xref: /llvm-project/third-party/benchmark/bindings/python/google_benchmark/__init__.py (revision a5b797172cc902db166e9a695716fb81405f86e4)
1# Copyright 2020 Google Inc. All rights reserved.
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#     http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14"""Python benchmarking utilities.
15
16Example usage:
17  import google_benchmark as benchmark
18
19  @benchmark.register
20  def my_benchmark(state):
21      ...  # Code executed outside `while` loop is not timed.
22
23      while state:
24        ...  # Code executed within `while` loop is timed.
25
26  if __name__ == '__main__':
27    benchmark.main()
28"""
29import atexit
30
31from absl import app
32
33from google_benchmark import _benchmark
34from google_benchmark._benchmark import (
35    Counter as Counter,
36    State as State,
37    kMicrosecond as kMicrosecond,
38    kMillisecond as kMillisecond,
39    kNanosecond as kNanosecond,
40    kSecond as kSecond,
41    o1 as o1,
42    oAuto as oAuto,
43    oLambda as oLambda,
44    oLogN as oLogN,
45    oN as oN,
46    oNCubed as oNCubed,
47    oNLogN as oNLogN,
48    oNone as oNone,
49    oNSquared as oNSquared,
50)
51from google_benchmark.version import __version__ as __version__
52
53
54class __OptionMaker:
55    """A stateless class to collect benchmark options.
56
57    Collect all decorator calls like @option.range(start=0, limit=1<<5).
58    """
59
60    class Options:
61        """Pure data class to store options calls, along with the benchmarked function."""
62
63        def __init__(self, func):
64            self.func = func
65            self.builder_calls = []
66
67    @classmethod
68    def make(cls, func_or_options):
69        """Make Options from Options or the benchmarked function."""
70        if isinstance(func_or_options, cls.Options):
71            return func_or_options
72        return cls.Options(func_or_options)
73
74    def __getattr__(self, builder_name):
75        """Append option call in the Options."""
76
77        # The function that get returned on @option.range(start=0, limit=1<<5).
78        def __builder_method(*args, **kwargs):
79            # The decorator that get called, either with the benchmared function
80            # or the previous Options
81            def __decorator(func_or_options):
82                options = self.make(func_or_options)
83                options.builder_calls.append((builder_name, args, kwargs))
84                # The decorator returns Options so it is not technically a decorator
85                # and needs a final call to @register
86                return options
87
88            return __decorator
89
90        return __builder_method
91
92
93# Alias for nicer API.
94# We have to instantiate an object, even if stateless, to be able to use __getattr__
95# on option.range
96option = __OptionMaker()
97
98
99def register(undefined=None, *, name=None):
100    """Register function for benchmarking."""
101    if undefined is None:
102        # Decorator is called without parenthesis so we return a decorator
103        return lambda f: register(f, name=name)
104
105    # We have either the function to benchmark (simple case) or an instance of Options
106    # (@option._ case).
107    options = __OptionMaker.make(undefined)
108
109    if name is None:
110        name = options.func.__name__
111
112    # We register the benchmark and reproduce all the @option._ calls onto the
113    # benchmark builder pattern
114    benchmark = _benchmark.RegisterBenchmark(name, options.func)
115    for name, args, kwargs in options.builder_calls[::-1]:
116        getattr(benchmark, name)(*args, **kwargs)
117
118    # return the benchmarked function because the decorator does not modify it
119    return options.func
120
121
122def _flags_parser(argv):
123    argv = _benchmark.Initialize(argv)
124    return app.parse_flags_with_usage(argv)
125
126
127def _run_benchmarks(argv):
128    if len(argv) > 1:
129        raise app.UsageError("Too many command-line arguments.")
130    return _benchmark.RunSpecifiedBenchmarks()
131
132
133def main(argv=None):
134    return app.run(_run_benchmarks, argv=argv, flags_parser=_flags_parser)
135
136
137# Methods for use with custom main function.
138initialize = _benchmark.Initialize
139run_benchmarks = _benchmark.RunSpecifiedBenchmarks
140atexit.register(_benchmark.ClearRegisteredBenchmarks)
141