Implement batch call for script subscribe

Author: RCasatta

src/api.rs

@@ -106,6 +106,13 @@ pub trait ElectrumApi {
     /// already subscribed to the script.
     fn script_subscribe(&self, script: &Script) -> Result<Option<ScriptStatus>, Error>;
 
+    /// Batch version of [`script_subscribe`](#method.script_subscribe).
+    ///
+    /// Takes a list of scripts and returns a list of script status responses.
+    fn batch_script_subscribe<'s, I>(&self, scripts: I) -> Result<Vec<Option<ScriptStatus>>, Error>
+    where
+        I: IntoIterator<Item = &'s Script> + Clone;
+
     /// Subscribes to notifications for activity on a specific *scriptPubKey*.
     ///
     /// Returns a `bool` with the server response when successful.

src/batch.rs

@@ -43,6 +43,13 @@ impl Batch {
             .push((String::from("blockchain.scripthash.get_balance"), params));
     }
 
+    /// Add one `blockchain.scripthash.listunspent` request to the batch queue
+    pub fn script_subscribe(&mut self, script: &Script) {
+        let params = vec![Param::String(script.to_electrum_scripthash().to_hex())];
+        self.calls
+            .push((String::from("blockchain.scripthash.subscribe"), params));
+    }
+
     /// Add one `blockchain.transaction.get` request to the batch queue
     pub fn transaction_get(&mut self, tx_hash: &Txid) {
         let params = vec![Param::String(tx_hash.to_hex())];

src/client.rs

@@ -222,6 +222,14 @@ impl ElectrumApi for Client {
         impl_inner_call!(self, script_subscribe, script)
     }
 
+    #[inline]
+    fn batch_script_subscribe<'s, I>(&self, scripts: I) -> Result<Vec<Option<ScriptStatus>>, Error>
+    where
+        I: IntoIterator<Item = &'s Script> + Clone,
+    {
+        impl_inner_call!(self, batch_script_subscribe, scripts.clone())
+    }
+
     #[inline]
     fn script_unsubscribe(&self, script: &Script) -> Result<bool, Error> {
         impl_inner_call!(self, script_unsubscribe, script)

src/raw_client.rs

@@ -848,6 +848,24 @@ impl<T: Read + Write> ElectrumApi for RawClient<T> {
         Ok(serde_json::from_value(value)?)
     }
 
+    fn batch_script_subscribe<'s, I>(&self, scripts: I) -> Result<Vec<Option<ScriptStatus>>, Error>
+    where
+        I: IntoIterator<Item = &'s Script> + Clone,
+    {
+        {
+            let mut script_notifications = self.script_notifications.lock()?;
+
+            for script in scripts.clone().into_iter() {
+                let script_hash = script.to_electrum_scripthash();
+                if script_notifications.contains_key(&script_hash) {
+                    return Err(Error::AlreadySubscribed(script_hash));
+                }
+                script_notifications.insert(script_hash, VecDeque::new());
+            }
+        }
+        impl_batch_call!(self, scripts, script_subscribe)
+    }
+
     fn script_unsubscribe(&self, script: &Script) -> Result<bool, Error> {
         let script_hash = script.to_electrum_scripthash();
         let mut script_notifications = self.script_notifications.lock()?;