Source code for canlib.kvmlib.kmf

import ctypes as ct
from collections import namedtuple

from ..versionnumber import VersionNumber
from .enums import Device
from .log import MountedLog
from .wrapper import dll

[docs]def openKmf(path, device_type=Device.MHYDRA_EXT): """Open a kmf file from disk Arguments: path (`str`): The filepath to the .KMF file (e.g. ``"data/kmf/LOG00000.KMF"``). device_type (`.Device`): The type of the memorator that created the .KMF file(s) (defaults to `.Device.MHYDRA_EXT`) Returns: `Kmf` .. versionadded:: 1.6 """ filename = ct.create_string_buffer(path.encode('utf8')) status = ct.c_int() major = ct.c_int() minor = ct.c_int() handle = dll.kvmKmfOpenEx( filename, ct.byref(status), device_type, ct.byref(major), ct.byref(minor) ) return Kmf(handle, VersionNumber(major.value, minor.value))
[docs]class KmfSystem: """The base class of `Kmf` and `Memorator` The `Kmf` and `Memorator` classes are very similar, they are different ways of reading log files (`LogFile`) created by a memorator. This class represents the common ground between all ways of accessing log files. All subclasses should have a `log` attribute which is an `UnmountedLog` or subclass thereof. This class automatically closes its internal handle when garbage collected. .. versionadded:: 1.6 """ DiskUsage = namedtuple('DiskUsage', 'used total') def __init__(self, handle): self.handle = handle def __enter__(self): return self def __exit__(self, exc_type, exc_value, traceback): self.close() def __del__(self): self.close() @property def disk_usage(self): """`namedtuple`: The disk usage Returns: `namedtuple`: containing - `used` (`int`): Used disk space in megabytes. - `total` (`int`): Total disk space in megabytes. """ total = ct.c_uint32() used = ct.c_uint32() dll.kvmKmfGetUsage(self.handle, ct.byref(total), ct.byref(used)) # convert to MB used = int(used.value * 512) / 10 ** 6 total = int(total.value * 512) / 10 ** 6 return self.DiskUsage(used=used, total=total)
[docs] def close(self): """Close the internal handle Warning: Closing invalidates the object. """ if self.handle is not None: dll.kvmClose(self.handle) self.handle = None
[docs]class Kmf(KmfSystem): """A kmf file opened with `openKmf` The main use of this class is using its `log` attribute, which is a `MountedLog` object (see its documentation for how to use it). Also see the base class `.KmfSystem` for inherited functionality. Attributes: log (`MountedLog`): Object representing the log of log files within the kmf container-file. .. versionadded:: 1.6 """ def __init__(self, handle, ldf_version): super().__init__(handle) self.log = MountedLog(self, ldf_version)