Fix performance issue for users with many orders

src/allmende_payment_system/tools.py

@@ -30,3 +30,78 @@ def get_jinja_renderer() -> Jinja2Templates:
 
     renderer.env.globals["production_mode"] = "APS_PRODUCTION_MODE" in os.environ
     return renderer
+
+
+def timer_context(name: str):
+    import time
+
+    class Timer:
+        def __enter__(self):
+            self.start = time.perf_counter()
+
+        def __exit__(self, exc_type, exc_val, exc_tb):
+            end = time.perf_counter()
+            print(f"{name} took {end - self.start:.4f} seconds")
+
+    return Timer()
+
+
+import cProfile, pstats, io
+from contextlib import contextmanager
+
+
+@contextmanager
+def profile(top_n: int = 20, sort_by: str = "cumulative", min_time: float = 0.001):
+    pr = cProfile.Profile()
+    pr.enable()
+    try:
+        yield
+    finally:
+        pr.disable()
+        s = io.StringIO()
+        ps = pstats.Stats(pr, stream=s).strip_dirs()
+        ps.sort_stats(sort_by)
+        ps.print_stats()
+
+        rows = []
+        for line in s.getvalue().splitlines():
+            parts = line.split(None, 5)
+            if len(parts) < 6:
+                continue
+            try:
+                cum = float(parts[3])
+                if cum >= min_time:
+                    rows.append(
+                        (
+                            int(parts[0].split("/")[0]),
+                            float(parts[1]),
+                            cum,
+                            float(parts[4]),
+                            parts[5].strip(),
+                        )
+                    )
+            except (ValueError, IndexError):
+                continue
+
+        rows = rows[:top_n]
+        if not rows:
+            print("[profiler] nothing exceeded min_time threshold")
+            return
+
+        w = 55
+        print(f"\n── profile ({sort_by}, ≥{min_time}s) ──────────────────────────────")
+        print(f"{'calls':>7} {'tot':>8} {'cum':>8} {'percall':>8}  {'function':<{w}}")
+        print("─" * (7 + 8 + 8 + 8 + w + 6))
+        for calls, tot, cum, percall, loc in rows:
+            c = (
+                f"\033[91m{cum:8.4f}\033[0m"
+                if cum > 1
+                else f"\033[93m{cum:8.4f}\033[0m" if cum > 0.1 else f"{cum:8.4f}"
+            )
+            print(
+                f"{calls:>7} {tot:8.4f} {c} {percall:8.4f}  {loc[-w:] if len(loc) > w else loc:<{w}}"
+            )
+        print(f"─" * (7 + 8 + 8 + 8 + w + 6))
+        print(
+            f"  {len(rows)} functions | tot accounted: {sum(r[1] for r in rows):.4f}s\n"
+        )