test(handlers): 添加基础处理器并行传输相关单元测试

- 实现 download_files_parallel 方法的并发下载功能测试
- 验证上传文件并行处理收集URL功能的正确性
- 测试下载文件时设置锁等待时间跨度属性
- 验证无缓存下载时锁等待时间为零的场景
- 测试上传文件时设置详细的跨度属性功能
- 添加渲染视频效果相关的参数解析测试
- 实现存储服务上传指标

tests/unit/test_tracing.py

@@ -0,0 +1,51 @@
+# -*- coding: utf-8 -*-
+
+import importlib
+from types import SimpleNamespace
+
+import util.tracing as tracing_module
+
+
+def _create_task_stub():
+    task_type = SimpleNamespace(value="RENDER_SEGMENT_VIDEO")
+    return SimpleNamespace(
+        task_id="task-1001",
+        task_type=task_type,
+        get_job_id=lambda: "job-2002",
+        get_segment_id=lambda: "seg-3003",
+    )
+
+
+def test_task_trace_scope_sets_and_resets_context(monkeypatch):
+    monkeypatch.setenv("OTEL_ENABLED", "false")
+    tracing = importlib.reload(tracing_module)
+
+    assert tracing.initialize_tracing("worker-1", "2.0.0") is False
+    assert tracing.get_current_task_context() is None
+
+    with tracing.task_trace_scope(_create_task_stub()) as span:
+        assert span is None
+        context = tracing.get_current_task_context()
+        assert context is not None
+        assert context.task_id == "task-1001"
+        assert context.task_type == "RENDER_SEGMENT_VIDEO"
+        assert context.job_id == "job-2002"
+        assert context.segment_id == "seg-3003"
+
+        with tracing.start_span("render.task.sample.step") as child_span:
+            assert child_span is None
+
+    assert tracing.get_current_task_context() is None
+
+
+def test_bind_trace_context_restores_previous_context(monkeypatch):
+    monkeypatch.setenv("OTEL_ENABLED", "false")
+    tracing = importlib.reload(tracing_module)
+
+    tracing.initialize_tracing("worker-1", "2.0.0")
+    context = tracing.TaskTraceContext(task_id="task-1", task_type="FINALIZE_MP4")
+
+    assert tracing.get_current_task_context() is None
+    with tracing.bind_trace_context(None, context):
+        assert tracing.get_current_task_context() == context
+    assert tracing.get_current_task_context() is None