PetrelBackend¶
- class mmengine.fileio.PetrelBackend(path_mapping=None, enable_mc=True, conf_path=None)[源代码]¶
Petrel storage backend (for internal usage).
PetrelBackend supports reading and writing data to multiple clusters. If the file path contains the cluster name, PetrelBackend will read data from specified cluster or write data to it. Otherwise, PetrelBackend will access the default cluster.
- 参数:
path_mapping (dict, optional) – Path mapping dict from local path to Petrel path. When
path_mapping={'src': 'dst'}
,src
infilepath
will be replaced bydst
. Defaults to None.enable_mc (bool, optional) – Whether to enable memcached support. Defaults to True.
conf_path (str, optional) – Config path of Petrel client. Default: None. New in version 0.3.3.
示例
>>> backend = PetrelBackend() >>> filepath1 = 'petrel://path/of/file' >>> filepath2 = 'cluster-name:petrel://path/of/file' >>> backend.get(filepath1) # get data from default cluster >>> client.get(filepath2) # get data from 'cluster-name' cluster
- copy_if_symlink_fails(src, dst)[源代码]¶
Create a symbolic link pointing to src named dst.
Directly copy src to dst because PetrelBacekend does not support create a symbolic link.
- 参数:
- 返回:
Return False because PetrelBackend does not support create a symbolic link.
- 返回类型:
示例
>>> backend = PetrelBackend() >>> src = 'petrel://path/of/file' >>> dst = 'petrel://path/of/your/file' >>> backend.copy_if_symlink_fails(src, dst) False >>> src = 'petrel://path/of/dir' >>> dst = 'petrel://path/of/your/dir' >>> backend.copy_if_symlink_fails(src, dst) False
- copyfile(src, dst)[源代码]¶
Copy a file src to dst and return the destination file.
src and dst should have the same prefix. If dst specifies a directory, the file will be copied into dst using the base filename from src. If dst specifies a file that already exists, it will be replaced.
- 参数:
- 返回:
The destination file.
- 返回类型:
- 抛出:
SameFileError – If src and dst are the same file, a SameFileError will be raised.
示例
>>> backend = PetrelBackend() >>> # dst is a file >>> src = 'petrel://path/of/file' >>> dst = 'petrel://path/of/file1' >>> backend.copyfile(src, dst) 'petrel://path/of/file1'
>>> # dst is a directory >>> dst = 'petrel://path/of/dir' >>> backend.copyfile(src, dst) 'petrel://path/of/dir/file'
- copyfile_from_local(src, dst)[源代码]¶
Upload a local file src to dst and return the destination file.
- 参数:
- 返回:
If dst specifies a directory, the file will be copied into dst using the base filename from src.
- 返回类型:
示例
>>> backend = PetrelBackend() >>> # dst is a file >>> src = 'path/of/your/file' >>> dst = 'petrel://path/of/file1' >>> backend.copyfile_from_local(src, dst) 'petrel://path/of/file1'
>>> # dst is a directory >>> dst = 'petrel://path/of/dir' >>> backend.copyfile_from_local(src, dst) 'petrel://path/of/dir/file'
- copyfile_to_local(src, dst)[源代码]¶
Copy the file src to local dst and return the destination file.
If dst specifies a directory, the file will be copied into dst using the base filename from src. If dst specifies a file that already exists, it will be replaced.
- 参数:
- 返回:
If dst specifies a directory, the file will be copied into dst using the base filename from src.
- 返回类型:
示例
>>> backend = PetrelBackend() >>> # dst is a file >>> src = 'petrel://path/of/file' >>> dst = 'path/of/your/file' >>> backend.copyfile_to_local(src, dst) 'path/of/your/file'
>>> # dst is a directory >>> dst = 'path/of/your/dir' >>> backend.copyfile_to_local(src, dst) 'path/of/your/dir/file'
- copytree(src, dst)[源代码]¶
Recursively copy an entire directory tree rooted at src to a directory named dst and return the destination directory.
src and dst should have the same prefix.
- 参数:
- 返回:
The destination directory.
- 返回类型:
- 抛出:
FileExistsError – If dst had already existed, a FileExistsError will be raised.
示例
>>> backend = PetrelBackend() >>> src = 'petrel://path/of/dir' >>> dst = 'petrel://path/of/dir1' >>> backend.copytree(src, dst) 'petrel://path/of/dir1'
- copytree_from_local(src, dst)[源代码]¶
Recursively copy an entire directory tree rooted at src to a directory named dst and return the destination directory.
- 参数:
- 返回:
The destination directory.
- 返回类型:
- 抛出:
FileExistsError – If dst had already existed, a FileExistsError will be raised.
示例
>>> backend = PetrelBackend() >>> src = 'path/of/your/dir' >>> dst = 'petrel://path/of/dir1' >>> backend.copytree_from_local(src, dst) 'petrel://path/of/dir1'
- copytree_to_local(src, dst)[源代码]¶
Recursively copy an entire directory tree rooted at src to a local directory named dst and return the destination directory.
- 参数:
- 返回:
The destination directory.
- 返回类型:
示例
>>> backend = PetrelBackend() >>> src = 'petrel://path/of/dir' >>> dst = 'path/of/your/dir' >>> backend.copytree_to_local(src, dst) 'path/of/your/dir'
- exists(filepath)[源代码]¶
Check whether a file path exists.
- 参数:
filepath (str or Path) – Path to be checked whether exists.
- 返回:
Return
True
iffilepath
exists,False
otherwise.- 返回类型:
示例
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.exists(filepath) True
- generate_presigned_url(url, client_method='get_object', expires_in=3600)[源代码]¶
Generate the presigned url of video stream which can be passed to mmcv.VideoReader. Now only work on Petrel backend.
备注
Now only work on Petrel backend.
- get(filepath)[源代码]¶
Read bytes from a given
filepath
with ‘rb’ mode.示例
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.get(filepath) b'hello world'
- get_local_path(filepath)[源代码]¶
Download a file from
filepath
to a local temporary directory, and return the temporary path.get_local_path
is decorated bycontxtlib.contextmanager()
. It can be called withwith
statement, and when exists from thewith
statement, the temporary path will be released.- 参数:
filepath (str or Path) – Download a file from
filepath
.- 生成器:
Iterable[str] – Only yield one temporary path.
- 返回类型:
示例
>>> backend = PetrelBackend() >>> # After existing from the ``with`` clause, >>> # the path will be removed >>> filepath = 'petrel://path/of/file' >>> with backend.get_local_path(filepath) as path: ... # do something here
- get_text(filepath, encoding='utf-8')[源代码]¶
Read text from a given
filepath
with ‘r’ mode.- 参数:
- 返回:
Expected text reading from
filepath
.- 返回类型:
示例
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.get_text(filepath) 'hello world'
- isdir(filepath)[源代码]¶
Check whether a file path is a directory.
- 参数:
filepath (str or Path) – Path to be checked whether it is a directory.
- 返回:
Return
True
iffilepath
points to a directory,False
otherwise.- 返回类型:
示例
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/dir' >>> backend.isdir(filepath) True
- isfile(filepath)[源代码]¶
Check whether a file path is a file.
- 参数:
filepath (str or Path) – Path to be checked whether it is a file.
- 返回:
Return
True
iffilepath
points to a file,False
otherwise.- 返回类型:
示例
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.isfile(filepath) True
- join_path(filepath, *filepaths)[源代码]¶
Concatenate all file paths.
Join one or more filepath components intelligently. The return value is the concatenation of filepath and any members of *filepaths.
- 参数:
- 返回:
The result after concatenation.
- 返回类型:
示例
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.join_path(filepath, 'another/path') 'petrel://path/of/file/another/path' >>> backend.join_path(filepath, '/another/path') 'petrel://path/of/file/another/path'
- list_dir_or_file(dir_path, list_dir=True, list_file=True, suffix=None, recursive=False)[源代码]¶
Scan a directory to find the interested directories or files in arbitrary order.
备注
Petrel has no concept of directories but it simulates the directory hierarchy in the filesystem through public prefixes. In addition, if the returned path ends with ‘/’, it means the path is a public prefix which is a logical directory.
备注
list_dir_or_file()
returns the path relative todir_path
. In addition, the returned path of directory will not contains the suffix ‘/’ which is consistent with other backends.- 参数:
dir_path (str | Path) – Path of the directory.
list_dir (bool) – List the directories. Defaults to True.
list_file (bool) – List the path of files. Defaults to True.
suffix (str or tuple[str], optional) – File suffix that we are interested in. Defaults to None.
recursive (bool) – If set to True, recursively scan the directory. Defaults to False.
- 生成器:
Iterable[str] – A relative path to
dir_path
.- 返回类型:
示例
>>> backend = PetrelBackend() >>> dir_path = 'petrel://path/of/dir' >>> # list those files and directories in current directory >>> for file_path in backend.list_dir_or_file(dir_path): ... print(file_path) >>> # only list files >>> for file_path in backend.list_dir_or_file(dir_path, list_dir=False): ... print(file_path) >>> # only list directories >>> for file_path in backend.list_dir_or_file(dir_path, list_file=False): ... print(file_path) >>> # only list files ending with specified suffixes >>> for file_path in backend.list_dir_or_file(dir_path, suffix='.txt'): ... print(file_path) >>> # list all files and directory recursively >>> for file_path in backend.list_dir_or_file(dir_path, recursive=True): ... print(file_path)
- put(obj, filepath)[源代码]¶
Write bytes to a given
filepath
.示例
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.put(b'hello world', filepath)
- put_text(obj, filepath, encoding='utf-8')[源代码]¶
Write text to a given
filepath
.- 参数:
- 返回类型:
None
示例
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.put_text('hello world', filepath)
- remove(filepath)[源代码]¶
Remove a file.
- 参数:
filepath (str or Path) – Path to be removed.
- 抛出:
FileNotFoundError – If filepath does not exist, an FileNotFoundError will be raised.
IsADirectoryError – If filepath is a directory, an IsADirectoryError will be raised.
- 返回类型:
None
示例
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.remove(filepath)