def _temporary_vfs(filenames_and_contents):
"""Creates a temporary VFS containing one or more files.
Args:
filenames_and_contents: A dict containing `{filename: contents}` pairs.
The length of each filename must not exceed 98 characters.
Yields:
A `types.MJVFS` instance.
Raises:
Error: If a file cannot be added to the VFS, or if an error occurs when
looking up the filename.
ValueError: If the length of a filename exceeds 98 characters.
"""
vfs = types.MJVFS()
mjlib.mj_defaultVFS(vfs)
for filename, contents in six.iteritems(filenames_and_contents):
if len(filename) > _MAX_VFS_FILENAME_CHARACTERS:
raise ValueError(
_VFS_FILENAME_TOO_LONG.format(
length=len(filename),
limit=_MAX_VFS_FILENAME_CHARACTERS,
filename=filename))
filename = util.to_binary_string(filename)
contents = util.to_binary_string(contents)
_, extension = os.path.splitext(filename)
# For XML files we need to append a NULL byte, otherwise MuJoCo's parser
# can sometimes read past the end of the string. However, we should *not*
# do this for other file types (in particular for STL meshes, where this
# causes MuJoCo's compiler to complain that the file size is incorrect).
append_null = extension.lower() == b".xml"
num_bytes = len(contents) + append_null
retcode = mjlib.mj_makeEmptyFileVFS(vfs, filename, num_bytes)
if retcode == 1:
raise Error("Failed to create {!r}: VFS is full.".format(filename))
elif retcode == 2:
raise Error(
"Failed to create {!r}: duplicate filename.".format(filename))
file_index = mjlib.mj_findFileVFS(vfs, filename)
if file_index == -1:
raise Error("Could not find {!r} in the VFS".format(filename))
vf = vfs.filedata[file_index]
vf_as_char_arr = ctypes.cast(vf,
ctypes.POINTER(ctypes.c_char * num_bytes))
vf_as_char_arr.contents[:len(contents)] = contents
if append_null:
vf_as_char_arr.contents[-1] = _NULL
try:
yield vfs
finally:
mjlib.mj_deleteVFS(vfs) # Ensure that we free the VFS afterwards.
def testFileNameTrimming(self):
original_filename = (
'THIS_IS_AN_EXTREMELY_LONG_FILENAME_THAT_WOULD_CAUSE_MUJOCO_TO_COMPLAIN'
'_THAT_ITS_INTERNAL_LENGTH_LIMIT_IS_EXCEEDED_IF_NOT_TRIMMED_DOWN')
extension = '.some_extension'
asset = attribute.Asset(
contents='', extension=extension, prefix=original_filename)
vfs_filename = asset.get_vfs_filename()
self.assertLen(vfs_filename, constants.MAX_VFS_FILENAME_LENGTH)
vfs = types.MJVFS()
mjlib.mj_defaultVFS(vfs)
success_code = 0
retval = mjlib.mj_makeEmptyFileVFS(
vfs, util.to_binary_string(vfs_filename), 1)
self.assertEqual(retval, success_code)
mjlib.mj_deleteVFS(vfs)
