260705_2

B03_FileInput/B03_FileInput_Engine.py

@@ -0,0 +1,60 @@
+"""B03 파일 입력 저장 엔진."""
+
+import os
+import tempfile
+from pathlib import Path
+
+from fastapi import UploadFile
+
+from B03_FileInput.B03_FileInput_Schema import FileUploadDescriptor
+from common_util.common_util_storage import get_project_stage_path
+from config.config_system import UPLOAD_CHUNK_SIZE_BYTES, UPLOAD_MAX_MB
+
+
+def resolve_upload_destination(
+    project_root: str | Path,
+    descriptor: FileUploadDescriptor,
+) -> Path:
+    """검증된 파일의 B03 입력 저장 경로를 생성해 반환한다."""
+    stage_root = Path(get_project_stage_path(str(project_root), "B03_FileInput")).resolve()
+    file_type = Path(descriptor.original_filename).suffix.lower().lstrip(".")
+    destination = (stage_root / "input" / file_type / descriptor.original_filename).resolve()
+
+    if os.path.commonpath((stage_root, destination)) != str(stage_root):
+        raise ValueError("업로드 저장 경로가 B03 단계 폴더를 벗어났습니다.")
+
+    destination.parent.mkdir(parents=True, exist_ok=True)
+    return destination
+
+
+async def save_upload_stream(upload: UploadFile, destination: Path) -> int:
+    """업로드 스트림을 크기 제한 내에서 임시 파일에 기록한 뒤 교체한다."""
+    maximum_bytes = UPLOAD_MAX_MB * 1024 * 1024
+    written_bytes = 0
+    temporary_path: Path | None = None
+
+    try:
+        with tempfile.NamedTemporaryFile(
+            mode="wb",
+            dir=destination.parent,
+            prefix=f".{destination.name}.",
+            suffix=".upload",
+            delete=False,
+        ) as temporary:
+            temporary_path = Path(temporary.name)
+            while chunk := await upload.read(UPLOAD_CHUNK_SIZE_BYTES):
+                written_bytes += len(chunk)
+                if written_bytes > maximum_bytes:
+                    raise ValueError(f"파일 크기는 {UPLOAD_MAX_MB}MB를 초과할 수 없습니다.")
+                temporary.write(chunk)
+            temporary.flush()
+            os.fsync(temporary.fileno())
+
+        if written_bytes == 0:
+            raise ValueError("빈 파일은 업로드할 수 없습니다.")
+        os.replace(temporary_path, destination)
+        temporary_path = None
+        return written_bytes
+    finally:
+        if temporary_path is not None:
+            temporary_path.unlink(missing_ok=True)