snd_pcm_poll_descriptors_revents() may return any error code; the
ALSA docs do not constrain the permitted values. A 'hw' device
will only ever return an error if the pfd array passed in is
invalid (-EINVAL), but other I/O plugins may return arbitary
errors. For example a network-based device may return -EPIPE etc.
The resulting exception thrown by
AlsaNonBlockPcm::DispatchSockets() must be caught to prevent the
mpd process from being aborted.
This is a big simplification of all IntrusiveHashSet users: instead of
having to implement multiple overloads of Hash and Equal, the
IntrusiveHashSet class can first extract the effective key from an
item and then pass it to the Hash/Equal functions.
Preparing to add a key extraction function. Without this "Operators"
template parameter, we'd have even more template parameters, and that
parameter list would grow too complex. Better wrap it in one single
template that contains all operators.
This is an API change which all callers need to adjust to, but it will
be worth it.
Let OnHeaders() check the status.
The status checking code was added by commit 4f021cbced in 2011,
but in 2008, commit a8e81326d0 enabled `CURLOPT_FAILONERROR`, which
means the status checking code never had any effect.
This allows `LoadExcludeListOrLog()` to hide boring "404 Not Found"
log messages via `IsFileNotFound()`.
Fixes a busy loop in BufferingInputStream::RunThreadLocked() because
the method never learns that seeking is ignored, even though the HTTP
stream is already broken and can never be read; nobody cared to check
for errors.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/1727
Some ALSA capture devices can have very large buffers, holding 10
seconds or more audio. Using the maximum buffer size with such
devices leads to unacceptably large, and unnecessary, latency.
Also, some ALSA drivers (e.g. HDA Intel PCH) report an invalid
maximum period size, and the period size that mpd calculates from
the maximum buffer size results in "Invalid argument" error when
applying the hw_params. Note that the "default" capture device on
many cards includes the "dsnoop" plugin which imposes a buffer
size of 16384 frames, so that "alsa://" works OK but
"alsa://plughw" or "alsa://hw" both fail.
Limit the maximum buffer time for ALSA input devices to a more useable
2 seconds, thereby avoiding both the above problems.
