milestone 20: declarative configuration for iac

src/storage/db.zig

@@ -57,6 +57,7 @@ pub const c = struct {
     pub extern fn sqlite3_column_bytes(stmt: *c.Stmt, col: c_int) c_int;
     pub extern fn sqlite3_last_insert_rowid(db: *Sqlite3) i64;
     pub extern fn sqlite3_changes(db: *Sqlite3) c_int;
+    pub extern fn sqlite3_total_changes(db: *Sqlite3) c_int;
 };
 
 /// Result codes, from the vendored `sqlite3.h` (3.53.4).
@@ -429,6 +430,15 @@ pub const Db = struct {
     pub fn changes(self: *Db) i64 {
         return c.sqlite3_changes(self.handle);
     }
+
+    /// Every row this connection has inserted, updated or deleted since it was
+    /// opened. Monotonic, so a caller proves "this call wrote nothing" by
+    /// reading it either side and comparing — which is stronger than comparing
+    /// content, because an UPDATE that rewrites identical values still moves
+    /// this counter.
+    pub fn totalChanges(self: *Db) i64 {
+        return c.sqlite3_total_changes(self.handle);
+    }
 };
 
 fn openHandle(filename: [:0]const u8, flags: c_int) Error!*c.Sqlite3 {