3.1.0 - Added SqliteCache + AsyncSqliteCache, plus minor fixes in privex.helpers.plugin

privex.helpers.cache

• Added SqliteCache module, containing the synchronous cache adapter SqliteCache which uses an Sqlite3 database for persistent cache storage without the need for any extra system service (unlike the memcached / redis adapters)

• Added asyncx.AsyncSqliteCache module, containing the AsyncIO cache adapter AsyncSqliteCache, which is simply an AsyncIO version of SqliteCache using the aiosqlite library.

  • NOTE: Due to the file-based nature of SQLite3, combined with the fact write operations generally result in the database being locked until the write is completed - use of the AsyncIO SQLite3 cache adapter only slightly improves performance, due to the blocking single-user nature of SQLite3.

• Added post_deps module, short for post-init dependencies. This module contains functions and classes which are known to have (or have a high risk of) recursive import conflicts - e.g. the new SQLite caching uses the privex-db package, and the privex-db package imports various things from privex.helpers causing a recursive import issue if we load privex.db within a class that's auto-loaded in an __init__.py file.

  The nature of this module means that none of it's contents are auto-loaded / aliased using __init__.py module constructor files. This shouldn't be a problem for most people though, as the functions/classes etc. within the module are primarily only useful for certain cache adapter classes, rather than intended for use by the users of privex-helpers (though there's nothing stopping you from importing things from post_deps in your own project).

  • sqlite_cache_set_dbfolder and sqlite_cache_set_dbname are two module level functions that are intended for use by users. These functions allow you to quickly override the DEFAULT_DB_FOLDER and/or DEFAULT_DB_NAME dynamically for both SqliteCacheManager and AsyncSqliteCacheManager.
  • SqliteCacheResult is a namedtuple that represents a row returned when querying the pvcache table within an SQLite cache database
  • _SQManagerBase is a mix-in class used by both SqliteCacheManager and AsyncSqliteCacheManager, containing code which is used by both classes.
  • SqliteCacheManager is a child class of SqliteWrapper, designed to provide easier interaction with an SQLite3 cache database, including automatic creation of the database file, and the pvcache table within it. This class is intended for use by privex.helpers.cache.SqliteCache
  • AsyncSqliteCacheManager is a child class of SqliteAsyncWrapper, and is simply an AsyncIO version of SqliteCacheManager. This class is intended for use by privex.helpers.cache.asyncx.AsyncSqliteCache

privex.helpers.plugins

• Added HAS_PRIVEX_DB attribute, for tracking whether the privex-db library is available for use.
• Added clean_threadstore to __all__ - seems I forgot to add it previously.

privex.helpers.settings

• Added SQLITE_APP_DB_NAME which can also be controlled via an env var of the same name - allowing you to adjust the base of the default DB filename for the SQLite3 cache adapters.
• Added SQLITE_APP_DB_FOLDER (can also be controlled via env) - similar to the DB_NAME attribute, controls the default base folder used by the SQLite3 cache adapters.