milestone 27: diagnostics — operational failures land in one curated log, resolved history purgeable

src/cli.zig

@@ -332,12 +332,14 @@ pub const DataDir = struct {
     /// `querylog_schema.open` resolves the path through SQLite's VFS as well as
     /// through the directory handle, so it is given `cwd` and the joined path
     /// rather than `self.dir` and a name (see its doc comment).
-    pub fn openQuerylogDb(self: *const DataDir, io: std.Io) !db.Db {
-        const opened = try querylog_schema.open(io, std.Io.Dir.cwd(), self.querylog_db_path);
-        var database = opened.database;
-        errdefer database.close();
+    /// Returns the whole `OpenResult`, recreate reason and aside name included:
+    /// the composition root records a recreate as a one-shot diagnostics event,
+    /// and the aside name is what tells an operator where the old file went.
+    pub fn openQuerylogDb(self: *const DataDir, io: std.Io) !querylog_schema.OpenResult {
+        var opened = try querylog_schema.open(io, std.Io.Dir.cwd(), self.querylog_db_path);
+        errdefer opened.database.close();
         try self.restrictQuerylogPermissions(io);
-        return database;
+        return opened;
     }
 
     /// An additional connection to a `querylog.db` that `openQuerylogDb` has