PetrelBackend¶
- class mmengine.fileio.PetrelBackend(path_mapping=None, enable_mc=True)[source]¶
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.
- Parameters
Examples
>>> 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)[source]¶
Create a symbolic link pointing to src named dst.
Directly copy src to dst because PetrelBacekend does not support create a symbolic link.
- Parameters
- Returns
Return False because PetrelBackend does not support create a symbolic link.
- Return type
Examples
>>> 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)[source]¶
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.
- Parameters
- Returns
The destination file.
- Return type
- Raises
SameFileError – If src and dst are the same file, a SameFileError will be raised.
Examples
>>> 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)[source]¶
Upload a local file src to dst and return the destination file.
- Parameters
- Returns
If dst specifies a directory, the file will be copied into dst using the base filename from src.
- Return type
Examples
>>> 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)[source]¶
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.
- Parameters
- Returns
If dst specifies a directory, the file will be copied into dst using the base filename from src.
- Return type
Examples
>>> 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)[source]¶
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.
- Parameters
- Returns
The destination directory.
- Return type
- Raises
FileExistsError – If dst had already existed, a FileExistsError will be raised.
Examples
>>> 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)[source]¶
Recursively copy an entire directory tree rooted at src to a directory named dst and return the destination directory.
- Parameters
- Returns
The destination directory.
- Return type
- Raises
FileExistsError – If dst had already existed, a FileExistsError will be raised.
Examples
>>> 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)[source]¶
Recursively copy an entire directory tree rooted at src to a local directory named dst and return the destination directory.
- Parameters
- Returns
The destination directory.
- Return type
Examples
>>> backend = PetrelBackend() >>> src = 'petrel://path/of/dir' >>> dst = 'path/of/your/dir' >>> backend.copytree_to_local(src, dst) 'path/of/your/dir'
- exists(filepath)[source]¶
Check whether a file path exists.
- Parameters
filepath (str or Path) – Path to be checked whether exists.
- Returns
Return
True
iffilepath
exists,False
otherwise.- Return type
Examples
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.exists(filepath) True
- generate_presigned_url(url, client_method='get_object', expires_in=3600)[source]¶
Generate the presigned url of video stream which can be passed to mmcv.VideoReader. Now only work on Petrel backend.
Note
Now only work on Petrel backend.
- get(filepath)[source]¶
Read bytes from a given
filepath
with ‘rb’ mode.- Parameters
filepath (str or Path) – Path to read data.
- Returns
Return bytes read from filepath.
- Return type
Examples
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.get(filepath) b'hello world'
- get_local_path(filepath)[source]¶
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.- Parameters
filepath (str or Path) – Download a file from
filepath
.- Yields
Iterable[str] – Only yield one temporary path.
- Return type
Generator[Union[str, pathlib.Path], None, None]
Examples
>>> 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')[source]¶
Read text from a given
filepath
with ‘r’ mode.- Parameters
- Returns
Expected text reading from
filepath
.- Return type
Examples
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.get_text(filepath) 'hello world'
- isdir(filepath)[source]¶
Check whether a file path is a directory.
- Parameters
filepath (str or Path) – Path to be checked whether it is a directory.
- Returns
Return
True
iffilepath
points to a directory,False
otherwise.- Return type
Examples
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/dir' >>> backend.isdir(filepath) True
- isfile(filepath)[source]¶
Check whether a file path is a file.
- Parameters
filepath (str or Path) – Path to be checked whether it is a file.
- Returns
Return
True
iffilepath
points to a file,False
otherwise.- Return type
Examples
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.isfile(filepath) True
- join_path(filepath, *filepaths)[source]¶
Concatenate all file paths.
Join one or more filepath components intelligently. The return value is the concatenation of filepath and any members of *filepaths.
- Parameters
filepath (str or Path) – Path to be concatenated.
filepaths (Union[str, pathlib.Path]) –
- Returns
The result after concatenation.
- Return type
Examples
>>> 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)[source]¶
Scan a directory to find the interested directories or files in arbitrary order.
Note
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.
Note
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.- Parameters
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.
- Yields
Iterable[str] – A relative path to
dir_path
.- Return type
Iterator[str]
Examples
>>> 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)[source]¶
Write bytes to a given
filepath
.- Parameters
- Return type
Examples
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.put(b'hello world', filepath)
- put_text(obj, filepath, encoding='utf-8')[source]¶
Write text to a given
filepath
.- Parameters
- Return type
Examples
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.put_text('hello world', filepath)
- remove(filepath)[source]¶
Remove a file.
- Parameters
filepath (str or Path) – Path to be removed.
- Raises
FileNotFoundError – If filepath does not exist, an FileNotFoundError will be raised.
IsADirectoryError – If filepath is a directory, an IsADirectoryError will be raised.
- Return type
Examples
>>> backend = PetrelBackend() >>> filepath = 'petrel://path/of/file' >>> backend.remove(filepath)