_ Git - rust-lightning/blob - lightning-block-sync/src/rest.rs

   1 //! Simple REST client implementation which implements [`BlockSource`] against a Bitcoin Core REST
   2 //! endpoint.
   3
   4 use crate::{BlockHeaderData, BlockSource, AsyncBlockSourceResult};
   5 use crate::http::{BinaryResponse, HttpEndpoint, HttpClient, JsonResponse};
   6
   7 use bitcoin::blockdata::block::Block;
   8 use bitcoin::hash_types::BlockHash;
   9 use bitcoin::hashes::hex::ToHex;
  10
  11 use futures::lock::Mutex;
  12
  13 use std::convert::TryFrom;
  14 use std::convert::TryInto;
  15
  16 /// A simple REST client for requesting resources using HTTP `GET`.
  17 pub struct RestClient {
  18         endpoint: HttpEndpoint,
  19         client: Mutex<HttpClient>,
  20 }
  21
  22 impl RestClient {
  23         /// Creates a new REST client connected to the given endpoint.
  24         ///
  25         /// The endpoint should contain the REST path component (e.g., http://127.0.0.1:8332/rest).
  26         pub fn new(endpoint: HttpEndpoint) -> std::io::Result<Self> {
  27                 let client = Mutex::new(HttpClient::connect(&endpoint)?);
  28                 Ok(Self { endpoint, client })
  29         }
  30
  31         /// Requests a resource encoded in `F` format and interpreted as type `T`.
  32         pub async fn request_resource<F, T>(&self, resource_path: &str) -> std::io::Result<T>
  33         where F: TryFrom<Vec<u8>, Error = std::io::Error> + TryInto<T, Error = std::io::Error> {
  34                 let host = format!("{}:{}", self.endpoint.host(), self.endpoint.port());
  35                 let uri = format!("{}/{}", self.endpoint.path().trim_end_matches("/"), resource_path);
  36                 self.client.lock().await.get::<F>(&uri, &host).await?.try_into()
  37         }
  38 }
  39
  40 impl BlockSource for RestClient {
  41         fn get_header<'a>(&'a self, header_hash: &'a BlockHash, _height: Option<u32>) -> AsyncBlockSourceResult<'a, BlockHeaderData> {
  42                 Box::pin(async move {
  43                         let resource_path = format!("headers/1/{}.json", header_hash.to_hex());
  44                         Ok(self.request_resource::<JsonResponse, _>(&resource_path).await?)
  45                 })
  46         }
  47
  48         fn get_block<'a>(&'a self, header_hash: &'a BlockHash) -> AsyncBlockSourceResult<'a, Block> {
  49                 Box::pin(async move {
  50                         let resource_path = format!("block/{}.bin", header_hash.to_hex());
  51                         Ok(self.request_resource::<BinaryResponse, _>(&resource_path).await?)
  52                 })
  53         }
  54
  55         fn get_best_block<'a>(&'a self) -> AsyncBlockSourceResult<'a, (BlockHash, Option<u32>)> {
  56                 Box::pin(async move {
  57                         Ok(self.request_resource::<JsonResponse, _>("chaininfo.json").await?)
  58                 })
  59         }
  60 }
  61
  62 #[cfg(test)]
  63 mod tests {
  64         use super::*;
  65         use crate::http::BinaryResponse;
  66         use crate::http::client_tests::{HttpServer, MessageBody};
  67
  68         /// Parses binary data as a string-encoded `u32`.
  69         impl TryInto<u32> for BinaryResponse {
  70                 type Error = std::io::Error;
  71
  72                 fn try_into(self) -> std::io::Result<u32> {
  73                         match std::str::from_utf8(&self.0) {
  74                                 Err(e) => Err(std::io::Error::new(std::io::ErrorKind::InvalidData, e)),
  75                                 Ok(s) => match u32::from_str_radix(s, 10) {
  76                                         Err(e) => Err(std::io::Error::new(std::io::ErrorKind::InvalidData, e)),
  77                                         Ok(n) => Ok(n),
  78                                 }
  79                         }
  80                 }
  81         }
  82
  83         #[tokio::test]
  84         async fn request_unknown_resource() {
  85                 let server = HttpServer::responding_with_not_found();
  86                 let client = RestClient::new(server.endpoint()).unwrap();
  87
  88                 match client.request_resource::<BinaryResponse, u32>("/").await {
  89                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::Other),
  90                         Ok(_) => panic!("Expected error"),
  91                 }
  92         }
  93
  94         #[tokio::test]
  95         async fn request_malformed_resource() {
  96                 let server = HttpServer::responding_with_ok(MessageBody::Content("foo"));
  97                 let client = RestClient::new(server.endpoint()).unwrap();
  98
  99                 match client.request_resource::<BinaryResponse, u32>("/").await {
 100                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::InvalidData),
 101                         Ok(_) => panic!("Expected error"),
 102                 }
 103         }
 104
 105         #[tokio::test]
 106         async fn request_valid_resource() {
 107                 let server = HttpServer::responding_with_ok(MessageBody::Content(42));
 108                 let client = RestClient::new(server.endpoint()).unwrap();
 109
 110                 match client.request_resource::<BinaryResponse, u32>("/").await {
 111                         Err(e) => panic!("Unexpected error: {:?}", e),
 112                         Ok(n) => assert_eq!(n, 42),
 113                 }
 114         }
 115 }