Update FileSystemPersister to work with Windows.

Mainly, use std::path::Path so that the constructed paths
are OS-agnostic.

Also, Windows necessitates the use of OpenOptions with the `write`
permission enabled to `sync_all` on a newly opened channel's
data file.

Author: valentinewallace

lightning-data-persister/src/lib.rs

@@ -9,6 +9,7 @@ use lightning::util::ser::{Writeable, Readable};
 use bitcoin::hash_types::{BlockHash, Txid};
 use bitcoin::hashes::hex::{ToHex, FromHex};
 use std::fs;
+use std::path::Path;
 use std::io::{Error, ErrorKind, Cursor};
 use std::collections::HashMap;
 use std::marker::PhantomData;
@@ -31,7 +32,10 @@ impl<ChanSigner: ChannelKeys + Readable + Writeable> FilesystemPersister<ChanSig
 	}
 
 	fn get_full_filepath(&self, funding_txo: OutPoint) -> String {
-		format!("{}/{}_{}", self.path_to_channel_data, funding_txo.txid.to_hex(), funding_txo.index)
+		let path = Path::new(&self.path_to_channel_data);
+		let mut path_buf = path.to_path_buf();
+		path_buf.push(format!("{}_{}", funding_txo.txid.to_hex(), funding_txo.index));
+		path_buf.to_str().unwrap().to_string()
 	}
 
 	fn write_channel_data(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChanSigner>) -> std::io::Result<()> {
@@ -65,13 +69,13 @@ impl<ChanSigner: ChannelKeys + Readable + Writeable> FilesystemPersister<ChanSig
 		if need_bk {
 			fs::copy(&filename, &bk_filename)?;
 			{
-				let f = fs::File::open(&bk_filename)?;
+				let f = fs::OpenOptions::new().write(true).open(&bk_filename)?;
 				f.sync_all()?;
 			}
 		}
 		fs::rename(&tmp_filename, &filename)?;
 		{
-			let f = fs::File::open(&filename)?;
+			let f = fs::OpenOptions::new().write(true).open(&filename)?;
 			f.sync_all()?;
 		}
 		if need_bk {
@@ -148,8 +152,8 @@ mod tests {
 	#[test]
 	fn test_filesystem_data_persister() {
 		// Create the nodes, giving them FilesystemPersisters for data persisters.
-		let data_persister_0: FilesystemPersister<EnforcingChannelKeys> = FilesystemPersister::new("./persister0".to_string());
-		let data_persister_1: FilesystemPersister<EnforcingChannelKeys> = FilesystemPersister::new("./persister1".to_string());
+		let data_persister_0: FilesystemPersister<EnforcingChannelKeys> = FilesystemPersister::new("persister0".to_string());
+		let data_persister_1: FilesystemPersister<EnforcingChannelKeys> = FilesystemPersister::new("persister1".to_string());
 		let chanmon_cfgs = create_chanmon_cfgs(2);
 		let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 		let chain_mon_0 = test_utils::TestChainMonitor::new(Some(&chanmon_cfgs[0].chain_source), &chanmon_cfgs[0].tx_broadcaster, &chanmon_cfgs[0].logger, &chanmon_cfgs[0].fee_estimator, &data_persister_0);