Working overlay

1 files changed, 40 insertions, 0 deletions

diff --git a/src/common/overlay/fig.rs b/src/common/overlay/fig.rs
new file mode 100644
index 0000000..b60f8e9
--- /dev/null
+++ b/src/common/overlay/fig.rs
@@ -0,0 +1,40 @@
+use std::io::{BufRead, Write};
+
+#[derive(Debug, Clone)]
+pub struct Message {
+    pub event: lexpr::Value,
+    pub data: lexpr::Value,
+}
+
+pub struct Client {
+    reader: std::io::BufReader<std::net::TcpStream>,
+}
+impl Client {
+    pub fn new(addr: &str, subs: &[lexpr::Value]) -> Self {
+        let mut socket = std::net::TcpStream::connect(addr).expect("failed to connect to message bus");
+        socket.set_nonblocking(true).expect("failed to set message bus socket nonblocking");
+        for s in subs {
+            write!(socket, "(sub {})\n", s).expect("failed to send subscribe message to bus");
+        }
+        let reader = std::io::BufReader::new(socket);
+        Self { reader, }
+    }
+    pub fn pump(&mut self) -> Option<Message> {
+        let mut buf = String::new();
+        match self.reader.read_line(&mut buf) {
+            Ok(l) => match lexpr::from_str(&buf) {
+                Ok(v) => {
+                    match v.as_cons() {
+                        Some(cs) => {
+                            Some(Message { event: cs.car().clone(), data: cs.cdr().clone() })
+                        },
+                        _ => { log::error!("malformed message bus input s-expression: {}", v); None },
+                    }
+                },
+                Err(e) => { log::error!("malformed message bus input line: {}", e); None },
+            },
+            Err(e) if e.kind() == std::io::ErrorKind::WouldBlock => None,
+            Err(e) => panic!("IO error on message bus: {}", e),
+        }
+    }
+}