def write_mutant_cache_file(mutant: Mutant) -> None:
"""Create the cache file for the mutant on disk in __pycache__.
Existing target cache files are removed to ensure clean overwrites.
Reference: https://github.com/python/cpython/blob/master/Lib/py_compile.py#L157
Args:
mutant: the mutant definition to create
Returns:
None, creates the cache file on disk.
"""
check_cache_invalidation_mode()
bytecode = importlib._bootstrap_external._code_to_timestamp_pyc( # type: ignore
mutant.mutant_code, mutant.source_stats["mtime"],
mutant.source_stats["size"])
remove_existing_cache_files(mutant.src_file)
create_cache_dirs(mutant.cfile)
LOGGER.debug("Writing mutant cache file: %s", mutant.cfile)
importlib._bootstrap_external._write_atomic(mutant.cfile, bytecode,
mutant.mode) # type: ignore
def test_create_cache_dirs(tmp_path):
"""The __pycache__ directory should only be created once."""
cache_file = tmp_path / "__pycache__" / "cfile.pyc"
# first run creates the __pycache__ directory
create_cache_dirs(cache_file)
# second run should do nothing since it already exists
create_cache_dirs(cache_file)
dir = list(tmp_path.iterdir())
# only one dirctory created, and should be __pycache__
assert len(dir) == 1
assert dir[0].parts[-1] == "__pycache__"
def create_mutation_run_parallelcache_trial(
genome: Genome, target_idx: LocIndex, mutation_op: Any,
test_cmds: List[str], max_runtime: float) -> MutantTrialResult:
"""Similar to run.create_mutation_run_trial() but using the parallel cache directory settings.
This function requires Python 3.8 and does not run with Python 3.7. Importantly, it has the
identical signature to run.create_mutation_run_trial() and is substituted in the
run.mutation_sample_dispatch().
Args:
genome: the genome to mutate
target_idx: the mutation location
mutation_op: the mutation operation
test_cmds: the test commands to execute with the mutated code
max_runtime: timeout for the subprocess trial
Returns:
MutantTrialResult
Raises:
EnvironmentError: if Python version is less than 3.8
"""
if sys.version_info < (3, 8):
raise EnvironmentError(
"Python 3.8 is required to use PYTHONPYCACHEPREFIX.")
# Note in coverage reports this shows as untested code due to the subprocess dispatching
# the 'slow' tests in `test_run.py` cover this.
cache.check_cache_invalidation_mode()
# create the mutant without writing the cache
mutant = genome.mutate(target_idx, mutation_op, write_cache=False)
# set up parallel cache structure
parallel_cache = Path.cwd() / PARALLEL_PYCACHE_DIR / uuid.uuid4().hex
resolved_source_parts = genome.source_file.resolve().parent.parts[
1:] # type: ignore
parallel_cfile = parallel_cache.joinpath(
*resolved_source_parts) / mutant.cfile.name
bytecode = importlib._bootstrap_external._code_to_timestamp_pyc( # type: ignore
mutant.mutant_code, mutant.source_stats["mtime"],
mutant.source_stats["size"])
LOGGER.debug("Writing parallel mutant cache file: %s", parallel_cfile)
cache.create_cache_dirs(parallel_cfile)
importlib._bootstrap_external._write_atomic( # type: ignore
parallel_cfile,
bytecode,
mutant.mode,
)
copy_env = os.environ.copy()
copy_env["PYTHONPYCACHEPREFIX"] = str(parallel_cache)
try:
mutant_trial = subprocess.run(
test_cmds,
env=copy_env,
capture_output=capture_output(LOGGER.getEffectiveLevel()),
timeout=max_runtime + MULTI_PROC_TIMEOUT_BUFFER,
)
return_code = mutant_trial.returncode
except subprocess.TimeoutExpired:
return_code = 3
LOGGER.debug("Removing parallel cache file: %s", parallel_cache.parts[-1])
shutil.rmtree(parallel_cache)
return MutantTrialResult(
mutant=MutantReport(src_file=mutant.src_file,
src_idx=mutant.src_idx,
mutation=mutant.mutation),
return_code=return_code,
)