diff options
Diffstat (limited to 'alsa/src/runnable.rs')
| -rw-r--r-- | alsa/src/runnable.rs | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/alsa/src/runnable.rs b/alsa/src/runnable.rs new file mode 100644 index 0000000..4835436 --- /dev/null +++ b/alsa/src/runnable.rs @@ -0,0 +1,397 @@ +use std::{cell::RefCell, fmt::Display, error::Error, ffi::CStr}; + +use formatable_float::FormattingError; +use libc::{c_int, c_char, c_uint, c_void, c_long, c_ushort, c_short}; +use swaystatus_plugin::*; + +use crate::{communication::MessagesFromMainReceiver, config::SElemAbstraction}; + +use super::config::AlsaVolumeConfig; + +pub struct AlsaVolumeRunnable<'r>{ + to_main : Box<dyn MsgModuleToMain + 'r>, + from_main : MessagesFromMainReceiver, + config : &'r AlsaVolumeConfig, +} + +impl<'r> AlsaVolumeRunnable<'r> { + pub fn new(to_main : Box<dyn MsgModuleToMain + 'r>, from_main : MessagesFromMainReceiver, config : &'r AlsaVolumeConfig) -> Self { + Self { to_main, from_main, config } + } + fn send_error_to_main<E>(&self, err : E) where E : std::error::Error { + self.to_main.send_update(Err(PluginError::ShowInsteadOfText(String::from("Error")))).expect("Tried to tell main thread that an error occured. Main thread isn't listening any more."); + self.to_main.send_update(Err(PluginError::PrintToStdErr(err.to_string()))).expect("Tried to tell main thread that an error occured. Main thread isn't listening any more."); + } + fn run_internal(&self) -> Result<(), AlsaVolumeError>{ + //Using C callbacks in Rust is a minefield. + //However, we can take the easy way out here, namely we only care about a single element, so we can just make a single data field ;-) + //It still needs to be in a Cell though. + let elem_scratch_space = RefCell::new(None); + let mixer_scratch_space = MixerScratchSpace{ + elem_name: &self.config.element, + elem_scratch: &elem_scratch_space, + }; + let mixer = open_mixer(0)?; + register_selem(mixer.handle, &self.config.device, self.config.abstraction)?; + unsafe { snd_mixer_set_callback(mixer.handle, Some(Self::mixer_callback)) }; + unsafe { snd_mixer_set_callback_private(mixer.handle, &mixer_scratch_space as *const MixerScratchSpace as *const c_void)}; + load_mixer(mixer.handle)?; + + let mut should_update_main_even_if_unchanged = true; + loop { + + let descriptor_count = unsafe{snd_mixer_poll_descriptors_count(mixer.handle)}; + if descriptor_count < 0 { + return Err(AlsaVolumeError::FailedToGetPollDescriptors); + } + let mut descriptors : Vec<libc::pollfd> = std::iter::once(libc::pollfd{ + fd: self.from_main.file_handle().get_raw(), + events: libc::POLLIN, + revents: 0 + }) + .chain(std::iter::repeat( + libc::pollfd{ + fd: 0, + events: 0, + revents: 0, + } + )) + .take(descriptor_count as usize + 1) + .collect(); + let descriptor_count = if descriptor_count > 0 { unsafe {snd_mixer_poll_descriptors(mixer.handle, &mut descriptors[1] , descriptor_count as c_uint)} } else { 0 }; + if descriptor_count < 0 { + return Err(AlsaVolumeError::FailedToGetPollDescriptors); + } + let n = unsafe {libc::poll(descriptors.as_mut_ptr(), descriptors.len() as u64, -1)}; + if n < 0 && n != libc::EINTR { + return Err(AlsaVolumeError::UnexpectedPollError); + } + //first check if there's any data on our pipe from main. + loop { + match self.from_main.receive(){ + Ok(Some(message)) => match message{ + crate::communication::MessagesFromMain::Quit => { return Ok(())}, + crate::communication::MessagesFromMain::Refresh => { should_update_main_even_if_unchanged = true; }, + }, + Ok(None) => break, //main has nothing more to say. + Err(e) => match e { + crate::communication::pipe_chan::ReceiveError::SenderHasHungUp => { return Err(AlsaVolumeError::MainHungUpWithoutQuit) }, + crate::communication::pipe_chan::ReceiveError::UnknownError => { return Err(AlsaVolumeError::ErrorInPluginCommunication) }, + }, + } + } + let old_values = mixer_scratch_space.elem_scratch.borrow().clone(); + let anything_new_from_alsa = n > (if descriptors[0].revents != 0 { 1 } else { 0 }); + if anything_new_from_alsa { + let mut revents = 0; + let worked = unsafe {snd_mixer_poll_descriptors_revents(mixer.handle, &descriptors[1], descriptor_count as c_uint,&mut revents) }; + if worked < 0{ + return Err(AlsaVolumeError::UnexpectedPollError); + } + if (revents as c_short) & (libc::POLLERR | libc::POLLNVAL) != 0 { + return Err(AlsaVolumeError::DeviceRemoved); + } + if (revents as c_short) & libc::POLLIN != 0 { + let handling_worked = unsafe {snd_mixer_handle_events(mixer.handle)}; + if handling_worked < 0 { + return Err(AlsaVolumeError::EventHandlingError); + } + } + } + let new_values = mixer_scratch_space.elem_scratch.borrow().clone(); + if new_values != old_values || should_update_main_even_if_unchanged { + self.send_updated_values_to_main(new_values).expect("Tried to update main thread, but it seems to be gone?"); + } + should_update_main_even_if_unchanged = false; + } + } + + fn send_updated_values_to_main(&self, volume : Option<ElemVolumeInfo>) -> Result<(),PluginCommunicationError> { + match volume{ + Some(volume) => { + let formatted_volume = self.config.format_volume(volume.volume, volume.mute); + match formatted_volume { + Ok(msg) => { self.to_main.send_update(Ok(msg)) } + Err(e) => { + let full_message = e.to_string(); + match e { + FormattingError::EmptyMap{ numeric_fallback } => { + self.to_main.send_update(Err(PluginError::ShowInsteadOfText(numeric_fallback)))?; + self.to_main.send_update(Err(PluginError::PrintToStdErr(full_message))) + } + } + } + } + }, + None => { + self.to_main.send_update(Err(PluginError::ShowInsteadOfText("Unknown".into()))) + }, + } + } + + extern "C" fn mixer_callback(mixer : SndMixerHandle, flags : c_uint, element : SndMixerElemHandle) -> c_int { + if flags & (1<<2) != 0 { //SND_CTL_EVENT_MASK_ADD + //check if the newly added element is the one we are looking for. + let scratch : &MixerScratchSpace = unsafe{&*(snd_mixer_get_callback_private(mixer) as *const MixerScratchSpace)}; + let elem_name = unsafe { CStr::from_ptr(snd_mixer_selem_get_name(element)) }; + if elem_name == scratch.elem_name { + unsafe {snd_mixer_elem_set_callback(element, Some(Self::element_callback))}; + unsafe {snd_mixer_elem_set_callback_private(element,scratch.elem_scratch as *const ElemScratchSpace as *const c_void)}; + 0 + } else { + 0 + } + } else { + 0 + } + } + + extern "C" fn element_callback(element : SndMixerElemHandle, flags : c_uint) -> c_int { + //okay, we hit the right element, sooo + if flags == (!0) { //SND_CTL_EVENT_MASK_REMOVE + 0 + } else { //could check further to exclude more spurious wake-ups, but for now... + //we don't do any magic here. Just sum up all channel's values and call it a day. + let (count, volume_sum) = ALL_CHANNELS.iter() + .filter_map(|channel| get_volume_for_channel(element, *channel)) + .fold((0,0), |(c, ov), v| (c+1, ov + v)); + let average = if count == 0 { None } else { Some(volume_sum / count)}; + let range = get_volume_range(element); + let normalized = average.zip(range).map(|(average, range)| ((average - range.0)*100000) / (range.1 - range.0)); + let scratch = unsafe{&*(snd_mixer_elem_get_callback_private(element) as *const ElemScratchSpace)}; + let has_mute = unsafe{ snd_mixer_selem_has_playback_switch(element) != 0}; + let is_mute = if has_mute { + !ALL_CHANNELS.iter().any(|channel| get_switch_for_channel(element, *channel)) + } else { false }; + *scratch.borrow_mut() = normalized.map(|volume| ElemVolumeInfo{volume : volume as f32 / 100000.0, mute : is_mute}); + 0 + } + } +} + +#[derive(Clone, Debug, PartialEq)] +struct ElemVolumeInfo{ + volume : f32, + mute : bool +} + +type ElemScratchSpace = RefCell<Option<ElemVolumeInfo>>; + +struct MixerScratchSpace<'a>{ + elem_name : &'a CStr, + elem_scratch : &'a ElemScratchSpace, +} + +impl<'r> SwayStatusModuleRunnable for AlsaVolumeRunnable<'r> { + fn run(&self) { + match self.run_internal(){ + Ok(()) => {}, + Err(e) => self.send_error_to_main(e), + } + } +} + +#[derive(Clone, Copy, Debug)] +enum AlsaVolumeError{ + FailedToOpenMixer, + FailedToLoadElements, + FailedToGetPollDescriptors, + UnexpectedPollError, + ErrorInPluginCommunication, + MainHungUpWithoutQuit, + DeviceRemoved, + EventHandlingError, +} + +impl Display for AlsaVolumeError{ + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + match self { + AlsaVolumeError::FailedToOpenMixer => write!(f, "Failed to open Mixer"), + AlsaVolumeError::FailedToLoadElements => write!(f, "Failed to load Mixer elements"), + AlsaVolumeError::FailedToGetPollDescriptors => write!(f, "Failed to get poll descriptors"), + AlsaVolumeError::UnexpectedPollError => write!(f, "Polling for updates failed for an unhandled reason. Debug."), + AlsaVolumeError::ErrorInPluginCommunication => write!(f, "Something went wrong with the pipe from main thread. Debug."), + AlsaVolumeError::MainHungUpWithoutQuit => write!(f, "Main thread ended communication without saying goodbye. Debug."), + AlsaVolumeError::DeviceRemoved => write!(f, "Device removed. Unsupported for now."), + AlsaVolumeError::EventHandlingError => write!(f, "Failure while handling mixer events. Debug."), + } + } +} +impl Error for AlsaVolumeError{} + +struct MixerHandleScopeGuard{ + handle : SndMixerHandle +} +impl Drop for MixerHandleScopeGuard{ + fn drop(&mut self) { + if !self.handle.is_null() { + unsafe {snd_mixer_close(self.handle)}; + } + } +} + +fn open_mixer(mode : c_int) -> Result<MixerHandleScopeGuard,AlsaVolumeError>{ + let mut handle : SndMixerHandle = std::ptr::null(); + let error_code = unsafe {snd_mixer_open(&mut handle, mode)}; + if error_code == 0 { + Ok(MixerHandleScopeGuard { handle }) + } else { + Err(AlsaVolumeError::FailedToOpenMixer) + } +} + +fn load_mixer(mixer : SndMixerHandle) -> Result<(), AlsaVolumeError>{ + let error_code = unsafe { snd_mixer_load(mixer)}; + if error_code == 0 { + Ok(()) + } else { + Err(AlsaVolumeError::FailedToLoadElements) + } +} + +fn register_selem(mixer : SndMixerHandle, device : &CStr, abstraction : SElemAbstraction) -> Result<(), AlsaVolumeError>{ + let options = SndMixerSelemRegopt{ + ver: 1, + abstraction: match abstraction { + SElemAbstraction::None => SndMixerSelemRegoptAbstract::None, + SElemAbstraction::Basic => SndMixerSelemRegoptAbstract::Basic, + }, + device: device.as_ptr(), + playback_pcm: std::ptr::null(), + capture_pcm: std::ptr::null(), + }; + let error_code = unsafe {snd_mixer_selem_register(mixer, &options, std::ptr::null_mut())}; + if error_code == 0 { + Ok(()) + } else { + Err(AlsaVolumeError::FailedToOpenMixer) + } +} + +fn get_volume_for_channel(element : SndMixerElemHandle, channel : SndMixerSelemChannelIdT) -> Option<c_long>{ + if unsafe {snd_mixer_selem_has_playback_channel(element, channel) > 0} { + let mut value : c_long = 0; + if unsafe { snd_mixer_selem_get_playback_volume(element, channel, &mut value) == 0}{ + Some(value) + } else { + None + } + } else { + None + } +} + +fn get_switch_for_channel(element : SndMixerElemHandle, channel : SndMixerSelemChannelIdT) -> bool { + let mut switch = 0; + let worked = unsafe { snd_mixer_selem_get_playback_switch(element, channel, &mut switch)}; + worked == 0 && switch != 0 +} + +fn get_volume_range(element : SndMixerElemHandle) -> Option<(c_long, c_long)>{ + let mut min = 0; + let mut max = 0; + if unsafe { snd_mixer_selem_get_playback_volume_range(element, &mut min, &mut max) == 0 } { + Some((min, max)) + } else { + None + } +} + +#[repr(C)] struct SndMixerT { _private: [u8; 0]} +#[repr(C)] struct SndPcmT { _private: [u8; 0]} +#[repr(C)] struct SndMixerClassT { _private: [u8; 0]} +#[repr(C)] struct SndMixerElemT { _private: [u8; 0]} + +type SndMixerHandle = *const SndMixerT; +type SndMixerElemHandle = *const SndMixerElemT; + +#[repr(C)] enum SndMixerSelemRegoptAbstract { + None, + Basic, +} +#[repr(C)] struct SndMixerSelemRegopt { + ver : c_int, + abstraction : SndMixerSelemRegoptAbstract, + device : *const c_char, + playback_pcm : *const SndPcmT, + capture_pcm : *const SndPcmT, +} + +#[derive(Clone,Copy)] +#[repr(C)] enum SndMixerSelemChannelIdT { + FrontLeft, + FrontRight, + RearLeft, + RearRight, + FrontCenter, + Woofer, + SideLeft, + SideRight, + RearCenter, +} + +static ALL_CHANNELS : [SndMixerSelemChannelIdT;9] = [ + SndMixerSelemChannelIdT::FrontLeft, + SndMixerSelemChannelIdT::FrontRight, + SndMixerSelemChannelIdT::RearLeft, + SndMixerSelemChannelIdT::RearRight, + SndMixerSelemChannelIdT::FrontCenter, + SndMixerSelemChannelIdT::Woofer, + SndMixerSelemChannelIdT::SideLeft, + SndMixerSelemChannelIdT::SideRight, + SndMixerSelemChannelIdT::RearCenter, +]; + + +type SndMixerCallbackT = extern "C" fn(SndMixerHandle, c_uint, SndMixerElemHandle) -> c_int; +type SndMixerElemCallbackT = extern "C" fn(SndMixerElemHandle, c_uint) -> c_int; +#[link(name = "asound")] +extern "C" { + //int snd_mixer_open ( snd_mixer_t ** mixerp, int mode ) + fn snd_mixer_open(mixer : *mut SndMixerHandle, mode : c_int) -> c_int; + //int snd_mixer_close ( snd_mixer_t * mixer ) + fn snd_mixer_close(mixer : SndMixerHandle) -> c_int; + //int snd_mixer_selem_register(snd_mixer_t *mixer, struct snd_mixer_selem_regopt *options, snd_mixer_class_t **classp); + fn snd_mixer_selem_register(mixer : SndMixerHandle, options: *const SndMixerSelemRegopt, class: *mut *const SndMixerClassT) -> c_int; + //void snd_mixer_set_callback ( snd_mixer_t * obj, snd_mixer_callback_t val ) + fn snd_mixer_set_callback(mixer : SndMixerHandle, callback : Option<SndMixerCallbackT>); + //void snd_mixer_set_callback_private ( snd_mixer_t * mixer, void * val ) + fn snd_mixer_set_callback_private(mixer : SndMixerHandle, value : *const c_void); //the *const is a lie, but one that we need for Stacked Borrows sanity. + //void* snd_mixer_get_callback_private ( const snd_mixer_t * mixer ) + fn snd_mixer_get_callback_private(mixer : SndMixerHandle) -> *const c_void; //the *const is a lie, but one that we need for Stacked Borrows sanity. + + //int snd_mixer_load ( snd_mixer_t * mixer ) + fn snd_mixer_load(mixer : SndMixerHandle) -> c_int; + + //const char* snd_mixer_selem_get_name ( snd_mixer_elem_t * elem ) + fn snd_mixer_selem_get_name(element: SndMixerElemHandle) -> *const c_char; + //void snd_mixer_elem_set_callback ( snd_mixer_elem_t * mixer, snd_mixer_elem_callback_t val ) + fn snd_mixer_elem_set_callback(element : SndMixerElemHandle, callback : Option<SndMixerElemCallbackT>); + //void snd_mixer_elem_set_callback_private ( snd_mixer_elem_t * mixer, void * val ) + fn snd_mixer_elem_set_callback_private(element : SndMixerElemHandle, value : *const c_void); + //void* snd_mixer_elem_get_callback_private ( const snd_mixer_elem_t * mixer ) + fn snd_mixer_elem_get_callback_private(element : SndMixerElemHandle) -> *const c_void; + + //int snd_mixer_selem_has_playback_channel ( snd_mixer_elem_t * elem, snd_mixer_selem_channel_id_t channel ) + fn snd_mixer_selem_has_playback_channel(element : SndMixerElemHandle, channel : SndMixerSelemChannelIdT) -> c_int; + //int snd_mixer_selem_get_playback_volume ( snd_mixer_elem_t * elem, snd_mixer_selem_channel_id_t channel, long * value ) + fn snd_mixer_selem_get_playback_volume(element : SndMixerElemHandle, channel : SndMixerSelemChannelIdT, value : *mut c_long) -> c_int; + //int snd_mixer_selem_get_playback_volume_range ( snd_mixer_elem_t * elem, long * min, long * max ) + fn snd_mixer_selem_get_playback_volume_range(element : SndMixerElemHandle, min: *mut c_long, max : *mut c_long) -> c_int; + + //int snd_mixer_selem_has_playback_switch ( snd_mixer_elem_t * elem ) + fn snd_mixer_selem_has_playback_switch(element : SndMixerElemHandle) -> c_int; + //int snd_mixer_selem_get_playback_switch ( snd_mixer_elem_t * elem, snd_mixer_selem_channel_id_t channel, int * value ) + fn snd_mixer_selem_get_playback_switch(element : SndMixerElemHandle, channel : SndMixerSelemChannelIdT, value : *mut c_int) -> c_int; + + //int snd_mixer_poll_descriptors_count ( snd_mixer_t * mixer ) + fn snd_mixer_poll_descriptors_count(mixer : SndMixerHandle) -> c_int; + //int snd_mixer_poll_descriptors ( snd_mixer_t * mixer, struct pollfd * pfds, unsigned int space ) + fn snd_mixer_poll_descriptors(mixer : SndMixerHandle, fds : *mut libc::pollfd, space : c_uint) -> c_int; + + //int snd_mixer_poll_descriptors_revents ( snd_mixer_t * mixer, struct pollfd * pfds, unsigned int nfds, unsigned short * revents ) + fn snd_mixer_poll_descriptors_revents(mixer : SndMixerHandle, fds : *const libc::pollfd, nfds : c_uint, revents : *mut c_ushort) -> c_int; + + //int snd_mixer_handle_events ( snd_mixer_t * mixer ) + fn snd_mixer_handle_events(mixer : SndMixerHandle) -> c_int; +}
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