As the 2016-10-07~09 downtime incident shows, it is paramount to take
further steps in guaranteeing that the server can't corrupt its own data
files (especially the add-ons database) when receiving
inappropriately-timed signals.
This commit adds and deploys an ostream wrapper that requires callers to
explicitly commit the results to disk when finished writing to the
stream, so that only then the real destination file is overwritten with
the working copy (a temporary in the same dir). This way, there should
never be a situation in which the destination is left in an inconsistent
state due to a signal or exception.
The temporary receives a predictable name right now in the interest of
simplicity, since we are more or less in control of the target directory
anyway. We definitely don't want it to be an unlinked file since that
would make it impossible for admins to inspect and compare the temporary
against the original afterwards.
The code makes some assumptions about the nature of the return value of
filesystem::ostream_file() which will never be broken in this stable
branch, which is why one helper function is in campaignd land rather
than in the global filesystem API for now. This should probably be
rectified when forward-porting to master. Maybe.
Nothing of this will work reliably on Windows but we don't care. There's
only one machine in the world where we support running campaignd at this
time and it runs Linux.
* Use separate files to build scons and to build lua for cmake
Move lists of source files into their own directory
Make scons use the lists of source files
Move lua build step to src/SConscript and delete src/lua/SConscript
Make cmake use the separate file with the list of lua sources to build
* Finish changing over to source lists
scons
move source files from libraries that don't appear in cmake over to existing source lists - libcampaignd, libcutter, libdummy_video, libtest_utils
add the defines FIFODIR and WESNOTH_PATH to all compiled source files, as cmake does, and move the single files those defines had previously been defined on into the source lists
remove WESNOTH_PREFIX, as not used
added schema_validator sources from cmake
added OBJPREFIX to - cutter, exploder, campaignd, schema_generator, schema_validator
cmake
change over to using the source lists
move source files from libraries that don't appear in scons over to existing source lists - wesnoth-gui_types, wesnoth-gui_event, wesnoth-gui_iterator, wesnoth-gui_placer, wesnoth-gui_tooltip, wesnoth-gui_widget, wesnoth-gui_widget_definition, wesnoth-gui1_widgets, wesnoth-schema_validator
