Until now the UDP download code prohibited downloading of maps from all
pak files. That was some kind of copy protection, without the limitation
demo users could download assets from the full version. Don't apply that
protection for all paks, but only for numbered .pak files.
This could be enhanced by limiting the protection to pak0 to pak2 for
baseq2 and pak0 for both xatrix and rogue.
The r1q2 URL generator was, like everything in this game, buggy. It took
cl.gamedir into account when generating the URLs, but overlooked that it
is only set when 'gamedir != BASEDIR'. So baseq2 assets ended up with
/maps/foo.bsp and mod assets with /mod/maps/foo.bsp. q2pro fixed that
to always include the gamedir...
Work around this by refactoring the HTTP -> UDP fallback logic to be
more generic: Count the number of iterations and depending on the
iteration set the gamedir to be used by the URL generator or force
UDP downloads.
Cleaning the download queue as soon as a file finished downloading leads
in combination with only one parallel download and multiple precacher
runs to an ugly problem: The generic filelist is requested several time
which can lead to cycles. Hack around this by rembering if we already
requested it and reset set reminder as soon as the precacher finished.
Yes, I'm feeling dirty.
If the server sends us an URL with trailing slash we're generating URIs
like http://example.com//maps/foo.bsp. While double // are perfectly
valid they might me rejected by some servers. So let's play save.
While at it replace the crappy Z_TagMalloc() with the standard malloc().
Z_TagMalloc() ist just a wrapper arround malloc(), there's no functional
change.
This looks easy, but is rather hacky... Downloading is implemented
through the precacher. The server sends an asset list, while loading
the map another one is generated. CL_RequestNextDownload() goes
through this list, in the order models / maps -> sounds -> images,
calls CL_CheckOrDownloadFile() for each file. CL_CheckOrDownloadFile()
checks if the file is already there, return true if it is and false
if not. If the return code is false CL_RequestNextDownload() itself
returns, it's called again by CL_ParseDownload() as soon as the just
queued file finished downloading. This way all missing files are
downloaded one after the other, when CL_RequestNextDownload() finally
reaches it's end (all files are there) it send 'begin' to the server,
thus putting the client into the game.
HTTP downloads are parallel, so CL_RequestNextDownload() cannot track
which files are there and which are missing. The work around for that is
to queue the file but have CL_CheckOrDownloadFile() return true. So
CL_RequestNextDownload() thinks the file is already there, continues
with the next one, until all missing files are queued. After that it
polls CL_PendingHTTPDownloads() and sends the 'begin' as soon as all
HTTP downloads are finished.
If a HTTP download fails we cannot just queue it as UDP download,
because the precacher things that the file is already there. And we
can't tell the precacher that it's not because the precacher tracks
files only by the number of downloaded files per asste type and not
their name. Just decreasing the number of downloaded files isn't
possible since the precacher may have progressed to the next asset
type.
So: On the HTTP side it's tracked if there was an error or not. After
CL_RequestNextDownload() has queued all files and waited for all HTTP
downloads to finish it checks the HTTP error status. If there was an
error the precacher state is reset and CL_RequestNextDownload() recurses
into itself to take another run. All files that couldn't be downloaded
are queued again, this time as UDP downloads.
My solution to this problem is somewhat hacky. A newly added function
OGG_SaveState() can be called to save the state and OGG_RecoverState()
at a later time to restore it. There's only one state and it works
only iff OGG is state playing.
This closes#347.
If we're passing file handles to libcurl to write the data into, the
game may crash under Windows due to incompatible C runtimes between cURL
and quake2. This is even mentioned in the official cURL doku.
Since the moment I took a very first look at the download code I wasn't
a friend of parallel downloads. There're several reasons for that:
- Parallel downloading needs some ugly hacks. For example downloading a
pak file has a high chance to make asset downloads running in parallel
unnecessary.
- Parallel downloads are hard to debug.
- There's just no need for them. I've tested several connection, 1
GBit/s LAN, 50 MBit/s DSL, 6 MBit/s DSL, and there wasn't a
significant difference between 1, 4 or even 16 parallel downloads.
I'm leaving the parallel download code in place. I someone really wants
parallel downloads he can bump the MAX_HTTP_HANDLES define.
The signal handler was always fishy since it modified the global process
state but worked on all common platforms. libcurl turns the process into
a multithreaded environment, thus breaking that fragile construction.
After the signal handler was called the global state is inconsistent and
there's a high chance of things going wrong. For example at the net curl
download or when setjmp() is called in Qcommon_Frame().
Until now download queues entries were created for each file, but only
removed in the unlikely event of changed download server. This leaked
about 4200 byte per file. Fix this by:
- Create a new function CL_RemoveFromQueue() that removes a queue entry
and call it everytime when a download either finished, failed or
aborted.
- Retire the 'download done' state, just the queue entries associated
with a download handle to NULL to communicate that the handle is
unused.
- Cleanup the full queue at shutdown.
Loading libcurl at runtime instead of linking it at compile time makes
things a lot easier and more reliable on Windows. On other platform
libcurl can be installed as optional dependency instead as an hard one.
We're printing only the two relevant informations: A download was queued
and a download finished or failed. That's enough to see what's going on
and not too noisy.
...and fix the bugs, that were worked around with that crap, instead.
This removes some corner cases like cancelation of all HTTP downloads
and fallback to UDP if too many 404 errors were generated. If this is
still a problem in reality - for example HTTP servers blocking the
client after too many 404 or even crashing HTTP server - fix the server
and don't force the clients to work around that.
We aren't in 1997 anymore, todays broadband connections are fast enough
to handle multiple large files. This may download some assets twice if
the server provides both a pak file with all assets and the assets as
plain files.
There's no need to parse the HTTP header on our side of things, CURL can
do that. And the old buffer code was overcomplicated, simplify it. While
at it switch to normal malloc().
While the download speed calculations may be useful their implementation
is crappy and the integration into the console is rather fragile. If we
really want to support the progress bar with HTTP downloads this needs
to be reimplemented.
The URL generation logic was buggy, it took the local fs_gamedir into
account when determining the files path on the server. That could have
worked in r1q2 or q2dos since they assume that the executable dir is
also the config dir. But it breaks in YQ2 were the executable dir and
the config dir differ.
These are:
- CL_ResetPrecacheCheck(): Resets the precacher, forces it to reevaluate
which assets are available and what needs to be downloaded.
- FS_FileInGamedir(): Checks if a file (and only a real file, not
somthing in a pak) is available in fs_gamedir.
- FS_AddPAKFromGamedir(): Adds a pak in fs_gamedir to the search path.
This is a very first cut:
* It compiles
* It doesn't crash
What's missing:
* cmake integration
* CURL should be loaded dynamically
* Integration between download code and filesystem
* Likely UTF-8 stuff
* cl_http.c needs cleanup
* Windows support
We're taking indices and converting them to pointer relative to the
hunks base. Yes, that's dirty. Since the indices are stored as 32 bit
values and hunks are generally small using 32 bit pointers is enough,
even on 64 bit platforms. So the code took the size of void* / 2...
See the problem? Yes, that's not a good idea on 32 bit platforms. Bite
the bullet and just take the size of void*. Shouldn't be a problem,
because the indices are the first thing that's loaded and the hunk is
trimmed right after it anyways. If, and just if, we really need each and
every byte in the early stages of map loading we need two cases. One for
64 bit and one for 32 bit.
This fixes issue #346. Kudos to @ricardosdl for the analysis.
