| """Benchmark some basic import use-cases. |
| |
| The assumption is made that this benchmark is run in a fresh interpreter and |
| thus has no external changes made to import-related attributes in sys. |
| |
| """ |
| from . import util |
| from .source import util as source_util |
| import decimal |
| import imp |
| import importlib |
| import os |
| import py_compile |
| import sys |
| import timeit |
| |
| |
| def bench(name, cleanup=lambda: None, *, seconds=1, repeat=3): |
| """Bench the given statement as many times as necessary until total |
| executions take one second.""" |
| stmt = "__import__({!r})".format(name) |
| timer = timeit.Timer(stmt) |
| for x in range(repeat): |
| total_time = 0 |
| count = 0 |
| while total_time < seconds: |
| try: |
| total_time += timer.timeit(1) |
| finally: |
| cleanup() |
| count += 1 |
| else: |
| # One execution too far |
| if total_time > seconds: |
| count -= 1 |
| yield count // seconds |
| |
| def from_cache(seconds, repeat): |
| """sys.modules""" |
| name = '<benchmark import>' |
| module = imp.new_module(name) |
| module.__file__ = '<test>' |
| module.__package__ = '' |
| with util.uncache(name): |
| sys.modules[name] = module |
| for result in bench(name, repeat=repeat, seconds=seconds): |
| yield result |
| |
| |
| def builtin_mod(seconds, repeat): |
| """Built-in module""" |
| name = 'errno' |
| if name in sys.modules: |
| del sys.modules[name] |
| # Relying on built-in importer being implicit. |
| for result in bench(name, lambda: sys.modules.pop(name), repeat=repeat, |
| seconds=seconds): |
| yield result |
| |
| |
| def source_wo_bytecode(seconds, repeat): |
| """Source w/o bytecode: simple""" |
| sys.dont_write_bytecode = True |
| try: |
| name = '__importlib_test_benchmark__' |
| # Clears out sys.modules and puts an entry at the front of sys.path. |
| with source_util.create_modules(name) as mapping: |
| assert not os.path.exists(imp.cache_from_source(mapping[name])) |
| for result in bench(name, lambda: sys.modules.pop(name), repeat=repeat, |
| seconds=seconds): |
| yield result |
| finally: |
| sys.dont_write_bytecode = False |
| |
| |
| def decimal_wo_bytecode(seconds, repeat): |
| """Source w/o bytecode: decimal""" |
| name = 'decimal' |
| decimal_bytecode = imp.cache_from_source(decimal.__file__) |
| if os.path.exists(decimal_bytecode): |
| os.unlink(decimal_bytecode) |
| sys.dont_write_bytecode = True |
| try: |
| for result in bench(name, lambda: sys.modules.pop(name), repeat=repeat, |
| seconds=seconds): |
| yield result |
| finally: |
| sys.dont_write_bytecode = False |
| |
| |
| def source_writing_bytecode(seconds, repeat): |
| """Source writing bytecode: simple""" |
| assert not sys.dont_write_bytecode |
| name = '__importlib_test_benchmark__' |
| with source_util.create_modules(name) as mapping: |
| def cleanup(): |
| sys.modules.pop(name) |
| os.unlink(imp.cache_from_source(mapping[name])) |
| for result in bench(name, cleanup, repeat=repeat, seconds=seconds): |
| assert not os.path.exists(imp.cache_from_source(mapping[name])) |
| yield result |
| |
| |
| def decimal_writing_bytecode(seconds, repeat): |
| """Source writing bytecode: decimal""" |
| assert not sys.dont_write_bytecode |
| name = 'decimal' |
| def cleanup(): |
| sys.modules.pop(name) |
| os.unlink(imp.cache_from_source(decimal.__file__)) |
| for result in bench(name, cleanup, repeat=repeat, seconds=seconds): |
| yield result |
| |
| |
| def source_using_bytecode(seconds, repeat): |
| """Bytecode w/ source: simple""" |
| name = '__importlib_test_benchmark__' |
| with source_util.create_modules(name) as mapping: |
| py_compile.compile(mapping[name]) |
| assert os.path.exists(imp.cache_from_source(mapping[name])) |
| for result in bench(name, lambda: sys.modules.pop(name), repeat=repeat, |
| seconds=seconds): |
| yield result |
| |
| |
| def decimal_using_bytecode(seconds, repeat): |
| """Bytecode w/ source: decimal""" |
| name = 'decimal' |
| py_compile.compile(decimal.__file__) |
| for result in bench(name, lambda: sys.modules.pop(name), repeat=repeat, |
| seconds=seconds): |
| yield result |
| |
| |
| def main(import_): |
| __builtins__.__import__ = import_ |
| benchmarks = (from_cache, builtin_mod, |
| source_using_bytecode, source_wo_bytecode, |
| source_writing_bytecode, |
| decimal_using_bytecode, decimal_writing_bytecode, |
| decimal_wo_bytecode,) |
| seconds = 1 |
| seconds_plural = 's' if seconds > 1 else '' |
| repeat = 3 |
| header = "Measuring imports/second over {} second{}, best out of {}\n" |
| print(header.format(seconds, seconds_plural, repeat)) |
| for benchmark in benchmarks: |
| print(benchmark.__doc__, "[", end=' ') |
| sys.stdout.flush() |
| results = [] |
| for result in benchmark(seconds=seconds, repeat=repeat): |
| results.append(result) |
| print(result, end=' ') |
| sys.stdout.flush() |
| assert not sys.dont_write_bytecode |
| print("]", "best is", format(max(results), ',d')) |
| |
| |
| if __name__ == '__main__': |
| import optparse |
| |
| parser = optparse.OptionParser() |
| parser.add_option('-b', '--builtin', dest='builtin', action='store_true', |
| default=False, help="use the built-in __import__") |
| options, args = parser.parse_args() |
| if args: |
| raise RuntimeError("unrecognized args: {}".format(args)) |
| import_ = __import__ |
| if not options.builtin: |
| import_ = importlib.__import__ |
| |
| main(import_) |