ballistica/tools/efrotools/filecache.py
2020-02-05 05:11:36 -08:00

113 lines
4.4 KiB
Python

# Copyright (c) 2011-2020 Eric Froemling
#
# 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.
# -----------------------------------------------------------------------------
"""Provides a system for caching linting/formatting operations."""
from __future__ import annotations
import json
import os
from typing import TYPE_CHECKING
from efrotools import get_files_hash
if TYPE_CHECKING:
from typing import Dict, Optional, Sequence, Any
from pathlib import Path
class FileCache:
"""A cache of file hashes/etc. used in linting/formatting/etc."""
def __init__(self, path: Path):
self._path = path
self.curhashes: Dict[str, Optional[str]] = {}
self.mtimes: Dict[str, float] = {}
self.entries: Dict[str, Any]
if not os.path.exists(path):
self.entries = {}
else:
with open(path, 'r') as infile:
self.entries = json.loads(infile.read())
def update(self, filenames: Sequence[str], extrahash: str) -> None:
"""Update the cache for the provided files and hash type.
Hashes will be checked for all files (incorporating extrahash)
and mismatched hash values cleared. Entries for no-longer-existing
files will be cleared as well.
"""
# First, completely prune entries for nonexistent files.
self.entries = {
path: val
for path, val in self.entries.items() if os.path.isfile(path)
}
# Also remove any not in our passed list.
self.entries = {
path: val
for path, val in self.entries.items() if path in filenames
}
# Add empty entries for files that lack them.
# Also check and store current hashes for all files and clear
# any entry hashes that differ so we know they're dirty.
for filename in filenames:
if filename not in self.entries:
self.entries[filename] = {}
self.curhashes[filename] = curhash = (get_files_hash([filename],
extrahash))
# Also store modtimes; we'll abort cache writes if
# anything changed.
self.mtimes[filename] = os.path.getmtime(filename)
entry = self.entries[filename]
if 'hash' in entry and entry['hash'] != curhash:
del entry['hash']
def get_dirty_files(self) -> Sequence[str]:
"""Return paths for all entries with no hash value."""
return [
key for key, value in self.entries.items() if 'hash' not in value
]
def mark_clean(self, files: Sequence[str]) -> None:
"""Marks provided files as up to date."""
for fname in files:
self.entries[fname]['hash'] = self.curhashes[fname]
# Also update their registered mtimes.
self.mtimes[fname] = os.path.getmtime(fname)
def write(self) -> None:
"""Writes the state back to its file."""
# Check all file mtimes against the ones we started with;
# if anything has been modified, don't write.
for fname, mtime in self.mtimes.items():
if os.path.getmtime(fname) != mtime:
print('File changed during run: "' + fname + '";' +
' cache not updated.')
return
out = json.dumps(self.entries)
with open(self._path, 'w') as outfile:
outfile.write(out)