feat(base): 添加单任务内文件传输并发功能

- 引入 ThreadPoolExecutor 实现并行下载和上传
- 新增 download_files_parallel 和 upload_files_parallel 方法
- 添加任务传输并发数配置选项 TASK_DOWNLOAD_CONCURRENCY 和 TASK_UPLOAD_CONCURRENCY
- 实现并发数配置的环境变量解析和验证逻辑
- 在多个处理器中应用并行下载优化文件获取性能
- 更新 .env.example 配置文件模板
- 移除 FFmpeg 命令日志长度限制

handlers/prepare_audio.py

@@ -55,32 +55,60 @@ class PrepareJobAudioHandler(BaseHandler):
             bgm_url = task.get_bgm_url()
             segments = task.get_segments()
 
-            # 1. 下载 BGM（如有）
-            bgm_file = None
+            # 1. 并行下载 BGM 与叠加音效
+            bgm_file = os.path.join(work_dir, 'bgm.mp3') if bgm_url else None
+            download_jobs = []
+            if bgm_url and bgm_file:
+                download_jobs.append({
+                    'key': 'bgm',
+                    'url': bgm_url,
+                    'dest': bgm_file,
+                    'required': False
+                })
+
+            sfx_download_candidates = []
+            for i, seg in enumerate(segments):
+                audio_spec_data = seg.get('audioSpecJson')
+                if not audio_spec_data:
+                    continue
+                audio_spec = AudioSpec.from_dict(audio_spec_data)
+                if not audio_spec or not audio_spec.audio_url:
+                    continue
+                sfx_file = os.path.join(work_dir, f'sfx_{i}.mp3')
+                job_key = f'sfx_{i}'
+                sfx_download_candidates.append({
+                    'key': job_key,
+                    'file': sfx_file,
+                    'spec': audio_spec,
+                    'segment': seg
+                })
+                download_jobs.append({
+                    'key': job_key,
+                    'url': audio_spec.audio_url,
+                    'dest': sfx_file,
+                    'required': False
+                })
+
+            download_results = self.download_files_parallel(download_jobs)
             if bgm_url:
-                bgm_file = os.path.join(work_dir, 'bgm.mp3')
-                if not self.download_file(bgm_url, bgm_file):
+                bgm_result = download_results.get('bgm')
+                if not bgm_result or not bgm_result['success']:
                     logger.warning(f"[task:{task.task_id}] Failed to download BGM")
                     bgm_file = None
 
-            # 2. 下载叠加音效
             sfx_files = []
-            for i, seg in enumerate(segments):
-                audio_spec_data = seg.get('audioSpecJson')
-                if audio_spec_data:
-                    audio_spec = AudioSpec.from_dict(audio_spec_data)
-                    if audio_spec and audio_spec.audio_url:
-                        sfx_file = os.path.join(work_dir, f'sfx_{i}.mp3')
-                        if self.download_file(audio_spec.audio_url, sfx_file):
-                            sfx_files.append({
-                                'file': sfx_file,
-                                'spec': audio_spec,
-                                'segment': seg
-                            })
-                        else:
-                            logger.warning(f"[task:{task.task_id}] Failed to download SFX {i}")
+            for sfx_candidate in sfx_download_candidates:
+                sfx_result = download_results.get(sfx_candidate['key'])
+                if sfx_result and sfx_result['success']:
+                    sfx_files.append({
+                        'file': sfx_candidate['file'],
+                        'spec': sfx_candidate['spec'],
+                        'segment': sfx_candidate['segment']
+                    })
+                else:
+                    logger.warning(f"[task:{task.task_id}] Failed to download SFX {sfx_candidate['key']}")
 
-            # 3. 构建音频混音命令
+            # 2. 构建音频混音命令
             output_file = os.path.join(work_dir, 'audio_full.aac')
             cmd = self._build_audio_command(
                 bgm_file=bgm_file,
@@ -90,21 +118,21 @@ class PrepareJobAudioHandler(BaseHandler):
                 audio_profile=audio_profile
             )
 
-            # 4. 执行 FFmpeg
+            # 3. 执行 FFmpeg
             if not self.run_ffmpeg(cmd, task.task_id):
                 return TaskResult.fail(
                     ErrorCode.E_FFMPEG_FAILED,
                     "Audio mixing failed"
                 )
 
-            # 5. 验证输出文件
+            # 4. 验证输出文件
             if not self.ensure_file_exists(output_file, min_size=1024):
                 return TaskResult.fail(
                     ErrorCode.E_FFMPEG_FAILED,
                     "Audio output file is missing or too small"
                 )
 
-            # 6. 上传产物
+            # 5. 上传产物
             audio_url = self.upload_file(task.task_id, 'audio', output_file)
             if not audio_url:
                 return TaskResult.fail(