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