loopd: [compact] threshold, summary_chars and summarise

Co-Authored-By: ornith-1.5-35b-a3b <agent@wntrmute.dev>

crates/loopd/src/config.rs

@@ -175,6 +175,8 @@ pub struct Config {
     pub broker: Broker,
     #[serde(default)]
     pub memory: Memory,
+    #[serde(default)]
+    pub compact: Compact,
 }
 
 /// `[memory]`: `memoryd`'s socket for `loopd` (M5a spec, section 9). An empty path means the
@@ -185,6 +187,26 @@ pub struct Memory {
     pub socket: std::path::PathBuf,
 }
 
+/// `[compact]`: when a session starts a new epoch, and how long a summary may be (M5d spec,
+/// section 5). `summarise` is stored here and unused until M5d-2.
+#[derive(Debug, Clone, PartialEq, Deserialize)]
+#[serde(deny_unknown_fields, default)]
+pub struct Compact {
+    pub threshold: f64,
+    pub summary_chars: usize,
+    pub summarise: Vec<String>,
+}
+
+impl Default for Compact {
+    fn default() -> Self {
+        Self {
+            threshold: 0.85,
+            summary_chars: 4_000,
+            summarise: vec!["http_fetch".to_string()],
+        }
+    }
+}
+
 #[derive(Debug)]
 pub enum ConfigError {
     Read(std::path::PathBuf, std::io::Error),
@@ -232,4 +254,9 @@ impl Config {
             self.channel.socket.clone()
         }
     }
+
+    /// `compact.md` beside the system prompt: the summary call's last user message.
+    pub fn compact_prompt(&self) -> std::path::PathBuf {
+        self.baseline.system.with_file_name("compact.md")
+    }
 }

crates/loopd/tests/config_compact.rs

@@ -0,0 +1,119 @@
+//! Tests for `[compact]` on `loopd.toml`. Do not edit.
+
+use loopd::config::Config;
+use std::path::{Path, PathBuf};
+
+fn fixture(name: &str) -> PathBuf {
+    Path::new(env!("CARGO_MANIFEST_DIR"))
+        .join("tests/fixtures/config")
+        .join(name)
+}
+
+fn minimal() -> String {
+    std::fs::read_to_string(fixture("minimal.toml")).unwrap()
+}
+
+#[test]
+fn missing_table_gets_the_documented_defaults() {
+    let c = Config::load(&fixture("minimal.toml")).unwrap();
+    assert_eq!(c.compact.threshold, 0.85);
+    assert_eq!(c.compact.summary_chars, 4_000);
+    assert_eq!(c.compact.summarise, vec!["http_fetch".to_string()]);
+}
+
+#[test]
+fn the_table_overrides_every_default() {
+    let text = format!(
+        "{}\n[compact]\nthreshold = 0.5\nsummary_chars = 100\nsummarise = [\"clock\"]\n",
+        minimal()
+    );
+    let c = Config::parse(&text).unwrap();
+    assert_eq!(c.compact.threshold, 0.5);
+    assert_eq!(c.compact.summary_chars, 100);
+    assert_eq!(c.compact.summarise, vec!["clock".to_string()]);
+}
+
+#[test]
+fn a_partial_table_keeps_the_other_defaults() {
+    let text = format!("{}\n[compact]\nthreshold = 0.9\n", minimal());
+    let c = Config::parse(&text).unwrap();
+    assert_eq!(c.compact.threshold, 0.9);
+    assert_eq!(c.compact.summary_chars, 4_000);
+    assert_eq!(c.compact.summarise, vec!["http_fetch".to_string()]);
+}
+
+#[test]
+fn unknown_keys_are_errors() {
+    let text = minimal();
+    let bad = format!("{text}\n[compact]\nzz_unknown = 1\n");
+    assert!(
+        Config::parse(&bad).is_err(),
+        "[compact] accepted an unknown key"
+    );
+    let misspelt = format!("{text}\n[compact]\nsummary_char = 10\n");
+    assert!(
+        Config::parse(&misspelt).is_err(),
+        "[compact] accepted a misspelt key"
+    );
+}
+
+#[test]
+fn empty_summarise_is_allowed() {
+    let text = format!("{}\n[compact]\nsummarise = []\n", minimal());
+    let c = Config::parse(&text).unwrap();
+    assert!(c.compact.summarise.is_empty());
+}
+
+#[test]
+fn compact_prompt_is_compact_md_beside_system_md() {
+    let c = Config::load(&fixture("minimal.toml")).unwrap();
+    assert_eq!(c.compact_prompt(), fixture("compact.md"));
+    let home = Scratch::new();
+    let cfg_path = home.dir.join("loopd.toml");
+    std::fs::write(&cfg_path, minimal()).unwrap();
+    std::fs::write(home.dir.join("system.md"), "sys\n").unwrap();
+    let c = Config::load(&cfg_path).unwrap();
+    assert_eq!(c.compact_prompt(), home.dir.join("compact.md"));
+}
+
+struct Scratch {
+    dir: PathBuf,
+}
+
+impl Scratch {
+    fn new() -> Scratch {
+        let dir = std::env::temp_dir().join(format!(
+            "loopd-compact-cfg-{}-{}",
+            std::process::id(),
+            std::time::SystemTime::now()
+                .duration_since(std::time::UNIX_EPOCH)
+                .unwrap()
+                .as_nanos()
+        ));
+        std::fs::create_dir_all(&dir).unwrap();
+        Scratch { dir }
+    }
+}
+
+impl Drop for Scratch {
+    fn drop(&mut self) {
+        let _ = std::fs::remove_dir_all(&self.dir);
+    }
+}
+
+#[test]
+fn compact_prompt_follows_an_overridden_system_path() {
+    let text = std::fs::read_to_string(fixture("m2b.toml")).unwrap();
+    let c = Config::load(&fixture("m2b.toml")).unwrap();
+    assert!(
+        text.contains("prompts/agent.md"),
+        "m2b fixture names a prompt in a subdirectory"
+    );
+    assert_eq!(c.compact_prompt(), fixture("prompts/compact.md"));
+}
+
+#[test]
+fn defaults_match_the_struct_default() {
+    let c = Config::load(&fixture("minimal.toml")).unwrap();
+    assert_eq!(c.compact, loopd::config::Compact::default());
+}