Merge #6: Add get_tip_hash API call

297172d Add `get_tip_hash` API call (Elias Rohrer)

Pull request description:

  This PR adds support for getting the `BlockHash` of the current blockchain tip.

  While this is currently not strictly necessary for LDK integration, it might be nice to have in the future.

Top commit has no ACKs.

Tree-SHA512: 07c0d37542f37fc3fc2b8dec6c0f5222e1e39ede7e0601d2e0bbbcb961282284ed34ad4df00f86f2715ba5a9ad80ac204ec1408eaeb35e62608f7e0f5ee8ffb3

Author: vladimirfomene

src/async.rs

@@ -12,11 +12,12 @@
 //! Esplora by way of `reqwest` HTTP client.
 
 use std::collections::HashMap;
+use std::str::FromStr;
 
 use bitcoin::consensus::{deserialize, serialize};
 use bitcoin::hashes::hex::{FromHex, ToHex};
 use bitcoin::hashes::{sha256, Hash};
-use bitcoin::{BlockHeader, Script, Transaction, Txid};
+use bitcoin::{BlockHash, BlockHeader, Script, Transaction, Txid};
 
 #[allow(unused_imports)]
 use log::{debug, error, info, trace};
@@ -176,6 +177,19 @@ impl AsyncClient {
         Ok(req.error_for_status()?.text().await?.parse()?)
     }
 
+    /// Get the [`BlockHash`] of the current blockchain tip.
+    pub async fn get_tip_hash(&self) -> Result<BlockHash, Error> {
+        let resp = self
+            .client
+            .get(&format!("{}/blocks/tip/hash", self.url))
+            .send()
+            .await?;
+
+        Ok(BlockHash::from_str(
+            &resp.error_for_status()?.text().await?,
+        )?)
+    }
+
     /// Get confirmed transaction history for the specified address/scripthash,
     /// sorted with newest first. Returns 25 transactions per page.
     /// More can be requested by specifying the last txid seen by the previous query.

src/blocking.rs

@@ -14,6 +14,7 @@
 use std::collections::HashMap;
 use std::io;
 use std::io::Read;
+use std::str::FromStr;
 use std::time::Duration;
 
 #[allow(unused_imports)]
@@ -24,7 +25,7 @@ use ureq::{Agent, Proxy, Response};
 use bitcoin::consensus::{deserialize, serialize};
 use bitcoin::hashes::hex::{FromHex, ToHex};
 use bitcoin::hashes::{sha256, Hash};
-use bitcoin::{BlockHeader, Script, Transaction, Txid};
+use bitcoin::{BlockHash, BlockHeader, Script, Transaction, Txid};
 
 use crate::{Builder, Error, MerkleProof, OutputStatus, Tx, TxStatus};
 
@@ -186,7 +187,7 @@ impl BlockingClient {
         }
     }
 
-    /// Get the current height of the blockchain tip
+    /// Get the height of the current blockchain tip.
     pub fn get_height(&self) -> Result<u32, Error> {
         let resp = self
             .agent
@@ -200,6 +201,20 @@ impl BlockingClient {
         }
     }
 
+    /// Get the [`BlockHash`] of the current blockchain tip.
+    pub fn get_tip_hash(&self) -> Result<BlockHash, Error> {
+        let resp = self
+            .agent
+            .get(&format!("{}/blocks/tip/hash", self.url))
+            .call();
+
+        match resp {
+            Ok(resp) => Ok(BlockHash::from_str(&resp.into_string()?)?),
+            Err(ureq::Error::Status(code, _)) => Err(Error::HttpResponse(code)),
+            Err(e) => Err(Error::Ureq(e)),
+        }
+    }
+
     /// Get an map where the key is the confirmation target (in number of blocks)
     /// and the value is the estimated feerate (in sat/vB).
     pub fn get_fee_estimates(&self) -> Result<HashMap<String, f64>, Error> {