| """BitBake Persistent Data Store |
| |
| Used to store data in a central location such that other threads/tasks can |
| access them at some future date. Acts as a convenience wrapper around sqlite, |
| currently, providing a key/value store accessed by 'domain'. |
| """ |
| |
| # Copyright (C) 2007 Richard Purdie |
| # Copyright (C) 2010 Chris Larson <chris_larson@mentor.com> |
| # |
| # SPDX-License-Identifier: GPL-2.0-only |
| # |
| |
| import collections |
| import contextlib |
| import functools |
| import logging |
| import os.path |
| import sqlite3 |
| import sys |
| import warnings |
| from collections import Mapping |
| |
| sqlversion = sqlite3.sqlite_version_info |
| if sqlversion[0] < 3 or (sqlversion[0] == 3 and sqlversion[1] < 3): |
| raise Exception("sqlite3 version 3.3.0 or later is required.") |
| |
| |
| logger = logging.getLogger("BitBake.PersistData") |
| |
| @functools.total_ordering |
| class SQLTable(collections.MutableMapping): |
| class _Decorators(object): |
| @staticmethod |
| def retry(*, reconnect=True): |
| """ |
| Decorator that restarts a function if a database locked sqlite |
| exception occurs. If reconnect is True, the database connection |
| will be closed and reopened each time a failure occurs |
| """ |
| def retry_wrapper(f): |
| def wrap_func(self, *args, **kwargs): |
| # Reconnect if necessary |
| if self.connection is None and reconnect: |
| self.reconnect() |
| |
| count = 0 |
| while True: |
| try: |
| return f(self, *args, **kwargs) |
| except sqlite3.OperationalError as exc: |
| if count < 500 and ('is locked' in str(exc) or 'locking protocol' in str(exc)): |
| count = count + 1 |
| if reconnect: |
| self.reconnect() |
| continue |
| raise |
| return wrap_func |
| return retry_wrapper |
| |
| @staticmethod |
| def transaction(f): |
| """ |
| Decorator that starts a database transaction and creates a database |
| cursor for performing queries. If no exception is thrown, the |
| database results are commited. If an exception occurs, the database |
| is rolled back. In all cases, the cursor is closed after the |
| function ends. |
| |
| Note that the cursor is passed as an extra argument to the function |
| after `self` and before any of the normal arguments |
| """ |
| def wrap_func(self, *args, **kwargs): |
| # Context manager will COMMIT the database on success, |
| # or ROLLBACK on an exception |
| with self.connection: |
| # Automatically close the cursor when done |
| with contextlib.closing(self.connection.cursor()) as cursor: |
| return f(self, cursor, *args, **kwargs) |
| return wrap_func |
| |
| """Object representing a table/domain in the database""" |
| def __init__(self, cachefile, table): |
| self.cachefile = cachefile |
| self.table = table |
| |
| self.connection = None |
| self._execute_single("CREATE TABLE IF NOT EXISTS %s(key TEXT PRIMARY KEY NOT NULL, value TEXT);" % table) |
| |
| @_Decorators.retry(reconnect=False) |
| @_Decorators.transaction |
| def _setup_database(self, cursor): |
| cursor.execute("pragma synchronous = off;") |
| # Enable WAL and keep the autocheckpoint length small (the default is |
| # usually 1000). Persistent caches are usually read-mostly, so keeping |
| # this short will keep readers running quickly |
| cursor.execute("pragma journal_mode = WAL;") |
| cursor.execute("pragma wal_autocheckpoint = 100;") |
| |
| def reconnect(self): |
| if self.connection is not None: |
| self.connection.close() |
| self.connection = sqlite3.connect(self.cachefile, timeout=5) |
| self.connection.text_factory = str |
| self._setup_database() |
| |
| @_Decorators.retry() |
| @_Decorators.transaction |
| def _execute_single(self, cursor, *query): |
| """ |
| Executes a single query and discards the results. This correctly closes |
| the database cursor when finished |
| """ |
| cursor.execute(*query) |
| |
| @_Decorators.retry() |
| def _row_iter(self, f, *query): |
| """ |
| Helper function that returns a row iterator. Each time __next__ is |
| called on the iterator, the provided function is evaluated to determine |
| the return value |
| """ |
| class CursorIter(object): |
| def __init__(self, cursor): |
| self.cursor = cursor |
| |
| def __iter__(self): |
| return self |
| |
| def __next__(self): |
| row = self.cursor.fetchone() |
| if row is None: |
| self.cursor.close() |
| raise StopIteration |
| return f(row) |
| |
| def __enter__(self): |
| return self |
| |
| def __exit__(self, typ, value, traceback): |
| self.cursor.close() |
| return False |
| |
| cursor = self.connection.cursor() |
| try: |
| cursor.execute(*query) |
| return CursorIter(cursor) |
| except: |
| cursor.close() |
| |
| def __enter__(self): |
| self.connection.__enter__() |
| return self |
| |
| def __exit__(self, *excinfo): |
| self.connection.__exit__(*excinfo) |
| |
| @_Decorators.retry() |
| @_Decorators.transaction |
| def __getitem__(self, cursor, key): |
| cursor.execute("SELECT * from %s where key=?;" % self.table, [key]) |
| row = cursor.fetchone() |
| if row is not None: |
| return row[1] |
| raise KeyError(key) |
| |
| @_Decorators.retry() |
| @_Decorators.transaction |
| def __delitem__(self, cursor, key): |
| if key not in self: |
| raise KeyError(key) |
| cursor.execute("DELETE from %s where key=?;" % self.table, [key]) |
| |
| @_Decorators.retry() |
| @_Decorators.transaction |
| def __setitem__(self, cursor, key, value): |
| if not isinstance(key, str): |
| raise TypeError('Only string keys are supported') |
| elif not isinstance(value, str): |
| raise TypeError('Only string values are supported') |
| |
| # Ensure the entire transaction (including SELECT) executes under write lock |
| cursor.execute("BEGIN EXCLUSIVE") |
| |
| cursor.execute("SELECT * from %s where key=?;" % self.table, [key]) |
| row = cursor.fetchone() |
| if row is not None: |
| cursor.execute("UPDATE %s SET value=? WHERE key=?;" % self.table, [value, key]) |
| else: |
| cursor.execute("INSERT into %s(key, value) values (?, ?);" % self.table, [key, value]) |
| |
| @_Decorators.retry() |
| @_Decorators.transaction |
| def __contains__(self, cursor, key): |
| cursor.execute('SELECT * from %s where key=?;' % self.table, [key]) |
| return cursor.fetchone() is not None |
| |
| @_Decorators.retry() |
| @_Decorators.transaction |
| def __len__(self, cursor): |
| cursor.execute("SELECT COUNT(key) FROM %s;" % self.table) |
| row = cursor.fetchone() |
| if row is not None: |
| return row[0] |
| |
| def __iter__(self): |
| return self._row_iter(lambda row: row[0], "SELECT key from %s;" % self.table) |
| |
| def __lt__(self, other): |
| if not isinstance(other, Mapping): |
| raise NotImplemented |
| |
| return len(self) < len(other) |
| |
| def get_by_pattern(self, pattern): |
| return self._row_iter(lambda row: row[1], "SELECT * FROM %s WHERE key LIKE ?;" % |
| self.table, [pattern]) |
| |
| def values(self): |
| return list(self.itervalues()) |
| |
| def itervalues(self): |
| return self._row_iter(lambda row: row[0], "SELECT value FROM %s;" % |
| self.table) |
| |
| def items(self): |
| return list(self.iteritems()) |
| |
| def iteritems(self): |
| return self._row_iter(lambda row: (row[0], row[1]), "SELECT * FROM %s;" % |
| self.table) |
| |
| @_Decorators.retry() |
| @_Decorators.transaction |
| def clear(self, cursor): |
| cursor.execute("DELETE FROM %s;" % self.table) |
| |
| def has_key(self, key): |
| return key in self |
| |
| |
| class PersistData(object): |
| """Deprecated representation of the bitbake persistent data store""" |
| def __init__(self, d): |
| warnings.warn("Use of PersistData is deprecated. Please use " |
| "persist(domain, d) instead.", |
| category=DeprecationWarning, |
| stacklevel=2) |
| |
| self.data = persist(d) |
| logger.debug(1, "Using '%s' as the persistent data cache", |
| self.data.filename) |
| |
| def addDomain(self, domain): |
| """ |
| Add a domain (pending deprecation) |
| """ |
| return self.data[domain] |
| |
| def delDomain(self, domain): |
| """ |
| Removes a domain and all the data it contains |
| """ |
| del self.data[domain] |
| |
| def getKeyValues(self, domain): |
| """ |
| Return a list of key + value pairs for a domain |
| """ |
| return list(self.data[domain].items()) |
| |
| def getValue(self, domain, key): |
| """ |
| Return the value of a key for a domain |
| """ |
| return self.data[domain][key] |
| |
| def setValue(self, domain, key, value): |
| """ |
| Sets the value of a key for a domain |
| """ |
| self.data[domain][key] = value |
| |
| def delValue(self, domain, key): |
| """ |
| Deletes a key/value pair |
| """ |
| del self.data[domain][key] |
| |
| def persist(domain, d): |
| """Convenience factory for SQLTable objects based upon metadata""" |
| import bb.utils |
| cachedir = (d.getVar("PERSISTENT_DIR") or |
| d.getVar("CACHE")) |
| if not cachedir: |
| logger.critical("Please set the 'PERSISTENT_DIR' or 'CACHE' variable") |
| sys.exit(1) |
| |
| bb.utils.mkdirhier(cachedir) |
| cachefile = os.path.join(cachedir, "bb_persist_data.sqlite3") |
| return SQLTable(cachefile, domain) |