Implement GetNumTransactions (#1629)

- Addresses #1541

zilliqa/src/api/zil.rs

@@ -91,6 +91,7 @@ pub fn rpc_module(node: Arc<Mutex<Node>>) -> RpcModule<Arc<Mutex<Node>>> {
             ("GetTxnBodiesForTxBlockEx", get_txn_bodies_for_tx_block_ex),
             ("GetNumDSBlocks", get_num_ds_blocks),
             ("GetRecentTransactions", get_recent_transactions),
+            ("GetNumTransactions", get_num_transactions),
         ],
     )
 }
@@ -1033,3 +1034,9 @@ fn get_recent_transactions(
         txn_hashes: txns,
     })
 }
+
+fn get_num_transactions(_params: Params, node: &Arc<Mutex<Node>>) -> Result<String> {
+    let node = node.lock().unwrap();
+    let num_transactions = node.consensus.block_store.get_num_transactions()?;
+    Ok(num_transactions.to_string())
+}

zilliqa/src/block_store.rs

@@ -318,4 +318,9 @@ impl BlockStore {
             .entry(peer)
             .or_insert_with(|| PeerInfo::new(capacity))
     }
+
+    pub fn get_num_transactions(&self) -> Result<usize> {
+        let count = self.db.get_total_transaction_count()?;
+        Ok(count)
+    }
 }

zilliqa/src/db.rs

@@ -775,6 +775,15 @@ impl Db {
             .execute("DELETE FROM receipts WHERE block_hash = ?1", [block_hash])?;
         Ok(())
     }
+
+    pub fn get_total_transaction_count(&self) -> Result<usize> {
+        let count: usize =
+            self.db
+                .lock()
+                .unwrap()
+                .query_row("SELECT COUNT(*) FROM transactions", [], |row| row.get(0))?;
+        Ok(count)
+    }
 }
 
 pub fn checkpoint_block_with_state<P: AsRef<Path> + Debug>(

zilliqa/tests/it/zil.rs

@@ -1400,3 +1400,88 @@ async fn get_recent_transactions_1(mut network: Network) {
     );
     assert_eq!(recent_transactions.number, 4);
 }
+
+#[zilliqa_macros::test]
+async fn get_num_transactions_0(mut network: Network) {
+    let wallet = network.genesis_wallet().await;
+
+    let response: Value = wallet
+        .provider()
+        .request("GetNumTransactions", [""])
+        .await
+        .expect("Failed to call GetNumTransactions API");
+
+    assert!(
+        response.is_string(),
+        "Expected response to be a string, got: {:?}",
+        response
+    );
+    response
+        .as_str()
+        .expect("Expected response to be a string")
+        .parse::<u64>()
+        .expect("Failed to parse response as u64");
+}
+
+#[zilliqa_macros::test]
+async fn get_num_transactions_1(mut network: Network) {
+    let wallet = network.random_wallet().await;
+
+    let (secret_key, _address) = zilliqa_account(&mut network).await;
+
+    let to_addr: H160 = "0x00000000000000000000000000000000deadbeef"
+        .parse()
+        .unwrap();
+    send_transaction(
+        &mut network,
+        &secret_key,
+        1,
+        to_addr,
+        200u128 * 10u128.pow(12),
+        50_000,
+        None,
+        None,
+    )
+    .await;
+
+    network.run_until_block(&wallet, 1.into(), 50).await;
+
+    let (secret_key, _address) = zilliqa_account(&mut network).await;
+
+    let to_addr: H160 = "0x00000000000000000000000000000000deadbeef"
+        .parse()
+        .unwrap();
+    send_transaction(
+        &mut network,
+        &secret_key,
+        1,
+        to_addr,
+        200u128 * 10u128.pow(12),
+        50_000,
+        None,
+        None,
+    )
+    .await;
+
+    network.run_until_block(&wallet, 2.into(), 50).await;
+
+    let response: Value = wallet
+        .provider()
+        .request("GetNumTransactions", [""])
+        .await
+        .expect("Failed to call GetNumTransactions API");
+
+    assert!(
+        response.is_string(),
+        "Expected response to be a string, got: {:?}",
+        response
+    );
+
+    let response_num = response
+        .as_str()
+        .expect("Expected response to be a string")
+        .parse::<u64>()
+        .expect("Failed to parse response as u64");
+
+    assert_eq!(response_num, 4);
+}