# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et: # Copyright 2014-2021 Florian Bruhin (The Compiler) # # This file is part of qutebrowser. # # qutebrowser is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # qutebrowser is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with qutebrowser. If not, see . """Parser for line-based files like histories.""" import os import os.path import contextlib from typing import Sequence from PyQt5.QtCore import pyqtSlot, pyqtSignal, QObject from qutebrowser.utils import log, utils, qtutils from qutebrowser.config import config class BaseLineParser(QObject): """A LineParser without any real data. Attributes: _configdir: Directory to read the config from, or None. _configfile: The config file path. _fname: Filename of the config. _binary: Whether to open the file in binary mode. Signals: changed: Emitted when the history was changed. """ changed = pyqtSignal() def __init__(self, configdir, fname, *, binary=False, parent=None): """Constructor. Args: configdir: Directory to read the config from. fname: Filename of the config file. binary: Whether to open the file in binary mode. _opened: Whether the underlying file is open """ super().__init__(parent) self._configdir = configdir self._configfile = os.path.join(self._configdir, fname) self._fname = fname self._binary = binary self._opened = False def __repr__(self): return utils.get_repr(self, constructor=True, configdir=self._configdir, fname=self._fname, binary=self._binary) def _prepare_save(self): """Prepare saving of the file. Return: True if the file should be saved, False otherwise. """ os.makedirs(self._configdir, 0o755, exist_ok=True) return True def _after_save(self): """Log a message after saving is done.""" log.destroy.debug("Saved to {}".format(self._configfile)) @contextlib.contextmanager def _open(self, mode): """Open self._configfile for reading. Args: mode: The mode to use ('a'/'r'/'w') Raises: OSError: if the file is already open Yields: a file object for the config file """ assert self._configfile is not None if self._opened: raise OSError("Refusing to double-open LineParser.") self._opened = True try: if self._binary: # pylint: disable=unspecified-encoding with open(self._configfile, mode + 'b') as f: yield f else: with open(self._configfile, mode, encoding='utf-8') as f: yield f finally: self._opened = False def _write(self, fp, data): """Write the data to a file. Args: fp: A file object to write the data to. data: The data to write. """ if not data: return if self._binary: fp.write(b'\n'.join(data)) fp.write(b'\n') else: fp.write('\n'.join(data)) fp.write('\n') def save(self): """Save the history to disk.""" raise NotImplementedError def clear(self): """Clear the contents of the file.""" raise NotImplementedError class LineParser(BaseLineParser): """Parser for configuration files which are simply line-based. Attributes: data: A list of lines. """ def __init__(self, configdir, fname, *, binary=False, parent=None): """Constructor. Args: configdir: Directory to read the config from. fname: Filename of the config file. binary: Whether to open the file in binary mode. """ super().__init__(configdir, fname, binary=binary, parent=parent) if not os.path.isfile(self._configfile): self.data: Sequence[str] = [] else: log.init.debug("Reading {}".format(self._configfile)) self._read() def __iter__(self): return iter(self.data) def __getitem__(self, key): return self.data[key] def _read(self): """Read the data from self._configfile.""" with self._open('r') as f: if self._binary: self.data = [line.rstrip(b'\n') for line in f] else: self.data = [line.rstrip('\n') for line in f] def save(self): """Save the config file.""" if self._opened: raise OSError("Refusing to double-open LineParser.") do_save = self._prepare_save() if not do_save: return self._opened = True try: assert self._configfile is not None with qtutils.savefile_open(self._configfile, self._binary) as f: self._write(f, self.data) finally: self._opened = False self._after_save() def clear(self): self.data = [] self.save() class LimitLineParser(LineParser): """A LineParser with a limited count of lines. Attributes: _limit: The config option used to limit the maximum number of lines. """ def __init__(self, configdir, fname, *, limit, binary=False, parent=None): """Constructor. Args: configdir: Directory to read the config from, or None. fname: Filename of the config file. limit: Config option which contains a limit. binary: Whether to open the file in binary mode. """ super().__init__(configdir, fname, binary=binary, parent=parent) self._limit = limit if limit is not None and configdir is not None: config.instance.changed.connect(self._cleanup_file) def __repr__(self): return utils.get_repr(self, constructor=True, configdir=self._configdir, fname=self._fname, limit=self._limit, binary=self._binary) @pyqtSlot(str) def _cleanup_file(self, option): """Delete the file if the limit was changed to 0.""" assert self._configfile is not None if option != self._limit: return value = config.instance.get(option) if value == 0: if os.path.exists(self._configfile): os.remove(self._configfile) def save(self): """Save the config file.""" limit = config.instance.get(self._limit) if limit == 0: return do_save = self._prepare_save() if not do_save: return assert self._configfile is not None with qtutils.savefile_open(self._configfile, self._binary) as f: self._write(f, self.data[-limit:]) self._after_save()