Bugfix for reading u256.

src/flow/adjacencies.rs

@@ -65,11 +65,12 @@ impl<'a> Adjacencies<'a> {
             .entry(from.clone())
             .or_insert_with(|| {
                 let mut result: HashMap<Node, U256> = HashMap::new();
-                for edge in &self.edges[source_address_of(from)] {
+                // Plain edges are (from, to, token) labeled with capacity
+                for edge in self.edges.get(source_address_of(from)).unwrap_or(&vec![]) {
                     match from {
                         Node::Node(_) => {
                             // One edge from "from" to "from x token" with a capacity
-                            // as the max over all contributing edges (the balance of the sender)
+                            // as the max over all "to" addresses (the balance of the sender)
                             result
                                 .entry(pseudo_node(*edge))
                                 .and_modify(|c| {

src/flow/mod.rs

@@ -1,12 +1,22 @@
-use crate::types::{Address};
+use crate::types::Address;
+use std::fmt::{Display, Formatter};
 
 mod adjacencies;
 mod flow;
 
-#[derive(Eq, PartialEq, Hash, Clone)]
-enum Node {
+#[derive(Debug, Eq, PartialEq, Hash, Clone)]
+pub enum Node {
     Node(Address),
     TokenEdge(Address, Address),
 }
 
+impl Display for Node {
+    fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
+        match self {
+            Node::Node(address) => write!(f, "{address}"),
+            Node::TokenEdge(address, token) => write!(f, "({address} x {token})"),
+        }
+    }
+}
+
 pub use crate::flow::flow::compute_flow;

src/io.rs

@@ -48,7 +48,7 @@ fn read_u256(file: &mut File) -> Result<U256, io::Error> {
     let mut bytes = [0u8; 32];
     file.read_exact(&mut bytes[32 - length..32])?;
     let high = u128::from_be_bytes(*<&[u8; 16]>::try_from(&bytes[0..16]).unwrap());
-    let low = u128::from_be_bytes(*<&[u8; 16]>::try_from(&bytes[0..16]).unwrap());
+    let low = u128::from_be_bytes(*<&[u8; 16]>::try_from(&bytes[16..32]).unwrap());
     Ok(U256::new(high, low))
 }
 

src/main.rs

@@ -1,6 +1,5 @@
 use std::env;
 
-
 mod flow;
 mod io;
 mod types;
@@ -16,6 +15,10 @@ fn main() {
 
     println!("Computing flow {from_str} -> {to_str} using {edges_file}");
     let edges = io::read_edges_binary(edges_file).expect("Error loading edges.");
-    print!("Read {} edges", edges.len());
-    flow::compute_flow(&Address::from(from_str.as_str()), &Address::from(to_str.as_str()), &edges);
+    println!("Read {} edges", edges.len());
+    flow::compute_flow(
+        &Address::from(from_str.as_str()),
+        &Address::from(to_str.as_str()),
+        &edges,
+    );
 }

src/types/address.rs

@@ -1,3 +1,5 @@
+use std::fmt::{Display, Formatter};
+
 #[derive(Clone, Copy, Debug, Default, Hash, Eq, PartialEq, PartialOrd)]
 pub struct Address([u8; 20]);
 
@@ -18,3 +20,13 @@ impl From<&str> for Address {
         Address(data)
     }
 }
+
+impl Display for Address {
+    fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
+        write!(f, "0x")?;
+        for b in self.0 {
+            write!(f, "{:02x}", b)?;
+        }
+        Ok(())
+    }
+}