Persist network graph

[ldk-sample] / src / disk.rs

diff --git a/src/disk.rs b/src/disk.rs
index 827cb7e9e79326f6a3b8ae5022748267c07bf72a..2c1834a6f0b7ac92caec7c712a659dd25786c718 100644 (file)
--- a/src/disk.rs
+++ b/src/disk.rs
@@ -1,11 +1,13 @@
 use crate::cli;
 use bitcoin::secp256k1::key::PublicKey;
+use bitcoin::BlockHash;
+use lightning::routing::network_graph::NetworkGraph;
 use lightning::util::logger::{Logger, Record};
-use lightning::util::ser::Writer;
+use lightning::util::ser::{Readable, Writeable, Writer};
 use std::collections::HashMap;
 use std::fs;
 use std::fs::File;
-use std::io::{BufRead, BufReader};
+use std::io::{BufRead, BufReader, BufWriter};
 use std::net::SocketAddr;
 use std::path::Path;
 use time::OffsetDateTime;
@@ -65,3 +67,25 @@ pub(crate) fn read_channel_peer_data(
        }
        Ok(peer_data)
 }
+
+pub(crate) fn persist_network(path: &Path, network_graph: &NetworkGraph) -> std::io::Result<()> {
+       let mut tmp_path = path.to_path_buf().into_os_string();
+       tmp_path.push(".tmp");
+       let file = fs::OpenOptions::new().write(true).create(true).open(&tmp_path)?;
+       let write_res = network_graph.write(&mut BufWriter::new(file));
+       if let Err(e) = write_res.and_then(|_| fs::rename(&tmp_path, path)) {
+               let _ = fs::remove_file(&tmp_path);
+               Err(e)
+       } else {
+               Ok(())
+       }
+}
+
+pub(crate) fn read_network(path: &Path, genesis_hash: BlockHash) -> NetworkGraph {
+       if let Ok(file) = File::open(path) {
+               if let Ok(graph) = NetworkGraph::read(&mut BufReader::new(file)) {
+                       return graph;
+               }
+       }
+       NetworkGraph::new(genesis_hash)
+}