memoryd: the crate, memoryd.toml, and listening on a socket

Implemented-By: OpenCode session (model recorded in docs/implementer-log.md)

crates/memoryd/src/config.rs

@@ -0,0 +1,140 @@
+//! `memoryd` configuration: read `memoryd.toml` into a typed `Config` (M5a spec, section 11).
+//!
+//! Unknown keys are errors in every table, as in the other roles: a misspelt key that silently
+//! fell back to its default would be a setting the owner believes is set and is not.
+
+use std::path::{Path, PathBuf};
+
+use proto::DataClass;
+use serde::Deserialize;
+
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[serde(deny_unknown_fields, default)]
+pub struct Paths {
+    pub home: PathBuf,
+}
+
+impl Default for Paths {
+    fn default() -> Self {
+        Self {
+            home: std::env::var_os("BOXMAKER_HOME")
+                .map(PathBuf::from)
+                .unwrap_or_else(|| PathBuf::from("/var/lib/boxmaker")),
+        }
+    }
+}
+
+/// `[memory]`: the starter `soul.md`, and whether identity writes wait for the owner.
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[serde(deny_unknown_fields, default)]
+pub struct Memory {
+    /// A relative path is resolved next to the config file by `Config::load`.
+    pub soul_starter: PathBuf,
+    pub review: bool,
+}
+
+impl Default for Memory {
+    fn default() -> Self {
+        Self {
+            soul_starter: PathBuf::from("soul.md"),
+            review: false,
+        }
+    }
+}
+
+/// `[index]`: records above `max_class` are not indexed.
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[serde(deny_unknown_fields, default)]
+pub struct Index {
+    pub max_class: DataClass,
+}
+
+impl Default for Index {
+    fn default() -> Self {
+        Self {
+            max_class: DataClass::Private,
+        }
+    }
+}
+
+/// An empty path means "the default under `home`".
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Default)]
+#[serde(deny_unknown_fields, default)]
+pub struct Sockets {
+    #[serde(rename = "loop")]
+    pub loopd: PathBuf,
+    pub broker: PathBuf,
+    pub admin: PathBuf,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Default)]
+#[serde(deny_unknown_fields, default)]
+pub struct Config {
+    pub paths: Paths,
+    pub memory: Memory,
+    pub index: Index,
+    pub sockets: Sockets,
+}
+
+#[derive(Debug)]
+pub enum ConfigError {
+    Read(PathBuf, std::io::Error),
+    Parse(PathBuf, toml::de::Error),
+}
+
+impl std::fmt::Display for ConfigError {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            ConfigError::Read(path, err) => write!(f, "{}: {err}", path.display()),
+            ConfigError::Parse(path, err) => write!(f, "{}: {err}", path.display()),
+        }
+    }
+}
+
+impl std::error::Error for ConfigError {}
+
+impl Config {
+    pub fn parse(text: &str) -> Result<Config, toml::de::Error> {
+        toml::from_str(text)
+    }
+
+    /// Read and parse `path`; a relative `soul_starter` is taken to be next to it.
+    pub fn load(path: &Path) -> Result<Config, ConfigError> {
+        let text =
+            std::fs::read_to_string(path).map_err(|e| ConfigError::Read(path.to_path_buf(), e))?;
+        let mut config =
+            Config::parse(&text).map_err(|e| ConfigError::Parse(path.to_path_buf(), e))?;
+        if config.memory.soul_starter.is_relative() {
+            let base = path.parent().unwrap_or_else(|| Path::new("."));
+            config.memory.soul_starter = base.join(&config.memory.soul_starter);
+        }
+        Ok(config)
+    }
+
+    fn socket(&self, set: &Path, default: &str) -> PathBuf {
+        if set.as_os_str().is_empty() {
+            self.paths.home.join(default)
+        } else {
+            set.to_path_buf()
+        }
+    }
+
+    pub fn loop_socket(&self) -> PathBuf {
+        self.socket(&self.sockets.loopd, "run/loop-memory/memory.sock")
+    }
+    pub fn broker_socket(&self) -> PathBuf {
+        self.socket(&self.sockets.broker, "run/broker-memory/memory.sock")
+    }
+    pub fn admin_socket(&self) -> PathBuf {
+        self.socket(&self.sockets.admin, "run/owner-memory/admin.sock")
+    }
+    pub fn memory_dir(&self) -> PathBuf {
+        self.paths.home.join("memory")
+    }
+    pub fn index_path(&self) -> PathBuf {
+        self.paths.home.join("index/memory.sqlite3")
+    }
+    pub fn sessions_dir(&self) -> PathBuf {
+        self.paths.home.join("sessions")
+    }
+}