[disorder] / README.developers

Dependencies:

   * You'll need, in addition to the packages mentioned in README:
     Automake         1.10           1.7 is no good; 1.8/9 might work
     Autoconf         2.61           Slightly older might work too
     Libtool          1.5.22         1.4 is no good
     Bazaar (bzr)                    You might be able to manage without
     Python           2.4

   * On Debian and derivatives this should work:

     apt-get install gcc libc-dev automake autoconf libtool libgtk2.0-dev \
		     libgc-dev libgcrypt-dev libpcre3-dev libvorbis-dev \
		     libao-dev libmad0-dev libasound2-dev libdb4.3-dev \
		     libflac-dev

     (Use the bzr from backports, the one in etch is obsolete.)

   * On FreeBSD you'll need at least these packages:
	 autotools
	 bash
	 flac
	 mad
         boehm-gc
         db43
         gmake
         gsed
         libao
         libgcrypt
         wget
         vorbis-tools

   * Please report unstated dependencies (here, README or debian/control).

Building:

   * Compiled versions of configure and the makefiles are including in bzr, so
     if you didn't use a source tarball, you must start as follows:

        bash ./prepare
        ./configure -C
        make

   * On FreeBSD you must use gmake.

Testing:

   * There is an extensive test suite in lib/test.c and tests/*.py.  You can
     run the tests with 'make check'.  If possible please add tests for new
     code to at least one of these.  At the very least the existing tests
     should continue to pass.

   * The tests will not currently pass in an ASCII locale.  This is essentially
     unavoidable given the need to test Unicode support.  ISO 8859-1 or UTF-8
     locales should be OK for the time being.

APIs And Formats:

   * To support a new sound API:
     1) Teach configure.ac how to detect any libraries required.
     2) Define a new BACKEND_ value and update configuration.[ch] for it.
     3) Create a suitable server/speaker-*.c along the pattern of the existing
        ones.
     4) If possible create a suitable lib/mixer-*.c.  This doesn't make sense
        for all APIs (e.g. network), but even for those it does, playback
        support without volume control support is likely to be acceptable (even
        if inferior to full support).
     5) Update doc/disorder_config.5.in.
     6) If relevant, create a suitable clients/playrtp-*.c and update
        doc/disorder-playrtp.1.in.

   * To support a new file format:
     1) Teach configure.ac how to detect any libraries required.
     2) Add a new section to server/decode.c.  NB this file may be split into
        several bits one day.
     3) Add a new section to plugins/tracklength.c.  Again this file may be
        split up in a future version.
     4) Update default_players[] in lib/configuration.c.
     5) Update doc/disorder_config.5.in.

The Server:

   * The server's command implementations must not block.  Waiting for a little
     disk IO is OK but blocking for extended periods on long-lasting
     transactions or external resources is not acceptable; it will wedge the
     server for all other users.

     Long-running subprocesses should use subprograms (rather than forking but
     not execing) if reasonably possible; see c_stats() for an example.
     c_reminder() is probably in the grey area.

   * The server process does not use threads and I would like to keep it that
     way.

   * The server uses the Boehm garbage collector.  This eliminates the need to
     call free() and similar functions in many cases, though teardown calls to
     that do more than free GC-allocated memory (such as fclose()) are still
     required.

   * DisOrder's *printf calls, such as byte_xasprintf(), are mostly preferred
     within the server to the ones built into libc.  An important distinction
     is that they will always accept UTF-8 strings whereas the built-in ones
     may reject them in non-UTF-8 locales (for instance Glibc does this) with
     EILSEQ.  Only where the data is guaranteed to be ASCII may the libc
     functions be used.

   * To add a new configuration directive:
     1) Add a new entry to the struct in lib/configuration.h
     2) Add a new table entry to conf[] in lib/configuration.c
     3) If the directive is entirely unlike existing ones add a new type_
        to lib/configuration.c
     4) Set the default if non-0 in config_default().  In some cases
        config_postdefaults() may be more appropriate.
     5) Document the new directive in doc/disorder_config.5.in

   * To add a new command:
     1) Add a new c_ function and table entry in server/server.c
     2) Document the new command in doc/disorder_protocol.5.in
     3) Add a new function to lib/client.c
     4) Add a new function to lib/eclient.c
     5) Add a new function to python/disorder.py.in
     6) Add a new command to clients/disorder.c and update doc/disorder.1.in
     7) Add a new test somewhere in tests/*.py
     Depending on the purpose of the command it may be acceptable to leave out
     some of the client side work - for instance commands only ever used by the
     web interface are not implemented in lib/eclient.c.

   * See disorder_protocol(5) for details of how the status code is
     constructed, and the existing commands for examples.

   * If the command needs a new right to be defined then update lib/rights.[ch]
     and doc/disorder_config.5.in.  New rights should definitely be mentioned
     in README.upgrades as existing users will not automatically get new rights
     even if they are in default_rights.  If the new right should not be in
     default_rights by default then you must update config_postdefaults().

Web Interface:

   * The web interface does not use Javascript or Flash and I would like to
     keep it that way.  Clever use of CSS is OK provided it works well on the
     mainstream browsers.

   * Update templates/help.tmpl for any changes you make.

Disobedience:

   * Disobedience does not currently use threads and I'd prefer to keep it that
     way.

   * Disobedience uses the Boehm garbage collector but not for GTK+/GLIB's
     memory allocation, as they are incompatible with it.  So you still have to
     do somewhat manual memory management for GTK+ objects.  Fortunately it has
     its own refcounting system which does most of the work for you.

   * Lengthy operations must not block.  In practice this seems to be a less of
     a problem for Disobedience than the server.  Use the GLIB event loop to
     deal with long-running operations if you do need any.

   * Update doc/disobedience.1.in for any changes you make.

New Platforms:

   * It is not mandatory to have an entry in configure's 'case $host' section,
     but may well be convenient.

   * Complete support for a new platform implies updating scripts/setup.in and
     scripts/teardown.in as well as getting the software to build and work (but
     this doesn't mean that patches that don't achieve this will be rejected).

Code And Patches:

   * Please follow the existing layout conventions.

   * Please try to write doc comments for new functions, types, etc using the
     same syntax as the existing ones.  Doxygen can be used to turn this into
     reference documentation (see http://www.stack.nl/~dimitri/doxygen/) but
     really the point is to have good inline code documentation, not the
     Doxygen output as such.

   * More importantly, new configuration directives, protocol commands,
     interface features etc should be documented in the relevant places.

   * If you add new dependencies please update README, README.developers and
     debian/control.

   * New dependencies that are not in Debian stable are likely to be rejected.
     (But if your new feature only makes sense on a given platform then
     obviously its new dependencies don't need to be available elsewhere.)

   * GCCisms such as typeof and C99isms such as mixed declarations and named
     structure initializers are used; the configure script asks for -std=gnu99
     by default.  Some supported platforms are still on GCC 4.0.

   * Please submit patches either using 'diff -u', or by publishing a bzr
     branch somewhere I can get at it.

   * Please make it clear that your changes can be distributed under DisOrder's
     licence (which is "GPL v3 or later").

Local Variables:
mode:text
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Commit	Line	Data
91d9a42d	1	Dependencies:
	2
	3	* You'll need, in addition to the packages mentioned in README:
	4	Automake 1.10 1.7 is no good; 1.8/9 might work
	5	Autoconf 2.61 Slightly older might work too
	6	Libtool 1.5.22 1.4 is no good
	7	Bazaar (bzr) You might be able to manage without
	8	Python 2.4
	9
	10	* On Debian and derivatives this should work:
	11
	12	apt-get install gcc libc-dev automake autoconf libtool libgtk2.0-dev \
	13	libgc-dev libgcrypt-dev libpcre3-dev libvorbis-dev \
	14	libao-dev libmad0-dev libasound2-dev libdb4.3-dev \
	15	libflac-dev
	16
50450a00 RK	17	(Use the bzr from backports, the one in etch is obsolete.)
50450a00 RK	18
42f43a11 RK	19	* On FreeBSD you'll need at least these packages:
	20	autotools
	21	bash
	22	flac
	23	mad
	24	boehm-gc
	25	db43
	26	gmake
	27	gsed
	28	libao
	29	libgcrypt
	30	wget
	31	vorbis-tools
	32
91d9a42d	33	* Please report unstated dependencies (here, README or debian/control).
91d9a42d	34
b30155e3 RK	35	Building:
	36
	37	* Compiled versions of configure and the makefiles are including in bzr, so
	38	if you didn't use a source tarball, you must start as follows:
	39
d558cce2 RK	40	bash ./prepare
d558cce2 RK	41	./configure -C
b30155e3 RK	42	make
	43
	44	* On FreeBSD you must use gmake.
	45
91d9a42d	46	Testing:
	47
	48	* There is an extensive test suite in lib/test.c and tests/*.py. You can
	49	run the tests with 'make check'. If possible please add tests for new
	50	code to at least one of these. At the very least the existing tests
	51	should continue to pass.
	52
	53	* The tests will not currently pass in an ASCII locale. This is essentially
	54	unavoidable given the need to test Unicode support. ISO 8859-1 or UTF-8
	55	locales should be OK for the time being.
	56
	57	APIs And Formats:
	58
	59	* To support a new sound API:
	60	1) Teach configure.ac how to detect any libraries required.
	61	2) Define a new BACKEND_ value and update configuration.[ch] for it.
	62	3) Create a suitable server/speaker-*.c along the pattern of the existing
	63	ones.
	64	4) If possible create a suitable lib/mixer-*.c. This doesn't make sense
	65	for all APIs (e.g. network), but even for those it does, playback
	66	support without volume control support is likely to be acceptable (even
	67	if inferior to full support).
	68	5) Update doc/disorder_config.5.in.
	69	6) If relevant, create a suitable clients/playrtp-*.c and update
	70	doc/disorder-playrtp.1.in.
	71
	72	* To support a new file format:
	73	1) Teach configure.ac how to detect any libraries required.
	74	2) Add a new section to server/decode.c. NB this file may be split into
	75	several bits one day.
	76	3) Add a new section to plugins/tracklength.c. Again this file may be
	77	split up in a future version.
	78	4) Update default_players[] in lib/configuration.c.
	79	5) Update doc/disorder_config.5.in.
	80
	81	The Server:
	82
	83	* The server's command implementations must not block. Waiting for a little
0590cedc RK	84	disk IO is OK but blocking for extended periods on long-lasting
	85	transactions or external resources is not acceptable; it will wedge the
	86	server for all other users.
	87
	88	Long-running subprocesses should use subprograms (rather than forking but
	89	not execing) if reasonably possible; see c_stats() for an example.
	90	c_reminder() is probably in the grey area.
91d9a42d	91
	92	* The server process does not use threads and I would like to keep it that
	93	way.
	94
	95	* The server uses the Boehm garbage collector. This eliminates the need to
	96	call free() and similar functions in many cases, though teardown calls to
	97	that do more than free GC-allocated memory (such as fclose()) are still
	98	required.
	99
	100	* DisOrder's *printf calls, such as byte_xasprintf(), are mostly preferred
	101	within the server to the ones built into libc. An important distinction
	102	is that they will always accept UTF-8 strings whereas the built-in ones
	103	may reject them in non-UTF-8 locales (for instance Glibc does this) with
	104	EILSEQ. Only where the data is guaranteed to be ASCII may the libc
	105	functions be used.
	106
	107	* To add a new configuration directive:
	108	1) Add a new entry to the struct in lib/configuration.h
	109	2) Add a new table entry to conf[] in lib/configuration.c
	110	3) If the directive is entirely unlike existing ones add a new type_
	111	to lib/configuration.c
	112	4) Set the default if non-0 in config_default(). In some cases
	113	config_postdefaults() may be more appropriate.
	114	5) Document the new directive in doc/disorder_config.5.in
	115
	116	* To add a new command:
	117	1) Add a new c_ function and table entry in server/server.c
	118	2) Document the new command in doc/disorder_protocol.5.in
	119	3) Add a new function to lib/client.c
	120	4) Add a new function to lib/eclient.c
	121	5) Add a new function to python/disorder.py.in
	122	6) Add a new command to clients/disorder.c and update doc/disorder.1.in
	123	7) Add a new test somewhere in tests/*.py
	124	Depending on the purpose of the command it may be acceptable to leave out
	125	some of the client side work - for instance commands only ever used by the
	126	web interface are not implemented in lib/eclient.c.
	127
	128	* See disorder_protocol(5) for details of how the status code is
	129	constructed, and the existing commands for examples.
	130
	131	* If the command needs a new right to be defined then update lib/rights.[ch]
	132	and doc/disorder_config.5.in. New rights should definitely be mentioned
	133	in README.upgrades as existing users will not automatically get new rights
	134	even if they are in default_rights. If the new right should not be in
	135	default_rights by default then you must update config_postdefaults().
	136
	137	Web Interface:
	138
	139	* The web interface does not use Javascript or Flash and I would like to
0590cedc RK	140	keep it that way. Clever use of CSS is OK provided it works well on the
0590cedc RK	141	mainstream browsers.
91d9a42d	142
50450a00	143	* Update templates/help.tmpl for any changes you make.
91d9a42d	144
	145	Disobedience:
	146
	147	* Disobedience does not currently use threads and I'd prefer to keep it that
	148	way.
	149
	150	* Disobedience uses the Boehm garbage collector but not for GTK+/GLIB's
	151	memory allocation, as they are incompatible with it. So you still have to
	152	do somewhat manual memory management for GTK+ objects. Fortunately it has
	153	its own refcounting system which does most of the work for you.
	154
	155	* Lengthy operations must not block. In practice this seems to be a less of
	156	a problem for Disobedience than the server. Use the GLIB event loop to
	157	deal with long-running operations if you do need any.
	158
	159	* Update doc/disobedience.1.in for any changes you make.
	160
0590cedc RK	161	New Platforms:
	162
	163	* It is not mandatory to have an entry in configure's 'case $host' section,
	164	but may well be convenient.
	165
	166	* Complete support for a new platform implies updating scripts/setup.in and
	167	scripts/teardown.in as well as getting the software to build and work (but
	168	this doesn't mean that patches that don't achieve this will be rejected).
	169
91d9a42d	170	Code And Patches:
	171
	172	* Please follow the existing layout conventions.
	173
	174	* Please try to write doc comments for new functions, types, etc using the
	175	same syntax as the existing ones. Doxygen can be used to turn this into
0590cedc RK	176	reference documentation (see http://www.stack.nl/~dimitri/doxygen/) but
	177	really the point is to have good inline code documentation, not the
	178	Doxygen output as such.
91d9a42d	179
	180	* More importantly, new configuration directives, protocol commands,
	181	interface features etc should be documented in the relevant places.
	182
	183	* If you add new dependencies please update README, README.developers and
	184	debian/control.
	185
	186	* New dependencies that are not in Debian stable are likely to be rejected.
	187	(But if your new feature only makes sense on a given platform then
	188	obviously its new dependencies don't need to be available elsewhere.)
	189
1b8ed51f RK	190	* GCCisms such as typeof and C99isms such as mixed declarations and named
	191	structure initializers are used; the configure script asks for -std=gnu99
	192	by default. Some supported platforms are still on GCC 4.0.
f0a76a4a	193
91d9a42d	194	* Please submit patches either using 'diff -u', or by publishing a bzr
	195	branch somewhere I can get at it.
	196
	197	* Please make it clear that your changes can be distributed under DisOrder's
7751df38	198	licence (which is "GPL v3 or later").
91d9a42d	199
	200	Local Variables:
	201	mode:text
	202	fill-column:79
	203	End: