sausage core part 1: a process per call, routing, tree, stop and kill, locks, journal, boot

Checkpoint. Removes the old host. A quality rework follows (modules,
journal writer thread, hash cache, finer tests).

cli/src/journal.rs

@@ -0,0 +1,42 @@
+//! SQLite journal entries and filters.
+use rusqlite::{Connection, params};
+use serde_json::{Value, json};
+use std::{collections::HashSet, path::Path, sync::Mutex};
+pub struct Journal {
+    db: Mutex<Connection>,
+    warned: Mutex<HashSet<String>>,
+}
+impl Journal {
+    pub fn open(path: &Path) -> anyhow::Result<Self> {
+        std::fs::create_dir_all(path.parent().unwrap())?;
+        let db = Connection::open(path)?;
+        db.execute_batch("CREATE TABLE IF NOT EXISTS journal (id TEXT PRIMARY KEY, pid TEXT, plugin TEXT, stream TEXT, line TEXT)")?;
+        Ok(Self {
+            db: Mutex::new(db),
+            warned: Mutex::new(HashSet::new()),
+        })
+    }
+    pub fn write(&self, pid: &str, plugin: &str, stream: &str, line: &str) {
+        self.db
+            .lock()
+            .unwrap()
+            .execute(
+                "INSERT INTO journal VALUES (?1,?2,?3,?4,?5)",
+                params![uuid::Uuid::now_v7().to_string(), pid, plugin, stream, line],
+            )
+            .expect("write journal");
+    }
+    pub fn warning(&self, pid: &str, plugin: &str) {
+        if self.warned.lock().unwrap().insert(pid.into()) {
+            self.write(pid, plugin, "core", "warning: discarded stdout");
+        }
+    }
+    pub fn query(&self, p: &Value) -> Value {
+        let db = self.db.lock().unwrap();
+        let mut stmt=db.prepare("SELECT id,pid,plugin,stream,line FROM journal WHERE (?1 IS NULL OR plugin=?1) AND (?2 IS NULL OR pid=?2) AND (?3 IS NULL OR id>=?3) AND (?4 IS NULL OR id<=?4) AND (?5 IS NULL OR instr(line,?5)>0) ORDER BY id DESC LIMIT ?6").unwrap();
+        let rows=stmt.query_map(params![p["plugin"].as_str(),p["pid"].as_str(),p["since"].as_str(),p["until"].as_str(),p["grep"].as_str(),p["limit"].as_i64().unwrap_or(100)],|r|Ok(json!({"id":r.get::<_,String>(0)?,"pid":r.get::<_,String>(1)?,"plugin":r.get::<_,String>(2)?,"stream":r.get::<_,String>(3)?,"line":r.get::<_,String>(4)?}))).unwrap();
+        let mut entries: Vec<_> = rows.map(Result::unwrap).collect();
+        entries.reverse();
+        json!(entries)
+    }
+}