Read graph from file

README.md

@@ -53,6 +53,16 @@ Path found, destination <0e1fb61e3b38e332868b331740642f41> is 4 hops away via <1
 
 For now, UDP ports are allocated to links in order from `42000` to `65535`.
 
+The graph can also be read from a text file listing edges, using option `-G <path>`. An edge is a space-separated list of two node indices. Separation can be any whitespace character. Example:
+
+```
+0 1
+1 2
+2 0
+1 3
+3 4
+```
+
 ## License
 
 [Support me via LiberaPay](https://liberapay.com/tuxmain/donate)

src/main.rs

@@ -1,10 +1,11 @@
 mod generator;
+mod reader;
 mod render;
 
 use std::{
 	collections::{HashMap, hash_map::Entry},
 	io::Write,
-	path::PathBuf,
+	path::{Path, PathBuf},
 };
 
 /// Generate configuration for local Reticulum networks
@@ -16,6 +17,9 @@ struct Cli {
 	/// Generate graph and create Reticulum configs
 	#[argp(switch, short = 'g', long = "gen")]
 	generate: bool,
+	/// Read graph file instead of generating random (one edge per line, node numbers separated by space)
+	#[argp(option, short = 'G')]
+	graph: Option<String>,
 	/// Number of nodes
 	#[argp(option, short = 'n', default = "5")]
 	nodes: usize,
@@ -35,13 +39,17 @@ fn main() {
 	let cli: Cli = argp::parse_args_or_exit(argp::DEFAULT);
 
 	if cli.generate {
-		let mut rng = rand::thread_rng();
+		let edges = if let Some(graph_file) = cli.graph {
+			reader::read_graph_file(Path::new(&graph_file))
+		} else {
+			let mut rng = rand::thread_rng();
 
-		assert!(
+			assert!(
-			cli.proba >= 0.0 && cli.proba <= 1.0,
+				cli.proba >= 0.0 && cli.proba <= 1.0,
-			"Probability should be between 0 and 1."
+				"Probability should be between 0 and 1."
-		);
+			);
-		let edges = generator::generate(cli.nodes, cli.proba, &mut rng);
+			generator::generate(cli.nodes, cli.proba, &mut rng)
+		};
 
 		let mut ports = HashMap::new();
 		let mut port: u16 = 42000;
@@ -49,6 +57,7 @@ fn main() {
 
 		#[cfg(feature = "render")]
 		if let Some(out_svg) = &cli.render {
+			let mut rng = rand::thread_rng();
 			render::render_to_svg(cli.nodes, &edges, out_svg, &mut rng);
 		}
 

src/reader.rs

@@ -0,0 +1,20 @@
+use std::{
+	io::{BufRead, BufReader},
+	path::Path,
+};
+
+pub fn read_graph_file(path: &Path) -> Vec<(usize, usize)> {
+	let file = std::fs::OpenOptions::new().read(true).open(path).unwrap();
+	let reader = BufReader::new(file);
+	let mut edges = Vec::new();
+	for line in reader.lines() {
+		let line = line.unwrap();
+		let mut cols = line.split_whitespace();
+		if let (Some(n1), Some(n2)) = (cols.next(), cols.next()) {
+			if let (Ok(n1), Ok(n2)) = (n1.parse(), n2.parse()) {
+				edges.push((n1, n2));
+			}
+		}
+	}
+	edges
+}