File System and Operating System Interface (Architecture Guide)

	Data Structures	Source Location
	WT_FILE_SYSTEM	src/include/os.h src/include/os_fhandle_inline.h src/include/os_fs_inline.h src/include/os_fstream_inline.h src/include/os_windows.h src/os_posix/ src/os_win/

Internally, a layer of abstraction is above all operating system calls, allowing main line WiredTiger code to make a call to single set of interfaces. There are currently OS specific APIs for POSIX and Windows.

Additionally, a program can use WT_CONNECTION::set_file_system to register a set of functions that will be called for each file system operation. WiredTiger will then call these functions at the appropriate time.