| blob | c889a63284a8aa9355d7027e6d1f4cdf9f9ea950 |
1 =================
2 libtorrent manual
3 =================
5 :Author: Arvid Norberg, arvid@rasterbar.com
7 .. contents:: Table of contents
8 :depth: 2
9 :backlinks: none
11 downloading and building
12 ========================
14 To acquire the latest version of libtorrent, you'll have to grab it from SVN.
15 You'll find instructions on how to do this here__ (see subversion access).
17 __ http://sourceforge.net/svn/?group_id=79942
19 The build systems supported "out of the box" in libtorrent are boost-build v2
20 (BBv2) and autotools (for unix-like systems). If you still can't build after
21 following these instructions, you can usually get help in the ``#libtorrent``
22 IRC channel on ``irc.freenode.net``.
24 Community contributed build tutorials can be found on the wiki_.
26 .. _wiki: http://code.rasterbar.com/libtorrent/wiki/Building
28 building from svn
29 -----------------
31 To build libtorrent from svn you need to check out the libtorrent sources from
32 sourceforge and also check out the asio sources from its sourceforge cvs.
33 If you downloaded a release tarball, you can skip this section.
35 To prepare the directory structure for building, follow these steps:
37 * Check out libtorrent (instructions__).
38 * Check out asio (instructions__).
39 * Copy the ``asio/include/asio/`` directory into the ``libtorrent/include/libtorrent/``
40 directory. Alternatively you can make a symbolic link.
41 * Copy ``asio/include/asio.hpp`` into ``libtorrent/include/libtorrent``.
43 __ http://sourceforge.net/svn/?group_id=79942
44 __ http://sourceforge.net/cvs/?group_id=122478
46 Now the libtorrent directory is ready for building. Follow the steps in one
47 of the following sections depending on which build system you prefer to use.
49 building with BBv2
50 ------------------
52 The primary reason to use boost-build is that it will automatically build the
53 dependent boost libraries with the correct compiler settings, in order to
54 ensure that the build targets are link compatible (see `boost guidelines`__
55 for some details on this issue).
57 __ http://boost.org/more/separate_compilation.html
59 Since BBv2 will build the boost libraries for you, you need the full boost
60 source package. Having boost installed via some package system is usually not
61 enough (and even if it is enough, the necessary environment variables are
62 usually not set by the package installer).
64 If you want to build against an installed copy of boost, you can skip directly
65 to step 3 (assuming you also have boost build installed).
68 Step 1: Download boost
69 ~~~~~~~~~~~~~~~~~~~~~~
71 You'll find boost here__.
73 __ http://sourceforge.net/project/showfiles.php?group_id=7586&package_id=8041&release_id=376197
75 Extract the archive to some directory where you want it. For the sake of this
76 guide, let's assume you extract the package to ``c:\boost_1_34_0`` (I'm using
77 a windows path in this example since if you're on linux/unix you're more likely
78 to use the autotools). You'll need at least version 1.34 of the boost library
79 in order to build libtorrent.
82 Step 2: Setup BBv2
83 ~~~~~~~~~~~~~~~~~~
85 First you need to build ``bjam``. You do this by opening a terminal (In
86 windows, run ``cmd``). Change directory to
87 ``c:\boost_1_34_0\tools\jam\src``. Then run the script called
88 ``build.bat`` or ``build.sh`` on a unix system. This will build ``bjam`` and
89 place it in a directory starting with ``bin.`` and then have the name of your
90 platform. Copy the ``bjam.exe`` (or ``bjam`` on a unix system) to a place
91 that's in you shell's ``PATH``. On linux systems a place commonly used may be
92 ``/usr/local/bin`` or on windows ``c:\windows`` (you can also add directories
93 to the search paths by modifying the environment variable called ``PATH``).
95 Now you have ``bjam`` installed. ``bjam`` can be considered an interpreter
96 that the boost-build system is implemented on. So boost-build uses ``bjam``.
97 So, to complete the installation you need to make two more things. You need to
98 set the environment variable ``BOOST_BUILD_PATH``. This is the path that tells
99 ``bjam`` where it can find boost-build, your configuration file and all the
100 toolsets (descriptions used by boost-build to know how to use different
101 compilers on different platforms). Assuming the boost install path above, set
102 it to ``c:\boost_1_34_0\tools\build\v2``.
104 To set an environment variable in windows, type for example::
106 set BOOST_BUILD_PATH=c:\boost_1_34_0\tools\build\v2
108 In a terminal window.
110 The last thing to do to complete the setup of BBv2 is to modify your
111 ``user-config.jam`` file. It is located in ``c:\boost_1_34_0\tools\build\v2``.
112 Depending on your platform and which compiler you're using, you should add a
113 line for each compiler and compiler version you have installed on your system
114 that you want to be able to use with BBv2. For example, if you're using
115 Microsoft Visual Studio 7.1 (2003), just add a line::
117 using msvc : 7.1 ;
119 If you use GCC, add the line::
121 using gcc ;
123 If you have more than one version of GCC installed, you can add the
124 commandline used to invoke g++ after the version number, like this::
126 using gcc : 3.3 : g++-3.3 ;
127 using gcc : 4.0 : g++-4.0 ;
129 Another toolset worth mentioning is the ``darwin`` toolset (For MacOS X).
130 From Tiger (10.4) MacOS X comes with both GCC 3.3 and GCC 4.0. Then you can
131 use the following toolsets::
133 using darwin : 3.3 : g++-3.3 ;
134 using darwin : 4.0 : g++-4.0 ;
136 Note that the spaces around the semi-colons and colons are important!
138 Also see the `official installation instructions`_.
140 .. _`official installation instructions`: http://www.boost.org/doc/html/bbv2/installation.html
143 Step 3: Building libtorrent
144 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
146 When building libtorrent, the ``Jamfile`` expects the environment variable
147 ``BOOST_ROOT`` to be set to the boost installation directory. It uses this to
148 find the boost libraries it depends on, so they can be built and their headers
149 files found. So, set this to ``c:\boost_1_34_0``. You only need this if you're
150 building against a source distribution of boost.
152 Then the only thing left is simply to invoke ``bjam``. If you want to specify
153 a specific toolset to use (compiler) you can just add that to the commandline.
154 For example::
156 bjam msvc-7.1 boost=source
157 bjam gcc-3.3 boost=source
158 bjam darwin-4.0 boost=source
160 If you're building against a system installed boost, specify ``boost=system``.
162 To build different versions you can also just add the name of the build
163 variant. Some default build variants in BBv2 are ``release``, ``debug``,
164 ``profile``.
166 You can build libtorrent as a dll too, by typing ``link=shared``, or
167 ``link=static`` to build a static library.
169 If you want to explicitly say how to link against the runtime library, you
170 can set the ``runtime-link`` feature on the commandline, either to ``shared``
171 or ``static``. Most operating systems will only allow linking shared against
172 the runtime, but on windows you can do both. Example::
174 bjam msvc-7.1 link=static runtime-link=static boost=source
176 .. warning::
178 If you link statically to the runtime library, you cannot build libtorrent
179 as a shared library (DLL), since you will get separate heaps in the library
180 and in the client application. It will result in crashes and possibly link
181 errors.
183 .. warning::
185 With boost-build V2 (Milestone 11), the darwin toolset uses the ``-s`` linker
186 option to strip debug symbols. This option is buggy in Apple's GCC, and
187 will make the executable crash on startup. On Mac OS X, instead build
188 your release executables with the ``debug-symbols=on`` option, and
189 later strip your executable with ``strip``.
191 .. warning::
193 Some linux systems requires linking against ``librt`` in order to access
194 the POSIX clock functions. If you get an error complaining about a missing
195 symbol ``clock_gettime``, you have to give ``need-librt=yes`` on the
196 bjam command line. This will make libtorrent link against ``librt``.
198 The build targets are put in a directory called bin, and under it they are
199 sorted in directories depending on the toolset and build variant used.
201 To build the examples, just change directory to the examples directory and
202 invoke ``bjam`` from there. To build and run the tests, go to the test
203 directory and run ``bjam``.
205 Note that if you're building on windows using the ``msvc`` toolset, you cannot run it
206 from a cygwin terminal, you'll have to run it from a ``cmd`` terminal. The same goes for
207 cygwin, if you're building with gcc in cygwin you'll have to run it from a cygwin terminal.
208 Also, make sure the paths are correct in the different environments. In cygwin, the paths
209 (``BOOST_BUILD_PATH`` and ``BOOST_ROOT``) should be in the typical unix-format (e.g.
210 ``/cygdrive/c/boost_1_34_0``). In the windows environment, they should have the typical
211 windows format (``c:/boost_1_34_0``).
213 The ``Jamfile`` will define ``NDEBUG`` when it's building a release build.
214 For more build configuration flags see `Build configurations`_.
216 Build features:
218 +------------------------+----------------------------------------------------+
219 | boost build feature | values |
220 +========================+====================================================+
221 | ``boost`` | * ``system`` - default. Tells the Jamfile that |
222 | | boost is installed and should be linked against |
223 | | the system libraries. |
224 | | * ``source`` - Specifies that boost is to be built |
225 | | from source. The environment variable |
226 | | ``BOOST_ROOT`` must be defined to point to the |
227 | | boost directory. |
228 +------------------------+----------------------------------------------------+
229 | ``boost-link`` | * ``static`` - links statically against the boost |
230 | | libraries. |
231 | | * ``shared`` - links dynamically against the boost |
232 | | libraries. |
233 +------------------------+----------------------------------------------------+
234 | ``logging`` | * ``none`` - no logging. |
235 | | * ``default`` - basic session logging. |
236 | | * ``verbose`` - verbose peer wire logging. |
237 | | * ``errors`` - like verbose, but limited to errors.|
238 +------------------------+----------------------------------------------------+
239 | ``dht-support`` | * ``on`` - build with support for tracker less |
240 | | torrents and DHT support. |
241 | | * ``logging`` - build with DHT support and verbose |
242 | | logging of the DHT protocol traffic. |
243 | | * ``off`` - build without DHT support. |
244 +------------------------+----------------------------------------------------+
245 | ``need-librt`` | * ``no`` - this platform does not need to link |
246 | | against librt to have POSIX time functions. |
247 | | * ``yes`` - specify this if your linux system |
248 | | requires you to link against librt.a. This is |
249 | | typically the case on x86 64 bit systems. |
250 +------------------------+----------------------------------------------------+
251 | ``zlib`` | * ``system`` - links against the zlib supplied |
252 | | with your operating system. |
253 | | * ``shipped`` - links against the zlib bundled |
254 | | with the libtorrent package. |
255 +------------------------+----------------------------------------------------+
256 | ``geoip`` | * ``off`` - geo ip lookups disabled |
257 | | * ``static`` - MaxMind_ geo ip lookup code linked |
258 | | in statically. Note that this code is under |
259 | | LGPL license. |
260 | | * ``shared`` - The MaxMind_ geo ip lookup library |
261 | | is expected to be installed on the system and |
262 | | it will be used. |
263 +------------------------+----------------------------------------------------+
264 | ``upnp-logging`` | * ``off`` - default. Does not log UPnP traffic. |
265 | | * ``on`` - creates "upnp.log" with the messages |
266 | | sent to and received from UPnP devices. |
267 +------------------------+----------------------------------------------------+
268 | ``openssl`` | * ``pe`` - turns on support for encrypted |
269 | | connections. requires openssl (libcrypto) |
270 | | * ``sha-1`` - openssl will be used instead of the |
271 | | public domain SHA-1 implementation shipped with |
272 | | libtorrent. ``libcrypto.a`` will be required for |
273 | | linking. Encryption support is still turned off. |
274 | | * ``off`` - turns off support for encrypted |
275 | | connections. openssl is not linked in. The |
276 | | shipped public domain SHA-1 implementation is |
277 | | used. |
278 +------------------------+----------------------------------------------------+
279 | ``pool-allocators`` | * ``on`` - default, uses pool allocators for send |
280 | | buffers. |
281 | | * ``off`` - uses ``malloc()`` and ``free()`` |
282 | | instead. Might be useful to debug buffer issues |
283 | | with tools like electric fence or libgmalloc. |
284 +------------------------+----------------------------------------------------+
285 | ``link`` | * ``static`` - builds libtorrent as a static |
286 | | library (.a / .lib) |
287 | | * ``shared`` - builds libtorrent as a shared |
288 | | library (.so / .dll). |
289 +------------------------+----------------------------------------------------+
290 | ``runtime-link`` | * ``static`` - links statically against the |
291 | | run-time library (if available on your |
292 | | platform). |
293 | | * ``shared`` - link dynamically against the |
294 | | run-time library (default). |
295 +------------------------+----------------------------------------------------+
296 | ``variant`` | * ``debug`` - builds libtorrent with debug |
297 | | information and invariant checks. |
298 | | * ``release`` - builds libtorrent in release mode |
299 | | without invariant checks and with optimization. |
300 | | * ``profile`` - builds libtorrent with profile |
301 | | information. |
302 +------------------------+----------------------------------------------------+
303 | ``character-set`` | This setting will only have an affect on windows. |
304 | | Other platforms are expected to support UTF-8. |
305 | | |
306 | | * ``unicode`` - The unicode version of the win32 |
307 | | API is used. This is default. |
308 | | * ``ansi`` - The ansi version of the win32 API is |
309 | | used. |
310 +------------------------+----------------------------------------------------+
311 | ``invariant-checks`` | This setting only affects debug builds (where |
312 | | ``NDEBUG`` is not defined). It defaults to ``on``. |
313 | | |
314 | | * ``on`` - internal invariant checks are enabled. |
315 | | * ``off`` - internal invariant checks are |
316 | | disabled. The resulting executable will run |
317 | | faster than a regular debug build. |
318 | | * ``full`` - turns on extra expensive invariant |
319 | | checks. |
320 +------------------------+----------------------------------------------------+
321 | ``debug-symbols`` | * ``on`` - default for debug builds. This setting |
322 | | is useful for building release builds with |
323 | | symbols. |
324 | | * ``off`` - default for release builds. |
325 +------------------------+----------------------------------------------------+
327 .. _MaxMind: http://www.maxmind.com/app/api
329 The ``variant`` feature is *implicit*, which means you don't need to specify
330 the name of the feature, just the value.
332 The logs created when building vlog or log mode are put in a directory called
333 ``libtorrent_logs`` in the current working directory.
335 When building the example client on windows, you need to build with
336 ``link=static`` otherwise you may get unresolved external symbols for some
337 boost.program-options symbols.
339 For more information, see the `Boost build v2 documentation`__, or more
340 specifically `the section on builtin features`__.
342 __ http://www.boost.org/tools/build/v2/index.html
343 __ http://www.boost.org/doc/html/bbv2/reference.html#bbv2.advanced.builtins.features
346 building with autotools
347 -----------------------
349 First of all, you need to install ``automake`` and ``autoconf``. Many
350 unix/linux systems comes with these preinstalled.
352 The prerequisites for building libtorrent are boost.thread, boost.date_time
353 and boost.filesystem. Those are the *compiled* boost libraries needed. The
354 headers-only libraries needed include (but is not necessarily limited to)
355 boost.bind, boost.ref, boost.multi_index, boost.optional, boost.lexical_cast,
356 boost.integer, boost.iterator, boost.tuple, boost.array, boost.function,
357 boost.smart_ptr, boost.preprocessor, boost.static_assert.
359 If you want to build the ``client_test`` example, you'll also need boost.regex
360 and boost.program_options.
362 Step 1: Generating the build system
363 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
365 No build system is present if libtorrent is checked out from CVS - it
366 needs to be generated first. If you're building from a released tarball,
367 you may skip directly to `Step 2: Running configure`_.
369 Execute the following commands, in the given order, to generate
370 the build system::
372 aclocal -I m4
373 autoheader
374 libtoolize --copy --force
375 automake --add-missing --copy --gnu
376 autoconf
378 On darwin/OSX you have to run ``glibtoolize`` instead of ``libtoolize``.
380 Step 2: Running configure
381 ~~~~~~~~~~~~~~~~~~~~~~~~~
383 In your shell, change directory to the libtorrent directory and run
384 ``./configure``. This will look for libraries and C++ features that libtorrent
385 is dependent on. If something is missing or can't be found it will print an
386 error telling you what failed.
388 The most likely problem you may encounter is that the configure script won't
389 find the boost libraries. Make sure you have boost installed on your system.
390 The easiest way to install boost is usually to use the preferred package
391 system on your platform. Usually libraries and headers are installed in
392 standard directories where the compiler will find them, but sometimes that
393 may not be the case. For example when installing boost on darwin using
394 darwinports (the package system based on BSD ports) all libraries are
395 installed to ``/opt/local/lib`` and headers are installed to
396 ``/opt/local/include``. By default the compiler will not look in these
397 directories. You have to set the enviornment variables ``LDFLAGS`` and
398 ``CXXFLAGS`` in order to make the compiler find those libs. In this example
399 you'd set them like this::
401 export LDFLAGS=-L/opt/local/lib
402 export CXXFLAGS=-I/opt/local/include
404 It was observed on FreeBSD (release 6.0) that one needs to add '-lpthread' to
405 LDFLAGS, as Boost::Thread detection will fail without it, even if
406 Boost::Thread is installed.
408 If you need to set these variables, it may be a good idea to add those lines
409 to your ``~/.profile`` or ``~/.tcshrc`` depending on your shell.
411 If the boost libraries are named with a suffix on your platform, you may use
412 the ``--with-boost-thread=`` option to specify the suffix used for the thread
413 library in this case. For more information about these options, run::
415 ./configure --help
417 On gentoo the boost libraries that are built with multi-threading support have
418 the suffix ``mt``.
420 You know that the boost libraries were found if you see the following output
421 from the configure script::
423 checking whether the Boost::DateTime library is available... yes
424 checking for main in -lboost_date_time... yes
425 checking whether the Boost::Filesystem library is available... yes
426 checking for main in -lboost_filesystem... yes
427 checking whether the Boost::Thread library is available... yes
428 checking for main in -lboost_thread... yes
430 Another possible source of problems may be if the path to your libtorrent
431 directory contains spaces. Make sure you either rename the directories with
432 spaces in their names to remove the spaces or move the libtorrent directory.
434 Creating a debug build
435 ~~~~~~~~~~~~~~~~~~~~~~
437 To tell configure to build a debug version (with debug info, asserts
438 and invariant checks enabled), you have to run the configure script
439 with the following option::
441 ./configure --enable-debug=yes
443 Creating a release build
444 ~~~~~~~~~~~~~~~~~~~~~~~~
446 To tell the configure to build a release version (without debug info,
447 asserts and invariant checks), you have to run the configure script
448 with the following option::
450 ./configure --enable-debug=no
452 The above option make use of -DNDEBUG, which is used throughout libtorrent.
454 Step 3: Building libtorrent
455 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
457 Once the configure script is run successfully, you just type ``make`` and
458 libtorrent, the examples and the tests will be built.
460 When libtorrent is built it may be a good idea to run the tests, you do this
461 by running ``make check``.
463 If you want to build a release version (without debug info, asserts and
464 invariant checks), you have to rerun the configure script and rebuild, like this::
466 ./configure --disable-debug
467 make clean
468 make
470 building with other build systems
471 ---------------------------------
473 If you're making your own project file, note that there are two versions of
474 the file abstraction. There's one ``file_win.cpp`` which relies on windows
475 file API that supports files larger than 2 Gigabytes. This does not work in
476 vc6 for some reason, possibly because it may require windows NT and above.
477 The other file, ``file.cpp`` is the default implementation that simply relies
478 on the standard low level io routines (``read()``, ``write()``, ``open()``
479 etc.), this implementation doesn't do anything special to support unicode
480 filenames, so if your target is Windows 2000 and up, you may want to use
481 ``file_win.cpp`` which supports unicode filenames.
483 If you're building in MS Visual Studio, you may have to set the compiler
484 options "force conformance in for loop scope", "treat wchar_t as built-in
485 type" and "Enable Run-Time Type Info" to Yes. For a detailed description
486 on how to build libtorrent with VS, see `the wiki`_.
488 .. _`the wiki`: http://code.rasterbar.com/libtorrent/wiki/Building
490 build configurations
491 --------------------
493 By default libtorrent is built In debug mode, and will have pretty expensive
494 invariant checks and asserts built into it. If you want to disable such checks
495 (you want to do that in a release build) you can see the table below for which
496 defines you can use to control the build.
498 +----------------------------------------+-------------------------------------------------+
499 | macro | description |
500 +========================================+=================================================+
501 | ``NDEBUG`` | If you define this macro, all asserts, |
502 | | invariant checks and general debug code will be |
503 | | removed. Since there is quite a lot of code in |
504 | | in header files in libtorrent, it may be |
505 | | important to define the symbol consistently |
506 | | across compilation units, including the clients |
507 | | files. Potential problems is different |
508 | | compilation units having different views of |
509 | | structs and class layouts and sizes. |
510 +----------------------------------------+-------------------------------------------------+
511 | ``TORRENT_LOGGING`` | This macro will enable logging of the session |
512 | | events, such as tracker announces and incoming |
513 | | connections (as well as blocked connections). |
514 +----------------------------------------+-------------------------------------------------+
515 | ``TORRENT_DISABLE_GEO_IP`` | This is defined by default by the Jamfile. It |
516 | | disables the GeoIP features, and avoids linking |
517 | | against LGPL:ed code. |
518 +----------------------------------------+-------------------------------------------------+
519 | ``TORRENT_VERBOSE_LOGGING`` | If you define this macro, every peer connection |
520 | | will log its traffic to a log file as well as |
521 | | the session log. |
522 +----------------------------------------+-------------------------------------------------+
523 | ``TORRENT_STORAGE_DEBUG`` | This will enable extra expensive invariant |
524 | | checks in the storage, including logging of |
525 | | piece sorting. |
526 +----------------------------------------+-------------------------------------------------+
527 | ``TORRENT_UPNP_LOGGING`` | Generates a "upnp.log" file with the UPnP |
528 | | traffic. This is very useful when debugging |
529 | | support for various UPnP routers. |
530 | | support for various UPnP routers. |
531 +----------------------------------------+-------------------------------------------------+
532 | ``TORRENT_DISK_STATS`` | This will create a log of all disk activity |
533 | | which later can parsed and graphed using |
534 | | ``parse_disk_log.py``. |
535 +----------------------------------------+-------------------------------------------------+
536 | ``TORRENT_STATS`` | This will generate a log with transfer rates, |
537 | | downloading torrents, seeding torrents, peers, |
538 | | connecting peers and disk buffers in use. The |
539 | | log can be parsed and graphed with |
540 | | ``parse_session_stats.py``. |
541 +----------------------------------------+-------------------------------------------------+
542 | ``UNICODE`` | If building on windows this will make sure the |
543 | | UTF-8 strings in pathnames are converted into |
544 | | UTF-16 before they are passed to the file |
545 | | operations. |
546 +----------------------------------------+-------------------------------------------------+
547 | ``LITTLE_ENDIAN`` | This will use the little endian version of the |
548 | | sha-1 code. If defined on a big-endian system |
549 | | the sha-1 hashes will be incorrect and fail. |
550 | | If it is not defined and ``__BIG_ENDIAN__`` |
551 | | isn't defined either (it is defined by Apple's |
552 | | GCC) both little-endian and big-endian versions |
553 | | will be built and the correct code will be |
554 | | chosen at run-time. |
555 +----------------------------------------+-------------------------------------------------+
556 | ``TORRENT_DISABLE_POOL_ALLOCATOR`` | Disables use of ``boost::pool<>``. |
557 +----------------------------------------+-------------------------------------------------+
558 | ``TORRENT_LINKING_SHARED`` | If this is defined when including the |
559 | | libtorrent headers, the classes and functions |
560 | | will be tagged with ``__declspec(dllimport)`` |
561 | | on msvc and default visibility on GCC 4 and |
562 | | later. Set this in your project if you're |
563 | | linking against libtorrent as a shared library. |
564 | | (This is set by the Jamfile when |
565 | | ``link=shared`` is set). |
566 +----------------------------------------+-------------------------------------------------+
567 | ``TORRENT_BUILDING_SHARED`` | If this is defined, the functions and classes |
568 | | in libtorrent are marked with |
569 | | ``__declspec(dllexport)`` on msvc, or with |
570 | | default visibility on GCC 4 and later. This |
571 | | should be defined when building libtorrent as |
572 | | a shared library. (This is set by the Jamfile |
573 | | when ``link=shared`` is set). |
574 +----------------------------------------+-------------------------------------------------+
575 | ``TORRENT_DISABLE_DHT`` | If this is defined, the support for trackerless |
576 | | torrents will be disabled. |
577 +----------------------------------------+-------------------------------------------------+
578 | ``TORRENT_DHT_VERBOSE_LOGGING`` | This will enable verbose logging of the DHT |
579 | | protocol traffic. |
580 +----------------------------------------+-------------------------------------------------+
581 | ``TORRENT_DISABLE_ENCRYPTION`` | This will disable any encryption support and |
582 | | the openssl dependency that comes with it. |
583 | | Encryption support is the peer connection |
584 | | encrypted supported by clients such as |
585 | | uTorrent, Azureus and KTorrent. |
586 +----------------------------------------+-------------------------------------------------+
587 | ``_UNICODE`` | On windows, this will cause the file IO |
588 | | use wide character API, to properly support |
589 | | non-ansi characters. |
590 +----------------------------------------+-------------------------------------------------+
591 | ``TORRENT_DISABLE_RESOLVE_COUNTRIES`` | Defining this will disable the ability to |
592 | | resolve countries of origin for peer IPs. |
593 +----------------------------------------+-------------------------------------------------+
594 | ``TORRENT_DISABLE_INVARIANT_CHECKS`` | This will disable internal invariant checks in |
595 | | libtorrent. The invariant checks can sometime |
596 | | be quite expensive, they typically don't scale |
597 | | very well. This option can be used to still |
598 | | build in debug mode, with asserts enabled, but |
599 | | make the resulting executable faster. |
600 +----------------------------------------+-------------------------------------------------+
601 | ``TORRENT_EXPENSIVE_INVARIANT_CHECKS`` | This will enable extra expensive invariant |
602 | | checks. Useful for finding particular bugs |
603 | | or for running before releases. |
604 +----------------------------------------+-------------------------------------------------+
607 If you experience that libtorrent uses unreasonable amounts of cpu, it will
608 definitely help to define ``NDEBUG``, since it will remove the invariant checks
609 within the library.