__copyright__ = """ Copyright (c) 2018 Uber Technologies, Inc. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. """ import numbers import threading from queue import Queue import numpy as np import math class SharedNoiseTable(object): def __init__(self): import ctypes, multiprocessing seed = 123 count = 250000000 # 1 gigabyte of 32-bit numbers. Will actually sample 2 gigabytes below. print('Sampling {} random numbers with seed {}'.format(count, seed)) self._shared_mem = multiprocessing.Array(ctypes.c_float, count) self.noise = np.ctypeslib.as_array(self._shared_mem.get_obj()) assert self.noise.dtype == np.float32 self.noise[:] = np.random.RandomState(seed).randn(count) # 64-bit to 32-bit conversion here print('Sampled {} bytes'.format(self.noise.size * 4)) def get(self, i, dim): return self.noise[i:i + dim] def sample_index(self, stream, dim): return stream.randint(0, len(self.noise) - dim + 1) class ConstantSchedule(object): def __init__(self, value): self._value = value def value(self, **kwargs): return self._value class LinearSchedule(object): def __init__(self, schedule, final_p, initial_p, field): self.schedule = schedule self.field = field self.final_p = final_p self.initial_p = initial_p def value(self, **kwargs): assert self.field in kwargs, "Argument {} not provided to scheduler Available: {}".format(self.field, kwargs) fraction = min(float(kwargs[self.field]) / self.schedule, 1.0) return self.initial_p + fraction * (self.final_p - self.initial_p) class ExponentialSchedule(object): def __init__(self, initial_p, final_p, schedule, field): self.initial_p = initial_p self.final_p = final_p self.schedule = schedule self.field = field self.linear = LinearSchedule( initial_p=math.log(self.initial_p), final_p=math.log(self.final_p), schedule=self.schedule, field=self.field) def value(self, **kwargs): return math.exp(self.linear(**kwargs)) def make_schedule(args): if isinstance(args, numbers.Number): return ConstantSchedule(args) else: return globals()[args['type']](**{key: value for key, value in args.items() if key != 'type'})