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