""" Pythonic wrapper for libusb-1.0. The first thing you must do is to get an "USB context". To do so, create an USBContext instance. Then, you can use it to browse available USB devices and open the one you want to talk to. At this point, you should have a USBDeviceHandle instance (as returned by USBContext or USBDevice instances), and you can start exchanging with the device. Features: - Basic device settings (configuration & interface selection, ...) - String descriptor lookups (ASCII & unicode), and list supported language codes - Synchronous I/O (control, bulk, interrupt) - Asynchronous I/O (control, bulk, interrupt, isochronous) Note: Isochronous support is not well tested. See USBPoller, USBTransfer and USBTransferHelper. """ import libusb1 from ctypes import byref, create_string_buffer, c_int, sizeof, POINTER, \ cast, c_uint16, c_ubyte, string_at, c_void_p, cdll import sys import threading from ctypes.util import find_library import warnings import weakref import collections try: namedtuple = collections.namedtuple except AttributeError: Version = lambda *x: x else: Version = namedtuple('Version', ['major', 'minor', 'micro', 'nano', 'rc', 'describe']) if sys.version_info[0] == 3: BYTE = bytes([0]) xrange = range long = int else: BYTE = '\x00' CONTROL_SETUP = BYTE * libusb1.LIBUSB_CONTROL_SETUP_SIZE __all__ = ['USBContext', 'USBDeviceHandle', 'USBDevice', 'USBPoller', 'USBTransfer', 'USBTransferHelper', 'EVENT_CALLBACK_SET', 'USBPollerThread', 'USBEndpoint', 'USBInterfaceSetting', 'USBInterface', 'USBConfiguration', 'DoomedTransferError', 'getVersion', ] if sys.version_info[:2] >= (2, 6): if sys.platform == 'win32': from ctypes import get_last_error as get_errno else: from ctypes import get_errno else: def get_errno(): raise NotImplementedError("Your python version doesn't support " "errno/last_error") __libc_name = find_library('c') if __libc_name is None: # Of course, will leak memory. # Should we warn user ? How ? _free = lambda x: None else: _free = getattr(cdll, __libc_name).free del __libc_name try: WeakSet = weakref.WeakSet except AttributeError: # Python < 2.7: tiny wrapper around WeakKeyDictionary class WeakSet(object): def __init__(self): self.__dict = weakref.WeakKeyDictionary() def add(self, item): self.__dict[item] = None def pop(self): return self.__dict.popitem()[0] # Default string length # From a comment in libusb-1.0: "Some devices choke on size > 255" STRING_LENGTH = 255 EVENT_CALLBACK_SET = frozenset(( libusb1.LIBUSB_TRANSFER_COMPLETED, libusb1.LIBUSB_TRANSFER_ERROR, libusb1.LIBUSB_TRANSFER_TIMED_OUT, libusb1.LIBUSB_TRANSFER_CANCELLED, libusb1.LIBUSB_TRANSFER_STALL, libusb1.LIBUSB_TRANSFER_NO_DEVICE, libusb1.LIBUSB_TRANSFER_OVERFLOW, )) DEFAULT_ASYNC_TRANSFER_ERROR_CALLBACK = lambda x: False def create_binary_buffer(string_or_len): # Prevent ctypes from adding a trailing null char. if isinstance(string_or_len, (int, long)): result = create_string_buffer(string_or_len) else: result = create_string_buffer(string_or_len, len(string_or_len)) return result class DoomedTransferError(Exception): """Exception raised when altering/submitting a doomed transfer.""" pass class USBTransfer(object): """ USB asynchronous transfer control & data. All modification methods will raise if called on a submitted transfer. Methods noted as "should not be called on a submitted transfer" will not prevent you from reading, but returned value is unspecified. Note on user_data: because of pypy's current ctype restrictions, user_data is not provided to C level, but is managed purely in python. It should change nothing for you, unless you are looking at underlying C transfer structure - which you should never have to. """ # Prevent garbage collector from freeing the free function before our # instances, as we need it to property destruct them. __libusb_free_transfer = libusb1.libusb_free_transfer __libusb_cancel_transfer = libusb1.libusb_cancel_transfer __USBError = libusb1.USBError __LIBUSB_ERROR_NOT_FOUND = libusb1.LIBUSB_ERROR_NOT_FOUND __transfer = None __initialized = False __submitted = False __callback = None __ctypesCallbackWrapper = None __doomed = False __user_data = None __transfer_buffer = None def __init__(self, handle, iso_packets, before_submit, after_completion): """ You should not instanciate this class directly. Call "getTransfer" method on an USBDeviceHandle instance to get instances of this class. """ if iso_packets < 0: raise ValueError('Cannot request a negative number of iso ' 'packets.') self.__handle = handle self.__before_submit = before_submit self.__after_completion = after_completion self.__num_iso_packets = iso_packets result = libusb1.libusb_alloc_transfer(iso_packets) if not result: raise libusb1.USBError('Unable to get a transfer object') self.__transfer = result self.__ctypesCallbackWrapper = libusb1.libusb_transfer_cb_fn_p( self.__callbackWrapper) def close(self): """ Break reference cycles to allow instance to be garbage-collected. Raises if called on a submitted transfer. """ if self.__submitted: raise ValueError('Cannot close a submitted transfer') self.doom() self.__initialized = False # Break possible external reference cycle self.__callback = None # Break libusb_transfer reference cycles self.__ctypesCallbackWrapper = None # For some reason, overwriting callback is not enough to remove this # reference cycle - though sometimes it works: # self -> self.__dict__ -> libusb_transfer -> dict[x] -> dict[x] -> # CThunkObject -> __callbackWrapper -> self # So free transfer altogether. if self.__transfer is not None: self.__libusb_free_transfer(self.__transfer) self.__transfer = None # Break USBDeviceHandle reference cycle self.__before_submit = None self.__after_completion = None def doom(self): """ Prevent transfer from being submitted again. """ self.__doomed = True def __del__(self): if self.__transfer is not None: try: # If this doesn't raise, we're doomed; transfer was submitted, # still python decided to garbage-collect this instance. # Stick to libusb's documentation, and don't free the # transfer. If interpreter is shutting down, kernel will # reclaim memory anyway. # Note: we can't prevent transfer's buffer from being # garbage-collected as soon as there will be no remaining # reference to transfer, so a segfault might happen anyway. # Should we warn user ? How ? self.cancel() except self.__USBError: if sys.exc_info()[1].value == self.__LIBUSB_ERROR_NOT_FOUND: # Transfer was not submitted, we can free it. self.__libusb_free_transfer(self.__transfer) else: raise def __callbackWrapper(self, transfer_p): """ Makes it possible for user-provided callback to alter transfer when fired (ie, mark transfer as not submitted upon call). """ self.__submitted = False self.__after_completion(self) callback = self.__callback if callback is not None: callback(self) if self.__doomed: self.close() def setCallback(self, callback): """ Change transfer's callback. """ self.__callback = callback def getCallback(self): """ Get currently set callback. """ return self.__callback def setControl(self, request_type, request, value, index, buffer_or_len, callback=None, user_data=None, timeout=0): """ Setup transfer for control use. request_type, request, value, index See USBDeviceHandle.controlWrite. request_type defines transfer direction (see libusb1.LIBUSB_ENDPOINT_OUT and libusb1.LIBUSB_ENDPOINT_IN)). buffer_or_len Either a string (when sending data), or expected data length (when receiving data). callback Callback function to be invoked on transfer completion. Called with transfer as parameter, return value ignored. user_data User data to pass to callback function. timeout Transfer timeout in milliseconds. 0 to disable. """ if self.__submitted: raise ValueError('Cannot alter a submitted transfer') if self.__doomed: raise DoomedTransferError('Cannot reuse a doomed transfer') if isinstance(buffer_or_len, (int, long)): length = buffer_or_len string_buffer = create_binary_buffer(length + \ libusb1.LIBUSB_CONTROL_SETUP_SIZE) else: length = len(buffer_or_len) string_buffer = create_binary_buffer(CONTROL_SETUP + buffer_or_len) self.__initialized = False self.__transfer_buffer = string_buffer self.__user_data = user_data libusb1.libusb_fill_control_setup(string_buffer, request_type, request, value, index, length) libusb1.libusb_fill_control_transfer(self.__transfer, self.__handle, string_buffer, self.__ctypesCallbackWrapper, None, timeout) self.__callback = callback self.__initialized = True def setBulk(self, endpoint, buffer_or_len, callback=None, user_data=None, timeout=0): """ Setup transfer for bulk use. endpoint Endpoint to submit transfer to. Defines transfer direction (see libusb1.LIBUSB_ENDPOINT_OUT and libusb1.LIBUSB_ENDPOINT_IN)). buffer_or_len Either a string (when sending data), or expected data length (when receiving data) callback Callback function to be invoked on transfer completion. Called with transfer as parameter, return value ignored. user_data User data to pass to callback function. timeout Transfer timeout in milliseconds. 0 to disable. """ if self.__submitted: raise ValueError('Cannot alter a submitted transfer') if self.__doomed: raise DoomedTransferError('Cannot reuse a doomed transfer') string_buffer = create_binary_buffer(buffer_or_len) self.__initialized = False self.__transfer_buffer = string_buffer self.__user_data = user_data libusb1.libusb_fill_bulk_transfer(self.__transfer, self.__handle, endpoint, string_buffer, sizeof(string_buffer), self.__ctypesCallbackWrapper, None, timeout) self.__callback = callback self.__initialized = True def setInterrupt(self, endpoint, buffer_or_len, callback=None, user_data=None, timeout=0): """ Setup transfer for interrupt use. endpoint Endpoint to submit transfer to. Defines transfer direction (see libusb1.LIBUSB_ENDPOINT_OUT and libusb1.LIBUSB_ENDPOINT_IN)). buffer_or_len Either a string (when sending data), or expected data length (when receiving data) callback Callback function to be invoked on transfer completion. Called with transfer as parameter, return value ignored. user_data User data to pass to callback function. timeout Transfer timeout in milliseconds. 0 to disable. """ if self.__submitted: raise ValueError('Cannot alter a submitted transfer') if self.__doomed: raise DoomedTransferError('Cannot reuse a doomed transfer') string_buffer = create_binary_buffer(buffer_or_len) self.__initialized = False self.__transfer_buffer = string_buffer self.__user_data = user_data libusb1.libusb_fill_interrupt_transfer(self.__transfer, self.__handle, endpoint, string_buffer, sizeof(string_buffer), self.__ctypesCallbackWrapper, None, timeout) self.__callback = callback self.__initialized = True def setIsochronous(self, endpoint, buffer_or_len, callback=None, user_data=None, timeout=0, iso_transfer_length_list=None): """ Setup transfer for isochronous use. endpoint Endpoint to submit transfer to. Defines transfer direction (see libusb1.LIBUSB_ENDPOINT_OUT and libusb1.LIBUSB_ENDPOINT_IN)). buffer_or_len Either a string (when sending data), or expected data length (when receiving data) callback Callback function to be invoked on transfer completion. Called with transfer as parameter, return value ignored. user_data User data to pass to callback function. timeout Transfer timeout in milliseconds. 0 to disable. iso_transfer_length_list List of individual transfer sizes. If not provided, buffer_or_len will be divided evenly among available transfers if possible, and raise ValueError otherwise. """ if self.__submitted: raise ValueError('Cannot alter a submitted transfer') num_iso_packets = self.__num_iso_packets if num_iso_packets == 0: raise TypeError('This transfer canot be used for isochronous I/O. ' 'You must get another one with a non-zero iso_packets ' 'parameter.') if self.__doomed: raise DoomedTransferError('Cannot reuse a doomed transfer') string_buffer = create_binary_buffer(buffer_or_len) buffer_length = sizeof(string_buffer) if iso_transfer_length_list is None: iso_length, remainder = divmod(buffer_length, num_iso_packets) if remainder: raise ValueError('Buffer size %i cannot be evenly ' 'distributed among %i transfers' % (buffer_length, num_iso_packets)) iso_transfer_length_list = [iso_length] * num_iso_packets configured_iso_packets = len(iso_transfer_length_list) if configured_iso_packets > num_iso_packets: raise ValueError('Too many ISO transfer lengths (%i), there are ' 'only %i ISO transfers available' % (configured_iso_packets, num_iso_packets)) if sum(iso_transfer_length_list) > buffer_length: raise ValueError('ISO transfers too long (%i), there are only ' '%i bytes available' % (sum(iso_transfer_length_list), buffer_length)) transfer_p = self.__transfer self.__initialized = False self.__transfer_buffer = string_buffer self.__user_data = user_data libusb1.libusb_fill_iso_transfer(transfer_p, self.__handle, endpoint, string_buffer, buffer_length, configured_iso_packets, self.__ctypesCallbackWrapper, None, timeout) for length, iso_packet_desc in zip(iso_transfer_length_list, libusb1.get_iso_packet_list(transfer_p)): if length <= 0: raise ValueError('Negative/null length transfers are not ' 'possible.') iso_packet_desc.length = length self.__callback = callback self.__initialized = True def getType(self): """ Get transfer type. See libusb1.libusb_transfer_type. """ return self.__transfer.contents.type def getEndpoint(self): """ Get endpoint. """ return self.__transfer.contents.endpoint def getStatus(self): """ Get transfer status. Should not be called on a submitted transfer. """ return self.__transfer.contents.status def getActualLength(self): """ Get actually transfered data length. Should not be called on a submitted transfer. """ return self.__transfer.contents.actual_length def getBuffer(self): """ Get data buffer content. Should not be called on a submitted transfer. """ transfer_p = self.__transfer transfer = transfer_p.contents if transfer.type == libusb1.LIBUSB_TRANSFER_TYPE_CONTROL: result = libusb1.libusb_control_transfer_get_data(transfer_p) else: result = string_at(transfer.buffer, transfer.length) return result def getUserData(self): """ Retrieve user data provided on setup. """ return self.__user_data def setUserData(self, user_data): """ Change user data. """ self.__user_data = user_data def getISOBufferList(self): """ Get individual ISO transfer's buffer. Returns a list with one item per ISO transfer, with their individually-configured sizes. Returned list is consistent with getISOSetupList return value. Should not be called on a submitted transfer. """ transfer_p = self.__transfer transfer = transfer_p.contents if transfer.type != libusb1.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS: raise TypeError('This method cannot be called on non-iso ' 'transfers.') return libusb1.get_iso_packet_buffer_list(transfer_p) def getISOSetupList(self): """ Get individual ISO transfer's setup. Returns a list of dicts, each containing an individual ISO transfer parameters: - length - actual_length - status (see libusb1's API documentation for their signification) Returned list is consistent with getISOBufferList return value. Should not be called on a submitted transfer (except for 'length' values). """ transfer_p = self.__transfer transfer = transfer_p.contents if transfer.type != libusb1.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS: raise TypeError('This method cannot be called on non-iso ' 'transfers.') return [{ 'length': x.length, 'actual_length': x.actual_length, 'status': x.status, } for x in libusb1.get_iso_packet_list(transfer_p)] def setBuffer(self, buffer_or_len): """ Replace buffer with a new one. Allows resizing read buffer and replacing data sent. Note: resizing is not allowed for isochronous buffer (use setIsochronous). Note: disallowed on control transfers (use setControl). """ if self.__submitted: raise ValueError('Cannot alter a submitted transfer') transfer = self.__transfer.contents if transfer.type == libusb1.LIBUSB_TRANSFER_TYPE_CONTROL: raise ValueError('To alter control transfer buffer, use ' 'setControl') buff = create_binary_buffer(buffer_or_len) if transfer.type == libusb1.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS and \ sizeof(buff) != transfer.length: raise ValueError('To alter isochronous transfer buffer length, ' 'use setIsochronous') self.__transfer_buffer = buff transfer.buffer = cast(buff, c_void_p) transfer.length = sizeof(buff) def isSubmitted(self): """ Tells if this transfer is submitted and still pending. """ return self.__submitted def submit(self): """ Submit transfer for asynchronous handling. """ if self.__submitted: raise ValueError('Cannot submit a submitted transfer') if not self.__initialized: raise ValueError('Cannot submit a transfer until it has been ' 'initialized') if self.__doomed: raise DoomedTransferError('Cannot submit doomed transfer') self.__before_submit(self) self.__submitted = True result = libusb1.libusb_submit_transfer(self.__transfer) if result: self.__after_completion(self) self.__submitted = False raise libusb1.USBError(result) def cancel(self): """ Cancel transfer. Note: cancellation happens asynchronously, so you must wait for LIBUSB_TRANSFER_CANCELLED. """ if not self.__submitted: # XXX: Workaround for a bug reported on libusb 1.0.8: calling # libusb_cancel_transfer on a non-submitted transfer might # trigger a segfault. raise self.__USBError(self.__LIBUSB_ERROR_NOT_FOUND) result = self.__libusb_cancel_transfer(self.__transfer) if result: raise self.__USBError(result) class USBTransferHelper(object): """ Simplifies subscribing to the same transfer over and over, and callback handling: - no need to read event status to execute apropriate code, just setup different functions for each status code - just return True instead of calling submit - no need to check if transfer is doomed before submitting it again, DoomedTransferError is caught. Callbacks used in this class must follow the callback API described in USBTransfer, and are expected to return a boolean: - True if transfer is to be submitted again (to receive/send more data) - False otherwise Note: as per libusb1 specifications, isochronous transfer global state might be LIBUSB_TRANSFER_COMPLETED although some individual packets might have an error status. You can check individual packet status by calling getISOSetupList on transfer object in your callback. """ def __init__(self, transfer=None): """ Create a transfer callback dispatcher. transfer parameter is deprecated. If provided, it will be equivalent to: helper = USBTransferHelper() transfer.setCallback(helper) and also allows using deprecated methods on this class (otherwise, they raise AttributeError). """ if transfer is not None: # Deprecated: to drop self.__transfer = transfer transfer.setCallback(self) self.__event_callback_dict = {} self.__errorCallback = DEFAULT_ASYNC_TRANSFER_ERROR_CALLBACK def submit(self): """ Submit the asynchronous read request. Deprecated. Use submit on transfer. """ # Deprecated: to drop self.__transfer.submit() def cancel(self): """ Cancel a pending read request. Deprecated. Use cancel on transfer. """ # Deprecated: to drop self.__transfer.cancel() def setEventCallback(self, event, callback): """ Set a function to call for a given event. Possible event identifiers are listed in EVENT_CALLBACK_SET. """ if event not in EVENT_CALLBACK_SET: raise ValueError('Unknown event %r.' % (event, )) self.__event_callback_dict[event] = callback def setDefaultCallback(self, callback): """ Set the function to call for event which don't have a specific callback registered. The initial default callback does nothing and returns False. """ self.__errorCallback = callback def getEventCallback(self, event, default=None): """ Return the function registered to be called for given event identifier. """ return self.__event_callback_dict.get(event, default) def __call__(self, transfer): """ Callback to set on transfers. """ if self.getEventCallback(transfer.getStatus(), self.__errorCallback)( transfer): try: transfer.submit() except DoomedTransferError: pass def isSubmited(self): """ Returns whether this reader is currently waiting for an event. Deprecatd. Use isSubmitted on transfer. """ # Deprecated: to drop return self.__transfer.isSubmitted() class USBPollerThread(threading.Thread): """ Implements libusb1 documentation about threaded, asynchronous applications. In short, instanciate this class once (...per LibUSBContext instance), call start() on the instance, and do whatever you need. This thread will be used to execute transfer completion callbacks, and you are free to use libusb1's synchronous API in another thread, and can forget about libusb1 file descriptors. See http://libusb.sourceforge.net/api-1.0/mtasync.html . """ def __init__(self, context, poller, exc_callback=None): """ Create a poller thread for given context. Warning: it will not check if another poller instance was already present for that context, and will replace it. poller (same as USBPoller.__init__ "poller" parameter) exc_callback (callable) Called with a libusb_error value as single parameter when event handling fails. If not given, an USBError will be raised, interrupting the thread. """ super(USBPollerThread, self).__init__() self.daemon = True self.__context = context self.__poller = poller self.__fd_set = set() context.setPollFDNotifiers(self._registerFD, self._unregisterFD) for fd, events in context.getPollFDList(): self._registerFD(fd, events, None) if exc_callback is not None: self.exceptionHandler = exc_callback def __del__(self): self.__context.setPollFDNotifiers(None, None) @staticmethod def exceptionHandler(exc): raise exc def run(self): # We expect quite some spinning in below loop, so move any unneeded # operation out of it. context = self.__context poll = self.__poller.poll try_lock_events = context.tryLockEvents lock_event_waiters = context.lockEventWaiters wait_for_event = context.waitForEvent unlock_event_waiters = context.unlockEventWaiters event_handling_ok = context.eventHandlingOK unlock_events = context.unlockEvents handle_events_locked = context.handleEventsLocked event_handler_active = context.eventHandlerActive getNextTimeout = context.getNextTimeout exceptionHandler = self.exceptionHandler fd_set = self.__fd_set while fd_set: if try_lock_events(): lock_event_waiters() while event_handler_active(): wait_for_event() unlock_event_waiters() else: try: while event_handling_ok(): if poll(getNextTimeout()): try: handle_events_locked() except libusb1.USBError: exceptionHandler(sys.exc_info()[1]) finally: unlock_events() def _registerFD(self, fd, events, _): self.__poller.register(fd, events) self.__fd_set.add(fd) def _unregisterFD(self, fd, _): self.__fd_set.discard(fd) self.__poller.unregister(fd) class USBPoller(object): """ Class allowing integration of USB event polling in a file-descriptor monitoring event loop. WARNING: Do not call "poll" from several threads concurently. Do not use synchronous USB transfers in a thread while "poll" is running. Doing so will result in unnecessarily long pauses in some threads. Opening and/or closing devices while polling can cause race conditions to occur. """ def __init__(self, context, poller): """ Create a poller for given context. Warning: it will not check if another poller instance was already present for that context, and will replace it. poller is a polling instance implementing the following methods: - register(fd, event_flags) event_flags have the same meaning as in poll API (POLLIN & POLLOUT) - unregister(fd) - poll(timeout) timeout being a float in seconds, or negative/None if there is no timeout. It must return a list of (descriptor, event) pairs. Note: USBPoller is itself a valid poller. Note2: select.poll uses a timeout in milliseconds, for some reason (all other select.* classes use seconds for timeout), so you should wrap it to convert & round/truncate timeout. """ self.__context = context self.__poller = poller self.__fd_set = set() context.setPollFDNotifiers(self._registerFD, self._unregisterFD) for fd, events in context.getPollFDList(): self._registerFD(fd, events) def __del__(self): self.__context.setPollFDNotifiers(None, None) def poll(self, timeout=None): """ Poll for events. timeout can be a float in seconds, or None for no timeout. Returns a list of (descriptor, event) pairs. """ next_usb_timeout = self.__context.getNextTimeout() if timeout is None or timeout < 0: usb_timeout = next_usb_timeout elif next_usb_timeout: usb_timeout = min(next_usb_timeout, timeout) else: usb_timeout = timeout event_list = self.__poller.poll(usb_timeout) if event_list: fd_set = self.__fd_set result = [(x, y) for x, y in event_list if x not in fd_set] if len(result) != len(event_list): self.__context.handleEventsTimeout() else: result = event_list self.__context.handleEventsTimeout() return result def register(self, fd, events): """ Register an USB-unrelated fd to poller. Convenience method. """ if fd in self.__fd_set: raise ValueError('This fd is a special USB event fd, it cannot ' 'be polled.') self.__poller.register(fd, events) def unregister(self, fd): """ Unregister an USB-unrelated fd from poller. Convenience method. """ if fd in self.__fd_set: raise ValueError('This fd is a special USB event fd, it must ' 'stay registered.') self.__poller.unregister(fd) def _registerFD(self, fd, events, user_data=None): self.register(fd, events) self.__fd_set.add(fd) def _unregisterFD(self, fd, user_data=None): self.__fd_set.discard(fd) self.unregister(fd) class USBDeviceHandle(object): """ Represents an opened USB device. """ __handle = None __libusb_close = libusb1.libusb_close __USBError = libusb1.USBError __LIBUSB_ERROR_NOT_FOUND = libusb1.LIBUSB_ERROR_NOT_FOUND __set = set def __init__(self, context, handle, device): """ You should not instanciate this class directly. Call "open" method on an USBDevice instance to get an USBDeviceHandle instance. """ self.__context = context # Weak reference to transfers about this device so we can clean up # before closing device. self.__transfer_set = WeakSet() # Strong references to inflight transfers so they do not get freed # even if user drops all strong references to them. If this instance # is garbage-collected, we close all transfers, so it's fine. self.__inflight = inflight = set() # XXX: For some reason, doing self.__inflight.{add|remove} inside # getTransfer causes extra intermediate python objects for each # allocated transfer. Storing them as properties solves this. Found # with objgraph. self.__inflight_add = inflight.add self.__inflight_remove = inflight.remove self.__handle = handle self.__device = device def __del__(self): self.close() def close(self): """ Close this handle. If not called explicitely, will be called by destructor. This method cancels any in-flight transfer when it is called. As cancellation is not immediate, this method needs to let libusb handle events until transfers are actually cancelled. In multi-threaded programs, this can lead to stalls. To avoid this, do not close nor let GC collect a USBDeviceHandle which has in-flight transfers. """ handle = self.__handle if handle is not None: # Build a strong set from weak self.__transfer_set so we can doom # and close all contained transfers. # Because of backward compatibility, self.__transfer_set might be a # wrapper around WeakKeyDictionary. As it might be modified by gc, # we must pop until there is not key left instead of iterating over # it. weak_transfer_set = self.__transfer_set transfer_set = self.__set() while True: try: transfer = weak_transfer_set.pop() except KeyError: break transfer_set.add(transfer) transfer.doom() inflight = self.__inflight for transfer in inflight: try: transfer.cancel() except self.__USBError: if sys.exc_info()[1].value != \ self.__LIBUSB_ERROR_NOT_FOUND: raise while inflight: self.__context.handleEvents() for transfer in transfer_set: transfer.close() self.__libusb_close(handle) self.__handle = None def getDevice(self): """ Get an USBDevice instance for the device accessed through this handle. Useful for example to query its configurations. """ return self.__device def getConfiguration(self): """ Get the current configuration number for this device. """ configuration = c_int() result = libusb1.libusb_get_configuration(self.__handle, byref(configuration)) if result: raise libusb1.USBError(result) return configuration.value def setConfiguration(self, configuration): """ Set the configuration number for this device. """ result = libusb1.libusb_set_configuration(self.__handle, configuration) if result: raise libusb1.USBError(result) def claimInterface(self, interface): """ Claim (= get exclusive access to) given interface number. Required to receive/send data. """ result = libusb1.libusb_claim_interface(self.__handle, interface) if result: raise libusb1.USBError(result) def releaseInterface(self, interface): """ Release interface, allowing another process to use it. """ result = libusb1.libusb_release_interface(self.__handle, interface) if result: raise libusb1.USBError(result) def setInterfaceAltSetting(self, interface, alt_setting): """ Set interface's alternative setting (both parameters are integers). """ result = libusb1.libusb_set_interface_alt_setting(self.__handle, interface, alt_setting) if result: raise libusb1.USBError(result) def clearHalt(self, endpoint): """ Clear a halt state on given endpoint number. """ result = libusb1.libusb_clear_halt(self.__handle, endpoint) if result: raise libusb1.USBError(result) def resetDevice(self): """ Reinitialise current device. Attempts to restore current configuration & alt settings. If this fails, will result in a device disconnect & reconnect, so you have to close current device and rediscover it (notified by a LIBUSB_ERROR_NOT_FOUND error code). """ result = libusb1.libusb_reset_device(self.__handle) if result: raise libusb1.USBError(result) def kernelDriverActive(self, interface): """ Tell whether a kernel driver is active on given interface number. """ result = libusb1.libusb_kernel_driver_active(self.__handle, interface) if result == 0: is_active = False elif result == 1: is_active = True else: raise libusb1.USBError(result) return is_active def detachKernelDriver(self, interface): """ Ask kernel driver to detach from given interface number. """ result = libusb1.libusb_detach_kernel_driver(self.__handle, interface) if result: raise libusb1.USBError(result) def attachKernelDriver(self, interface): """ Ask kernel driver to re-attach to given interface number. """ result = libusb1.libusb_attach_kernel_driver(self.__handle, interface) if result: raise libusb1.USBError(result) def getSupportedLanguageList(self): """ Return a list of USB language identifiers (as integers) supported by current device for its string descriptors. Note: language identifiers seem (I didn't check them all...) very similar to windows language identifiers, so you may want to use locales.windows_locale to get an rfc3066 representation. The 5 standard HID language codes are missing though. """ descriptor_string = create_binary_buffer(STRING_LENGTH) result = libusb1.libusb_get_string_descriptor(self.__handle, 0, 0, descriptor_string, sizeof(descriptor_string)) if result < 0: if result == libusb1.LIBUSB_ERROR_PIPE: # From libusb_control_transfer doc: # control request not supported by the device return [] raise libusb1.USBError(result) length = cast(descriptor_string, POINTER(c_ubyte))[0] langid_list = cast(descriptor_string, POINTER(c_uint16)) result = [] append = result.append for offset in xrange(1, length / 2): append(libusb1.libusb_le16_to_cpu(langid_list[offset])) return result def getStringDescriptor(self, descriptor, lang_id): """ Fetch description string for given descriptor and in given language. Use getSupportedLanguageList to know which languages are available. Return value is an unicode string. Return None if there is no such descriptor on device. """ descriptor_string = create_binary_buffer(STRING_LENGTH) result = libusb1.libusb_get_string_descriptor(self.__handle, descriptor, lang_id, descriptor_string, sizeof(descriptor_string)) if result == libusb1.LIBUSB_ERROR_NOT_FOUND: return None if result < 0: raise libusb1.USBError(result) return descriptor_string.value.decode('UTF-16-LE') def getASCIIStringDescriptor(self, descriptor): """ Fetch description string for given descriptor in first available language. Return value is an ASCII string. Return None if there is no such descriptor on device. """ descriptor_string = create_binary_buffer(STRING_LENGTH) result = libusb1.libusb_get_string_descriptor_ascii(self.__handle, descriptor, descriptor_string, sizeof(descriptor_string)) if result == libusb1.LIBUSB_ERROR_NOT_FOUND: return None if result < 0: raise libusb1.USBError(result) return descriptor_string.value.decode('ASCII') # Sync I/O def _controlTransfer(self, request_type, request, value, index, data, length, timeout): result = libusb1.libusb_control_transfer(self.__handle, request_type, request, value, index, data, length, timeout) if result < 0: raise libusb1.USBError(result) return result def controlWrite(self, request_type, request, value, index, data, timeout=0): """ Synchronous control write. request_type: request type bitmask (bmRequestType), see libusb1 constants LIBUSB_TYPE_* and LIBUSB_RECIPIENT_*. request: request id (some values are standard). value, index, data: meaning is request-dependent. timeout: in milliseconds, how long to wait for device acknowledgement. Set to 0 to disable. Returns the number of bytes actually sent. """ request_type = (request_type & ~libusb1.USB_ENDPOINT_DIR_MASK) | \ libusb1.LIBUSB_ENDPOINT_OUT data = create_binary_buffer(data) return self._controlTransfer(request_type, request, value, index, data, sizeof(data), timeout) def controlRead(self, request_type, request, value, index, length, timeout=0): """ Synchronous control read. timeout: in milliseconds, how long to wait for data. Set to 0 to disable. See controlWrite for other parameters description. Returns received data. """ request_type = (request_type & ~libusb1.USB_ENDPOINT_DIR_MASK) | \ libusb1.LIBUSB_ENDPOINT_IN data = create_binary_buffer(length) transferred = self._controlTransfer(request_type, request, value, index, data, length, timeout) return data.raw[:transferred] def _bulkTransfer(self, endpoint, data, length, timeout): transferred = c_int() result = libusb1.libusb_bulk_transfer(self.__handle, endpoint, data, length, byref(transferred), timeout) if result: raise libusb1.USBError(result) return transferred.value def bulkWrite(self, endpoint, data, timeout=0): """ Synchronous bulk write. endpoint: endpoint to send data to. data: data to send. timeout: in milliseconds, how long to wait for device acknowledgement. Set to 0 to disable. Returns the number of bytes actually sent. """ endpoint = (endpoint & ~libusb1.USB_ENDPOINT_DIR_MASK) | \ libusb1.LIBUSB_ENDPOINT_OUT data = create_binary_buffer(data) return self._bulkTransfer(endpoint, data, sizeof(data), timeout) def bulkRead(self, endpoint, length, timeout=0): """ Synchronous bulk read. timeout: in milliseconds, how long to wait for data. Set to 0 to disable. See bulkWrite for other parameters description. Returns received data. """ endpoint = (endpoint & ~libusb1.USB_ENDPOINT_DIR_MASK) | \ libusb1.LIBUSB_ENDPOINT_IN data = create_binary_buffer(length) transferred = self._bulkTransfer(endpoint, data, length, timeout) return data.raw[:transferred] def _interruptTransfer(self, endpoint, data, length, timeout): transferred = c_int() result = libusb1.libusb_interrupt_transfer(self.__handle, endpoint, data, length, byref(transferred), timeout) if result: raise libusb1.USBError(result) return transferred.value def interruptWrite(self, endpoint, data, timeout=0): """ Synchronous interrupt write. endpoint: endpoint to send data to. data: data to send. timeout: in milliseconds, how long to wait for device acknowledgement. Set to 0 to disable. Returns the number of bytes actually sent. """ endpoint = (endpoint & ~libusb1.USB_ENDPOINT_DIR_MASK) | \ libusb1.LIBUSB_ENDPOINT_OUT data = create_binary_buffer(data) return self._interruptTransfer(endpoint, data, sizeof(data), timeout) def interruptRead(self, endpoint, length, timeout=0): """ Synchronous interrupt write. timeout: in milliseconds, how long to wait for data. Set to 0 to disable. See interruptRead for other parameters description. Returns received data. """ endpoint = (endpoint & ~libusb1.USB_ENDPOINT_DIR_MASK) | \ libusb1.LIBUSB_ENDPOINT_IN data = create_binary_buffer(length) transferred = self._interruptTransfer(endpoint, data, length, timeout) return data.raw[:transferred] def getTransfer(self, iso_packets=0): """ Get an USBTransfer instance for asynchronous use. iso_packets: the number of isochronous transfer descriptors to allocate. """ result = USBTransfer(self.__handle, iso_packets, self.__inflight_add, self.__inflight_remove, ) self.__transfer_set.add(result) return result class USBConfiguration(object): def __init__(self, config): """ You should not instanciate this class directly. Call USBDevice methods to get instances of this class. """ if not isinstance(config, libusb1.libusb_config_descriptor): raise TypeError('Unexpected descriptor type.') self.__config = config def getNumInterfaces(self): return self.__config.bNumInterfaces def getConfigurationValue(self): return self.__config.bConfigurationValue def getDescriptor(self): return self.__config.iConfiguration def getAttributes(self): return self.__config.bmAttributes def getMaxPower(self): """ Returns device's power consumption in mW. Beware of unit: USB descriptor uses 2mW increments, this method converts it to mW units. """ return self.__config.MaxPower * 2 def getExtra(self): """ Returns a list of extra (non-basic) descriptors (DFU, HID, ...). """ return libusb1.get_extra(self.__config) def __iter__(self): """ Iterates over interfaces available in this configuration, yielding USBInterface instances. """ interface_list = self.__config.interface for interface_num in xrange(self.getNumInterfaces()): yield USBInterface(interface_list[interface_num]) # BBB iterInterfaces = __iter__ def __getitem__(self, interface): """ Returns an USBInterface instance. """ if not isinstance(interface, int): raise TypeError('interface parameter must be an integer') if not (0 <= interface < self.getNumInterfaces()): raise IndexError('No such interface: %r' % (interface, )) return USBInterface(self.__config.interface[interface]) class USBInterface(object): def __init__(self, interface): """ You should not instanciate this class directly. Call USBConfiguration methods to get instances of this class. """ if not isinstance(interface, libusb1.libusb_interface): raise TypeError('Unexpected descriptor type.') self.__interface = interface def getNumSettings(self): return self.__interface.num_altsetting def __iter__(self): """ Iterates over settings in this insterface, yielding USBInterfaceSetting instances. """ alt_setting_list = self.__interface.altsetting for alt_setting_num in xrange(self.getNumSettings()): yield USBInterfaceSetting(alt_setting_list[alt_setting_num]) # BBB iterSettings = __iter__ def __getitem__(self, alt_setting): """ Returns an USBInterfaceSetting instance. """ if not isinstance(alt_setting, int): raise TypeError('alt_setting parameter must be an integer') if not (0 <= alt_setting < self.getNumSettings()): raise IndexError('No such setting: %r' % (alt_setting, )) return USBInterfaceSetting(self.__interface.altsetting[alt_setting]) class USBInterfaceSetting(object): def __init__(self, alt_setting): """ You should not instanciate this class directly. Call USBDevice or USBInterface methods to get instances of this class. """ if not isinstance(alt_setting, libusb1.libusb_interface_descriptor): raise TypeError('Unexpected descriptor type.') self.__alt_setting = alt_setting def getNumber(self): return self.__alt_setting.bInterfaceNumber def getAlternateSetting(self): return self.__alt_setting.bAlternateSetting def getNumEndpoints(self): return self.__alt_setting.bNumEndpoints def getClass(self): return self.__alt_setting.bInterfaceClass def getSubClass(self): return self.__alt_setting.bInterfaceSubClass def getClassTupple(self): """ For convenience: class and subclass are probably often matched simultaneously. """ alt_setting = self.__alt_setting return (alt_setting.bInterfaceClass, alt_setting.bInterfaceSubClass) def getProtocol(self): return self.__alt_setting.bInterfaceProtocol def getDescriptor(self): return self.__alt_setting.iInterface def getExtra(self): return libusb1.get_extra(self.__alt_setting) def __iter__(self): """ Iterates over endpoints in this interface setting , yielding USBEndpoint instances. """ endpoint_list = self.__alt_setting.endpoint for endpoint_num in xrange(self.getNumEndpoints()): yield USBEndpoint(endpoint_list[endpoint_num]) # BBB iterEndpoints = __iter__ def __getitem__(self, endpoint): """ Returns an USBEndpoint instance. """ if not isinstance(endpoint, int): raise TypeError('endpoint parameter must be an integer') if not (0 <= endpoint < self.getNumEndpoints()): raise ValueError('No such endpoint: %r' % (endpoint, )) return USBEndpoint(self.__alt_setting.endpoint[endpoint]) class USBEndpoint(object): def __init__(self, endpoint): if not isinstance(endpoint, libusb1.libusb_endpoint_descriptor): raise TypeError('Unexpected descriptor type.') self.__endpoint = endpoint def getAddress(self): return self.__endpoint.bEndpointAddress def getAttributes(self): return self.__endpoint.bmAttributes def getMaxPacketSize(self): return self.__endpoint.wMaxPacketSize def getInterval(self): return self.__endpoint.bInterval def getRefresh(self): return self.__endpoint.bRefresh def getSyncAddress(self): return self.__endpoint.bSynchAddress def getExtra(self): return libusb1.get_extra(self.__endpoint) class USBDevice(object): """ Represents a USB device. """ __configuration_descriptor_list = () __libusb_unref_device = libusb1.libusb_unref_device __libusb_free_config_descriptor = libusb1.libusb_free_config_descriptor __byref = byref def __init__(self, context, device_p): """ You should not instanciate this class directly. Call LibUSBContext methods to receive instances of this class. """ # Important: device_p refcount must be incremented before being given # to this constructor. This class will decrement refcount upon # destruction. self.__context = context self.device_p = device_p # Fetch device descriptor device_descriptor = libusb1.libusb_device_descriptor() result = libusb1.libusb_get_device_descriptor(device_p, byref(device_descriptor)) if result: raise libusb1.USBError(result) self.device_descriptor = device_descriptor # Fetch all configuration descriptors self.__configuration_descriptor_list = [] append = self.__configuration_descriptor_list.append for configuration_id in xrange(device_descriptor.bNumConfigurations): config = libusb1.libusb_config_descriptor_p() result = libusb1.libusb_get_config_descriptor(device_p, configuration_id, byref(config)) if result == libusb1.LIBUSB_ERROR_NOT_FOUND: # Some devices (ex windows' root hubs) tell they have one # configuration, but they have no configuration descriptor. continue if result: raise libusb1.USBError(result) append(config.contents) def __del__(self): self.__libusb_unref_device(self.device_p) byref = self.__byref for config in self.__configuration_descriptor_list: self.__libusb_free_config_descriptor(byref(config)) def __str__(self): return 'Bus %03i Device %03i: ID %04x:%04x' % ( self.getBusNumber(), self.getDeviceAddress(), self.getVendorID(), self.getProductID(), ) def __getitem__(self, index): return USBConfiguration(self.__configuration_descriptor_list[index]) def iterConfigurations(self): for config in self.__configuration_descriptor_list: yield USBConfiguration(config) # BBB iterConfiguations = iterConfigurations def iterSettings(self): for config in self.__configuration_descriptor_list: for interface in USBConfiguration(config): for setting in interface: yield setting def getBusNumber(self): """ Get device's bus number. """ return libusb1.libusb_get_bus_number(self.device_p) def getDeviceAddress(self): """ Get device's address on its bus. """ return libusb1.libusb_get_device_address(self.device_p) def getbcdUSB(self): """ Get the USB spec version device complies to, in BCD format. """ return self.device_descriptor.bcdUSB def getDeviceClass(self): """ Get device's class id. """ return self.device_descriptor.bDeviceClass def getDeviceSubClass(self): """ Get device's subclass id. """ return self.device_descriptor.bDeviceSubClass def getDeviceProtocol(self): """ Get device's protocol id. """ return self.device_descriptor.bDeviceProtocol def getMaxPacketSize0(self): """ Get device's max packet size for endpoint 0 (control). """ return self.device_descriptor.bMaxPacketSize0 def getMaxPacketSize(self, endpoint): """ Get device's max packet size for given endpoint. Warning: this function will not always give you the expected result. See https://libusb.org/ticket/77 . You should instead consult the endpoint descriptor of current configuration and alternate setting. """ result = libusb1.libusb_get_max_packet_size(self.device_p, endpoint) if result < 0: raise libusb1.USBError(result) return result def getMaxISOPacketSize(self, endpoint): """ Get the maximum size for a single isochronous packet for given endpoint. Warning: this function will not always give you the expected result. See https://libusb.org/ticket/77 . You should instead consult the endpoint descriptor of current configuration and alternate setting. """ result = libusb1.libusb_get_max_iso_packet_size(self.device_p, endpoint) if result < 0: raise libusb1.USBError(result) return result def getVendorID(self): """ Get device's vendor id. """ return self.device_descriptor.idVendor def getProductID(self): """ Get device's product id. """ return self.device_descriptor.idProduct def getbcdDevice(self): """ Get device's release number. """ return self.device_descriptor.bcdDevice def getSupportedLanguageList(self): """ Get the list of language ids device has string descriptors for. """ temp_handle = self.open() return temp_handle.getSupportedLanguageList() def _getStringDescriptor(self, descriptor, lang_id): if descriptor == 0: result = None else: temp_handle = self.open() result = temp_handle.getStringDescriptor(descriptor, lang_id) return result def _getASCIIStringDescriptor(self, descriptor): if descriptor == 0: result = None else: temp_handle = self.open() result = temp_handle.getASCIIStringDescriptor(descriptor) return result def getManufacturer(self): """ Get device's manufaturer name. Note: opens the device temporarily. """ return self._getASCIIStringDescriptor( self.device_descriptor.iManufacturer) def getProduct(self): """ Get device's product name. Note: opens the device temporarily. """ return self._getASCIIStringDescriptor(self.device_descriptor.iProduct) def getSerialNumber(self): """ Get device's serial number. Note: opens the device temporarily. """ return self._getASCIIStringDescriptor( self.device_descriptor.iSerialNumber) def getNumConfigurations(self): """ Get device's number of possible configurations. """ return self.device_descriptor.bNumConfigurations def getDeviceSpeed(self): """ Get device's speed (see libusb1.libusb_speed for possible return values). """ return libusb1.libusb_get_device_speed(self.device_p) def open(self): """ Open device. Returns an USBDeviceHandle instance. """ handle = libusb1.libusb_device_handle_p() result = libusb1.libusb_open(self.device_p, byref(handle)) if result: raise libusb1.USBError(result) return USBDeviceHandle(self.__context, handle, self) _zero_tv = libusb1.timeval(0, 0) _zero_tv_p = byref(_zero_tv) class USBContext(object): """ libusb1 USB context. Provides methods to enumerate & look up USB devices. Also provides access to global (device-independent) libusb1 functions. """ __libusb_exit = libusb1.libusb_exit __context_p = None __added_cb = None __removed_cb = None __libusb_set_pollfd_notifiers = libusb1.libusb_set_pollfd_notifiers def _validContext(func): # Defined inside LibUSBContext so we can access "self.__*". def wrapper(self, *args, **kw): self.__context_cond.acquire() self.__context_refcount += 1 self.__context_cond.release() try: if self.__context_p is not None: return func(self, *args, **kw) finally: self.__context_cond.acquire() self.__context_refcount -= 1 if not self.__context_refcount: self.__context_cond.notifyAll() self.__context_cond.release() return wrapper def __init__(self): """ Create a new USB context. """ # Used to prevent an exit to cause a segfault if a concurrent thread # is still in libusb. self.__context_refcount = 0 self.__context_cond = threading.Condition() context_p = libusb1.libusb_context_p() result = libusb1.libusb_init(byref(context_p)) if result: raise libusb1.USBError(result) self.__context_p = context_p def __del__(self): # Avoid locking. # XXX: Assumes __del__ should not normally be called while any # instance's method is being executed. It seems unlikely (they hold a # reference to their instance). self._exit() def exit(self): """ Close (destroy) this USB context. When this method has been called, methods on its instance will become mosty no-ops, returning None. """ self.__context_cond.acquire() try: while self.__context_refcount and self.__context_p is not None: self.__context_cond.wait() self._exit() finally: self.__context_cond.notifyAll() self.__context_cond.release() def _exit(self): context_p = self.__context_p if context_p is not None: self.__libusb_exit(context_p) self.__context_p = None self.__added_cb = None self.__removed_cb = None @_validContext def getDeviceList(self, skip_on_access_error=False, skip_on_error=False): """ Return a list of all USB devices currently plugged in, as USBDevice instances. skip_on_error (bool) If True, ignore devices which raise USBError. skip_on_access_error (bool) DEPRECATED. Alias for skip_on_error. """ skip_on_error = skip_on_error or skip_on_access_error device_p_p = libusb1.libusb_device_p_p() libusb_device_p = libusb1.libusb_device_p device_list_len = libusb1.libusb_get_device_list(self.__context_p, byref(device_p_p)) if device_list_len < 0: raise libusb1.USBError(device_list_len) try: result = [] append = result.append for device_p in device_p_p[:device_list_len]: try: # Instanciate our own libusb_device_p object so we can free # libusb-provided device list. Is this a bug in ctypes that it # doesn't copy pointer value (=pointed memory address) ? At # least, it's not so convenient and forces using such weird # code. device = USBDevice(self, libusb_device_p(device_p.contents)) except libusb1.USBError: if not skip_on_error: raise else: append(device) finally: libusb1.libusb_free_device_list(device_p_p, 0) return result def getByVendorIDAndProductID(self, vendor_id, product_id, skip_on_access_error=False, skip_on_error=False): """ Get the first USB device matching given vendor and product ids. Returns an USBDevice instance, or None if no present device match. skip_on_error (bool) (see getDeviceList) skip_on_access_error (bool) (see getDeviceList) """ for device in self.getDeviceList( skip_on_access_error=skip_on_access_error, skip_on_error=skip_on_error): if device.getVendorID() == vendor_id and \ device.getProductID() == product_id: result = device break else: result = None return result def openByVendorIDAndProductID(self, vendor_id, product_id, skip_on_access_error=False, skip_on_error=False): """ Get the first USB device matching given vendor and product ids. Returns an USBDeviceHandle instance, or None if no present device match. skip_on_error (bool) (see getDeviceList) skip_on_access_error (bool) (see getDeviceList) """ result = self.getByVendorIDAndProductID(vendor_id, product_id, skip_on_access_error=skip_on_access_error, skip_on_error=skip_on_error) if result is not None: result = result.open() return result @_validContext def getPollFDList(self): """ Return file descriptors to be used to poll USB events. You should not have to call this method, unless you are integrating this class with a polling mechanism. """ pollfd_p_p = libusb1.libusb_get_pollfds(self.__context_p) if not pollfd_p_p: errno = get_errno() if errno: raise OSError(errno) else: # Assume not implemented raise NotImplementedError("Your libusb doesn't seem to " "implement pollable FDs") try: result = [] append = result.append fd_index = 0 while pollfd_p_p[fd_index]: append((pollfd_p_p[fd_index].contents.fd, pollfd_p_p[fd_index].contents.events)) fd_index += 1 finally: _free(pollfd_p_p) return result @_validContext def handleEvents(self): """ Handle any pending event (blocking). See libusb1 documentation for details (there is a timeout, so it's not "really" blocking). """ result = libusb1.libusb_handle_events(self.__context_p) if result: raise libusb1.USBError(result) # TODO: handleEventsCompleted @_validContext def handleEventsTimeout(self, tv=0): """ Handle any pending event. If tv is 0, will return immediately after handling already-pending events. Otherwise, defines the maximum amount of time to wait for events, in seconds. """ if tv is None: tv = 0 tv_s = int(tv) tv = libusb1.timeval(tv_s, int((tv - tv_s) * 1000000)) result = libusb1.libusb_handle_events_timeout(self.__context_p, byref(tv)) if result: raise libusb1.USBError(result) # TODO: handleEventsTimeoutCompleted @_validContext def setPollFDNotifiers(self, added_cb=None, removed_cb=None, user_data=None): """ Give libusb1 methods to call when it should add/remove file descriptor for polling. You should not have to call this method, unless you are integrating this class with a polling mechanism. """ if added_cb is None: added_cb = POINTER(None) else: added_cb = libusb1.libusb_pollfd_added_cb_p(added_cb) if removed_cb is None: removed_cb = POINTER(None) else: removed_cb = libusb1.libusb_pollfd_removed_cb_p(removed_cb) self.__added_cb = added_cb self.__removed_cb = removed_cb self.__libusb_set_pollfd_notifiers(self.__context_p, added_cb, removed_cb, user_data) @_validContext def getNextTimeout(self): """ Returns the next internal timeout that libusb needs to handle, in seconds, or None if no timeout is needed. You should not have to call this method, unless you are integrating this class with a polling mechanism. """ timeval = libusb1.timeval() result = libusb1.libusb_get_next_timeout(self.__context_p, byref(timeval)) if result == 0: result = None elif result == 1: result = timeval.tv_sec + (timeval.tv_usec * 0.000001) else: raise libusb1.USBError(result) return result @_validContext def setDebug(self, level): """ Set debugging level. Note: depending on libusb compilation settings, this might have no effect. """ libusb1.libusb_set_debug(self.__context_p, level) @_validContext def tryLockEvents(self): """ See libusb_try_lock_events doc. """ return libusb1.libusb_try_lock_events(self.__context_p) @_validContext def lockEvents(self): """ See libusb_lock_events doc. """ libusb1.libusb_lock_events(self.__context_p) @_validContext def lockEventWaiters(self): """ See libusb_lock_event_waiters doc. """ libusb1.libusb_lock_event_waiters(self.__context_p) @_validContext def waitForEvent(self): """ See libusb_wait_for_event doc. """ libusb1.libusb_wait_for_event(self.__context_p) @_validContext def unlockEventWaiters(self): """ See libusb_unlock_event_waiters doc. """ libusb1.libusb_unlock_event_waiters(self.__context_p) @_validContext def eventHandlingOK(self): """ See libusb_event_handling_ok doc. """ return libusb1.libusb_event_handling_ok(self.__context_p) @_validContext def unlockEvents(self): """ See libusb_unlock_events doc. """ libusb1.libusb_unlock_events(self.__context_p) @_validContext def handleEventsLocked(self): """ See libusb_handle_events_locked doc. """ # XXX: does tv parameter need to be exposed ? result = libusb1.libusb_handle_events_locked(self.__context_p, _zero_tv_p) if result: raise libusb1.USBError(result) @_validContext def eventHandlerActive(self): """ See libusb_event_handler_active doc. """ return libusb1.libusb_event_handler_active(self.__context_p) def hasCapability(self, capability): """ Tests feature presence. See libusb1.libusb_capability . """ return libusb1.libusb_has_capability(capability) del USBContext._validContext def getVersion(): """ Returns underlying libusb's version information as a 6-namedtuple (or 6-tuple if namedtuples are not avaiable): - major - minor - micro - nano - rc - describe Returns (0, 0, 0, 0, '', '') if libusb doesn't have required entry point. """ version = libusb1.libusb_get_version().contents return Version(version.major, version.minor, version.micro, version.nano, version.rc, version.describe) class LibUSBContext(USBContext): """ Backward-compatibility alias for USBContext. """ def __init__(self): warnings.warn('LibUSBContext is being renamed to USBContext', DeprecationWarning) super(LibUSBContext, self).__init__()