Merge pull request #51 from TheBlueMatt/main

[ldk-c-bindings] / lightning-c-bindings / src / lightning_background_processor.rs

// This file is Copyright its original authors, visible in version control
// history and in the source files from which this was generated.
//
// This file is licensed under the license available in the LICENSE or LICENSE.md
// file in the root of this repository or, if no such file exists, the same
// license as that which applies to the original source files from which this
// source was automatically generated.

//! Utilities that take care of tasks that (1) need to happen periodically to keep Rust-Lightning
//! running properly, and (2) either can or should be run in the background. See docs for
//! [`BackgroundProcessor`] for more details on the nitty-gritty.

use std::str::FromStr;
use std::ffi::c_void;
use core::convert::Infallible;
use bitcoin::hashes::Hash;
use crate::c_types::*;


use lightning_background_processor::BackgroundProcessor as nativeBackgroundProcessorImport;
pub(crate) type nativeBackgroundProcessor = nativeBackgroundProcessorImport;

/// `BackgroundProcessor` takes care of tasks that (1) need to happen periodically to keep
/// Rust-Lightning running properly, and (2) either can or should be run in the background. Its
/// responsibilities are:
/// * Processing [`Event`]s with a user-provided [`EventHandler`].
/// * Monitoring whether the [`ChannelManager`] needs to be re-persisted to disk, and if so,
///   writing it to disk/backups by invoking the callback given to it at startup.
///   [`ChannelManager`] persistence should be done in the background.
/// * Calling [`ChannelManager::timer_tick_occurred`] and [`PeerManager::timer_tick_occurred`]
///   at the appropriate intervals.
/// * Calling [`NetworkGraph::remove_stale_channels`] (if a [`NetGraphMsgHandler`] is provided to
///   [`BackgroundProcessor::start`]).
///
/// It will also call [`PeerManager::process_events`] periodically though this shouldn't be relied
/// upon as doing so may result in high latency.
///
/// # Note
///
/// If [`ChannelManager`] persistence fails and the persisted manager becomes out-of-date, then
/// there is a risk of channels force-closing on startup when the manager realizes it's outdated.
/// However, as long as [`ChannelMonitor`] backups are sound, no funds besides those used for
/// unilateral chain closure fees are at risk.
///
/// [`ChannelMonitor`]: lightning::chain::channelmonitor::ChannelMonitor
/// [`Event`]: lightning::util::events::Event
///BackgroundProcessor will immediately stop on drop. It should be stored until shutdown.
#[must_use]
#[repr(C)]
pub struct BackgroundProcessor {
        /// A pointer to the opaque Rust object.

        /// Nearly everywhere, inner must be non-null, however in places where
        /// the Rust equivalent takes an Option, it may be set to null to indicate None.
        pub inner: *mut nativeBackgroundProcessor,
        /// Indicates that this is the only struct which contains the same pointer.

        /// Rust functions which take ownership of an object provided via an argument require
        /// this to be true and invalidate the object pointed to by inner.
        pub is_owned: bool,
}

impl Drop for BackgroundProcessor {
        fn drop(&mut self) {
                if self.is_owned && !<*mut nativeBackgroundProcessor>::is_null(self.inner) {
                        let _ = unsafe { Box::from_raw(ObjOps::untweak_ptr(self.inner)) };
                }
        }
}
/// Frees any resources used by the BackgroundProcessor, if is_owned is set and inner is non-NULL.
#[no_mangle]
pub extern "C" fn BackgroundProcessor_free(this_obj: BackgroundProcessor) { }
#[allow(unused)]
/// Used only if an object of this type is returned as a trait impl by a method
pub(crate) extern "C" fn BackgroundProcessor_free_void(this_ptr: *mut c_void) {
        unsafe { let _ = Box::from_raw(this_ptr as *mut nativeBackgroundProcessor); }
}
#[allow(unused)]
impl BackgroundProcessor {
        pub(crate) fn get_native_ref(&self) -> &'static nativeBackgroundProcessor {
                unsafe { &*ObjOps::untweak_ptr(self.inner) }
        }
        pub(crate) fn get_native_mut_ref(&self) -> &'static mut nativeBackgroundProcessor {
                unsafe { &mut *ObjOps::untweak_ptr(self.inner) }
        }
        /// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy
        pub(crate) fn take_inner(mut self) -> *mut nativeBackgroundProcessor {
                assert!(self.is_owned);
                let ret = ObjOps::untweak_ptr(self.inner);
                self.inner = std::ptr::null_mut();
                ret
        }
}
/// Trait which handles persisting a [`ChannelManager`] to disk.
///
/// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
#[repr(C)]
pub struct ChannelManagerPersister {
        /// An opaque pointer which is passed to your function implementations as an argument.
        /// This has no meaning in the LDK, and can be NULL or any other value.
        pub this_arg: *mut c_void,
        /// Persist the given [`ChannelManager`] to disk, returning an error if persistence failed
        /// (which will cause the [`BackgroundProcessor`] which called this method to exit.
        ///
        /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
        #[must_use]
        pub persist_manager: extern "C" fn (this_arg: *const c_void, channel_manager: &crate::lightning::ln::channelmanager::ChannelManager) -> crate::c_types::derived::CResult_NoneErrorZ,
        /// Frees any resources associated with this object given its this_arg pointer.
        /// Does not need to free the outer struct containing function pointers and may be NULL is no resources need to be freed.
        pub free: Option<extern "C" fn(this_arg: *mut c_void)>,
}
unsafe impl Send for ChannelManagerPersister {}
unsafe impl Sync for ChannelManagerPersister {}
#[no_mangle]
pub(crate) extern "C" fn ChannelManagerPersister_clone_fields(orig: &ChannelManagerPersister) -> ChannelManagerPersister {
        ChannelManagerPersister {
                this_arg: orig.this_arg,
                persist_manager: Clone::clone(&orig.persist_manager),
                free: Clone::clone(&orig.free),
        }
}

use lightning_background_processor::ChannelManagerPersister as rustChannelManagerPersister;
impl rustChannelManagerPersister<crate::lightning::chain::keysinterface::Sign, crate::lightning::chain::Watch, crate::lightning::chain::chaininterface::BroadcasterInterface, crate::lightning::chain::keysinterface::KeysInterface, crate::lightning::chain::chaininterface::FeeEstimator, crate::lightning::util::logger::Logger> for ChannelManagerPersister {
        fn persist_manager(&self, mut channel_manager: &lightning::ln::channelmanager::ChannelManager<crate::lightning::chain::keysinterface::Sign, crate::lightning::chain::Watch, crate::lightning::chain::chaininterface::BroadcasterInterface, crate::lightning::chain::keysinterface::KeysInterface, crate::lightning::chain::chaininterface::FeeEstimator, crate::lightning::util::logger::Logger>) -> Result<(), std::io::Error> {
                let mut ret = (self.persist_manager)(self.this_arg, &crate::lightning::ln::channelmanager::ChannelManager { inner: unsafe { ObjOps::nonnull_ptr_to_inner((channel_manager as *const lightning::ln::channelmanager::ChannelManager<_, _, _, _, _, _, >) as *mut _) }, is_owned: false });
                let mut local_ret = match ret.result_ok { true => Ok( { () /*(*unsafe { Box::from_raw(<*mut _>::take_ptr(&mut ret.contents.result)) })*/ }), false => Err( { (*unsafe { Box::from_raw(<*mut _>::take_ptr(&mut ret.contents.err)) }).to_rust() })};
                local_ret
        }
}

// We're essentially a pointer already, or at least a set of pointers, so allow us to be used
// directly as a Deref trait in higher-level structs:
impl std::ops::Deref for ChannelManagerPersister {
        type Target = Self;
        fn deref(&self) -> &Self {
                self
        }
}
/// Calls the free function if one is set
#[no_mangle]
pub extern "C" fn ChannelManagerPersister_free(this_ptr: ChannelManagerPersister) { }
impl Drop for ChannelManagerPersister {
        fn drop(&mut self) {
                if let Some(f) = self.free {
                        f(self.this_arg);
                }
        }
}
/// Start a background thread that takes care of responsibilities enumerated in the [top-level
/// documentation].
///
/// The thread runs indefinitely unless the object is dropped, [`stop`] is called, or
/// `persist_manager` returns an error. In case of an error, the error is retrieved by calling
/// either [`join`] or [`stop`].
///
/// # Data Persistence
///
/// `persist_manager` is responsible for writing out the [`ChannelManager`] to disk, and/or
/// uploading to one or more backup services. See [`ChannelManager::write`] for writing out a
/// [`ChannelManager`]. See [`FilesystemPersister::persist_manager`] for Rust-Lightning's
/// provided implementation.
///
/// Typically, users should either implement [`ChannelManagerPersister`] to never return an
/// error or call [`join`] and handle any error that may arise. For the latter case,
/// `BackgroundProcessor` must be restarted by calling `start` again after handling the error.
///
/// # Event Handling
///
/// `event_handler` is responsible for handling events that users should be notified of (e.g.,
/// payment failed). [`BackgroundProcessor`] may decorate the given [`EventHandler`] with common
/// functionality implemented by other handlers.
/// * [`NetGraphMsgHandler`] if given will update the [`NetworkGraph`] based on payment failures.
///
/// [top-level documentation]: BackgroundProcessor
/// [`join`]: Self::join
/// [`stop`]: Self::stop
/// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
/// [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
/// [`FilesystemPersister::persist_manager`]: lightning_persister::FilesystemPersister::persist_manager
/// [`NetworkGraph`]: lightning::routing::network_graph::NetworkGraph
///
/// Note that net_graph_msg_handler (or a relevant inner pointer) may be NULL or all-0s to represent None
#[must_use]
#[no_mangle]
pub extern "C" fn BackgroundProcessor_start(mut persister: crate::lightning_background_processor::ChannelManagerPersister, mut event_handler: crate::lightning::util::events::EventHandler, chain_monitor: &crate::lightning::chain::chainmonitor::ChainMonitor, channel_manager: &crate::lightning::ln::channelmanager::ChannelManager, mut net_graph_msg_handler: crate::lightning::routing::network_graph::NetGraphMsgHandler, peer_manager: &crate::lightning::ln::peer_handler::PeerManager, mut logger: crate::lightning::util::logger::Logger) -> BackgroundProcessor {
        let mut local_net_graph_msg_handler = if net_graph_msg_handler.inner.is_null() { None } else { Some( { net_graph_msg_handler.get_native_ref() }) };
        let mut ret = lightning_background_processor::BackgroundProcessor::start(persister, event_handler, chain_monitor.get_native_ref(), channel_manager.get_native_ref(), local_net_graph_msg_handler, peer_manager.get_native_ref(), logger);
        BackgroundProcessor { inner: ObjOps::heap_alloc(ret), is_owned: true }
}

/// Join `BackgroundProcessor`'s thread, returning any error that occurred while persisting
/// [`ChannelManager`].
///
/// # Panics
///
/// This function panics if the background thread has panicked such as while persisting or
/// handling events.
///
/// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
#[must_use]
#[no_mangle]
pub extern "C" fn BackgroundProcessor_join(mut this_arg: BackgroundProcessor) -> crate::c_types::derived::CResult_NoneErrorZ {
        let mut ret = (*unsafe { Box::from_raw(this_arg.take_inner()) }).join();
        let mut local_ret = match ret { Ok(mut o) => crate::c_types::CResultTempl::ok( { () /*o*/ }).into(), Err(mut e) => crate::c_types::CResultTempl::err( { crate::c_types::IOError::from_rust(e) }).into() };
        local_ret
}

/// Stop `BackgroundProcessor`'s thread, returning any error that occurred while persisting
/// [`ChannelManager`].
///
/// # Panics
///
/// This function panics if the background thread has panicked such as while persisting or
/// handling events.
///
/// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
#[must_use]
#[no_mangle]
pub extern "C" fn BackgroundProcessor_stop(mut this_arg: BackgroundProcessor) -> crate::c_types::derived::CResult_NoneErrorZ {
        let mut ret = (*unsafe { Box::from_raw(this_arg.take_inner()) }).stop();
        let mut local_ret = match ret { Ok(mut o) => crate::c_types::CResultTempl::ok( { () /*o*/ }).into(), Err(mut e) => crate::c_types::CResultTempl::err( { crate::c_types::IOError::from_rust(e) }).into() };
        local_ret
}