The output gets the standard MPD log format with domain curl and a timestamp.
Using CURLOPT_DEBUGFUNCTION that is only called when CURLOPT_VERBOSE is in effect
when MPD log level is verbose.
The BlockingCall() in InitUringInputPlugin() did not work because the
EventThread was not yet started. This was never noticed until commit
e309941646 which enabled `IORING_SETUP_SINGLE_ISSUER`, and suddenly
the kernel refused to accept io_uring_submit() calls from the
io_thread because io_uring_setup() had been called from the main
thread.
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.
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()`.
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.
These settings do not work if CURL was compiled with
CURL_DISABLE_PROXY, and cause error "An unknown option was passed in
to libcurl".
Fixes regression by commit 7ab0dfc8ce
