Extend the temporal network binary format to include node addition and removal.

measurements/src/bin/temporal_network.rs

-use std::env::args_os;
-use std::io::{stdout, BufWriter, Write};
-
-use measurements::collect;
-
-fn main() {
-    let stdout = stdout();
-    let mut stdout = BufWriter::with_capacity(1024 * 1024, stdout.lock());
-
-    collect(args_os().nth(1).unwrap(), |_tick, worlds| {
-        for temporal_network in worlds.iter().map(|world| &world.temporal_network) {
-            for (tick, source, destination) in &temporal_network.edges {
-                let tick = tick.as_seconds() as u32;
-
-                stdout.write_all(&tick.to_ne_bytes()).unwrap();
-                stdout.write_all(&source.to_ne_bytes()).unwrap();
-                stdout.write_all(&destination.to_ne_bytes()).unwrap();
-            }
-        }
-    });
-}
+use std::env::args_os;
+use std::io::{stdout, BufWriter, Write};
+
+use hashbrown::HashMap;
+
+use measurements::collect;
+use model::insect::Species as InsectSpecies;
+
+fn main() {
+    let stdout = stdout();
+    let mut stdout = BufWriter::with_capacity(1024 * 1024, stdout.lock());
+
+    let mut node_species = HashMap::<u32, u32>::default();
+
+    // The two highest bit of the tick determine the record type:
+    // 00 => edge = tick|source|destination
+    // 10 => node removed = tick|id
+    // 11 => node added = tick|id|species
+    const MASK: u32 = 1 << 31 | 1 << 30;
+
+    collect(args_os().nth(1).unwrap(), |_tick, worlds| {
+        for temporal_network in worlds.iter().map(|world| &world.temporal_network) {
+            for (tick, source, destination) in &temporal_network.edges {
+                let tick = tick.as_seconds() as u32;
+                assert!(MASK & tick == 0);
+
+                stdout.write_all(&tick.to_ne_bytes()).unwrap();
+                stdout.write_all(&source.to_ne_bytes()).unwrap();
+                stdout.write_all(&destination.to_ne_bytes()).unwrap();
+            }
+
+            for (tick, old_node, new_node) in &temporal_network.nodes {
+                let mut tick = tick.as_seconds() as u32;
+                assert!(MASK & tick == 0);
+
+                // remove old node
+                tick |= 1 << 31;
+
+                stdout.write_all(&tick.to_ne_bytes()).unwrap();
+                stdout.write_all(&old_node.to_ne_bytes()).unwrap();
+                stdout.write_all(&[0; 4]).unwrap();
+
+                // either we know the species as a node is replaced,
+                // or this is an initial node and we can index into `species`
+                let species = if let Some(species) = node_species.get(old_node) {
+                    *species
+                } else {
+                    let species = match temporal_network.species[*old_node as usize] {
+                        InsectSpecies::Hoverfly(species) => species as u32,
+                        InsectSpecies::SolitaryBee(species) => 256 + species as u32,
+                        InsectSpecies::Bumblebee(species) => 512 + species as u32,
+                    };
+
+                    stdout.write_all(&[0; 4]).unwrap();
+                    stdout.write_all(&old_node.to_ne_bytes()).unwrap();
+                    stdout.write_all(&species.to_ne_bytes()).unwrap();
+
+                    species
+                };
+
+                node_species.insert(*new_node, species);
+
+                // insert new node
+                tick |= 1 << 30;
+
+                stdout.write_all(&tick.to_ne_bytes()).unwrap();
+                stdout.write_all(&new_node.to_ne_bytes()).unwrap();
+                stdout.write_all(&species.to_ne_bytes()).unwrap();
+            }
+        }
+    });
+}