Fix and refactor imports (#11010)

### What problem does this PR solve?

1. Move EMBEDDING_CFG to common.globals
2. Fix error imports
3. Move signal handles to common/signal_utils.py

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

common/globals.py

@@ -0,0 +1,17 @@
+#
+#  Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+EMBEDDING_CFG = ""

common/signal_utils.py

@@ -0,0 +1,55 @@
+#
+#  Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+import os
+import sys
+from datetime import datetime
+import logging
+import tracemalloc
+from common.log_utils import get_project_base_directory
+
+# SIGUSR1 handler: start tracemalloc and take snapshot
+def start_tracemalloc_and_snapshot(signum, frame):
+    if not tracemalloc.is_tracing():
+        logging.info("start tracemalloc")
+        tracemalloc.start()
+    else:
+        logging.info("tracemalloc is already running")
+
+    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+    snapshot_file = f"snapshot_{timestamp}.trace"
+    snapshot_file = os.path.abspath(os.path.join(get_project_base_directory(), "logs", f"{os.getpid()}_snapshot_{timestamp}.trace"))
+
+    snapshot = tracemalloc.take_snapshot()
+    snapshot.dump(snapshot_file)
+    current, peak = tracemalloc.get_traced_memory()
+    if sys.platform == "win32":
+        import  psutil
+        process = psutil.Process()
+        max_rss = process.memory_info().rss / 1024
+    else:
+        import resource
+        max_rss = resource.getrusage(resource.RUSAGE_SELF).ru_maxrss
+    logging.info(f"taken snapshot {snapshot_file}. max RSS={max_rss / 1000:.2f} MB, current memory usage: {current / 10**6:.2f} MB, Peak memory usage: {peak / 10**6:.2f} MB")
+
+
+# SIGUSR2 handler: stop tracemalloc
+def stop_tracemalloc(signum, frame):
+    if tracemalloc.is_tracing():
+        logging.info("stop tracemalloc")
+        tracemalloc.stop()
+    else:
+        logging.info("tracemalloc not running")