_ 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 use crate::gossip::UtxoSource;
   7 use crate::convert::GetUtxosResponse;
   8
   9 use bitcoin::OutPoint;
  10 use bitcoin::hash_types::BlockHash;
  11 use bitcoin::hashes::hex::ToHex;
  12
  13 use std::convert::TryFrom;
  14 use std::convert::TryInto;
  15 use std::sync::Mutex;
  16
  17 /// A simple REST client for requesting resources using HTTP `GET`.
  18 pub struct RestClient {
  19         endpoint: HttpEndpoint,
  20         client: Mutex<Option<HttpClient>>,
  21 }
  22
  23 impl RestClient {
  24         /// Creates a new REST client connected to the given endpoint.
  25         ///
  26         /// The endpoint should contain the REST path component (e.g., http://127.0.0.1:8332/rest).
  27         pub fn new(endpoint: HttpEndpoint) -> std::io::Result<Self> {
  28                 Ok(Self { endpoint, client: Mutex::new(None) })
  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                 let mut client = if let Some(client) = self.client.lock().unwrap().take() { client }
  37                         else { HttpClient::connect(&self.endpoint)? };
  38                 let res = client.get::<F>(&uri, &host).await?.try_into();
  39                 *self.client.lock().unwrap() = Some(client);
  40                 res
  41         }
  42 }
  43
  44 impl BlockSource for RestClient {
  45         fn get_header<'a>(&'a self, header_hash: &'a BlockHash, _height: Option<u32>) -> AsyncBlockSourceResult<'a, BlockHeaderData> {
  46                 Box::pin(async move {
  47                         let resource_path = format!("headers/1/{}.json", header_hash.to_hex());
  48                         Ok(self.request_resource::<JsonResponse, _>(&resource_path).await?)
  49                 })
  50         }
  51
  52         fn get_block<'a>(&'a self, header_hash: &'a BlockHash) -> AsyncBlockSourceResult<'a, BlockData> {
  53                 Box::pin(async move {
  54                         let resource_path = format!("block/{}.bin", header_hash.to_hex());
  55                         Ok(BlockData::FullBlock(self.request_resource::<BinaryResponse, _>(&resource_path).await?))
  56                 })
  57         }
  58
  59         fn get_best_block<'a>(&'a self) -> AsyncBlockSourceResult<'a, (BlockHash, Option<u32>)> {
  60                 Box::pin(async move {
  61                         Ok(self.request_resource::<JsonResponse, _>("chaininfo.json").await?)
  62                 })
  63         }
  64 }
  65
  66 impl UtxoSource for RestClient {
  67         fn get_block_hash_by_height<'a>(&'a self, block_height: u32) -> AsyncBlockSourceResult<'a, BlockHash> {
  68                 Box::pin(async move {
  69                         let resource_path = format!("blockhashbyheight/{}.bin", block_height);
  70                         Ok(self.request_resource::<BinaryResponse, _>(&resource_path).await?)
  71                 })
  72         }
  73
  74         fn is_output_unspent<'a>(&'a self, outpoint: OutPoint) -> AsyncBlockSourceResult<'a, bool> {
  75                 Box::pin(async move {
  76                         let resource_path = format!("getutxos/{}-{}.json", outpoint.txid.to_hex(), outpoint.vout);
  77                         let utxo_result =
  78                                 self.request_resource::<JsonResponse, GetUtxosResponse>(&resource_path).await?;
  79                         Ok(utxo_result.hit_bitmap_nonempty)
  80                 })
  81         }
  82 }
  83
  84 #[cfg(test)]
  85 mod tests {
  86         use super::*;
  87         use crate::http::BinaryResponse;
  88         use crate::http::client_tests::{HttpServer, MessageBody};
  89         use bitcoin::hashes::Hash;
  90
  91         /// Parses binary data as a string-encoded `u32`.
  92         impl TryInto<u32> for BinaryResponse {
  93                 type Error = std::io::Error;
  94
  95                 fn try_into(self) -> std::io::Result<u32> {
  96                         match std::str::from_utf8(&self.0) {
  97                                 Err(e) => Err(std::io::Error::new(std::io::ErrorKind::InvalidData, e)),
  98                                 Ok(s) => match u32::from_str_radix(s, 10) {
  99                                         Err(e) => Err(std::io::Error::new(std::io::ErrorKind::InvalidData, e)),
 100                                         Ok(n) => Ok(n),
 101                                 }
 102                         }
 103                 }
 104         }
 105
 106         #[tokio::test]
 107         async fn request_unknown_resource() {
 108                 let server = HttpServer::responding_with_not_found();
 109                 let client = RestClient::new(server.endpoint()).unwrap();
 110
 111                 match client.request_resource::<BinaryResponse, u32>("/").await {
 112                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::Other),
 113                         Ok(_) => panic!("Expected error"),
 114                 }
 115         }
 116
 117         #[tokio::test]
 118         async fn request_malformed_resource() {
 119                 let server = HttpServer::responding_with_ok(MessageBody::Content("foo"));
 120                 let client = RestClient::new(server.endpoint()).unwrap();
 121
 122                 match client.request_resource::<BinaryResponse, u32>("/").await {
 123                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::InvalidData),
 124                         Ok(_) => panic!("Expected error"),
 125                 }
 126         }
 127
 128         #[tokio::test]
 129         async fn request_valid_resource() {
 130                 let server = HttpServer::responding_with_ok(MessageBody::Content(42));
 131                 let client = RestClient::new(server.endpoint()).unwrap();
 132
 133                 match client.request_resource::<BinaryResponse, u32>("/").await {
 134                         Err(e) => panic!("Unexpected error: {:?}", e),
 135                         Ok(n) => assert_eq!(n, 42),
 136                 }
 137         }
 138
 139         #[tokio::test]
 140         async fn parses_negative_getutxos() {
 141                 let server = HttpServer::responding_with_ok(MessageBody::Content(
 142                         // A real response contains a few more fields, but we actually only look at the
 143                         // "bitmap" field, so this should suffice for testing
 144                         "{\"chainHeight\": 1, \"bitmap\":\"0\",\"utxos\":[]}"
 145                 ));
 146                 let client = RestClient::new(server.endpoint()).unwrap();
 147
 148                 let outpoint = OutPoint::new(bitcoin::Txid::from_inner([0; 32]), 0);
 149                 let unspent_output = client.is_output_unspent(outpoint).await.unwrap();
 150                 assert_eq!(unspent_output, false);
 151         }
 152
 153         #[tokio::test]
 154         async fn parses_positive_getutxos() {
 155                 let server = HttpServer::responding_with_ok(MessageBody::Content(
 156                         // A real response contains lots more data, but we actually only look at the "bitmap"
 157                         // field, so this should suffice for testing
 158                         "{\"chainHeight\": 1, \"bitmap\":\"1\",\"utxos\":[]}"
 159                 ));
 160                 let client = RestClient::new(server.endpoint()).unwrap();
 161
 162                 let outpoint = OutPoint::new(bitcoin::Txid::from_inner([0; 32]), 0);
 163                 let unspent_output = client.is_output_unspent(outpoint).await.unwrap();
 164                 assert_eq!(unspent_output, true);
 165         }
 166 }