chore(starknet_sequencer_infra): add available ports test util

commit-id:1955bc0a

crates/starknet_sequencer_infra/src/test_utils.rs

@@ -1,7 +1,63 @@
-use std::net::SocketAddr;
+use std::net::{IpAddr, Ipv4Addr, SocketAddr};
 
 use tokio::net::TcpListener;
 
+const PORTS_PER_INSTANCE: u16 = 20;
+const MAX_NUMBER_OF_INSTANCES_PER_TEST: u16 = 10;
+const MAX_NUMBER_OF_TESTS: u16 = 10;
+const BASE_PORT: u16 = 55000;
+
+// Ensure available ports don't exceed u16::MAX.
+const _: () = {
+    assert!(
+        BASE_PORT + MAX_NUMBER_OF_TESTS * MAX_NUMBER_OF_INSTANCES_PER_TEST * PORTS_PER_INSTANCE
+            < u16::MAX,
+        "Port numbers potentially exceeding u16::MAX"
+    );
+};
+
+pub struct AvailablePorts {
+    current_port: u16,
+    max_port: u16,
+}
+
+impl AvailablePorts {
+    pub fn new(test_unique_index: u16, instance_index: u16) -> Self {
+        assert!(
+            test_unique_index < MAX_NUMBER_OF_TESTS,
+            "Test unique index {:?} exceeded bound {:?}",
+            test_unique_index,
+            MAX_NUMBER_OF_TESTS
+        );
+        assert!(
+            instance_index < MAX_NUMBER_OF_INSTANCES_PER_TEST,
+            "Instance index {:?} exceeded bound {:?}",
+            instance_index,
+            MAX_NUMBER_OF_INSTANCES_PER_TEST
+        );
+
+        let test_offset: u16 =
+            test_unique_index * MAX_NUMBER_OF_INSTANCES_PER_TEST * PORTS_PER_INSTANCE;
+        let instance_in_test_offset: u16 = instance_index * PORTS_PER_INSTANCE;
+        let base_port = BASE_PORT + test_offset + instance_in_test_offset;
+        let max_port: u16 = base_port + PORTS_PER_INSTANCE;
+
+        AvailablePorts { current_port: base_port, max_port }
+    }
+
+    pub fn get_next_port(&mut self) -> u16 {
+        let port = self.current_port;
+        self.current_port += 1;
+        assert!(self.current_port < self.max_port, "Exceeded available ports.");
+
+        port
+    }
+
+    pub fn get_next_local_host_socket(&mut self) -> SocketAddr {
+        SocketAddr::new(IpAddr::from(Ipv4Addr::LOCALHOST), self.get_next_port())
+    }
+}
+
 /// Returns a unique IP address and port for testing purposes.
 /// Tests run in parallel, so servers (like RPC or web) running on separate tests must have
 /// different ports, otherwise the server will fail with "address already in use".