def can_open(cls, path, *args, **kwargs):
h5file = None
# before we try to open it with h5py, we check the signature (quicker)
try:
with s3.open(path, "rb") as f:
signature = f.read(4)
hdf5file = signature == b"\x89\x48\x44\x46"
except:
logger.exception("could not read 4 bytes from %r", path)
return
if hdf5file:
with s3.open(path, "rb") as f:
try:
h5file = h5py.File(f, "r")
except:
logger.exception("could not open file as hdf5")
return False
if h5file is not None:
with h5file:
root_datasets = [
dataset for name, dataset in h5file.items()
if isinstance(dataset, h5py.Dataset)
]
return ("data" in h5file) or ("columns" in h5file) or ("table" in h5file) or \
len(root_datasets) > 0
else:
logger.debug("file %s has no data or columns group" % path)
return False
def __init__(self, filename, write=False):
if isinstance(filename, six.string_types):
super(Hdf5MemoryMapped,
self).__init__(filename,
write=write,
nommap=filename.startswith('s3://'))
else:
super(Hdf5MemoryMapped, self).__init__(filename.name,
write=write,
nommap=True)
if hasattr(filename, 'read'):
fp = filename # support file handle for testing
self.file_map[self.filename] = fp
else:
mode = 'rb+' if write else 'rb'
if s3.is_s3_path(filename):
fp = s3.open(self.filename)
self.file_map[self.filename] = fp
else:
if self.nommap:
fp = open(self.filename, mode)
self.file_map[self.filename] = fp
else:
# this is the only path that will have regular mmapping
fp = self.filename
self.h5file = h5py.File(fp, "r+" if write else "r")
self.h5table_root_name = None
self._version = 1
self._load()
def _open(self, path):
if hasattr(path, 'read'):
fp = path # support file handle for testing
self.file_map[self.path] = fp
else:
mode = 'rb+' if self.write else 'rb'
if s3.is_s3_path(path):
fp = s3.open(self.path)
self.file_map[self.path] = fp
elif gcs.is_gs_path(path):
fp = gcs.open(self.path)
self.file_map[self.path] = fp
else:
if self.nommap:
fp = open(self.path, mode)
self.file_map[self.path] = fp
else:
# this is the only path that will have regular mmapping
fp = self.path
self.h5file = h5py.File(fp, "r+" if self.write else "r")