diff options
Diffstat (limited to 'r_basicsr/utils/file_client.py')
| -rw-r--r-- | r_basicsr/utils/file_client.py | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/r_basicsr/utils/file_client.py b/r_basicsr/utils/file_client.py new file mode 100644 index 0000000..8f6340e --- /dev/null +++ b/r_basicsr/utils/file_client.py @@ -0,0 +1,167 @@ +# Modified from https://github.com/open-mmlab/mmcv/blob/master/mmcv/fileio/file_client.py # noqa: E501
+from abc import ABCMeta, abstractmethod
+
+
+class BaseStorageBackend(metaclass=ABCMeta):
+ """Abstract class of storage backends.
+
+ All backends need to implement two apis: ``get()`` and ``get_text()``.
+ ``get()`` reads the file as a byte stream and ``get_text()`` reads the file
+ as texts.
+ """
+
+ @abstractmethod
+ def get(self, filepath):
+ pass
+
+ @abstractmethod
+ def get_text(self, filepath):
+ pass
+
+
+class MemcachedBackend(BaseStorageBackend):
+ """Memcached storage backend.
+
+ Attributes:
+ server_list_cfg (str): Config file for memcached server list.
+ client_cfg (str): Config file for memcached client.
+ sys_path (str | None): Additional path to be appended to `sys.path`.
+ Default: None.
+ """
+
+ def __init__(self, server_list_cfg, client_cfg, sys_path=None):
+ if sys_path is not None:
+ import sys
+ sys.path.append(sys_path)
+ try:
+ import mc
+ except ImportError:
+ raise ImportError('Please install memcached to enable MemcachedBackend.')
+
+ self.server_list_cfg = server_list_cfg
+ self.client_cfg = client_cfg
+ self._client = mc.MemcachedClient.GetInstance(self.server_list_cfg, self.client_cfg)
+ # mc.pyvector servers as a point which points to a memory cache
+ self._mc_buffer = mc.pyvector()
+
+ def get(self, filepath):
+ filepath = str(filepath)
+ import mc
+ self._client.Get(filepath, self._mc_buffer)
+ value_buf = mc.ConvertBuffer(self._mc_buffer)
+ return value_buf
+
+ def get_text(self, filepath):
+ raise NotImplementedError
+
+
+class HardDiskBackend(BaseStorageBackend):
+ """Raw hard disks storage backend."""
+
+ def get(self, filepath):
+ filepath = str(filepath)
+ with open(filepath, 'rb') as f:
+ value_buf = f.read()
+ return value_buf
+
+ def get_text(self, filepath):
+ filepath = str(filepath)
+ with open(filepath, 'r') as f:
+ value_buf = f.read()
+ return value_buf
+
+
+class LmdbBackend(BaseStorageBackend):
+ """Lmdb storage backend.
+
+ Args:
+ db_paths (str | list[str]): Lmdb database paths.
+ client_keys (str | list[str]): Lmdb client keys. Default: 'default'.
+ readonly (bool, optional): Lmdb environment parameter. If True,
+ disallow any write operations. Default: True.
+ lock (bool, optional): Lmdb environment parameter. If False, when
+ concurrent access occurs, do not lock the database. Default: False.
+ readahead (bool, optional): Lmdb environment parameter. If False,
+ disable the OS filesystem readahead mechanism, which may improve
+ random read performance when a database is larger than RAM.
+ Default: False.
+
+ Attributes:
+ db_paths (list): Lmdb database path.
+ _client (list): A list of several lmdb envs.
+ """
+
+ def __init__(self, db_paths, client_keys='default', readonly=True, lock=False, readahead=False, **kwargs):
+ try:
+ import lmdb
+ except ImportError:
+ raise ImportError('Please install lmdb to enable LmdbBackend.')
+
+ if isinstance(client_keys, str):
+ client_keys = [client_keys]
+
+ if isinstance(db_paths, list):
+ self.db_paths = [str(v) for v in db_paths]
+ elif isinstance(db_paths, str):
+ self.db_paths = [str(db_paths)]
+ assert len(client_keys) == len(self.db_paths), ('client_keys and db_paths should have the same length, '
+ f'but received {len(client_keys)} and {len(self.db_paths)}.')
+
+ self._client = {}
+ for client, path in zip(client_keys, self.db_paths):
+ self._client[client] = lmdb.open(path, readonly=readonly, lock=lock, readahead=readahead, **kwargs)
+
+ def get(self, filepath, client_key):
+ """Get values according to the filepath from one lmdb named client_key.
+
+ Args:
+ filepath (str | obj:`Path`): Here, filepath is the lmdb key.
+ client_key (str): Used for distinguishing different lmdb envs.
+ """
+ filepath = str(filepath)
+ assert client_key in self._client, (f'client_key {client_key} is not in lmdb clients.')
+ client = self._client[client_key]
+ with client.begin(write=False) as txn:
+ value_buf = txn.get(filepath.encode('ascii'))
+ return value_buf
+
+ def get_text(self, filepath):
+ raise NotImplementedError
+
+
+class FileClient(object):
+ """A general file client to access files in different backend.
+
+ The client loads a file or text in a specified backend from its path
+ and return it as a binary file. it can also register other backend
+ accessor with a given name and backend class.
+
+ Attributes:
+ backend (str): The storage backend type. Options are "disk",
+ "memcached" and "lmdb".
+ client (:obj:`BaseStorageBackend`): The backend object.
+ """
+
+ _backends = {
+ 'disk': HardDiskBackend,
+ 'memcached': MemcachedBackend,
+ 'lmdb': LmdbBackend,
+ }
+
+ def __init__(self, backend='disk', **kwargs):
+ if backend not in self._backends:
+ raise ValueError(f'Backend {backend} is not supported. Currently supported ones'
+ f' are {list(self._backends.keys())}')
+ self.backend = backend
+ self.client = self._backends[backend](**kwargs)
+
+ def get(self, filepath, client_key='default'):
+ # client_key is used only for lmdb, where different fileclients have
+ # different lmdb environments.
+ if self.backend == 'lmdb':
+ return self.client.get(filepath, client_key)
+ else:
+ return self.client.get(filepath)
+
+ def get_text(self, filepath):
+ return self.client.get_text(filepath)
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