mypy.fscache

Interface for accessing the file system with automatic caching. The idea is to cache the results of any file system state reads during a single transaction. This has two main benefits: * This avoids redundant syscalls, as we won't perform the same OS operations multiple times. * This makes it easier to reason about concurrent FS updates, as different operations targeting the same paths can't report different state during a transaction. Note that this only deals with reading state, not writing. Properties maintained by the API: * The contents of the file are always from the same or later time compared to the reported mtime of the file, even if mtime is queried after reading a file. * Repeating an operation produces the same result as the first one during a transaction. * Call flush() to start a new transaction (flush the caches). The API is a bit limited. It's easy to add new cached operations, however. You should perform all file system reads through the API to actually take advantage of the benefits.