
let params: Option<serde_json::Value> = match params {
None => Some(serde_json::Value::Array(vec![])),
Some(x) => Some(x),
};
let single = JsonRpcRequest {
jsonrpc,
id,
method,
params,
};
Ok(JsonRpcRequestEnum::Single(single))
}
}
let batch_visitor = JsonRpcBatchVisitor {};
deserializer.deserialize_any(batch_visitor)
}
}
// TODO: impl Error on this?
/// All jsonrpc errors use this structure
#[derive(Debug, Deserialize, Serialize, Clone)]
pub struct JsonRpcErrorData {
/// The error code
pub code: i64,
/// The error message
pub message: String,
/// Additional data
#[serde(skip_serializing_if = "Option::is_none")]
pub data: Option<serde_json::Value>,
}
/// A complete response
/// TODO: better Debug response
#[derive(Clone, Debug, Deserialize, Serialize)]
pub struct JsonRpcForwardedResponse {
// TODO: jsonrpc a &str?
#[serde(default = "default_jsonrpc")]
pub jsonrpc: String,
pub id: Box<RawValue>,
#[serde(skip_serializing_if = "Option::is_none")]
pub result: Option<Box<RawValue>>,
#[serde(skip_serializing_if = "Option::is_none")]
pub error: Option<JsonRpcErrorData>,
}
impl JsonRpcRequest {
pub fn num_bytes(&self) -> usize {
// TODO: not sure how to do this without wasting a ton of allocations
serde_json::to_string(self)
.expect("this should always be valid json")
.len()
}
}
impl JsonRpcForwardedResponse {
pub fn from_anyhow_error(
err: anyhow::Error,
code: Option<i64>,
id: Option<Box<RawValue>>,
) -> Self {
let message = format!("{:?}", err);
Self::from_string(message, code, id)
}
pub fn from_str(message: &str, code: Option<i64>, id: Option<Box<RawValue>>) -> Self {
Self::from_string(message.to_string(), code, id)
}
pub fn from_string(message: String, code: Option<i64>, id: Option<Box<RawValue>>) -> Self {
// TODO: this is too verbose. plenty of errors are valid, like users giving an invalid address. no need to log that
// TODO: can we somehow get the initial request here? if we put that into a tracing span, will things slow down a ton?
JsonRpcForwardedResponse {
jsonrpc: "2.0".to_string(),
id: id.unwrap_or_else(|| JsonRpcId::None.to_raw_value()),
result: None,
error: Some(JsonRpcErrorData {
code: code.unwrap_or(-32099),
message,
// TODO: accept data as an argument
data: None,
}),
}
}
pub fn from_response(partial_response: Box<RawValue>, id: Box<RawValue>) -> Self {
JsonRpcForwardedResponse {
jsonrpc: "2.0".to_string(),
id,
// TODO: since we only use the result here, should that be all we return from try_send_request?
result: Some(partial_response),
error: None,
}
}
pub fn from_value(partial_response: serde_json::Value, id: Box<RawValue>) -> Self {
let partial_response =
to_raw_value(&partial_response).expect("Value to RawValue should always work");
JsonRpcForwardedResponse {
jsonrpc: "2.0".to_string(),
id,
result: Some(partial_response),
error: None,
}
}
pub fn from_ethers_error(e: ProviderError, id: Box<RawValue>) -> Web3ProxyResult<Self> {
// TODO: move turning ClientError into json to a helper function?
let code;
let message: String;
let data;
match e {
ProviderError::JsonRpcClientError(err) => {
if let Some(err) = err.as_error_response() {
code = err.code;
message = err.message.clone();
data = err.data.clone();
} else if let Some(err) = err.as_serde_error() {
// this is not an rpc error. keep it as an error
return Err(Web3ProxyError::BadRequest(format!("bad request: {}", err)));
} else {
return Err(anyhow::anyhow!("unexpected ethers error!").into());
}
}
e => return Err(e.into()),
}
Ok(Self {
jsonrpc: "2.0".to_string(),
id,
result: None,
error: Some(JsonRpcErrorData {
code,
message,
data,
}),
})
}
pub fn try_from_response_result(
result: Result<Box<RawValue>, ProviderError>,
id: Box<RawValue>,
) -> Web3ProxyResult<Self> {
match result {
Ok(response) => Ok(Self::from_response(response, id)),
Err(e) => Self::from_ethers_error(e, id),
}
}
pub fn num_bytes(&self) -> usize {
// TODO: not sure how to do this without wasting a ton of allocations
serde_json::to_string(self)
.expect("this should always be valid json")
.len()
}
}
/// JSONRPC Responses can include one or many response objects.
#[derive(Clone, Debug, From, Serialize)]
#[serde(untagged)]
pub enum JsonRpcForwardedResponseEnum {
Single(JsonRpcForwardedResponse),
Batch(Vec<JsonRpcForwardedResponse>),
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn this_deserialize_single() {
let input = r#"{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}"#;
// test deserializing it directly to a single request object
let output: JsonRpcRequest = serde_json::from_str(input).unwrap();
assert_eq!(output.id.to_string(), "1");
assert_eq!(output.method, "eth_blockNumber");
assert_eq!(output.params.unwrap().to_string(), "[]");
// test deserializing it into an enum
let output: JsonRpcRequestEnum = serde_json::from_str(input).unwrap();
assert!(matches!(output, JsonRpcRequestEnum::Single(_)));
}
#[test]
fn this_deserialize_batch() {
let input = r#"[{"jsonrpc":"2.0","method":"eth_getCode","params":["0x5ba1e12693dc8f9c48aad8770482f4739beed696","0xe0e6a4"],"id":27},{"jsonrpc":"2.0","method":"eth_getTransactionCount","params":["0x5ba1e12693dc8f9c48aad8770482f4739beed696","0xe0e6a4"],"id":28},{"jsonrpc":"2.0","method":"eth_getBalance","params":["0x5ba1e12693dc8f9c48aad8770482f4739beed696","0xe0e6a4"],"id":29}]"#;
// test deserializing it directly to a batch of request objects
let output: Vec<JsonRpcRequest> = serde_json::from_str(input).unwrap();
assert_eq!(output.len(), 3);
assert_eq!(output[0].id.to_string(), "27");
assert_eq!(output[0].method, "eth_getCode");
assert_eq!(
output[0].params.as_ref().unwrap().to_string(),
r#"["0x5ba1e12693dc8f9c48aad8770482f4739beed696","0xe0e6a4"]"#
);
assert_eq!(output[1].id.to_string(), "28");
assert_eq!(output[2].id.to_string(), "29");
// test deserializing it into an enum
let output: JsonRpcRequestEnum = serde_json::from_str(input).unwrap();
assert!(matches!(output, JsonRpcRequestEnum::Batch(_)));
}
}