Merge bitcoindevkit/bdk#764: Use the esplora client crate

d7bfe68e2df270ab799d36ebf3563e178ae50c6e Fix broken nightly docs (Alekos Filini)
b11c86d074a8f56f99bd5f3af77d3b056af71de4 Rename internal esplora modules, fix docs (Alekos Filini)
b5b92248c76aeb42ac747931efd45bc2e7af5ebd Rename esplora features to -async and -blocking (Alekos Filini)
cf2bc388f22b069fc25fba482e59da6305207864 Re-export `esplora_client` (Elias Rohrer)
5baf46f84d41fb714f200a7b26170c9b77823dc1 Use the external esplora client library (Alekos Filini)

Pull request description:

  ### Description

  Use the external esplora client crate now that it's published

  ### Changelog notice

  - Start using the external esplora client crate
  - Deprecate the `use-esplora-reqwest` and `use-esplora-ureq` features in favor of `use-esplora-async` and `use-esplora-blocking`

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)
  * [x] I ran `cargo fmt` and `cargo clippy` before committing

  #### New Features:

  * [ ] I've added tests for the new feature
  * [ ] I've added docs for the new feature

  #### Bugfixes:

  * [ ] This pull request breaks the existing API
  * [ ] I've added tests to reproduce the issue which are now passing
  * [ ] I'm linking the issue being fixed by this PR

ACKs for top commit:
  notmandatory:
    ACK d7bfe68e2df270ab799d36ebf3563e178ae50c6e

Tree-SHA512: 23bd47536fe6f723602cbcc51d909eb9aed28376430f4453eea832e30a587be3d312cdca993d114391132bfb39c48637030f974ab1a742f7defe44f40a82ef8b

.github/workflows/cont_integration.yml

@@ -17,16 +17,16 @@ jobs:
           - default
           - minimal
           - all-keys
-          - minimal,use-esplora-ureq
+          - minimal,use-esplora-blocking
           - key-value-db
           - electrum
           - compact_filters
-          - esplora,ureq,key-value-db,electrum
+          - use-esplora-blocking,key-value-db,electrum
           - compiler
           - rpc
           - verify
           - async-interface
-          - use-esplora-reqwest
+          - use-esplora-async
           - sqlite
           - sqlite-bundled
     steps:
@@ -100,10 +100,10 @@ jobs:
             features: test-rpc-legacy
           - name: esplora
             testprefix: esplora
-            features: test-esplora,use-esplora-reqwest,verify
+            features: test-esplora,use-esplora-async,verify
           - name: esplora
             testprefix: esplora
-            features: test-esplora,use-esplora-ureq,verify
+            features: test-esplora,use-esplora-blocking,verify
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -154,7 +154,7 @@ jobs:
       - name: Update toolchain
         run: rustup update
       - name: Check
-        run: cargo check --target wasm32-unknown-unknown --features use-esplora-reqwest --no-default-features
+        run: cargo check --target wasm32-unknown-unknown --features use-esplora-async --no-default-features
 
   fmt:
     name: Rust fmt

.github/workflows/nightly_docs.yml

@@ -24,7 +24,7 @@ jobs:
       - name: Update toolchain
         run: rustup update
       - name: Build docs
-        run: cargo rustdoc --verbose --features=compiler,electrum,esplora,ureq,compact_filters,key-value-db,all-keys,sqlite -- --cfg docsrs -Dwarnings
+        run: cargo rustdoc --verbose --features=compiler,electrum,esplora,use-esplora-blocking,compact_filters,rpc,key-value-db,sqlite,all-keys,verify,hardware-signer -- --cfg docsrs -Dwarnings
       - name: Upload artifact
         uses: actions/upload-artifact@v2
         with:

Cargo.toml

@@ -23,10 +23,9 @@ rand = "^0.7"
 # Optional dependencies
 sled = { version = "0.34", optional = true }
 electrum-client = { version = "0.11", optional = true }
+esplora-client = { version = "0.1.1", default-features = false, optional = true }
 rusqlite = { version = "0.27.0", optional = true }
 ahash = { version = "0.7.6", optional = true }
-reqwest = { version = "0.11", optional = true, default-features = false, features = ["json"] }
-ureq = { version = "~2.2.0", features = ["json"], optional = true }
 futures = { version = "0.3", optional = true }
 async-trait = { version = "0.1", optional = true }
 rocksdb = { version = "0.14", default-features = false, features = ["snappy"], optional = true }
@@ -69,23 +68,26 @@ hardware-signer = ["hwi"]
 #
 # - Users wanting asynchronous HTTP calls should enable `async-interface` to get
 #   access to the asynchronous method implementations. Then, if Esplora is wanted,
-#   enable `esplora` AND `reqwest` (`--features=use-esplora-reqwest`).
+#   enable the `use-esplora-async` feature.
 # - Users wanting blocking HTTP calls can use any of the other blockchain
 #   implementations (`compact_filters`, `electrum`, or `esplora`). Users wanting to
-#   use Esplora should enable `esplora` AND `ureq`  (`--features=use-esplora-ureq`).
+#   use Esplora should enable the `use-esplora-blocking` feature.
 #
 # WARNING: Please take care with the features below, various combinations will
 # fail to build. We cannot currently build `bdk` with `--all-features`.
 async-interface = ["async-trait"]
 electrum = ["electrum-client"]
 # MUST ALSO USE `--no-default-features`.
-use-esplora-reqwest = ["esplora", "reqwest", "reqwest/socks", "futures"]
+use-esplora-async = ["esplora", "esplora-client/async", "futures"]
-use-esplora-ureq = ["esplora", "ureq", "ureq/socks"]
+use-esplora-blocking = ["esplora", "esplora-client/blocking"]
+# Deprecated aliases
+use-esplora-reqwest = ["use-esplora-async"]
+use-esplora-ureq = ["use-esplora-blocking"]
 # Typical configurations will not need to use `esplora` feature directly.
 esplora = []
 
-# Use below feature with `use-esplora-reqwest` to enable reqwest default TLS support
+# Use below feature with `use-esplora-async` to enable reqwest default TLS support
-reqwest-default-tls = ["reqwest/default-tls"]
+reqwest-default-tls = ["esplora-client/async-https"]
 
 # Debug/Test features
 test-blockchains = ["bitcoincore-rpc", "electrum-client"]
@@ -129,6 +131,6 @@ required-features = ["electrum"]
 [workspace]
 members = ["macros"]
 [package.metadata.docs.rs]
-features = ["compiler", "electrum", "esplora", "use-esplora-ureq", "compact_filters", "rpc", "key-value-db", "sqlite", "all-keys", "verify", "hardware-signer"]
+features = ["compiler", "electrum", "esplora", "use-esplora-blocking", "compact_filters", "rpc", "key-value-db", "sqlite", "all-keys", "verify", "hardware-signer"]
 # defines the configuration attribute `docsrs`
 rustdoc-args = ["--cfg", "docsrs"]

src/blockchain/esplora/api.rs

@@ -1,117 +0,0 @@
-//! structs from the esplora API
-//!
-//! see: <https://github.com/Blockstream/esplora/blob/master/API.md>
-use crate::BlockTime;
-use bitcoin::{OutPoint, Script, Transaction, TxIn, TxOut, Txid, Witness};
-
-#[derive(serde::Deserialize, Clone, Debug)]
-pub struct PrevOut {
-    pub value: u64,
-    pub scriptpubkey: Script,
-}
-
-#[derive(serde::Deserialize, Clone, Debug)]
-pub struct Vin {
-    pub txid: Txid,
-    pub vout: u32,
-    // None if coinbase
-    pub prevout: Option<PrevOut>,
-    pub scriptsig: Script,
-    #[serde(deserialize_with = "deserialize_witness", default)]
-    pub witness: Vec<Vec<u8>>,
-    pub sequence: u32,
-    pub is_coinbase: bool,
-}
-
-#[derive(serde::Deserialize, Clone, Debug)]
-pub struct Vout {
-    pub value: u64,
-    pub scriptpubkey: Script,
-}
-
-#[derive(serde::Deserialize, Clone, Debug)]
-pub struct TxStatus {
-    pub confirmed: bool,
-    pub block_height: Option<u32>,
-    pub block_time: Option<u64>,
-}
-
-#[derive(serde::Deserialize, Clone, Debug)]
-pub struct Tx {
-    pub txid: Txid,
-    pub version: i32,
-    pub locktime: u32,
-    pub vin: Vec<Vin>,
-    pub vout: Vec<Vout>,
-    pub status: TxStatus,
-    pub fee: u64,
-}
-
-impl Tx {
-    pub fn to_tx(&self) -> Transaction {
-        Transaction {
-            version: self.version,
-            lock_time: self.locktime,
-            input: self
-                .vin
-                .iter()
-                .cloned()
-                .map(|vin| TxIn {
-                    previous_output: OutPoint {
-                        txid: vin.txid,
-                        vout: vin.vout,
-                    },
-                    script_sig: vin.scriptsig,
-                    sequence: vin.sequence,
-                    witness: Witness::from_vec(vin.witness),
-                })
-                .collect(),
-            output: self
-                .vout
-                .iter()
-                .cloned()
-                .map(|vout| TxOut {
-                    value: vout.value,
-                    script_pubkey: vout.scriptpubkey,
-                })
-                .collect(),
-        }
-    }
-
-    pub fn confirmation_time(&self) -> Option<BlockTime> {
-        match self.status {
-            TxStatus {
-                confirmed: true,
-                block_height: Some(height),
-                block_time: Some(timestamp),
-            } => Some(BlockTime { timestamp, height }),
-            _ => None,
-        }
-    }
-
-    pub fn previous_outputs(&self) -> Vec<Option<TxOut>> {
-        self.vin
-            .iter()
-            .cloned()
-            .map(|vin| {
-                vin.prevout.map(|po| TxOut {
-                    script_pubkey: po.scriptpubkey,
-                    value: po.value,
-                })
-            })
-            .collect()
-    }
-}
-
-fn deserialize_witness<'de, D>(d: D) -> Result<Vec<Vec<u8>>, D::Error>
-where
-    D: serde::de::Deserializer<'de>,
-{
-    use crate::serde::Deserialize;
-    use bitcoin::hashes::hex::FromHex;
-    let list = Vec::<String>::deserialize(d)?;
-    list.into_iter()
-        .map(|hex_str| Vec::<u8>::from_hex(&hex_str))
-        .collect::<Result<Vec<Vec<u8>>, _>>()
-        .map_err(serde::de::Error::custom)
-}

src/blockchain/esplora/async.rs

@@ -14,49 +14,36 @@
 use std::collections::{HashMap, HashSet};
 use std::ops::Deref;
 
-use bitcoin::consensus::{deserialize, serialize};
+use bitcoin::{Transaction, Txid};
-use bitcoin::hashes::hex::{FromHex, ToHex};
-use bitcoin::hashes::{sha256, Hash};
-use bitcoin::{BlockHeader, Script, Transaction, Txid};
 
 #[allow(unused_imports)]
 use log::{debug, error, info, trace};
 
-use ::reqwest::{Client, StatusCode};
+use esplora_client::{convert_fee_rate, AsyncClient, Builder, Tx};
 use futures::stream::{FuturesOrdered, TryStreamExt};
 
-use super::api::Tx;
-use crate::blockchain::esplora::EsploraError;
 use crate::blockchain::*;
 use crate::database::BatchDatabase;
 use crate::error::Error;
 use crate::FeeRate;
 
-/// Structure encapsulates Esplora client
-#[derive(Debug)]
-pub struct UrlClient {
-    url: String,
-    // We use the async client instead of the blocking one because it automatically uses `fetch`
-    // when the target platform is wasm32.
-    client: Client,
-    concurrency: u8,
-}
-
 /// Structure that implements the logic to sync with Esplora
 ///
 /// ## Example
 /// See the [`blockchain::esplora`](crate::blockchain::esplora) module for a usage example.
 #[derive(Debug)]
 pub struct EsploraBlockchain {
-    url_client: UrlClient,
+    url_client: AsyncClient,
     stop_gap: usize,
+    concurrency: u8,
 }
 
-impl std::convert::From<UrlClient> for EsploraBlockchain {
+impl std::convert::From<AsyncClient> for EsploraBlockchain {
-    fn from(url_client: UrlClient) -> Self {
+    fn from(url_client: AsyncClient) -> Self {
         EsploraBlockchain {
             url_client,
             stop_gap: 20,
+            concurrency: super::DEFAULT_CONCURRENT_REQUESTS,
         }
     }
 }
@@ -64,19 +51,25 @@ impl std::convert::From<UrlClient> for EsploraBlockchain {
 impl EsploraBlockchain {
     /// Create a new instance of the client from a base URL and `stop_gap`.
     pub fn new(base_url: &str, stop_gap: usize) -> Self {
+        let url_client = Builder::new(base_url)
+            .build_async()
+            .expect("Should never fail with no proxy and timeout");
+
+        Self::from_client(url_client, stop_gap)
+    }
+
+    /// Build a new instance given a client
+    pub fn from_client(url_client: AsyncClient, stop_gap: usize) -> Self {
         EsploraBlockchain {
-            url_client: UrlClient {
+            url_client,
-                url: base_url.to_string(),
-                client: Client::new(),
-                concurrency: super::DEFAULT_CONCURRENT_REQUESTS,
-            },
             stop_gap,
+            concurrency: super::DEFAULT_CONCURRENT_REQUESTS,
         }
     }
 
     /// Set the concurrency to use when doing batch queries against the Esplora instance.
     pub fn with_concurrency(mut self, concurrency: u8) -> Self {
-        self.url_client.concurrency = concurrency;
+        self.concurrency = concurrency;
         self
     }
 }
@@ -94,17 +87,19 @@ impl Blockchain for EsploraBlockchain {
     }
 
     fn broadcast(&self, tx: &Transaction) -> Result<(), Error> {
-        Ok(await_or_block!(self.url_client._broadcast(tx))?)
+        Ok(await_or_block!(self.url_client.broadcast(tx))?)
     }
 
     fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
-        let estimates = await_or_block!(self.url_client._get_fee_estimates())?;
+        let estimates = await_or_block!(self.url_client.get_fee_estimates())?;
-        super::into_fee_rate(target, estimates)
+        Ok(FeeRate::from_sat_per_vb(convert_fee_rate(
+            target, estimates,
+        )?))
     }
 }
 
 impl Deref for EsploraBlockchain {
-    type Target = UrlClient;
+    type Target = AsyncClient;
 
     fn deref(&self) -> &Self::Target {
         &self.url_client
@@ -116,21 +111,21 @@ impl StatelessBlockchain for EsploraBlockchain {}
 #[maybe_async]
 impl GetHeight for EsploraBlockchain {
     fn get_height(&self) -> Result<u32, Error> {
-        Ok(await_or_block!(self.url_client._get_height())?)
+        Ok(await_or_block!(self.url_client.get_height())?)
     }
 }
 
 #[maybe_async]
 impl GetTx for EsploraBlockchain {
     fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
-        Ok(await_or_block!(self.url_client._get_tx(txid))?)
+        Ok(await_or_block!(self.url_client.get_tx(txid))?)
     }
 }
 
 #[maybe_async]
 impl GetBlockHash for EsploraBlockchain {
     fn get_block_hash(&self, height: u64) -> Result<BlockHash, Error> {
-        let block_header = await_or_block!(self.url_client._get_header(height as u32))?;
+        let block_header = await_or_block!(self.url_client.get_header(height as u32))?;
         Ok(block_header.block_hash())
     }
 }
@@ -151,10 +146,10 @@ impl WalletSync for EsploraBlockchain {
                 Request::Script(script_req) => {
                     let futures: FuturesOrdered<_> = script_req
                         .request()
-                        .take(self.url_client.concurrency as usize)
+                        .take(self.concurrency as usize)
                         .map(|script| async move {
                             let mut related_txs: Vec<Tx> =
-                                self.url_client._scripthash_txs(script, None).await?;
+                                self.url_client.scripthash_txs(script, None).await?;
 
                             let n_confirmed =
                                 related_txs.iter().filter(|tx| tx.status.confirmed).count();
@@ -164,7 +159,7 @@ impl WalletSync for EsploraBlockchain {
                                 loop {
                                     let new_related_txs: Vec<Tx> = self
                                         .url_client
-                                        ._scripthash_txs(
+                                        .scripthash_txs(
                                             script,
                                             Some(related_txs.last().unwrap().txid),
                                         )
@@ -204,6 +199,7 @@ impl WalletSync for EsploraBlockchain {
                                 .get(txid)
                                 .expect("must be in index")
                                 .confirmation_time()
+                                .map(Into::into)
                         })
                         .collect();
                     conftime_req.satisfy(conftimes)?
@@ -227,132 +223,26 @@ impl WalletSync for EsploraBlockchain {
     }
 }
 
-impl UrlClient {
-    async fn _get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, EsploraError> {
-        let resp = self
-            .client
-            .get(&format!("{}/tx/{}/raw", self.url, txid))
-            .send()
-            .await?;
-
-        if let StatusCode::NOT_FOUND = resp.status() {
-            return Ok(None);
-        }
-
-        Ok(Some(deserialize(&resp.error_for_status()?.bytes().await?)?))
-    }
-
-    async fn _get_tx_no_opt(&self, txid: &Txid) -> Result<Transaction, EsploraError> {
-        match self._get_tx(txid).await {
-            Ok(Some(tx)) => Ok(tx),
-            Ok(None) => Err(EsploraError::TransactionNotFound(*txid)),
-            Err(e) => Err(e),
-        }
-    }
-
-    async fn _get_header(&self, block_height: u32) -> Result<BlockHeader, EsploraError> {
-        let resp = self
-            .client
-            .get(&format!("{}/block-height/{}", self.url, block_height))
-            .send()
-            .await?;
-
-        if let StatusCode::NOT_FOUND = resp.status() {
-            return Err(EsploraError::HeaderHeightNotFound(block_height));
-        }
-        let bytes = resp.bytes().await?;
-        let hash = std::str::from_utf8(&bytes)
-            .map_err(|_| EsploraError::HeaderHeightNotFound(block_height))?;
-
-        let resp = self
-            .client
-            .get(&format!("{}/block/{}/header", self.url, hash))
-            .send()
-            .await?;
-
-        let header = deserialize(&Vec::from_hex(&resp.text().await?)?)?;
-
-        Ok(header)
-    }
-
-    async fn _broadcast(&self, transaction: &Transaction) -> Result<(), EsploraError> {
-        self.client
-            .post(&format!("{}/tx", self.url))
-            .body(serialize(transaction).to_hex())
-            .send()
-            .await?
-            .error_for_status()?;
-
-        Ok(())
-    }
-
-    async fn _get_height(&self) -> Result<u32, EsploraError> {
-        let req = self
-            .client
-            .get(&format!("{}/blocks/tip/height", self.url))
-            .send()
-            .await?;
-
-        Ok(req.error_for_status()?.text().await?.parse()?)
-    }
-
-    async fn _scripthash_txs(
-        &self,
-        script: &Script,
-        last_seen: Option<Txid>,
-    ) -> Result<Vec<Tx>, EsploraError> {
-        let script_hash = sha256::Hash::hash(script.as_bytes()).into_inner().to_hex();
-        let url = match last_seen {
-            Some(last_seen) => format!(
-                "{}/scripthash/{}/txs/chain/{}",
-                self.url, script_hash, last_seen
-            ),
-            None => format!("{}/scripthash/{}/txs", self.url, script_hash),
-        };
-        Ok(self
-            .client
-            .get(url)
-            .send()
-            .await?
-            .error_for_status()?
-            .json::<Vec<Tx>>()
-            .await?)
-    }
-
-    async fn _get_fee_estimates(&self) -> Result<HashMap<String, f64>, EsploraError> {
-        Ok(self
-            .client
-            .get(&format!("{}/fee-estimates", self.url,))
-            .send()
-            .await?
-            .error_for_status()?
-            .json::<HashMap<String, f64>>()
-            .await?)
-    }
-}
-
 impl ConfigurableBlockchain for EsploraBlockchain {
     type Config = super::EsploraBlockchainConfig;
 
     fn from_config(config: &Self::Config) -> Result<Self, Error> {
-        let map_e = |e: reqwest::Error| Error::Esplora(Box::new(e.into()));
+        let mut builder = Builder::new(config.base_url.as_str());
 
-        let mut blockchain = EsploraBlockchain::new(config.base_url.as_str(), config.stop_gap);
-        if let Some(concurrency) = config.concurrency {
-            blockchain.url_client.concurrency = concurrency;
-        }
-        let mut builder = Client::builder();
-        #[cfg(not(target_arch = "wasm32"))]
-        if let Some(proxy) = &config.proxy {
-            builder = builder.proxy(reqwest::Proxy::all(proxy).map_err(map_e)?);
-        }
-
-        #[cfg(not(target_arch = "wasm32"))]
         if let Some(timeout) = config.timeout {
-            builder = builder.timeout(core::time::Duration::from_secs(timeout));
+            builder = builder.timeout(timeout);
         }
 
-        blockchain.url_client.client = builder.build().map_err(map_e)?;
+        if let Some(proxy) = &config.proxy {
+            builder = builder.proxy(proxy);
+        }
+
+        let mut blockchain =
+            EsploraBlockchain::from_client(builder.build_async()?, config.stop_gap);
+
+        if let Some(concurrency) = config.concurrency {
+            blockchain = blockchain.with_concurrency(concurrency);
+        }
 
         Ok(blockchain)
     }

src/blockchain/esplora/blocking.rs

@@ -12,42 +12,26 @@
 //! Esplora by way of `ureq` HTTP client.
 
 use std::collections::{HashMap, HashSet};
-use std::io;
-use std::io::Read;
-use std::ops::Deref;
-use std::time::Duration;
 
 #[allow(unused_imports)]
 use log::{debug, error, info, trace};
 
-use ureq::{Agent, Proxy, Response};
+use bitcoin::{Transaction, Txid};
 
-use bitcoin::consensus::{deserialize, serialize};
+use esplora_client::{convert_fee_rate, BlockingClient, Builder, Tx};
-use bitcoin::hashes::hex::{FromHex, ToHex};
-use bitcoin::hashes::{sha256, Hash};
-use bitcoin::{BlockHeader, Script, Transaction, Txid};
 
-use super::api::Tx;
-use crate::blockchain::esplora::EsploraError;
 use crate::blockchain::*;
 use crate::database::BatchDatabase;
 use crate::error::Error;
 use crate::FeeRate;
 
-/// Structure encapsulates ureq Esplora client
-#[derive(Debug, Clone)]
-pub struct UrlClient {
-    url: String,
-    agent: Agent,
-}
-
 /// Structure that implements the logic to sync with Esplora
 ///
 /// ## Example
 /// See the [`blockchain::esplora`](crate::blockchain::esplora) module for a usage example.
 #[derive(Debug)]
 pub struct EsploraBlockchain {
-    url_client: UrlClient,
+    url_client: BlockingClient,
     stop_gap: usize,
     concurrency: u8,
 }
@@ -55,22 +39,22 @@ pub struct EsploraBlockchain {
 impl EsploraBlockchain {
     /// Create a new instance of the client from a base URL and the `stop_gap`.
     pub fn new(base_url: &str, stop_gap: usize) -> Self {
+        let url_client = Builder::new(base_url)
+            .build_blocking()
+            .expect("Should never fail with no proxy and timeout");
+
+        Self::from_client(url_client, stop_gap)
+    }
+
+    /// Build a new instance given a client
+    pub fn from_client(url_client: BlockingClient, stop_gap: usize) -> Self {
         EsploraBlockchain {
-            url_client: UrlClient {
+            url_client,
-                url: base_url.to_string(),
-                agent: Agent::new(),
-            },
             concurrency: super::DEFAULT_CONCURRENT_REQUESTS,
             stop_gap,
         }
     }
 
-    /// Set the inner `ureq` agent.
-    pub fn with_agent(mut self, agent: Agent) -> Self {
-        self.url_client.agent = agent;
-        self
-    }
-
     /// Set the number of parallel requests the client can make.
     pub fn with_concurrency(mut self, concurrency: u8) -> Self {
         self.concurrency = concurrency;
@@ -90,18 +74,20 @@ impl Blockchain for EsploraBlockchain {
     }
 
     fn broadcast(&self, tx: &Transaction) -> Result<(), Error> {
-        self.url_client._broadcast(tx)?;
+        self.url_client.broadcast(tx)?;
         Ok(())
     }
 
     fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
-        let estimates = self.url_client._get_fee_estimates()?;
+        let estimates = self.url_client.get_fee_estimates()?;
-        super::into_fee_rate(target, estimates)
+        Ok(FeeRate::from_sat_per_vb(convert_fee_rate(
+            target, estimates,
+        )?))
     }
 }
 
 impl Deref for EsploraBlockchain {
-    type Target = UrlClient;
+    type Target = BlockingClient;
 
     fn deref(&self) -> &Self::Target {
         &self.url_client
@@ -112,19 +98,19 @@ impl StatelessBlockchain for EsploraBlockchain {}
 
 impl GetHeight for EsploraBlockchain {
     fn get_height(&self) -> Result<u32, Error> {
-        Ok(self.url_client._get_height()?)
+        Ok(self.url_client.get_height()?)
     }
 }
 
 impl GetTx for EsploraBlockchain {
     fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
-        Ok(self.url_client._get_tx(txid)?)
+        Ok(self.url_client.get_tx(txid)?)
     }
 }
 
 impl GetBlockHash for EsploraBlockchain {
     fn get_block_hash(&self, height: u64) -> Result<BlockHash, Error> {
-        let block_header = self.url_client._get_header(height as u32)?;
+        let block_header = self.url_client.get_header(height as u32)?;
         Ok(block_header.block_hash())
     }
 }
@@ -151,7 +137,7 @@ impl WalletSync for EsploraBlockchain {
                         let client = self.url_client.clone();
                         // make each request in its own thread.
                         handles.push(std::thread::spawn(move || {
-                            let mut related_txs: Vec<Tx> = client._scripthash_txs(&script, None)?;
+                            let mut related_txs: Vec<Tx> = client.scripthash_txs(&script, None)?;
 
                             let n_confirmed =
                                 related_txs.iter().filter(|tx| tx.status.confirmed).count();
@@ -159,7 +145,7 @@ impl WalletSync for EsploraBlockchain {
                             // keep requesting to see if there's more.
                             if n_confirmed >= 25 {
                                 loop {
-                                    let new_related_txs: Vec<Tx> = client._scripthash_txs(
+                                    let new_related_txs: Vec<Tx> = client.scripthash_txs(
                                         &script,
                                         Some(related_txs.last().unwrap().txid),
                                     )?;
@@ -202,6 +188,7 @@ impl WalletSync for EsploraBlockchain {
                                 .get(txid)
                                 .expect("must be in index")
                                 .confirmation_time()
+                                .map(Into::into)
                         })
                         .collect();
                     conftime_req.satisfy(conftimes)?
@@ -226,159 +213,22 @@ impl WalletSync for EsploraBlockchain {
     }
 }
 
-impl UrlClient {
-    fn _get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, EsploraError> {
-        let resp = self
-            .agent
-            .get(&format!("{}/tx/{}/raw", self.url, txid))
-            .call();
-
-        match resp {
-            Ok(resp) => Ok(Some(deserialize(&into_bytes(resp)?)?)),
-            Err(ureq::Error::Status(code, _)) => {
-                if is_status_not_found(code) {
-                    return Ok(None);
-                }
-                Err(EsploraError::HttpResponse(code))
-            }
-            Err(e) => Err(EsploraError::Ureq(e)),
-        }
-    }
-
-    fn _get_tx_no_opt(&self, txid: &Txid) -> Result<Transaction, EsploraError> {
-        match self._get_tx(txid) {
-            Ok(Some(tx)) => Ok(tx),
-            Ok(None) => Err(EsploraError::TransactionNotFound(*txid)),
-            Err(e) => Err(e),
-        }
-    }
-
-    fn _get_header(&self, block_height: u32) -> Result<BlockHeader, EsploraError> {
-        let resp = self
-            .agent
-            .get(&format!("{}/block-height/{}", self.url, block_height))
-            .call();
-
-        let bytes = match resp {
-            Ok(resp) => Ok(into_bytes(resp)?),
-            Err(ureq::Error::Status(code, _)) => Err(EsploraError::HttpResponse(code)),
-            Err(e) => Err(EsploraError::Ureq(e)),
-        }?;
-
-        let hash = std::str::from_utf8(&bytes)
-            .map_err(|_| EsploraError::HeaderHeightNotFound(block_height))?;
-
-        let resp = self
-            .agent
-            .get(&format!("{}/block/{}/header", self.url, hash))
-            .call();
-
-        match resp {
-            Ok(resp) => Ok(deserialize(&Vec::from_hex(&resp.into_string()?)?)?),
-            Err(ureq::Error::Status(code, _)) => Err(EsploraError::HttpResponse(code)),
-            Err(e) => Err(EsploraError::Ureq(e)),
-        }
-    }
-
-    fn _broadcast(&self, transaction: &Transaction) -> Result<(), EsploraError> {
-        let resp = self
-            .agent
-            .post(&format!("{}/tx", self.url))
-            .send_string(&serialize(transaction).to_hex());
-
-        match resp {
-            Ok(_) => Ok(()), // We do not return the txid?
-            Err(ureq::Error::Status(code, _)) => Err(EsploraError::HttpResponse(code)),
-            Err(e) => Err(EsploraError::Ureq(e)),
-        }
-    }
-
-    fn _get_height(&self) -> Result<u32, EsploraError> {
-        let resp = self
-            .agent
-            .get(&format!("{}/blocks/tip/height", self.url))
-            .call();
-
-        match resp {
-            Ok(resp) => Ok(resp.into_string()?.parse()?),
-            Err(ureq::Error::Status(code, _)) => Err(EsploraError::HttpResponse(code)),
-            Err(e) => Err(EsploraError::Ureq(e)),
-        }
-    }
-
-    fn _get_fee_estimates(&self) -> Result<HashMap<String, f64>, EsploraError> {
-        let resp = self
-            .agent
-            .get(&format!("{}/fee-estimates", self.url,))
-            .call();
-
-        let map = match resp {
-            Ok(resp) => {
-                let map: HashMap<String, f64> = resp.into_json()?;
-                Ok(map)
-            }
-            Err(ureq::Error::Status(code, _)) => Err(EsploraError::HttpResponse(code)),
-            Err(e) => Err(EsploraError::Ureq(e)),
-        }?;
-
-        Ok(map)
-    }
-
-    fn _scripthash_txs(
-        &self,
-        script: &Script,
-        last_seen: Option<Txid>,
-    ) -> Result<Vec<Tx>, EsploraError> {
-        let script_hash = sha256::Hash::hash(script.as_bytes()).into_inner().to_hex();
-        let url = match last_seen {
-            Some(last_seen) => format!(
-                "{}/scripthash/{}/txs/chain/{}",
-                self.url, script_hash, last_seen
-            ),
-            None => format!("{}/scripthash/{}/txs", self.url, script_hash),
-        };
-        Ok(self.agent.get(&url).call()?.into_json()?)
-    }
-}
-
-fn is_status_not_found(status: u16) -> bool {
-    status == 404
-}
-
-fn into_bytes(resp: Response) -> Result<Vec<u8>, io::Error> {
-    const BYTES_LIMIT: usize = 10 * 1_024 * 1_024;
-
-    let mut buf: Vec<u8> = vec![];
-    resp.into_reader()
-        .take((BYTES_LIMIT + 1) as u64)
-        .read_to_end(&mut buf)?;
-    if buf.len() > BYTES_LIMIT {
-        return Err(io::Error::new(
-            io::ErrorKind::Other,
-            "response too big for into_bytes",
-        ));
-    }
-
-    Ok(buf)
-}
-
 impl ConfigurableBlockchain for EsploraBlockchain {
     type Config = super::EsploraBlockchainConfig;
 
     fn from_config(config: &Self::Config) -> Result<Self, Error> {
-        let mut agent_builder = ureq::AgentBuilder::new();
+        let mut builder = Builder::new(config.base_url.as_str());
 
         if let Some(timeout) = config.timeout {
-            agent_builder = agent_builder.timeout(Duration::from_secs(timeout));
+            builder = builder.timeout(timeout);
         }
 
         if let Some(proxy) = &config.proxy {
-            agent_builder = agent_builder
+            builder = builder.proxy(proxy);
-                .proxy(Proxy::new(proxy).map_err(|e| Error::Esplora(Box::new(e.into())))?);
         }
 
-        let mut blockchain = EsploraBlockchain::new(config.base_url.as_str(), config.stop_gap)
+        let mut blockchain =
-            .with_agent(agent_builder.build());
+            EsploraBlockchain::from_client(builder.build_blocking()?, config.stop_gap);
 
         if let Some(concurrency) = config.concurrency {
             blockchain = blockchain.with_concurrency(concurrency);
@@ -387,12 +237,3 @@ impl ConfigurableBlockchain for EsploraBlockchain {
         Ok(blockchain)
     }
 }
-
-impl From<ureq::Error> for EsploraError {
-    fn from(e: ureq::Error) -> Self {
-        match e {
-            ureq::Error::Status(code, _) => EsploraError::HttpResponse(code),
-            e => EsploraError::Ureq(e),
-        }
-    }
-}

src/blockchain/esplora/mod.rs

@@ -15,86 +15,22 @@
 //! depending on your needs (blocking or async respectively).
 //!
 //! Please note, to configure the Esplora HTTP client correctly use one of:
-//! Blocking:  --features='esplora,ureq'
+//! Blocking:  --features='use-esplora-blocking'
-//! Async:     --features='async-interface,esplora,reqwest' --no-default-features
+//! Async:     --features='async-interface,use-esplora-async' --no-default-features
-use std::collections::HashMap;
-use std::fmt;
-use std::io;
 
-use bitcoin::consensus;
+pub use esplora_client::Error as EsploraError;
-use bitcoin::{BlockHash, Txid};
 
-use crate::error::Error;
+#[cfg(feature = "use-esplora-async")]
-use crate::FeeRate;
+mod r#async;
 
-#[cfg(feature = "reqwest")]
+#[cfg(feature = "use-esplora-async")]
-mod reqwest;
+pub use self::r#async::*;
 
-#[cfg(feature = "reqwest")]
+#[cfg(feature = "use-esplora-blocking")]
-pub use self::reqwest::*;
+mod blocking;
 
-#[cfg(feature = "ureq")]
+#[cfg(feature = "use-esplora-blocking")]
-mod ureq;
+pub use self::blocking::*;
-
-#[cfg(feature = "ureq")]
-pub use self::ureq::*;
-
-mod api;
-
-fn into_fee_rate(target: usize, estimates: HashMap<String, f64>) -> Result<FeeRate, Error> {
-    let fee_val = {
-        let mut pairs = estimates
-            .into_iter()
-            .filter_map(|(k, v)| Some((k.parse::<usize>().ok()?, v)))
-            .collect::<Vec<_>>();
-        pairs.sort_unstable_by_key(|(k, _)| std::cmp::Reverse(*k));
-        pairs
-            .into_iter()
-            .find(|(k, _)| k <= &target)
-            .map(|(_, v)| v)
-            .unwrap_or(1.0)
-    };
-    Ok(FeeRate::from_sat_per_vb(fee_val as f32))
-}
-
-/// Errors that can happen during a sync with [`EsploraBlockchain`]
-#[derive(Debug)]
-pub enum EsploraError {
-    /// Error during ureq HTTP request
-    #[cfg(feature = "ureq")]
-    Ureq(::ureq::Error),
-    /// Transport error during the ureq HTTP call
-    #[cfg(feature = "ureq")]
-    UreqTransport(::ureq::Transport),
-    /// Error during reqwest HTTP request
-    #[cfg(feature = "reqwest")]
-    Reqwest(::reqwest::Error),
-    /// HTTP response error
-    HttpResponse(u16),
-    /// IO error during ureq response read
-    Io(io::Error),
-    /// No header found in ureq response
-    NoHeader,
-    /// Invalid number returned
-    Parsing(std::num::ParseIntError),
-    /// Invalid Bitcoin data returned
-    BitcoinEncoding(bitcoin::consensus::encode::Error),
-    /// Invalid Hex data returned
-    Hex(bitcoin::hashes::hex::Error),
-
-    /// Transaction not found
-    TransactionNotFound(Txid),
-    /// Header height not found
-    HeaderHeightNotFound(u32),
-    /// Header hash not found
-    HeaderHashNotFound(BlockHash),
-}
-
-impl fmt::Display for EsploraError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "{:?}", self)
-    }
-}
 
 /// Configuration for an [`EsploraBlockchain`]
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone, PartialEq)]
@@ -138,16 +74,11 @@ impl EsploraBlockchainConfig {
     }
 }
 
-impl std::error::Error for EsploraError {}
+impl From<esplora_client::BlockTime> for crate::BlockTime {
-
+    fn from(esplora_client::BlockTime { timestamp, height }: esplora_client::BlockTime) -> Self {
-#[cfg(feature = "ureq")]
+        Self { timestamp, height }
-impl_error!(::ureq::Transport, UreqTransport, EsploraError);
+    }
-#[cfg(feature = "reqwest")]
+}
-impl_error!(::reqwest::Error, Reqwest, EsploraError);
-impl_error!(io::Error, Io, EsploraError);
-impl_error!(std::num::ParseIntError, Parsing, EsploraError);
-impl_error!(consensus::encode::Error, BitcoinEncoding, EsploraError);
-impl_error!(bitcoin::hashes::hex::Error, Hex, EsploraError);
 
 #[cfg(test)]
 #[cfg(feature = "test-esplora")]
@@ -161,58 +92,11 @@ const DEFAULT_CONCURRENT_REQUESTS: u8 = 4;
 
 #[cfg(test)]
 mod test {
-    use super::*;
-
-    #[test]
-    fn feerate_parsing() {
-        let esplora_fees = serde_json::from_str::<HashMap<String, f64>>(
-            r#"{
-  "25": 1.015,
-  "5": 2.3280000000000003,
-  "12": 2.0109999999999997,
-  "15": 1.018,
-  "17": 1.018,
-  "11": 2.0109999999999997,
-  "3": 3.01,
-  "2": 4.9830000000000005,
-  "6": 2.2359999999999998,
-  "21": 1.018,
-  "13": 1.081,
-  "7": 2.2359999999999998,
-  "8": 2.2359999999999998,
-  "16": 1.018,
-  "20": 1.018,
-  "22": 1.017,
-  "23": 1.017,
-  "504": 1,
-  "9": 2.2359999999999998,
-  "14": 1.018,
-  "10": 2.0109999999999997,
-  "24": 1.017,
-  "1008": 1,
-  "1": 4.9830000000000005,
-  "4": 2.3280000000000003,
-  "19": 1.018,
-  "144": 1,
-  "18": 1.018
-}
-"#,
-        )
-        .unwrap();
-        assert_eq!(
-            into_fee_rate(6, esplora_fees.clone()).unwrap(),
-            FeeRate::from_sat_per_vb(2.236)
-        );
-        assert_eq!(
-            into_fee_rate(26, esplora_fees).unwrap(),
-            FeeRate::from_sat_per_vb(1.015),
-            "should inherit from value for 25"
-        );
-    }
-
     #[test]
     #[cfg(feature = "test-esplora")]
     fn test_esplora_with_variable_configs() {
+        use super::*;
+
         use crate::testutils::{
             blockchain_tests::TestClient,
             configurable_blockchain_tests::ConfigurableBlockchainTester,

src/lib.rs

@@ -237,6 +237,9 @@ pub extern crate bitcoincore_rpc;
 #[cfg(feature = "electrum")]
 pub extern crate electrum_client;
 
+#[cfg(feature = "esplora")]
+pub extern crate esplora_client;
+
 #[cfg(feature = "key-value-db")]
 pub extern crate sled;
 

src/wallet/verify.rs

@@ -29,6 +29,8 @@ use crate::error::Error;
 /// Depending on the [capabilities](crate::blockchain::Blockchain::get_capabilities) of the
 /// [`Blockchain`] backend, the method could fail when called with old "historical" transactions or
 /// with unconfirmed transactions that have been evicted from the backend's memory.
+///
+/// [`Blockchain`]: crate::blockchain::Blockchain
 pub fn verify_tx<D: Database, B: GetTx>(
     tx: &Transaction,
     database: &D,