Port libtransmission to C++. This PR doesn't refactor everything to c++.
Its code changes are only what was necessary to compile and link as c++.
See libtransmission/README.md for details on how to submit modernization
patches!
Co-authored-by: Mike Gelfand <mikedld@mikedld.com>
* perf: use scrape to know when a swarm is all-seeds
For private torrents, the tracker is the sole source of peers. So when a
private torrent's tracker responds that there are 0 leechers, we can use
that information to mark the entire swarm as seeders and to not initiate
connections to those peers if we are seeding. This can help seedboxes to
more efficiently pick which swarms to prioritize.
This strategy is not used on public torrents, since new seeder-to-seeder
connections can be useful there for pex.
This PR changes tr_peerMgrAddPex() to (1) remove tr_atom.seedProbability
field (which was not as robust as intended) and (2) add batches of peers
instead of a single peer.
* fix: only use all-seeds check for private torrents
* refactor: const correctness
* refactor: use getpwuid_r instead of getpwuid
* chore: simplify dict walking loop logic
* refactor: remove dead store assignment in announcer
* refactor: use std::make_shared
Since there is no way to mark parameters as [potentially] unused in
standard C and when using MSVC compiler, use the widely accepted
cast-to-void approach instead.
This way all the qualifiers (`const`, `volatile`, `mutable`) are grouped
together, e.g. `T const* const x` vs. `const T* const x`. Also helps reading
types right-to-left, e.g. "constant pointer to constant T" vs. "constant
pointer to T which is constant".
There're places where manual intervention is still required as uncrustify
is not ideal (unfortunately), but at least one may rely on it to do the
right thing most of the time (e.g. when sending in a patch).
The style itself is quite different from what we had before but making it
uniform across all the codebase is the key. I also hope that it'll make the
code more readable (YMMV) and less sensitive to further changes.
Test socket validity by comparing to TR_BAD_SOCKET instead of various
(and sometimes wrong) other tests like `x >= 0`, `x != -1`, `x > 0`,
`x > -1`, `x` (valid), and `x < 0`, `x == -1` (invalid).
This should not affect non-Win32 platforms in any way.
As for Win32 (both MinGW and MSVC), this should hopefully allow for
unpatched compilation. Correct functioning is not yet guaranteed though.
I'm less certain that these are unneeded because networking APIs seem to have more variation between platforms, but it's better to remove the cruft and then add back whatever headers $PLATFORM users complain about, than to not remove the cruft at all...
We currently implement our own versions of these on mingw because that platform doesn't have them... but why reinvent the wheel; libevent has already done the same thing. Let's use libevent2's implementation.
has already done it for us.