chore: 添加虚拟环境到仓库

- 添加 backend_service/venv 虚拟环境
- 包含所有Python依赖包
- 注意：虚拟环境约393MB，包含12655个文件

backend_service/venv/lib/python3.13/site-packages/backoff/_sync.py

@@ -0,0 +1,132 @@
+# coding:utf-8
+import datetime
+import functools
+import time
+from datetime import timedelta
+
+from backoff._common import (_init_wait_gen, _maybe_call, _next_wait)
+
+
+def _call_handlers(hdlrs, target, args, kwargs, tries, elapsed, **extra):
+    details = {
+        'target': target,
+        'args': args,
+        'kwargs': kwargs,
+        'tries': tries,
+        'elapsed': elapsed,
+    }
+    details.update(extra)
+    for hdlr in hdlrs:
+        hdlr(details)
+
+
+def retry_predicate(target, wait_gen, predicate,
+                    *,
+                    max_tries, max_time, jitter,
+                    on_success, on_backoff, on_giveup,
+                    wait_gen_kwargs):
+
+    @functools.wraps(target)
+    def retry(*args, **kwargs):
+        max_tries_value = _maybe_call(max_tries)
+        max_time_value = _maybe_call(max_time)
+
+        tries = 0
+        start = datetime.datetime.now()
+        wait = _init_wait_gen(wait_gen, wait_gen_kwargs)
+        while True:
+            tries += 1
+            elapsed = timedelta.total_seconds(datetime.datetime.now() - start)
+            details = {
+                "target": target,
+                "args": args,
+                "kwargs": kwargs,
+                "tries": tries,
+                "elapsed": elapsed,
+            }
+
+            ret = target(*args, **kwargs)
+            if predicate(ret):
+                max_tries_exceeded = (tries == max_tries_value)
+                max_time_exceeded = (max_time_value is not None and
+                                     elapsed >= max_time_value)
+
+                if max_tries_exceeded or max_time_exceeded:
+                    _call_handlers(on_giveup, **details, value=ret)
+                    break
+
+                try:
+                    seconds = _next_wait(wait, ret, jitter, elapsed,
+                                         max_time_value)
+                except StopIteration:
+                    _call_handlers(on_giveup, **details)
+                    break
+
+                _call_handlers(on_backoff, **details,
+                               value=ret, wait=seconds)
+
+                time.sleep(seconds)
+                continue
+            else:
+                _call_handlers(on_success, **details, value=ret)
+                break
+
+        return ret
+
+    return retry
+
+
+def retry_exception(target, wait_gen, exception,
+                    *,
+                    max_tries, max_time, jitter, giveup,
+                    on_success, on_backoff, on_giveup, raise_on_giveup,
+                    wait_gen_kwargs):
+
+    @functools.wraps(target)
+    def retry(*args, **kwargs):
+        max_tries_value = _maybe_call(max_tries)
+        max_time_value = _maybe_call(max_time)
+
+        tries = 0
+        start = datetime.datetime.now()
+        wait = _init_wait_gen(wait_gen, wait_gen_kwargs)
+        while True:
+            tries += 1
+            elapsed = timedelta.total_seconds(datetime.datetime.now() - start)
+            details = {
+                "target": target,
+                "args": args,
+                "kwargs": kwargs,
+                "tries": tries,
+                "elapsed": elapsed,
+            }
+
+            try:
+                ret = target(*args, **kwargs)
+            except exception as e:
+                max_tries_exceeded = (tries == max_tries_value)
+                max_time_exceeded = (max_time_value is not None and
+                                     elapsed >= max_time_value)
+
+                if giveup(e) or max_tries_exceeded or max_time_exceeded:
+                    _call_handlers(on_giveup, **details, exception=e)
+                    if raise_on_giveup:
+                        raise
+                    return None
+
+                try:
+                    seconds = _next_wait(wait, e, jitter, elapsed,
+                                         max_time_value)
+                except StopIteration:
+                    _call_handlers(on_giveup, **details, exception=e)
+                    raise e
+
+                _call_handlers(on_backoff, **details, wait=seconds,
+                               exception=e)
+
+                time.sleep(seconds)
+            else:
+                _call_handlers(on_success, **details)
+
+                return ret
+    return retry