""" History related magics and functionality """ from __future__ import annotations # Copyright (c) IPython Development Team. # Distributed under the terms of the Modified BSD License. import atexit import datetime import re import threading from pathlib import Path from decorator import decorator from traitlets import ( Any, Bool, Dict, Instance, Integer, List, TraitError, Unicode, Union, default, observe, ) from traitlets.config.configurable import LoggingConfigurable from IPython.paths import locate_profile from IPython.utils.decorators import undoc from typing import Iterable, Tuple, Optional, TYPE_CHECKING import typing if TYPE_CHECKING: from IPython.core.interactiveshell import InteractiveShell from IPython.config.Configuration import Configuration try: from sqlite3 import DatabaseError, OperationalError import sqlite3 sqlite3_found = True except ModuleNotFoundError: sqlite3_found = False class DatabaseError(Exception): # type: ignore [no-redef] pass class OperationalError(Exception): # type: ignore [no-redef] pass InOrInOut = typing.Union[str, Tuple[str, Optional[str]]] #----------------------------------------------------------------------------- # Classes and functions #----------------------------------------------------------------------------- @undoc class DummyDB: """Dummy DB that will act as a black hole for history. Only used in the absence of sqlite""" def execute(*args: typing.Any, **kwargs: typing.Any) -> typing.List: return [] def commit(self, *args, **kwargs): # type: ignore [no-untyped-def] pass def __enter__(self, *args, **kwargs): # type: ignore [no-untyped-def] pass def __exit__(self, *args, **kwargs): # type: ignore [no-untyped-def] pass @decorator def only_when_enabled(f, self, *a, **kw): # type: ignore [no-untyped-def] """Decorator: return an empty list in the absence of sqlite.""" if not self.enabled: return [] else: return f(self, *a, **kw) # use 16kB as threshold for whether a corrupt history db should be saved # that should be at least 100 entries or so _SAVE_DB_SIZE = 16384 @decorator def catch_corrupt_db(f, self, *a, **kw): # type: ignore [no-untyped-def] """A decorator which wraps HistoryAccessor method calls to catch errors from a corrupt SQLite database, move the old database out of the way, and create a new one. We avoid clobbering larger databases because this may be triggered due to filesystem issues, not just a corrupt file. """ try: return f(self, *a, **kw) except (DatabaseError, OperationalError) as e: self._corrupt_db_counter += 1 self.log.error("Failed to open SQLite history %s (%s).", self.hist_file, e) if self.hist_file != ':memory:': if self._corrupt_db_counter > self._corrupt_db_limit: self.hist_file = ':memory:' self.log.error("Failed to load history too many times, history will not be saved.") elif self.hist_file.is_file(): # move the file out of the way base = str(self.hist_file.parent / self.hist_file.stem) ext = self.hist_file.suffix size = self.hist_file.stat().st_size if size >= _SAVE_DB_SIZE: # if there's significant content, avoid clobbering now = datetime.datetime.now().isoformat().replace(':', '.') newpath = base + '-corrupt-' + now + ext # don't clobber previous corrupt backups for i in range(100): if not Path(newpath).exists(): break else: newpath = base + '-corrupt-' + now + (u'-%i' % i) + ext else: # not much content, possibly empty; don't worry about clobbering # maybe we should just delete it? newpath = base + '-corrupt' + ext self.hist_file.rename(newpath) self.log.error("History file was moved to %s and a new file created.", newpath) self.init_db() return [] else: # Failed with :memory:, something serious is wrong raise class HistoryAccessorBase(LoggingConfigurable): """An abstract class for History Accessors """ def get_tail( self, n: int = 10, raw: bool = True, output: bool = False, include_latest: bool = False, ) -> Iterable[Tuple[int, int, InOrInOut]]: raise NotImplementedError def search( self, pattern: str = "*", raw: bool = True, search_raw: bool = True, output: bool = False, n: Optional[int] = None, unique: bool = False, ) -> Iterable[Tuple[int, int, InOrInOut]]: raise NotImplementedError def get_range( self, session: int, start: int = 1, stop: Optional[int] = None, raw: bool = True, output: bool = False, ) -> Iterable[Tuple[int, int, InOrInOut]]: raise NotImplementedError def get_range_by_str( self, rangestr: str, raw: bool = True, output: bool = False ) -> Iterable[Tuple[int, int, InOrInOut]]: raise NotImplementedError class HistoryAccessor(HistoryAccessorBase): """Access the history database without adding to it. This is intended for use by standalone history tools. IPython shells use HistoryManager, below, which is a subclass of this.""" # counter for init_db retries, so we don't keep trying over and over _corrupt_db_counter = 0 # after two failures, fallback on :memory: _corrupt_db_limit = 2 # String holding the path to the history file hist_file = Union( [Instance(Path), Unicode()], help="""Path to file to use for SQLite history database. By default, IPython will put the history database in the IPython profile directory. If you would rather share one history among profiles, you can set this value in each, so that they are consistent. Due to an issue with fcntl, SQLite is known to misbehave on some NFS mounts. If you see IPython hanging, try setting this to something on a local disk, e.g:: ipython --HistoryManager.hist_file=/tmp/ipython_hist.sqlite you can also use the specific value `:memory:` (including the colon at both end but not the back ticks), to avoid creating an history file. """, ).tag(config=True) enabled = Bool( sqlite3_found, help="""enable the SQLite history set enabled=False to disable the SQLite history, in which case there will be no stored history, no SQLite connection, and no background saving thread. This may be necessary in some threaded environments where IPython is embedded. """, ).tag(config=True) connection_options = Dict( help="""Options for configuring the SQLite connection These options are passed as keyword args to sqlite3.connect when establishing database connections. """ ).tag(config=True) @default("connection_options") def _default_connection_options(self) -> typing.Dict[str, bool]: return dict(check_same_thread=False) # The SQLite database db = Any() @observe('db') @only_when_enabled def _db_changed(self, change): # type: ignore [no-untyped-def] """validate the db, since it can be an Instance of two different types""" new = change['new'] connection_types = (DummyDB, sqlite3.Connection) if not isinstance(new, connection_types): msg = "%s.db must be sqlite3 Connection or DummyDB, not %r" % \ (self.__class__.__name__, new) raise TraitError(msg) def __init__( self, profile: str = "default", hist_file: str = "", **traits: typing.Any ) -> None: """Create a new history accessor. Parameters ---------- profile : str The name of the profile from which to open history. hist_file : str Path to an SQLite history database stored by IPython. If specified, hist_file overrides profile. config : :class:`~traitlets.config.loader.Config` Config object. hist_file can also be set through this. """ super(HistoryAccessor, self).__init__(**traits) # defer setting hist_file from kwarg until after init, # otherwise the default kwarg value would clobber any value # set by config if hist_file: self.hist_file = hist_file try: self.hist_file except TraitError: # No one has set the hist_file, yet. self.hist_file = self._get_hist_file_name(profile) self.init_db() def _get_hist_file_name(self, profile: str = "default") -> Path: """Find the history file for the given profile name. This is overridden by the HistoryManager subclass, to use the shell's active profile. Parameters ---------- profile : str The name of a profile which has a history file. """ return Path(locate_profile(profile)) / "history.sqlite" @catch_corrupt_db def init_db(self) -> None: """Connect to the database, and create tables if necessary.""" if not self.enabled: self.db = DummyDB() return # use detect_types so that timestamps return datetime objects kwargs = dict(detect_types=sqlite3.PARSE_DECLTYPES|sqlite3.PARSE_COLNAMES) kwargs.update(self.connection_options) self.db = sqlite3.connect(str(self.hist_file), **kwargs) # type: ignore [call-overload] with self.db: self.db.execute( """CREATE TABLE IF NOT EXISTS sessions (session integer primary key autoincrement, start timestamp, end timestamp, num_cmds integer, remark text)""" ) self.db.execute( """CREATE TABLE IF NOT EXISTS history (session integer, line integer, source text, source_raw text, PRIMARY KEY (session, line))""" ) # Output history is optional, but ensure the table's there so it can be # enabled later. self.db.execute( """CREATE TABLE IF NOT EXISTS output_history (session integer, line integer, output text, PRIMARY KEY (session, line))""" ) # success! reset corrupt db count self._corrupt_db_counter = 0 def writeout_cache(self) -> None: """Overridden by HistoryManager to dump the cache before certain database lookups.""" pass ## ------------------------------- ## Methods for retrieving history: ## ------------------------------- def _run_sql( self, sql: str, params: typing.Tuple, raw: bool = True, output: bool = False, latest: bool = False, ) -> Iterable[Tuple[int, int, InOrInOut]]: """Prepares and runs an SQL query for the history database. Parameters ---------- sql : str Any filtering expressions to go after SELECT ... FROM ... params : tuple Parameters passed to the SQL query (to replace "?") raw, output : bool See :meth:`get_range` latest : bool Select rows with max (session, line) Returns ------- Tuples as :meth:`get_range` """ toget = 'source_raw' if raw else 'source' sqlfrom = "history" if output: sqlfrom = "history LEFT JOIN output_history USING (session, line)" toget = "history.%s, output_history.output" % toget if latest: toget += ", MAX(session * 128 * 1024 + line)" this_querry = "SELECT session, line, %s FROM %s " % (toget, sqlfrom) + sql cur = self.db.execute(this_querry, params) if latest: cur = (row[:-1] for row in cur) if output: # Regroup into 3-tuples, and parse JSON return ((ses, lin, (inp, out)) for ses, lin, inp, out in cur) return cur @only_when_enabled @catch_corrupt_db def get_session_info( self, session: int ) -> Tuple[int, datetime.datetime, Optional[datetime.datetime], Optional[int], str]: """Get info about a session. Parameters ---------- session : int Session number to retrieve. Returns ------- session_id : int Session ID number start : datetime Timestamp for the start of the session. end : datetime Timestamp for the end of the session, or None if IPython crashed. num_cmds : int Number of commands run, or None if IPython crashed. remark : unicode A manually set description. """ query = "SELECT * from sessions where session == ?" return self.db.execute(query, (session,)).fetchone() @catch_corrupt_db def get_last_session_id(self) -> Optional[int]: """Get the last session ID currently in the database. Within IPython, this should be the same as the value stored in :attr:`HistoryManager.session_number`. """ for record in self.get_tail(n=1, include_latest=True): return record[0] return None @catch_corrupt_db def get_tail( self, n: int = 10, raw: bool = True, output: bool = False, include_latest: bool = False, ) -> Iterable[Tuple[int, int, InOrInOut]]: """Get the last n lines from the history database. Parameters ---------- n : int The number of lines to get raw, output : bool See :meth:`get_range` include_latest : bool If False (default), n+1 lines are fetched, and the latest one is discarded. This is intended to be used where the function is called by a user command, which it should not return. Returns ------- Tuples as :meth:`get_range` """ self.writeout_cache() if not include_latest: n += 1 cur = self._run_sql( "ORDER BY session DESC, line DESC LIMIT ?", (n,), raw=raw, output=output ) if not include_latest: return reversed(list(cur)[1:]) return reversed(list(cur)) @catch_corrupt_db def search( self, pattern: str = "*", raw: bool = True, search_raw: bool = True, output: bool = False, n: Optional[int] = None, unique: bool = False, ) -> Iterable[Tuple[int, int, InOrInOut]]: """Search the database using unix glob-style matching (wildcards * and ?). Parameters ---------- pattern : str The wildcarded pattern to match when searching search_raw : bool If True, search the raw input, otherwise, the parsed input raw, output : bool See :meth:`get_range` n : None or int If an integer is given, it defines the limit of returned entries. unique : bool When it is true, return only unique entries. Returns ------- Tuples as :meth:`get_range` """ tosearch = "source_raw" if search_raw else "source" if output: tosearch = "history." + tosearch self.writeout_cache() sqlform = "WHERE %s GLOB ?" % tosearch params: typing.Tuple[typing.Any, ...] = (pattern,) if unique: sqlform += ' GROUP BY {0}'.format(tosearch) if n is not None: sqlform += " ORDER BY session DESC, line DESC LIMIT ?" params += (n,) elif unique: sqlform += " ORDER BY session, line" cur = self._run_sql(sqlform, params, raw=raw, output=output, latest=unique) if n is not None: return reversed(list(cur)) return cur @catch_corrupt_db def get_range( self, session: int, start: int = 1, stop: Optional[int] = None, raw: bool = True, output: bool = False, ) -> Iterable[Tuple[int, int, InOrInOut]]: """Retrieve input by session. Parameters ---------- session : int Session number to retrieve. start : int First line to retrieve. stop : int End of line range (excluded from output itself). If None, retrieve to the end of the session. raw : bool If True, return untranslated input output : bool If True, attempt to include output. This will be 'real' Python objects for the current session, or text reprs from previous sessions if db_log_output was enabled at the time. Where no output is found, None is used. Returns ------- entries An iterator over the desired lines. Each line is a 3-tuple, either (session, line, input) if output is False, or (session, line, (input, output)) if output is True. """ params: typing.Tuple[typing.Any, ...] if stop: lineclause = "line >= ? AND line < ?" params = (session, start, stop) else: lineclause = "line>=?" params = (session, start) return self._run_sql("WHERE session==? AND %s" % lineclause, params, raw=raw, output=output) def get_range_by_str( self, rangestr: str, raw: bool = True, output: bool = False ) -> Iterable[Tuple[int, int, InOrInOut]]: """Get lines of history from a string of ranges, as used by magic commands %hist, %save, %macro, etc. Parameters ---------- rangestr : str A string specifying ranges, e.g. "5 ~2/1-4". If empty string is used, this will return everything from current session's history. See the documentation of :func:`%history` for the full details. raw, output : bool As :meth:`get_range` Returns ------- Tuples as :meth:`get_range` """ for sess, s, e in extract_hist_ranges(rangestr): for line in self.get_range(sess, s, e, raw=raw, output=output): yield line class HistoryManager(HistoryAccessor): """A class to organize all history-related functionality in one place. """ # Public interface # An instance of the IPython shell we are attached to shell = Instance( "IPython.core.interactiveshell.InteractiveShellABC", allow_none=False ) # Lists to hold processed and raw history. These start with a blank entry # so that we can index them starting from 1 input_hist_parsed = List([""]) input_hist_raw = List([""]) # A list of directories visited during session dir_hist: List = List() @default("dir_hist") def _dir_hist_default(self) -> typing.List[Path]: try: return [Path.cwd()] except OSError: return [] # A dict of output history, keyed with ints from the shell's # execution count. output_hist = Dict() # The text/plain repr of outputs. output_hist_reprs: typing.Dict[int, str] = Dict() # type: ignore [assignment] # The number of the current session in the history database session_number: int = Integer() # type: ignore [assignment] db_log_output = Bool(False, help="Should the history database include output? (default: no)" ).tag(config=True) db_cache_size = Integer(0, help="Write to database every x commands (higher values save disk access & power).\n" "Values of 1 or less effectively disable caching." ).tag(config=True) # The input and output caches db_input_cache: List[Tuple[int, str, str]] = List() db_output_cache: List[Tuple[int, str]] = List() # History saving in separate thread save_thread = Instance('IPython.core.history.HistorySavingThread', allow_none=True) save_flag = Instance(threading.Event, allow_none=False) # Private interface # Variables used to store the three last inputs from the user. On each new # history update, we populate the user's namespace with these, shifted as # necessary. _i00 = Unicode("") _i = Unicode("") _ii = Unicode("") _iii = Unicode("") # A regex matching all forms of the exit command, so that we don't store # them in the history (it's annoying to rewind the first entry and land on # an exit call). _exit_re = re.compile(r"(exit|quit)(\s*\(.*\))?$") def __init__( self, shell: InteractiveShell, config: Optional[Configuration] = None, **traits: typing.Any, ): """Create a new history manager associated with a shell instance.""" super().__init__(shell=shell, config=config, **traits) self.save_flag = threading.Event() self.db_input_cache_lock = threading.Lock() self.db_output_cache_lock = threading.Lock() try: self.new_session() except OperationalError: self.log.error("Failed to create history session in %s. History will not be saved.", self.hist_file, exc_info=True) self.hist_file = ':memory:' if self.enabled and self.hist_file != ':memory:': self.save_thread = HistorySavingThread(self) try: self.save_thread.start() except RuntimeError: self.log.error( "Failed to start history saving thread. History will not be saved.", exc_info=True, ) self.hist_file = ":memory:" def _get_hist_file_name(self, profile: Optional[str] = None) -> Path: """Get default history file name based on the Shell's profile. The profile parameter is ignored, but must exist for compatibility with the parent class.""" profile_dir = self.shell.profile_dir.location return Path(profile_dir) / "history.sqlite" @only_when_enabled def new_session(self, conn: Optional[sqlite3.Connection] = None) -> None: """Get a new session number.""" if conn is None: conn = self.db with conn: cur = conn.execute( """INSERT INTO sessions VALUES (NULL, ?, NULL, NULL, '') """, (datetime.datetime.now().isoformat(" "),), ) assert isinstance(cur.lastrowid, int) self.session_number = cur.lastrowid def end_session(self) -> None: """Close the database session, filling in the end time and line count.""" self.writeout_cache() with self.db: self.db.execute( """UPDATE sessions SET end=?, num_cmds=? WHERE session==?""", ( datetime.datetime.now().isoformat(" "), len(self.input_hist_parsed) - 1, self.session_number, ), ) self.session_number = 0 def name_session(self, name: str) -> None: """Give the current session a name in the history database.""" with self.db: self.db.execute("UPDATE sessions SET remark=? WHERE session==?", (name, self.session_number)) def reset(self, new_session: bool = True) -> None: """Clear the session history, releasing all object references, and optionally open a new session.""" self.output_hist.clear() # The directory history can't be completely empty self.dir_hist[:] = [Path.cwd()] if new_session: if self.session_number: self.end_session() self.input_hist_parsed[:] = [""] self.input_hist_raw[:] = [""] self.new_session() # ------------------------------ # Methods for retrieving history # ------------------------------ def get_session_info( self, session: int = 0 ) -> Tuple[int, datetime.datetime, Optional[datetime.datetime], Optional[int], str]: """Get info about a session. Parameters ---------- session : int Session number to retrieve. The current session is 0, and negative numbers count back from current session, so -1 is the previous session. Returns ------- session_id : int Session ID number start : datetime Timestamp for the start of the session. end : datetime Timestamp for the end of the session, or None if IPython crashed. num_cmds : int Number of commands run, or None if IPython crashed. remark : unicode A manually set description. """ if session <= 0: session += self.session_number return super(HistoryManager, self).get_session_info(session=session) @catch_corrupt_db def get_tail( self, n: int = 10, raw: bool = True, output: bool = False, include_latest: bool = False, ) -> Iterable[Tuple[int, int, InOrInOut]]: """Get the last n lines from the history database. Most recent entry last. Completion will be reordered so that that the last ones are when possible from current session. Parameters ---------- n : int The number of lines to get raw, output : bool See :meth:`get_range` include_latest : bool If False (default), n+1 lines are fetched, and the latest one is discarded. This is intended to be used where the function is called by a user command, which it should not return. Returns ------- Tuples as :meth:`get_range` """ self.writeout_cache() if not include_latest: n += 1 # cursor/line/entry this_cur = list( self._run_sql( "WHERE session == ? ORDER BY line DESC LIMIT ? ", (self.session_number, n), raw=raw, output=output, ) ) other_cur = list( self._run_sql( "WHERE session != ? ORDER BY session DESC, line DESC LIMIT ?", (self.session_number, n), raw=raw, output=output, ) ) everything: typing.List[Tuple[int, int, InOrInOut]] = this_cur + other_cur everything = everything[:n] if not include_latest: return list(everything)[:0:-1] return list(everything)[::-1] def _get_range_session( self, start: int = 1, stop: Optional[int] = None, raw: bool = True, output: bool = False, ) -> Iterable[Tuple[int, int, InOrInOut]]: """Get input and output history from the current session. Called by get_range, and takes similar parameters.""" input_hist = self.input_hist_raw if raw else self.input_hist_parsed n = len(input_hist) if start < 0: start += n if not stop or (stop > n): stop = n elif stop < 0: stop += n line: InOrInOut for i in range(start, stop): if output: line = (input_hist[i], self.output_hist_reprs.get(i)) else: line = input_hist[i] yield (0, i, line) def get_range( self, session: int = 0, start: int = 1, stop: Optional[int] = None, raw: bool = True, output: bool = False, ) -> Iterable[Tuple[int, int, InOrInOut]]: """Retrieve input by session. Parameters ---------- session : int Session number to retrieve. The current session is 0, and negative numbers count back from current session, so -1 is previous session. start : int First line to retrieve. stop : int End of line range (excluded from output itself). If None, retrieve to the end of the session. raw : bool If True, return untranslated input output : bool If True, attempt to include output. This will be 'real' Python objects for the current session, or text reprs from previous sessions if db_log_output was enabled at the time. Where no output is found, None is used. Returns ------- entries An iterator over the desired lines. Each line is a 3-tuple, either (session, line, input) if output is False, or (session, line, (input, output)) if output is True. """ if session <= 0: session += self.session_number if session==self.session_number: # Current session return self._get_range_session(start, stop, raw, output) return super(HistoryManager, self).get_range(session, start, stop, raw, output) ## ---------------------------- ## Methods for storing history: ## ---------------------------- def store_inputs( self, line_num: int, source: str, source_raw: Optional[str] = None ) -> None: """Store source and raw input in history and create input cache variables ``_i*``. Parameters ---------- line_num : int The prompt number of this input. source : str Python input. source_raw : str, optional If given, this is the raw input without any IPython transformations applied to it. If not given, ``source`` is used. """ if source_raw is None: source_raw = source source = source.rstrip('\n') source_raw = source_raw.rstrip('\n') # do not store exit/quit commands if self._exit_re.match(source_raw.strip()): return self.input_hist_parsed.append(source) self.input_hist_raw.append(source_raw) with self.db_input_cache_lock: self.db_input_cache.append((line_num, source, source_raw)) # Trigger to flush cache and write to DB. if len(self.db_input_cache) >= self.db_cache_size: self.save_flag.set() # update the auto _i variables self._iii = self._ii self._ii = self._i self._i = self._i00 self._i00 = source_raw # hackish access to user namespace to create _i1,_i2... dynamically new_i = '_i%s' % line_num to_main = {'_i': self._i, '_ii': self._ii, '_iii': self._iii, new_i : self._i00 } if self.shell is not None: self.shell.push(to_main, interactive=False) def store_output(self, line_num: int) -> None: """If database output logging is enabled, this saves all the outputs from the indicated prompt number to the database. It's called by run_cell after code has been executed. Parameters ---------- line_num : int The line number from which to save outputs """ if (not self.db_log_output) or (line_num not in self.output_hist_reprs): return lnum: int = line_num output = self.output_hist_reprs[line_num] with self.db_output_cache_lock: self.db_output_cache.append((line_num, output)) if self.db_cache_size <= 1: self.save_flag.set() def _writeout_input_cache(self, conn: sqlite3.Connection) -> None: with conn: for line in self.db_input_cache: conn.execute("INSERT INTO history VALUES (?, ?, ?, ?)", (self.session_number,)+line) def _writeout_output_cache(self, conn: sqlite3.Connection) -> None: with conn: for line in self.db_output_cache: conn.execute("INSERT INTO output_history VALUES (?, ?, ?)", (self.session_number,)+line) @only_when_enabled def writeout_cache(self, conn: Optional[sqlite3.Connection] = None) -> None: """Write any entries in the cache to the database.""" if conn is None: conn = self.db with self.db_input_cache_lock: try: self._writeout_input_cache(conn) except sqlite3.IntegrityError: self.new_session(conn) print("ERROR! Session/line number was not unique in", "database. History logging moved to new session", self.session_number) try: # Try writing to the new session. If this fails, don't # recurse self._writeout_input_cache(conn) except sqlite3.IntegrityError: pass finally: self.db_input_cache = [] with self.db_output_cache_lock: try: self._writeout_output_cache(conn) except sqlite3.IntegrityError: print("!! Session/line number for output was not unique", "in database. Output will not be stored.") finally: self.db_output_cache = [] class HistorySavingThread(threading.Thread): """This thread takes care of writing history to the database, so that the UI isn't held up while that happens. It waits for the HistoryManager's save_flag to be set, then writes out the history cache. The main thread is responsible for setting the flag when the cache size reaches a defined threshold.""" daemon = True stop_now = False enabled = True history_manager: HistoryManager def __init__(self, history_manager: HistoryManager) -> None: super(HistorySavingThread, self).__init__(name="IPythonHistorySavingThread") self.history_manager = history_manager self.enabled = history_manager.enabled @only_when_enabled def run(self) -> None: atexit.register(self.stop) # We need a separate db connection per thread: try: self.db = sqlite3.connect( str(self.history_manager.hist_file), **self.history_manager.connection_options, ) while True: self.history_manager.save_flag.wait() if self.stop_now: self.db.close() return self.history_manager.save_flag.clear() self.history_manager.writeout_cache(self.db) except Exception as e: print(("The history saving thread hit an unexpected error (%s)." "History will not be written to the database.") % repr(e)) finally: atexit.unregister(self.stop) def stop(self) -> None: """This can be called from the main thread to safely stop this thread. Note that it does not attempt to write out remaining history before exiting. That should be done by calling the HistoryManager's end_session method.""" self.stop_now = True self.history_manager.save_flag.set() self.join() # To match, e.g. ~5/8-~2/3 range_re = re.compile(r""" ((?P~?\d+)/)? (?P\d+)? ((?P[\-:]) ((?P~?\d+)/)? (?P\d+))? $""", re.VERBOSE) def extract_hist_ranges(ranges_str: str) -> Iterable[Tuple[int, int, Optional[int]]]: """Turn a string of history ranges into 3-tuples of (session, start, stop). Empty string results in a `[(0, 1, None)]`, i.e. "everything from current session". Examples -------- >>> list(extract_hist_ranges("~8/5-~7/4 2")) [(-8, 5, None), (-7, 1, 5), (0, 2, 3)] """ if ranges_str == "": yield (0, 1, None) # Everything from current session return for range_str in ranges_str.split(): rmatch = range_re.match(range_str) if not rmatch: continue start = rmatch.group("start") if start: start = int(start) end = rmatch.group("end") # If no end specified, get (a, a + 1) end = int(end) if end else start + 1 else: # start not specified if not rmatch.group('startsess'): # no startsess continue start = 1 end = None # provide the entire session hist if rmatch.group("sep") == "-": # 1-3 == 1:4 --> [1, 2, 3] assert end is not None end += 1 startsess = rmatch.group("startsess") or "0" endsess = rmatch.group("endsess") or startsess startsess = int(startsess.replace("~","-")) endsess = int(endsess.replace("~","-")) assert endsess >= startsess, "start session must be earlier than end session" if endsess == startsess: yield (startsess, start, end) continue # Multiple sessions in one range: yield (startsess, start, None) for sess in range(startsess+1, endsess): yield (sess, 1, None) yield (endsess, 1, end) def _format_lineno(session: int, line: int) -> str: """Helper function to format line numbers properly.""" if session == 0: return str(line) return "%s#%s" % (session, line)