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// Copyright 2017 Lyndon Brown // // This file is part of the PulseAudio Rust language binding. // // Licensed under the MIT license or the Apache license (version 2.0), at your option. You may not // copy, modify, or distribute this file except in compliance with said license. You can find copies // of these licenses either in the LICENSE-MIT and LICENSE-APACHE files, or alternatively at // <http://opensource.org/licenses/MIT> and <http://www.apache.org/licenses/LICENSE-2.0> // respectively. // // Portions of documentation are copied from the LGPL 2.1+ licensed PulseAudio C headers on a // fair-use basis, as discussed in the overall project readme (available in the git repository). //! Connection contexts for asynchronous communication with a server. //! //! A `Context` object wraps a connection to a PulseAudio server using its native protocol. //! //! # Overview //! //! A context is the basic object for a connection to a PulseAudio server. It multiplexes commands, //! data streams and events through a single channel. //! //! There is no need for more than one context per application, unless connections to multiple //! servers are needed. //! //! # Operations //! //! All operations on the context are performed asynchronously. I.e. the client will not wait for //! the server to complete the request. To keep track of all these in-flight operations, the //! application is given an [`operation::Operation`] object for each asynchronous operation. //! //! There are only two actions (besides reference counting) that can be performed on an //! [`operation::Operation`]: querying its state with [`operation::Operation::get_state`] and //! aborting it with [`operation::Operation::cancel`]. //! //! An [`operation::Operation`] object is reference counted, so an application must make sure to //! unreference it, even if it has no intention of using it. This however is taken care of //! automatically in this Rust binding via the implementation of the `Drop` trait on the object. //! //! # Connecting //! //! A context must be connected to a server before any operation can be issued. Calling //! [`Context::connect`] will initiate the connection procedure. Unlike most asynchronous //! operations, connecting does not result in an [`operation::Operation`] object. Instead, the //! application should register a callback using [`Context::set_state_callback`]. //! //! # Disconnecting //! //! When the sound support is no longer needed, the connection needs to be closed using //! [`Context::disconnect`]. This is an immediate function that works synchronously. //! //! Since the context object has references to other objects it must be disconnected after use or //! there is a high risk of memory leaks. If the connection has terminated by itself, then there is //! no need to explicitly disconnect the context using [`Context::disconnect`]. //! //! # Functions //! //! The sound server’s functionality can be divided into a number of subsections: //! //! * [`stream`] //! * [`context::scache`] //! * [`context::introspect`] //! * [`context::subscribe`] //! //! [`Context::connect`]: struct.Context.html#method.connect //! [`Context::disconnect`]: struct.Context.html#method.disconnect //! [`Context::set_state_callback`]: struct.Context.html#method.set_state_callback //! [`context::introspect`]: ../context/introspect/index.html //! [`context::scache`]: ../context/scache/index.html //! [`context::subscribe`]: ../context/subscribe/index.html //! [`operation::Operation::cancel`]: ../operation/struct.Operation.html#method.cancel //! [`operation::Operation::get_state`]: ../operation/struct.Operation.html#method.get_state //! [`operation::Operation`]: ../operation/struct.Operation.html //! [`stream`]: ../stream/index.html pub mod ext_device_manager; pub mod ext_device_restore; pub mod ext_stream_restore; pub mod introspect; pub mod scache; pub mod subscribe; use std::os::raw::{c_char, c_void}; use std::ffi::{CStr, CString}; use std::ptr::{null, null_mut}; use std::rc::Rc; use crate::{def, sample}; use crate::mainloop::api::{Mainloop, MainloopInnerType}; use crate::mainloop::events; use crate::mainloop::events::timer::{TimeEvent, TimeEventRef}; use crate::operation::Operation; use crate::error::PAErr; use crate::time::MonotonicTs; use crate::proplist::{self, Proplist, ProplistInternal}; use crate::callbacks::{box_closure_get_capi_ptr, get_su_callback, MultiUseCallback}; use crate::capi::pa_context as ContextInternal; /// An opaque connection context to a daemon. /// /// Note: Saves a copy of active multi-use closure callbacks, which it frees on drop. pub struct Context { /// The actual C object. pub(crate) ptr: *mut ContextInternal, /// Used to avoid freeing the internal object when used as a weak wrapper in callbacks. weak: bool, /// Multi-use callback closure pointers. cb_ptrs: CallbackPointers, } unsafe impl Send for Context {} unsafe impl Sync for Context {} /// Holds copies of callback closure pointers, for those that are “multi-use” (may be fired multiple /// times), for freeing at the appropriate time. #[derive(Default)] struct CallbackPointers { set_state: NotifyCb, subscribe: self::subscribe::Callback, event: EventCb, } type NotifyCb = MultiUseCallback<dyn FnMut(), extern "C" fn(*mut ContextInternal, *mut c_void)>; type EventCb = MultiUseCallback<dyn FnMut(String, Proplist), extern "C" fn(*mut ContextInternal, name: *const c_char, pl: *mut ProplistInternal, *mut c_void)>; type ExtSubscribeCb = MultiUseCallback<dyn FnMut(), extern "C" fn(*mut ContextInternal, *mut c_void)>; /// The state of a connection context. #[repr(C)] #[derive(Debug, Copy, Clone, PartialEq, Eq)] pub enum State { /* NOTE: This enum’s variants and variant values **must** remain identical to the `sys` crate (C API) equivalent */ /// The context hasn’t been connected yet. Unconnected, /// A connection is being established. Connecting, /// The client is authorizing itself to the daemon. Authorizing, /// The client is passing its application name to the daemon. SettingName, /// The connection is established, the context is ready to execute operations. Ready, /// The connection failed or was disconnected. Failed, /// The connection was terminated cleanly. Terminated, } /// Test size is equal to `sys` equivalent (duplicated here for different documentation) #[test] fn state_compare_capi(){ assert_eq!(std::mem::size_of::<State>(), std::mem::size_of::<capi::pa_context_state_t>()); assert_eq!(std::mem::align_of::<State>(), std::mem::align_of::<capi::pa_context_state_t>()); } impl From<State> for capi::pa_context_state_t { #[inline] fn from(s: State) -> Self { unsafe { std::mem::transmute(s) } } } impl From<capi::pa_context_state_t> for State { #[inline] fn from(s: capi::pa_context_state_t) -> Self { unsafe { std::mem::transmute(s) } } } impl State { /// Checks if the passed state is one of the connected states (returns `true` if so). pub fn is_good(self) -> bool { self == State::Connecting || self == State::Authorizing || self == State::SettingName || self == State::Ready } } pub type FlagSet = capi::pa_context_flags_t; /// Some special flags for contexts. pub mod flags { use capi; use super::FlagSet; pub const NOFLAGS: FlagSet = capi::PA_CONTEXT_NOFLAGS; /// Disable autospawning of the PulseAudio daemon if required. pub const NOAUTOSPAWN: FlagSet = capi::PA_CONTEXT_NOAUTOSPAWN; /// Don’t fail if the daemon is not available when /// [`Context::connect`](../struct.Context.html#method.connect) is called, instead enter /// [`State::Connecting`](../enum.State.html#Connecting.v) state and wait for the daemon to /// appear. pub const NOFAIL: FlagSet = capi::PA_CONTEXT_NOFAIL; } impl Context { /// Instantiates a new connection context with an abstract mainloop API and an application name. /// /// It is recommended to use [`new_with_proplist`](#method.new_with_proplist) instead and /// specify some initial properties. pub fn new(mainloop: &impl Mainloop, name: &str) -> Option<Self> { // Warning: New CStrings will be immediately freed if not bound to a variable, leading to // as_ptr() giving dangling pointers! let c_name = CString::new(name.clone()).unwrap(); let ptr = unsafe { capi::pa_context_new(mainloop.inner().get_api().as_ref(), c_name.as_ptr()) }; match ptr.is_null() { false => Some(Self::from_raw(ptr)), true => None } } /// Instantiates a new connection context with an abstract mainloop API and an application name, /// and specify the initial client property list. pub fn new_with_proplist(mainloop: &impl Mainloop, name: &str, proplist: &Proplist) -> Option<Self> { // Warning: New CStrings will be immediately freed if not bound to a variable, leading to // as_ptr() giving dangling pointers! let c_name = CString::new(name.clone()).unwrap(); let ptr = unsafe { capi::pa_context_new_with_proplist(mainloop.inner().get_api().as_ref(), c_name.as_ptr(), proplist.0.ptr) }; match ptr.is_null() { false => Some(Self::from_raw(ptr)), true => None } } /// Creates a new `Context` from an existing [`ContextInternal`](enum.ContextInternal.html) /// pointer. #[inline] pub(crate) fn from_raw(ptr: *mut ContextInternal) -> Self { assert_eq!(false, ptr.is_null()); Self { ptr: ptr, weak: false, cb_ptrs: Default::default() } } /// Sets a callback function that is called whenever the context status changes. pub fn set_state_callback(&mut self, callback: Option<Box<dyn FnMut() + 'static>>) { let saved = &mut self.cb_ptrs.set_state; *saved = NotifyCb::new(callback); let (cb_fn, cb_data) = saved.get_capi_params(notify_cb_proxy_multi); unsafe { capi::pa_context_set_state_callback(self.ptr, cb_fn, cb_data); } } /// Sets a callback function that is called whenever a meta/policy control event is received. /// /// The callback is given a name which represents what event occurred. The set of defined events /// can be extended at any time. Also, server modules may introduce additional message types so /// make sure that your callback function ignores messages it doesn’t know. It is also given an /// (owned) property list. pub fn set_event_callback(&mut self, callback: Option<Box<dyn FnMut(String, Proplist) + 'static>>) { let saved = &mut self.cb_ptrs.event; *saved = EventCb::new(callback); let (cb_fn, cb_data) = saved.get_capi_params(event_cb_proxy); unsafe { capi::pa_context_set_event_callback(self.ptr, cb_fn, cb_data); } } /// Gets the error number of the last failed operation. #[inline] pub fn errno(&self) -> PAErr { PAErr(unsafe { capi::pa_context_errno(self.ptr) }) } /// Checks if some data is pending to be written to the connection (returns `true` if so). #[inline] pub fn is_pending(&self) -> bool { unsafe { capi::pa_context_is_pending(self.ptr) != 0 } } /// Gets the current context status. #[inline] pub fn get_state(&self) -> State { unsafe { capi::pa_context_get_state(self.ptr).into() } } /// Connects the context to the specified server. /// /// If server is `None`, connect to the default server. This routine may but will not always /// return synchronously on error. Use [`set_state_callback`](#method.set_state_callback) to be /// notified when the connection is established. If `flags` doesn’t have /// [`flags::NOAUTOSPAWN`](flags/constant.NOAUTOSPAWN.html) set and no specific server is /// specified or accessible, a new daemon is spawned. If `api` is not `None`, the functions /// specified in the structure are used when forking a new child process. pub fn connect(&mut self, server: Option<&str>, flags: FlagSet, api: Option<&def::SpawnApi>) -> Result<(), PAErr> { // Warning: New CStrings will be immediately freed if not bound to a variable, leading to // as_ptr() giving dangling pointers! let c_server = match server { Some(server) => CString::new(server.clone()).unwrap(), None => CString::new("").unwrap(), }; let p_api = api.map_or(null::<capi::pa_spawn_api>(), |a| a.as_ref()); let p_server = server.map_or(null::<c_char>(), |_| c_server.as_ptr() as *const c_char); match unsafe { capi::pa_context_connect(self.ptr, p_server, flags, p_api) } { 0 => Ok(()), e => Err(PAErr(e)), } } /// Terminates the context connection immediately. #[inline] pub fn disconnect(&mut self) { unsafe { capi::pa_context_disconnect(self.ptr); } } /// Drains the context. /// /// If there is nothing to drain, the function returns `None`. /// /// Note that it can also return `None` under other conditions. Many functions in the C API /// perform internal state validation checks and return a null pointer if they detect a problem, /// just as they return a null pointer on invalid input. Other functions panic on getting a null /// pointer return, however this function is unique in a null pointer also signalling something /// useful, and it is not possible to tell the difference. However, while I feel the need to be /// clear about the possibility, I believe that such invalid state conditions should only occur /// if there were a serious bug within PA, thus you are probably safe to just ignore this and /// always take a `None` return to indicate only that there is nothing to drain. pub fn drain<F>(&mut self, callback: F) -> Option<Operation<dyn FnMut()>> where F: FnMut() + 'static { let cb_data = box_closure_get_capi_ptr::<dyn FnMut()>(Box::new(callback)); let ptr = unsafe { capi::pa_context_drain(self.ptr, Some(notify_cb_proxy_single), cb_data) }; // NOTE: this function is unique in NEEDING the `Option` wrapper on the return value, since // a null pointer may be returned if there is nothing to drain! Do not remove it! match ptr.is_null() { false => Some(Operation::from_raw(ptr, cb_data as *mut Box<dyn FnMut()>)), true => None, } } /// Tells the daemon to exit. /// /// The returned operation is unlikely to complete successfully, since the daemon probably died /// before returning a success notification. /// /// The callback must accept a `bool`, which indicates success. /// /// Panics if the underlying C function returns a null pointer. pub fn exit_daemon<F>(&mut self, callback: F) -> Operation<dyn FnMut(bool)> where F: FnMut(bool) + 'static { let cb_data = box_closure_get_capi_ptr::<dyn FnMut(bool)>(Box::new(callback)); let ptr = unsafe { capi::pa_context_exit_daemon(self.ptr, Some(success_cb_proxy), cb_data) }; assert!(!ptr.is_null()); Operation::from_raw(ptr, cb_data as *mut Box<dyn FnMut(bool)>) } /// Sets the name of the default sink. /// /// The callback must accept a `bool`, which indicates success. /// /// Panics if the underlying C function returns a null pointer. pub fn set_default_sink<F>(&mut self, name: &str, callback: F) -> Operation<dyn FnMut(bool)> where F: FnMut(bool) + 'static { // Warning: New CStrings will be immediately freed if not bound to a variable, leading to // as_ptr() giving dangling pointers! let c_name = CString::new(name.clone()).unwrap(); let cb_data = box_closure_get_capi_ptr::<dyn FnMut(bool)>(Box::new(callback)); let ptr = unsafe { capi::pa_context_set_default_sink(self.ptr, c_name.as_ptr(), Some(success_cb_proxy), cb_data) }; assert!(!ptr.is_null()); Operation::from_raw(ptr, cb_data as *mut Box<dyn FnMut(bool)>) } /// Sets the name of the default source. /// /// The callback must accept a `bool`, which indicates success. /// /// Panics if the underlying C function returns a null pointer. pub fn set_default_source<F>(&mut self, name: &str, callback: F) -> Operation<dyn FnMut(bool)> where F: FnMut(bool) + 'static { // Warning: New CStrings will be immediately freed if not bound to a variable, leading to // as_ptr() giving dangling pointers! let c_name = CString::new(name.clone()).unwrap(); let cb_data = box_closure_get_capi_ptr::<dyn FnMut(bool)>(Box::new(callback)); let ptr = unsafe { capi::pa_context_set_default_source(self.ptr, c_name.as_ptr(), Some(success_cb_proxy), cb_data) }; assert!(!ptr.is_null()); Operation::from_raw(ptr, cb_data as *mut Box<dyn FnMut(bool)>) } /// Checks if this is a connection to a local daemon. /// /// Returns `true` when the connection is to a local daemon. Returns `None` on error, for /// instance when no connection has been made yet. pub fn is_local(&self) -> Option<bool> { match unsafe { capi::pa_context_is_local(self.ptr) } { 1 => Some(true), 0 => Some(false), _ => None, } } /// Sets a different application name for context on the server. /// /// Panics if the underlying C function returns a null pointer. pub fn set_name<F>(&mut self, name: &str, callback: F) -> Operation<dyn FnMut(bool)> where F: FnMut(bool) + 'static { // Warning: New CStrings will be immediately freed if not bound to a variable, leading to // as_ptr() giving dangling pointers! let c_name = CString::new(name.clone()).unwrap(); let cb_data = box_closure_get_capi_ptr::<dyn FnMut(bool)>(Box::new(callback)); let ptr = unsafe { capi::pa_context_set_name(self.ptr, c_name.as_ptr(), Some(success_cb_proxy), cb_data) }; assert!(!ptr.is_null()); Operation::from_raw(ptr, cb_data as *mut Box<dyn FnMut(bool)>) } /// Gets the server name this context is connected to. pub fn get_server(&self) -> Option<String> { let ptr = unsafe { capi::pa_context_get_server(self.ptr) }; match ptr.is_null() { false => Some(unsafe { CStr::from_ptr(ptr).to_string_lossy().into_owned() }), true => None, } } /// Gets the protocol version of the library. #[inline] pub fn get_protocol_version(&self) -> u32 { unsafe { capi::pa_context_get_protocol_version(self.ptr) } } /// Gets the protocol version of the connected server. /// /// Returns `None` on error. pub fn get_server_protocol_version(&self) -> Option<u32> { match unsafe { capi::pa_context_get_server_protocol_version(self.ptr) } { def::INVALID_INDEX => None, r => Some(r), } } /// Updates the property list of the client, adding new entries. /// /// Please note that it is highly recommended to set as many properties initially via /// [`new_with_proplist`](#method.new_with_proplist) as possible instead a posteriori with this /// function, since that information may then be used to route streams of the client to the /// right device. /// /// Panics if the underlying C function returns a null pointer. pub fn proplist_update<F>(&mut self, mode: proplist::UpdateMode, pl: &Proplist, callback: F) -> Operation<dyn FnMut(bool)> where F: FnMut(bool) + 'static { let cb_data = box_closure_get_capi_ptr::<dyn FnMut(bool)>(Box::new(callback)); let ptr = unsafe { capi::pa_context_proplist_update(self.ptr, mode, pl.0.ptr, Some(success_cb_proxy), cb_data) }; assert!(!ptr.is_null()); Operation::from_raw(ptr, cb_data as *mut Box<dyn FnMut(bool)>) } /// Updates the property list of the client, remove entries. /// /// Panics if the underlying C function returns a null pointer. pub fn proplist_remove<F>(&mut self, keys: &[&str], callback: F) -> Operation<dyn FnMut(bool)> where F: FnMut(bool) + 'static { // Warning: New CStrings will be immediately freed if not bound to a variable, leading to // as_ptr() giving dangling pointers! let mut c_keys: Vec<CString> = Vec::with_capacity(keys.len()); for key in keys { c_keys.push(CString::new(key.clone()).unwrap()); } // Capture array of pointers to the above CString values. // We also add a NULL pointer entry on the end, as expected by the C function called here. let mut c_key_ptrs: Vec<*const c_char> = Vec::with_capacity(c_keys.len() + 1); for c_key in c_keys { c_key_ptrs.push(c_key.as_ptr()); } c_key_ptrs.push(null()); let cb_data = box_closure_get_capi_ptr::<dyn FnMut(bool)>(Box::new(callback)); let ptr = unsafe { capi::pa_context_proplist_remove(self.ptr, c_key_ptrs.as_ptr(), Some(success_cb_proxy), cb_data) }; assert!(!ptr.is_null()); Operation::from_raw(ptr, cb_data as *mut Box<dyn FnMut(bool)>) } /// Gets the client index this context is identified in the server with. /// /// This is useful for usage with the introspection functions, such as /// [`introspect::Introspector::get_client_info`]. /// /// Returns `None` on error. /// /// [`introspect::Introspector::get_client_info`]: introspect/struct.Introspector.html#method.get_client_info pub fn get_index(&self) -> Option<u32> { match unsafe { capi::pa_context_get_index(self.ptr) } { def::INVALID_INDEX => None, r => Some(r), } } /// Creates a new timer event source for the specified time. /// /// This is an alternative to the mainloop `new_timer_event_rt` method. /// /// A reference to the mainloop object is needed, in order to associate the event object with /// it. The association is done to ensure the event does not outlive the mainloop. /// /// If pointer returned by underlying C function is `NULL`, `None` will be returned, otherwise a /// [`mainloop::events::timer::TimeEvent`] object will be returned. /// /// Example event set to fire in five seconds time: /// /// ```rust,ignore /// use pulse::time::{MonotonicTs, MicroSeconds, MICROS_PER_SEC}; /// let _t_event = context.rttime_new::<Mainloop, _>(&mainloop, /// MonotonicTs::now() + MicroSeconds(5 * MICROS_PER_SEC), /// || { println!("Timer event fired!"); }); /// ``` /// /// **Note**: You must ensure that the returned event object lives for as long as you want its /// event(s) to fire, as its `Drop` implementation destroys the event source. I.e. if you create /// a new event, but then immediately drop the object returned here, no event will fire! /// /// [`mainloop::events::timer::TimeEvent`]: ../mainloop/events/timer/struct.TimeEvent.html pub fn rttime_new<T, F>(&self, mainloop: &dyn Mainloop<MI=T::MI>, time: MonotonicTs, mut callback: F) -> Option<TimeEvent<T::MI>> where T: Mainloop + 'static, F: FnMut(TimeEventRef<T::MI>) + 'static { let inner_for_wrapper = mainloop.inner(); let wrapper_cb = Box::new(move |ptr| { let ref_obj = TimeEventRef::<T::MI>::from_raw(ptr, Rc::clone(&inner_for_wrapper)); callback(ref_obj); }); let to_save = events::timer::EventCb::new(Some(wrapper_cb)); let (cb_fn, cb_data) = to_save.get_capi_params(events::timer::event_cb_proxy); let ptr = unsafe { capi::pa_context_rttime_new(self.ptr, (time.0).0, std::mem::transmute(cb_fn), cb_data) }; match ptr.is_null() { false => Some(TimeEvent::<T::MI>::from_raw(ptr, mainloop.inner(), to_save)), true => None, } } /// Gets the optimal block size for passing around audio buffers. /// /// It is recommended to allocate buffers of the size returned here when writing audio data to /// playback streams, if the latency constraints permit this. It is not recommended writing /// larger blocks than this because usually they will then be split up internally into chunks of /// this size. It is not recommended writing smaller blocks than this (unless required due to /// latency demands) because this increases CPU usage. /// /// If `ss` is `None` you will be returned the byte-exact tile size. /// /// If `ss` is invalid, returns `None`, else returns tile size rounded down to multiple of the /// frame size. /// /// This is supposed to be used in a construct such as: /// /// ```rust,ignore /// let ss = stream.get_sample_spec().unwrap(); /// let size = stream.get_context().get_tile_size(Some(ss)).unwrap(); /// ``` pub fn get_tile_size(&self, ss: Option<&sample::Spec>) -> Option<usize> { let p_ss = ss.map_or(null::<capi::pa_sample_spec>(), |s| s.as_ref()); match unsafe { capi::pa_context_get_tile_size(self.ptr, p_ss) } { std::usize::MAX => None, r => Some(r), } } /// Loads the authentication cookie from a file. /// /// This function is primarily meant for PulseAudio’s own tunnel modules, which need to load the /// cookie from a custom location. Applications don’t usually need to care about the cookie at /// all, but if it happens that you know what the authentication cookie is and your application /// needs to load it from a non-standard location, feel free to use this function. /// /// Available since PA version 5. #[cfg(any(feature = "pa_v5", feature = "dox"))] pub fn load_cookie_from_file(&mut self, cookie_file_path: &str) -> Result<(), PAErr> { // Warning: New CStrings will be immediately freed if not bound to a variable, leading to // as_ptr() giving dangling pointers! let c_path = CString::new(cookie_file_path.clone()).unwrap(); match unsafe { capi::pa_context_load_cookie_from_file(self.ptr, c_path.as_ptr()) } { 0 => Ok(()), e => Err(PAErr(e)), } } } impl Drop for Context { fn drop(&mut self) { if !self.weak { unsafe { capi::pa_context_unref(self.ptr) }; } self.ptr = null_mut::<ContextInternal>(); } } /// Proxy for completion success callbacks. /// /// Warning: This is for single-use cases only! It destroys the actual closure callback. extern "C" fn success_cb_proxy(_: *mut ContextInternal, success: i32, userdata: *mut c_void) { let success_actual = match success { 0 => false, _ => true }; let _ = std::panic::catch_unwind(|| { assert!(!userdata.is_null()); // Note, destroys closure callback after use - restoring outer box means it gets dropped let mut callback = unsafe { Box::from_raw(userdata as *mut Box<dyn FnMut(bool)>) }; (callback)(success_actual); }); } /// Proxy for notification callbacks (single use). /// /// Warning: This is for single-use cases only! It destroys the actual closure callback. extern "C" fn notify_cb_proxy_single(_: *mut ContextInternal, userdata: *mut c_void) { let _ = std::panic::catch_unwind(|| { assert!(!userdata.is_null()); // Note, destroys closure callback after use - restoring outer box means it gets dropped let mut callback = unsafe { Box::from_raw(userdata as *mut Box<dyn FnMut()>) }; (callback)(); }); } /// Proxy for notification callbacks (multi use). /// /// Warning: This is for multi-use cases! It does **not** destroy the actual closure callback, which /// must be accomplished separately to avoid a memory leak. extern "C" fn notify_cb_proxy_multi(_: *mut ContextInternal, userdata: *mut c_void) { let _ = std::panic::catch_unwind(|| { let callback = NotifyCb::get_callback(userdata); (callback)(); }); } /// Proxy for event callbacks. /// /// Warning: This is for multi-use cases! It does **not** destroy the actual closure callback, which /// must be accomplished separately to avoid a memory leak. extern "C" fn event_cb_proxy(_: *mut ContextInternal, name: *const c_char, proplist: *mut ProplistInternal, userdata: *mut c_void) { let _ = std::panic::catch_unwind(|| { assert!(!name.is_null()); let n = { let tmp = unsafe { CStr::from_ptr(name) }; tmp.to_string_lossy().into_owned() }; let pl = Proplist::from_raw_weak(proplist); let callback = EventCb::get_callback(userdata); (callback)(n, pl); }); } /// Proxy for extension test callbacks. /// /// Warning: This is for single-use cases only! It destroys the actual closure callback. extern "C" fn ext_test_cb_proxy(_: *mut ContextInternal, version: u32, userdata: *mut c_void) { let _ = std::panic::catch_unwind(|| { // Note, destroys closure callback after use - restoring outer box means it gets dropped let mut callback = get_su_callback::<dyn FnMut(u32)>(userdata); (callback)(version); }); } /// Proxy for extension subscribe callbacks. /// /// Warning: This is for multi-use cases! It does **not** destroy the actual closure callback, which /// must be accomplished separately to avoid a memory leak. extern "C" fn ext_subscribe_cb_proxy(_: *mut ContextInternal, userdata: *mut c_void) { let _ = std::panic::catch_unwind(|| { let callback = ExtSubscribeCb::get_callback(userdata); (callback)(); }); }