It's too ugly and broken (both technically and usability-wise)
to be worth supporting in any stable release.
In one sentence: The queue is a very crippled version of the
playlist that takes precedence over the normal playlist.
How is it crippled?
* The "queueid" command only allows the queuing of songs
ALREADY IN THE PLAYLIST! This promotes having the entire mpd
database of songs in the playlist, which is a stupid practice
to begin with.
* It doesn't allow for meaningful rearranging and movement
of songs within the queue. To move a song, you'd need to
dequeue and requeue it (and other songs on the list).
Why? The playlist already allows _all_ these features
and shows everything a client needs to know about the ordering
of songs in a _single_ command!
* Random was a stupid idea to begin with and unfortunately
we're stuck supporting it since we've always had it. Users
should learn to use "shuffle" instead and not look at their
playlists. Implementing queue because we have the problem of
random is just a bandage fix and digging ourselves a new hole.
This protocol addition was never in a stable release of mpd, so
reverting it will only break things for people following trunk;
which I'm not too worried about. I am however worried about
long-term support of this misfeature, so I'm removing it.
Additionally, there are other points:
* It's trivially DoS-able:
(while true; do echo queueid $song_id; done) | nc $MPD_HOST $MPD_PORT
The above commands would cause the queue to become infinitely
expanding, taking up all available memory in the system. The
mpd playlist was implemented as an array with a fixed (but
configurable) size limit for this reason.
* It's not backwards-compatible. All clients would require
upgrades (and additional complexity) to even know what the
next song in the playlist is. mpd is a shared architecture,
and we should not violate the principle of least astonishment
here.
This removes the following commands:
queueid, dequeue, queueinfo
Additionally, the status field of "playlistqueue: " is removed
from the status command.
While this DoS is trivial to fix, the design is simply too
broken to ever support in a real release.
The overloading of the "addid" command and the allowing of
negative numbers to be used as offsets is far more flexible.
This improved "addid" is completely backwards-compatible with
all clients, and does not require clients to have UI changes or
run additional commands to display the queue.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7155 09075e82-0dd4-0310-85a5-a0d7c8717e4f
While mpd has always protected against the infinite expansion of
the main playlist by limiting its size in memory, however the
new storedPlaylist code has never checked for this limit.
Malicious (or clumsy) users could repeatedly append songs to
stored playlists, causing files to grow increasingly large
on disk. Attempting to load extremely large files into memory
will require mpd to slurp that all into memory, and ultimately
the file would be unusable by mpd because of the configurable
playlist size limit.
Now we limit stored playlists to the max_playlist_length
configuration variable set by the user (default is 16384). We
will refuse to append to playlist files if they hit that limit;
and also refuse to load more than the specified amount of songs
into memory.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7154 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Instead of printing out the Id from playlist.c, instead set
the integer that added_id poitns to if added_id is non-NULL.
This makes the API cleaner and will allow us to use additional
commands to manipulate the newly-added song_id. Callers
(handleAddId) that relied on printId to print it to the given
fd have now been modified to print the ID at a higher-level;
making playlist.c less-dependent on protocol details.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7149 09075e82-0dd4-0310-85a5-a0d7c8717e4f
This will make refactoring features easier, especially now that
pthreads support and larger refactorings are on the horizon.
Hopefully, this will make porting to other platforms (even
non-UNIX-like ones for masochists) easier, too.
os_compat.h will house all the #includes for system headers
considered to be the "core" of MPD. Headers for optional
features will be left to individual source files.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7130 09075e82-0dd4-0310-85a5-a0d7c8717e4f
It was a nice way to double the memory needed to write the
playlist to a file.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7116 09075e82-0dd4-0310-85a5-a0d7c8717e4f
This adds the following commands:
* queueid <id> Add song <id> to the queue.
* dequeue <pos> Remove song from <pos> from the queue
* queueinfo List the queue
To the statusfield it adds the following entry:
playlistqueue: <uid> UID can be used by clients to track changes in the playlist queue.
git-svn-id: https://svn.musicpd.org/mpd/trunk@6927 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Add -Wmissing-prototypes if compiling with gcc
Static where possible
git-svn-id: https://svn.musicpd.org/mpd/trunk@4657 09075e82-0dd4-0310-85a5-a0d7c8717e4f
This patch massively reduces the amount of heap allocations at
the interface/command layer. Most commands with minimal output
should not allocate memory from the heap at all. Things like
repeatedly polling status, currentsong, and volume changes
should be faster as a result, and more importantly, not a source
of memory fragmentation.
These changes should be safe in that there's no way for a
remote-client to corrupt memory or otherwise do bad stuff to
MPD, but an extra set of eyes to review would be good. Of
course there's never any warranty :)
No longer do we use FILE * structures in the interface, which means
we don't have to allocate any new memory for most connections.
Now, before you go on about losing the buffering that FILE *
+implies+, remember that myfprintf() never took advantage of
any of the stdio buffering features.
To reduce the diff and make bugs easier to spot in the diff,
I've kept myfprintf in places where we write to files (and not
network interfaces). Expect myfprintf to go away entirely soon
(we'll use fprintf for writing regular files).
git-svn-id: https://svn.musicpd.org/mpd/trunk@4483 09075e82-0dd4-0310-85a5-a0d7c8717e4f
