//! Simple RPC client implementation which implements [`BlockSource`] against a Bitcoin Core RPC
//! endpoint.
-use crate::{BlockHeaderData, BlockSource, AsyncBlockSourceResult};
-use crate::http::{HttpClient, HttpEndpoint, JsonResponse};
+use crate::{BlockData, BlockHeaderData, BlockSource, AsyncBlockSourceResult};
+use crate::http::{HttpClient, HttpEndpoint, HttpError, JsonResponse};
-use bitcoin::blockdata::block::Block;
use bitcoin::hash_types::BlockHash;
use bitcoin::hashes::hex::ToHex;
+use std::sync::Mutex;
+
use serde_json;
use std::convert::TryFrom;
use std::convert::TryInto;
+use std::error::Error;
+use std::fmt;
use std::sync::atomic::{AtomicUsize, Ordering};
+/// An error returned by the RPC server.
+#[derive(Debug)]
+pub struct RpcError {
+ /// The error code.
+ pub code: i64,
+ /// The error message.
+ pub message: String,
+}
+
+impl fmt::Display for RpcError {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ write!(f, "RPC error {}: {}", self.code, self.message)
+ }
+}
+
+impl Error for RpcError {}
+
/// A simple RPC client for calling methods using HTTP `POST`.
+///
+/// Implements [`BlockSource`] and may return an `Err` containing [`RpcError`]. See
+/// [`RpcClient::call_method`] for details.
pub struct RpcClient {
basic_auth: String,
endpoint: HttpEndpoint,
- client: HttpClient,
+ client: Mutex<Option<HttpClient>>,
id: AtomicUsize,
}
/// credentials should be a base64 encoding of a user name and password joined by a colon, as is
/// required for HTTP basic access authentication.
pub fn new(credentials: &str, endpoint: HttpEndpoint) -> std::io::Result<Self> {
- let client = HttpClient::connect(&endpoint)?;
Ok(Self {
basic_auth: "Basic ".to_string() + credentials,
endpoint,
- client,
+ client: Mutex::new(None),
id: AtomicUsize::new(0),
})
}
/// Calls a method with the response encoded in JSON format and interpreted as type `T`.
- pub async fn call_method<T>(&mut self, method: &str, params: &[serde_json::Value]) -> std::io::Result<T>
+ ///
+ /// When an `Err` is returned, [`std::io::Error::into_inner`] may contain an [`RpcError`] if
+ /// [`std::io::Error::kind`] is [`std::io::ErrorKind::Other`].
+ pub async fn call_method<T>(&self, method: &str, params: &[serde_json::Value]) -> std::io::Result<T>
where JsonResponse: TryFrom<Vec<u8>, Error = std::io::Error> + TryInto<T, Error = std::io::Error> {
let host = format!("{}:{}", self.endpoint.host(), self.endpoint.port());
let uri = self.endpoint.path();
"id": &self.id.fetch_add(1, Ordering::AcqRel).to_string()
});
- let mut response = self.client.post::<JsonResponse>(&uri, &host, &self.basic_auth, content)
- .await?.0;
+ let mut client = if let Some(client) = self.client.lock().unwrap().take() { client }
+ else { HttpClient::connect(&self.endpoint)? };
+ let http_response = client.post::<JsonResponse>(&uri, &host, &self.basic_auth, content).await;
+ *self.client.lock().unwrap() = Some(client);
+
+ let mut response = match http_response {
+ Ok(JsonResponse(response)) => response,
+ Err(e) if e.kind() == std::io::ErrorKind::Other => {
+ match e.get_ref().unwrap().downcast_ref::<HttpError>() {
+ Some(http_error) => match JsonResponse::try_from(http_error.contents.clone()) {
+ Ok(JsonResponse(response)) => response,
+ Err(_) => Err(e)?,
+ },
+ None => Err(e)?,
+ }
+ },
+ Err(e) => Err(e)?,
+ };
+
if !response.is_object() {
return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "expected JSON object"));
}
let error = &response["error"];
if !error.is_null() {
// TODO: Examine error code for a more precise std::io::ErrorKind.
- let message = error["message"].as_str().unwrap_or("unknown error");
- return Err(std::io::Error::new(std::io::ErrorKind::Other, message));
+ let rpc_error = RpcError {
+ code: error["code"].as_i64().unwrap_or(-1),
+ message: error["message"].as_str().unwrap_or("unknown error").to_string()
+ };
+ return Err(std::io::Error::new(std::io::ErrorKind::Other, rpc_error));
}
let result = &mut response["result"];
}
impl BlockSource for RpcClient {
- fn get_header<'a>(&'a mut self, header_hash: &'a BlockHash, _height: Option<u32>) -> AsyncBlockSourceResult<'a, BlockHeaderData> {
+ fn get_header<'a>(&'a self, header_hash: &'a BlockHash, _height: Option<u32>) -> AsyncBlockSourceResult<'a, BlockHeaderData> {
Box::pin(async move {
let header_hash = serde_json::json!(header_hash.to_hex());
Ok(self.call_method("getblockheader", &[header_hash]).await?)
})
}
- fn get_block<'a>(&'a mut self, header_hash: &'a BlockHash) -> AsyncBlockSourceResult<'a, Block> {
+ fn get_block<'a>(&'a self, header_hash: &'a BlockHash) -> AsyncBlockSourceResult<'a, BlockData> {
Box::pin(async move {
let header_hash = serde_json::json!(header_hash.to_hex());
let verbosity = serde_json::json!(0);
- Ok(self.call_method("getblock", &[header_hash, verbosity]).await?)
+ Ok(BlockData::FullBlock(self.call_method("getblock", &[header_hash, verbosity]).await?))
})
}
- fn get_best_block<'a>(&'a mut self) -> AsyncBlockSourceResult<'a, (BlockHash, Option<u32>)> {
+ fn get_best_block<'a>(&'a self) -> AsyncBlockSourceResult<'a, (BlockHash, Option<u32>)> {
Box::pin(async move {
Ok(self.call_method("getblockchaininfo", &[]).await?)
})
#[tokio::test]
async fn call_method_returning_unknown_response() {
let server = HttpServer::responding_with_not_found();
- let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
+ let client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
match client.call_method::<u64>("getblockcount", &[]).await {
Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::Other),
async fn call_method_returning_malfomred_response() {
let response = serde_json::json!("foo");
let server = HttpServer::responding_with_ok(MessageBody::Content(response));
- let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
+ let client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
match client.call_method::<u64>("getblockcount", &[]).await {
Err(e) => {
let response = serde_json::json!({
"error": { "code": -8, "message": "invalid parameter" },
});
- let server = HttpServer::responding_with_ok(MessageBody::Content(response));
- let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
+ let server = HttpServer::responding_with_server_error(response);
+ let client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
let invalid_block_hash = serde_json::json!("foo");
match client.call_method::<u64>("getblock", &[invalid_block_hash]).await {
Err(e) => {
assert_eq!(e.kind(), std::io::ErrorKind::Other);
- assert_eq!(e.get_ref().unwrap().to_string(), "invalid parameter");
+ let rpc_error: Box<RpcError> = e.into_inner().unwrap().downcast().unwrap();
+ assert_eq!(rpc_error.code, -8);
+ assert_eq!(rpc_error.message, "invalid parameter");
},
Ok(_) => panic!("Expected error"),
}
async fn call_method_returning_missing_result() {
let response = serde_json::json!({ "result": null });
let server = HttpServer::responding_with_ok(MessageBody::Content(response));
- let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
+ let client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
match client.call_method::<u64>("getblockcount", &[]).await {
Err(e) => {
async fn call_method_returning_malformed_result() {
let response = serde_json::json!({ "result": "foo" });
let server = HttpServer::responding_with_ok(MessageBody::Content(response));
- let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
+ let client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
match client.call_method::<u64>("getblockcount", &[]).await {
Err(e) => {
async fn call_method_returning_valid_result() {
let response = serde_json::json!({ "result": 654470 });
let server = HttpServer::responding_with_ok(MessageBody::Content(response));
- let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
+ let client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
match client.call_method::<u64>("getblockcount", &[]).await {
Err(e) => panic!("Unexpected error: {:?}", e),