Function choose_backend

memory_profiler.py:1201–1227

Function that tries to setup backend, chosen by user, and if failed, setup one of the allowable backends

(new_backend=None)

def choose_backend(new_backend=None):
    """
    Function that tries to setup backend, chosen by user, and if failed,
    setup one of the allowable backends
    """

    _backend = 'no_backend'
    all_backends = [
        ('psutil', True),
        ('psutil_pss', True),
        ('psutil_uss', True),
        ('posix', os.name == 'posix'),
        ('tracemalloc', has_tracemalloc),
    ]
    backends_indices = dict((b[0], i) for i, b in enumerate(all_backends))

    if new_backend is not None:
        all_backends.insert(0, all_backends.pop(backends_indices[new_backend]))

    for n_backend, is_available in all_backends:
        if is_available:
            _backend = n_backend
            break
    if _backend != new_backend and new_backend is not None:
        warnings.warn('{0} can not be used, {1} used instead'.format(
            new_backend, _backend))
    return _backend


# Insert in the built-ins to have profile