Add the /headers[/:from_hash[/:count]] endpoint

src/new_index/schema.rs

@@ -424,6 +424,25 @@ impl ChainQuery {
  }
  }
 
+ pub fn get_headers(&self, from: &BlockHash, count: usize) -> Option<Vec<BlockHeader>> {
+ let _timer = self.start_timer("get_headers");
+ let store = self.store.indexed_headers.read().unwrap();
+
+ if let Some(from_header) = store.header_by_blockhash(from) {
+ Some(
+ store
+ .iter()
+ .rev()
+ .skip(self.best_height() - from_header.height())
+ .take(count)
+ .map(|e| e.header().clone())
+ .collect(),
+ )
+ } else {
+ None
+ }
+ }
+
  pub fn get_block_header(&self, hash: &BlockHash) -> Option<BlockHeader> {
  let _timer = self.start_timer("get_block_header");
  Some(self.header_by_hash(hash)?.header().clone())

src/rest.rs

@@ -627,6 +627,40 @@ fn handle_request(
  path.get(3),
  path.get(4),
  ) {
+ (&Method::GET, Some(&"headers"), hash, count, None, None) => {
+ let count = count
+ .and_then(|c| c.parse::<usize>().ok())
+ .map(|c| c.max(1).min(2000))
+ .unwrap_or(2000);
+ let from_hash = hash
+ .map(|h| BlockHash::from_hex(h))
+ .transpose()?
+ .unwrap_or_else(|| query.chain().best_hash());
+
+ let headers = match query.chain().get_headers(&from_hash, count) {
+ Some(headers) => headers,
+ None => return Err(HttpError::not_found("Block not found".to_string())),
+ };
+
+ let mut raw = Vec::with_capacity(8 + 80 * headers.len());
+ raw.append(&mut encode::serialize(
+ &encode::VarInt(headers.len() as u64),
+ ));
+ for header in headers.into_iter() {
+ raw.append(&mut encode::serialize(&header));
+ }
+
+ let cache_ttl = match hash {
+ None => TTL_SHORT,
+ Some(_) => TTL_SHORT,
+ };
+ Ok(Response::builder()
+ .status(StatusCode::OK)
+ .header("Content-Type", "application/octet-stream")
+ .header("Cache-Control", format!("public, max-age={:}", cache_ttl))
+ .body(Body::from(raw))
+ .unwrap())
+ }
  (&Method::GET, Some(&"blocks"), Some(&"tip"), Some(&"hash"), None, None) => http_message(
  StatusCode::OK,
  query.chain().best_hash().to_hex(),