Public release release-6756e5208c8b

Source commit: 6756e5208c8b79e83d55610251430bc1baef53a3

Public tree identity: sha256:2f58837c3759b4f466cbc274571ee71bc0d24c7552dc009c186394e99123da87

crates/clusterflux-dap/src/dap_protocol.rs

@@ -0,0 +1,129 @@
+use std::io::{self, BufRead, Write};
+
+use anyhow::{anyhow, Result};
+use serde_json::{json, Value};
+
+#[derive(Clone)]
+pub(crate) struct DapWriter {
+    seq: i64,
+}
+
+impl DapWriter {
+    pub(crate) fn new() -> Self {
+        Self { seq: 1 }
+    }
+
+    pub(crate) fn response(
+        &mut self,
+        request: &Value,
+        success: bool,
+        body: Value,
+    ) -> io::Result<()> {
+        let command = request
+            .get("command")
+            .and_then(Value::as_str)
+            .unwrap_or("<unknown>");
+        let request_seq = request.get("seq").and_then(Value::as_i64).unwrap_or(0);
+        let seq = self.next_seq();
+        self.write(json!({
+            "seq": seq,
+            "type": "response",
+            "request_seq": request_seq,
+            "success": success,
+            "command": command,
+            "body": body,
+        }))
+    }
+
+    pub(crate) fn error_response(
+        &mut self,
+        request: &Value,
+        message: impl Into<String>,
+    ) -> io::Result<()> {
+        let command = request
+            .get("command")
+            .and_then(Value::as_str)
+            .unwrap_or("<unknown>");
+        let request_seq = request.get("seq").and_then(Value::as_i64).unwrap_or(0);
+        let seq = self.next_seq();
+        self.write(json!({
+            "seq": seq,
+            "type": "response",
+            "request_seq": request_seq,
+            "success": false,
+            "command": command,
+            "message": message.into(),
+        }))
+    }
+
+    pub(crate) fn event(&mut self, event: &str, body: Value) -> io::Result<()> {
+        let seq = self.next_seq();
+        self.write(json!({
+            "seq": seq,
+            "type": "event",
+            "event": event,
+            "body": body,
+        }))
+    }
+
+    pub(crate) fn output(&mut self, category: &str, output: impl Into<String>) -> io::Result<()> {
+        self.event(
+            "output",
+            json!({
+                "category": category,
+                "output": output.into(),
+            }),
+        )
+    }
+
+    fn next_seq(&mut self) -> i64 {
+        let seq = self.seq;
+        self.seq += 1;
+        seq
+    }
+
+    fn write(&mut self, message: Value) -> io::Result<()> {
+        let payload = serde_json::to_vec(&message)?;
+        let mut out = io::stdout().lock();
+        write!(out, "Content-Length: {}\r\n\r\n", payload.len())?;
+        out.write_all(&payload)?;
+        out.flush()
+    }
+}
+
+pub(crate) fn initialize_capabilities() -> Value {
+    json!({
+        "supportsConfigurationDoneRequest": true,
+        "supportsTerminateRequest": true,
+        "supportsRestartRequest": true,
+        "supportsRestartFrame": true,
+        "supportsEvaluateForHovers": true,
+        "supportsStepBack": false,
+    })
+}
+
+pub(crate) fn read_message<R: BufRead>(reader: &mut R) -> Result<Option<Value>> {
+    let mut content_length = None;
+
+    loop {
+        let mut line = String::new();
+        let bytes = reader.read_line(&mut line)?;
+        if bytes == 0 {
+            return Ok(None);
+        }
+
+        let line = line.trim_end_matches(['\r', '\n']);
+        if line.is_empty() {
+            break;
+        }
+
+        if let Some(value) = line.strip_prefix("Content-Length:") {
+            content_length = Some(value.trim().parse::<usize>()?);
+        }
+    }
+
+    let length = content_length.ok_or_else(|| anyhow!("DAP message missing Content-Length"))?;
+    let mut payload = vec![0; length];
+    reader.read_exact(&mut payload)?;
+    Ok(Some(serde_json::from_slice(&payload)?))
+}