Reflink(Copy On Write)支持 (#39)

* nothing

* >W<

* 形参类型

* (×﹏×)

* copy_file_range_supported

* with open

* Simpler cpcow

* config

* up

README.md

@@ -105,6 +105,12 @@ mcd_root/
 
 是否在备份时临时关闭自动保存
 
+### copy_on_write
+
+默认值: `false`
+
+使用某些文件系统的写时拷贝(一种增量备份)
+
 ### ignored_files
 
 默认值:

README_en.md

@@ -105,6 +105,12 @@ Default: `true`
 
 If turn off auto save when making backup or not
 
+### copy_on_write
+
+Default: `false`
+
+Useing copy_on_write in some File system(incremental backup)
+
 ### ignored_files
 
 If ignore file `session.lock` during backup, which can

quick_backup_multi/__init__.py

@@ -76,6 +76,30 @@ def get_backup_file_name(backup_format: BackupFormat):
 		raise ValueError('unknown backup mode {}'.format(backup_format))
 
 
+copy_file_range_supported=hasattr(os, "copy_file_range")
+COW_COPY_BUFFER_SIZE = 2**30  # 1GB / need int, may overflow, so cannot copy files larger than 2GB in a single pass
+
+#copy using "Copy On Write"
+def _cpcow(src_path: str, dst_path: str):
+	if not copy_file_range_supported or not config.copy_on_write:
+		return shutil.copy2(src_path, dst_path)
+
+	if os.path.isdir(dst_path):
+		dst_path = os.path.join(dst_path, os.path.basename(src_path))
+
+	try:
+		with open(src_path,'rb') as fsrc, open(dst_path,'wb+') as fdst:
+			while os.copy_file_range(fsrc.fileno(), fdst.fileno(), COW_COPY_BUFFER_SIZE):
+				pass
+
+	except Exception as e:
+		server_inst.logger.warning(str(e) + str(src_path) + "->" + str(dst_path) + ",Retry with other functions")
+		shutil.copy(src_path, dst_path)
+
+	shutil.copystat(src_path, dst_path)  # copy2 
+	return dst_path
+
+
 def copy_worlds(src: str, dst: str, intent: CopyWorldIntent, *, backup_format: Optional[BackupFormat] = None):
 	if backup_format is None:
 		backup_format = get_backup_format()
@@ -96,12 +120,12 @@ def copy_worlds(src: str, dst: str, intent: CopyWorldIntent, *, backup_format: O
 
 			server_inst.logger.info('copying {} -> {}'.format(src_path, dst_path))
 			if os.path.isdir(src_path):
-				shutil.copytree(src_path, dst_path, ignore=lambda path, files: set(filter(config.is_file_ignored, files)))
+				shutil.copytree(src_path, dst_path, ignore=lambda path, files: set(filter(config.is_file_ignored, files)), copy_function=_cpcow)
 			elif os.path.isfile(src_path):
 				dst_dir = os.path.dirname(dst_path)
 				if not os.path.isdir(dst_dir):
 					os.makedirs(dst_dir)
-				shutil.copy(src_path, dst_path)
+				_cpcow(src_path, dst_path)
 			else:
 				server_inst.logger.warning('{} does not exist while copying ({} -> {})'.format(src_path, src_path, dst_path))
 	elif backup_format == BackupFormat.tar or backup_format == BackupFormat.tar_gz:

quick_backup_multi/config.py

@@ -10,6 +10,7 @@ class SlotInfo(Serializable):
 class Configuration(Serializable):
 	size_display: bool = True
 	turn_off_auto_save: bool = True
+	copy_on_write: bool = False
 	ignored_files: List[str] = [
 		'session.lock'
 	]