Add network and serde feature flags (#2)

Cargo.toml

@@ -14,11 +14,19 @@ asim-macros = { path="macros" }
 log = "0.4"
 futures = "0.3"
 parking_lot = "0.12"
-tokio = { version="1", features=["sync", "time", "macros", "rt"], default-features=false }
-instant = "0.1"
-serde = { version="1", features=["derive"] }
+tokio = { version="1", features=["sync"], default-features=false }
+serde = { version="1", features=["derive"], optional=true }
 async-trait = "0.1"
-rand = "0.8"
+rand = { version="0.8", optional=true }
+
+[[test]]
+name = "speed-test"
+path = "tests/speed_test.rs"
+required-features = ["network"]
 
 [dev-dependencies]
 env_logger = "0.4"
+
+[features]
+default = ["network", "serde"]
+network = ["dep:rand"]

NEWS

@@ -2,6 +2,7 @@
     - Add asim::spawn() function similar to tokio::spawn()
     - Add asim::time::sleep() function similar to tokio::time::sleep()
     - Improve documentation and add examples
+    - Move serde and network module behind feature gates
 
 0.1:
     - Initial Release

README.md

@@ -10,7 +10,11 @@ The main goal of this crate is to make simulation code look very similar to that
 This is achieved by providing an API similar to that of the standard library or tokio but with an implementation based on discrete events.
 
 This crate provides the simulator itself, a timer that allows an asynchronous task to sleep, and synchronization primitives.
-Additionally, it includes basic primitives for processes and links that can be used to jump start your process.
+Additionally, it includes basic primitives to simulate networking (guarded behind the "network" feature).
+
+## Features
+* `network`: Enable networking primitives
+* `serde`: Support serialization of (some) asim objects using serde
 
 ## Usage
 Take a look at the tests and examples to get an idea how this library is intended to be used.

src/lib.rs

@@ -11,6 +11,7 @@ use std::future::Future;
 
 pub mod sync;
 
+#[cfg(feature = "network")]
 pub mod network;
 
 pub mod time;

src/network/node.rs

@@ -182,6 +182,10 @@ impl<Message: NetworkMessage, Data: NodeData> Node<Message, Data> {
 
     /// Returns the connection to another node with the specified identifier (if it exists)
     pub fn get_link_to(&self, node_id: &ObjectId) -> Option<Rc<Link<Message, Data>>> {
+        if *node_id == self.identifier {
+            panic!("There cannot be a link to the node itself");
+        }
+
         match self.network_links.borrow().get(node_id) {
             Some(link) => Some(link.clone()),
             None => {

src/time/primitives.rs

@@ -1,7 +1,9 @@
+#[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
 /// Elapsed simulated time in nanoseconds
-#[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, PartialOrd, Ord, Eq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[derive(Debug, Clone, Copy, PartialEq, PartialOrd, Ord, Eq)]
 pub struct Time(u64);
 
 /// A period of simulated time