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# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
"""
Support for optimizing tasks based on the set of files that have changed.
"""
import logging
import os
from subprocess import CalledProcessError
from mozbuild.util import memoize
from mozpack.path import join as join_path
from mozpack.path import match as mozpackmatch
from mozversioncontrol import InvalidRepoPath, get_repository_object
from gecko_taskgraph import GECKO
from gecko_taskgraph.util.hg import get_json_pushchangedfiles
logger = logging.getLogger(__name__)
@memoize
def get_changed_files(repository, revision):
"""
Get the set of files changed in the push headed by the given revision.
Responses are cached, so multiple calls with the same arguments are OK.
"""
try:
return get_json_pushchangedfiles(repository, revision)["files"]
except KeyError:
# We shouldn't hit this error in CI.
if os.environ.get("MOZ_AUTOMATION"):
raise
# We're likely on an unpublished commit, grab changed files from
# version control.
return get_locally_changed_files(GECKO)
def check(params, file_patterns):
"""Determine whether any of the files changed in the indicated push to
repository = params.get("head_repository")
revision = params.get("head_rev")
if not repository or not revision:
logger.warning(
"Missing `head_repository` or `head_rev` parameters; "
"assuming all files have changed"
)
return True
changed_files = get_changed_files(repository, revision)
if "comm_head_repository" in params:
repository = params.get("comm_head_repository")
revision = params.get("comm_head_rev")
if not revision:
logger.warning(
"Missing `comm_head_rev` parameters; assuming all files have changed"
)
return True
changed_files |= {
join_path("comm", file) for file in get_changed_files(repository, revision)
}
for pattern in file_patterns:
for path in changed_files:
if mozpackmatch(path, pattern):
return True
return False
def _get_locally_changed_files(repo):
try:
vcs = get_repository_object(repo)
s = set(vcs.get_outgoing_files("AM"))
return s
except (InvalidRepoPath, CalledProcessError):
return set()
class PreloadedGetLocallyChangedFiles:
"""
Function-like class that performs eager computation of _get_locally_changed_files
for what looks the default repo.
The rationale is the following:
- computing _get_locally_changed_files is relatively slow (~600ms)
- it's already done through an external command
So we do that in a background thread as soon as possible, so that at the
point when we need the result, it's already "prefetched".
"""
def __init__(self):
self.preloaded_repo = None
self.preloading_thread = None
self.preloaded_answer = None
def preload(self, repo):
"""
Fire off preloading of get_locally_changed_files(repo).
For the sake of simplicity, there can be only one preloaded repo.
"""
import threading
from pathlib import Path
if self.preloaded_repo is not None:
raise ValueError("Can only preload one repo")
self.preloaded_repo = Path(repo)
def preloading():
self.preloaded_answer = _get_locally_changed_files(self.preloaded_repo)
self.preloading_thread = threading.Thread(target=preloading, daemon=True)
self.preloading_thread.start()
@memoize
def __call__(self, repo):
if repo == self.preloaded_repo:
# A thread can be joined many times, but it's going to happen only
# once, thanks to @memoize.
self.preloading_thread.join()
return self.preloaded_answer
return _get_locally_changed_files(repo)
get_locally_changed_files = PreloadedGetLocallyChangedFiles()