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//! See [super]
use super::super::{
stream_executor::StreamExecutor,
mutiny_stream::MutinyStream,
types::FullDuplexMultiChannel,
};
use std::{
sync::Arc,
fmt::Debug,
time::Duration,
future::Future,
marker::PhantomData,
};
use indexmap::IndexMap;
use futures::Stream;
use tokio::sync::RwLock;
/// `Multi` is an event handler capable of having several "listeners" -- all of which receives all events.\
/// With this struct, it is possible to:
/// - produce events
/// - spawn new `Stream`s & executors
/// - close `Stream`s (and executors)
/// Example:
/// ```nocompile
/// {reactive_mutiny::Instruments::MetricsWithoutLogs.into()}
pub struct Multi<ItemType: Debug + Sync + Send + 'static,
MultiChannelType: FullDuplexMultiChannel<ItemType=ItemType, DerivedItemType=DerivedItemType> + Sync + Send + 'static,
const INSTRUMENTS: usize,
DerivedItemType: Debug + Sync + Send + 'static> {
pub multi_name: String,
pub channel: Arc<MultiChannelType>,
pub executor_infos: RwLock<IndexMap<String, ExecutorInfo>>,
_phantom: PhantomData<(ItemType, MultiChannelType, DerivedItemType)>,
}
impl<ItemType: Debug + Send + Sync + 'static,
MultiChannelType: FullDuplexMultiChannel<ItemType=ItemType, DerivedItemType=DerivedItemType> + Sync + Send + 'static,
const INSTRUMENTS: usize,
DerivedItemType: Debug + Sync + Send + 'static>
GenericMulti<INSTRUMENTS> for
Multi<ItemType, MultiChannelType, INSTRUMENTS, DerivedItemType> {
const INSTRUMENTS: usize = INSTRUMENTS;
type ItemType = ItemType;
type MultiChannelType = MultiChannelType;
type DerivedItemType = DerivedItemType;
type MutinyStreamType = MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>;
fn new<IntoString: Into<String>>(multi_name: IntoString) -> Self {
Self::new(multi_name)
}
fn to_multi(self) -> Multi<ItemType, MultiChannelType, INSTRUMENTS, DerivedItemType> {
self
}
}
impl<ItemType: Debug + Send + Sync + 'static,
MultiChannelType: FullDuplexMultiChannel<ItemType=ItemType, DerivedItemType=DerivedItemType> + Sync + Send + 'static,
const INSTRUMENTS: usize,
DerivedItemType: Debug + Sync + Send + 'static>
Multi<ItemType, MultiChannelType, INSTRUMENTS, DerivedItemType> {
/// Creates a [Multi], which implements the `listener pattern`, capable of:
/// - creating `Stream`s;
/// - applying a user-provided `processor` to the `Stream`s and executing them to depletion --
/// the final `Stream`s may produce a combination of fallible/non-fallible &
/// futures/non-futures events;
/// - producing events that are sent to those `Stream`s.
/// `multi_name` is used for instrumentation purposes, depending on the `INSTRUMENT` generic
/// argument passed to the [Multi] struct.
pub fn new<IntoString: Into<String>>(multi_name: IntoString) -> Self {
let multi_name = multi_name.into();
Multi {
multi_name: multi_name.clone(),
channel: MultiChannelType::new(multi_name.clone()),
executor_infos: RwLock::new(IndexMap::new()),
_phantom: PhantomData,
}
}
/// Returns this Multi's name
pub fn name(&self) -> &str {
&self.multi_name
}
#[inline(always)]
#[must_use = "The return type should be examined in case retrying is needed -- or call map(...).into() to transform it into a `Result<(), ItemType>`"]
pub fn send(&self, item: ItemType) -> keen_retry::RetryConsumerResult<(), ItemType, ()> {
self.channel.send(item)
}
#[inline(always)]
#[must_use = "The return type should be examined in case retrying is needed -- or call map(...).into() to transform it into a `Result<(), F>`"]
pub fn send_with<F: FnOnce(&mut ItemType)>(&self, setter: F) -> keen_retry::RetryConsumerResult<(), F, ()> {
self.channel.send_with(setter)
}
#[inline(always)]
#[must_use = "The return type should be examined in case retrying is needed"]
pub fn send_derived(&self, arc_item: &DerivedItemType) -> bool {
self.channel.send_derived(arc_item)
}
#[inline(always)]
#[must_use]
pub fn buffer_size(&self) -> u32 {
self.channel.buffer_size()
}
#[inline(always)]
#[must_use]
pub fn pending_items_count(&self) -> u32 {
self.channel.pending_items_count()
}
/// Spawns a new listener of all subsequent events sent to this `Multi`, processing them through the `Stream` returned by `pipeline_builder()`,
/// which generates events that are Futures & Fallible.
pub async fn spawn_executor<IntoString: Into<String>,
OutItemType: Send + Debug,
OutStreamType: Stream<Item=OutType> + Send + 'static,
OutType: Future<Output=Result<OutItemType, Box<dyn std::error::Error + Send + Sync>>> + Send,
ErrVoidAsyncType: Future<Output=()> + Send + 'static,
CloseVoidAsyncType: Future<Output=()> + Send + 'static>
(&self,
concurrency_limit: u32,
futures_timeout: Duration,
pipeline_name: IntoString,
pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> OutStreamType,
on_err_callback: impl Fn(Box<dyn std::error::Error + Send + Sync>) -> ErrVoidAsyncType + Send + Sync + 'static,
on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> CloseVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let (in_stream, in_stream_id) = self.channel.create_stream_for_new_events();
let out_stream = pipeline_builder(in_stream);
self.spawn_executor_from_stream(concurrency_limit, futures_timeout, pipeline_name, in_stream_id, out_stream, on_err_callback, on_close_callback).await
}
/// For channels that allow it (like [channels::reference::mmap_log::MmapLog]), spawns two listeners for events sent to this `Multi`:
/// 1) One for past events -- to be processed by the stream returned by `oldies_pipeline_builder()`;
/// 2) Another one for subsequent events -- to be processed by the stream returned by `newies_pipeline_builder()`.
/// By using this method, it is assumed that both pipeline builders returns `Future<Result>` events. If this is not so, see one of the sibling methods.\
/// The stream splitting is guaranteed not to drop any events and `sequential_transition` may be used to indicate if old events should be processed first or if both old and new events
/// may be processed simultaneously (in an inevitable out-of-order fashion).
pub async fn spawn_oldies_executor<IntoString: Into<String>,
OutItemType: Send + Debug,
OldiesOutStreamType: Stream<Item=OldiesOutType> + Sync + Send + 'static,
NewiesOutStreamType: Stream<Item=NewiesOutType> + Sync + Send + 'static,
OldiesOutType: Future<Output=Result<OutItemType, Box<dyn std::error::Error + Send + Sync>>> + Send,
NewiesOutType: Future<Output=Result<OutItemType, Box<dyn std::error::Error + Send + Sync>>> + Send,
ErrVoidAsyncType: Future<Output=()> + Send + 'static,
OldiesCloseVoidAsyncType: Future<Output=()> + Send + 'static,
NewiesCloseVoidAsyncType: Future<Output=()> + Send + 'static>
(self: &Arc<Self>,
concurrency_limit: u32,
sequential_transition: bool,
futures_timeout: Duration,
oldies_pipeline_name: IntoString,
oldies_pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> OldiesOutStreamType,
oldies_on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> OldiesCloseVoidAsyncType + Send + Sync + 'static,
newies_pipeline_name: IntoString,
newies_pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> NewiesOutStreamType + Send + Sync + 'static,
newies_on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> NewiesCloseVoidAsyncType + Send + Sync + 'static,
on_err_callback: impl Fn(Box<dyn std::error::Error + Send + Sync>) -> ErrVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let ((oldies_in_stream, oldies_in_stream_id),
(newies_in_stream, newies_in_stream_id)) = self.channel.create_streams_for_old_and_new_events();
let cloned_self = Arc::clone(&self);
let oldies_pipeline_name = oldies_pipeline_name.into();
let newies_pipeline_name = Arc::new(newies_pipeline_name.into());
let on_err_callback_ref1 = Arc::new(on_err_callback);
let on_err_callback_ref2 = Arc::clone(&on_err_callback_ref1);
let oldies_out_stream = oldies_pipeline_builder(oldies_in_stream);
let newies_out_stream = newies_pipeline_builder(newies_in_stream);
match sequential_transition {
true => {
self.spawn_executor_from_stream(concurrency_limit, futures_timeout, oldies_pipeline_name, oldies_in_stream_id, oldies_out_stream,
move |err| on_err_callback_ref1(err),
move |executor| {
let cloned_self = Arc::clone(&cloned_self);
let on_err_callback_ref2 = Arc::clone(&on_err_callback_ref2);
let newies_pipeline_name = Arc::clone(&newies_pipeline_name);
async move {
cloned_self.spawn_executor_from_stream(concurrency_limit, futures_timeout, newies_pipeline_name.as_str(), newies_in_stream_id, newies_out_stream,
move |err| on_err_callback_ref2(err),
newies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `newies`/sequential executor: {:?}", err))
.expect("CANNOT SPAWN NEWIES EXECUTOR AFTER OLDIES HAD COMPLETE");
oldies_on_close_callback(executor).await;
}
} ).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `oldies`/sequential executor: {:?}", err))?;
},
false => {
self.spawn_executor_from_stream(concurrency_limit, futures_timeout, oldies_pipeline_name, oldies_in_stream_id, oldies_out_stream,
move |err| on_err_callback_ref1(err),
oldies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `oldies` executor: {:?}", err))?;
self.spawn_executor_from_stream(concurrency_limit, futures_timeout, newies_pipeline_name.as_str(), newies_in_stream_id, newies_out_stream,
move |err| on_err_callback_ref2(err),
newies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `newies` executor: {:?}", err))?;
},
}
Ok(())
}
/// Internal method with common code for [Self::spawn_executor()] & [Self::spawn_oldies_executor()].
async fn spawn_executor_from_stream<IntoString: Into<String>,
OutItemType: Send + Debug,
OutStreamType: Stream<Item=OutType> + Send + 'static,
OutType: Future<Output=Result<OutItemType, Box<dyn std::error::Error + Send + Sync>>> + Send,
ErrVoidAsyncType: Future<Output=()> + Send + 'static,
CloseVoidAsyncType: Future<Output=()> + Send + 'static>
(&self,
concurrency_limit: u32,
futures_timeout: Duration,
pipeline_name: IntoString,
stream_id: u32,
pipelined_stream: OutStreamType,
on_err_callback: impl Fn(Box<dyn std::error::Error + Send + Sync>) -> ErrVoidAsyncType + Send + Sync + 'static,
on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> CloseVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let executor = StreamExecutor::<INSTRUMENTS>::with_futures_timeout(format!("{}: {}", self.name(), pipeline_name.into()), futures_timeout);
self.add_executor(executor.clone(), stream_id).await?;
executor
.spawn_executor::<_, _, _, _>(
concurrency_limit,
on_err_callback,
on_close_callback,
pipelined_stream
);
Ok(())
}
/// Spawns a new listener of all subsequent events sent to this `Multi`, processing them through the `Stream` returned by `pipeline_builder()`,
/// which generates events that are Futures.
pub async fn spawn_futures_executor<IntoString: Into<String>,
OutItemType: Send + Debug,
OutStreamType: Stream<Item=OutType> + Send + 'static,
OutType: Future<Output=OutItemType> + Send,
CloseVoidAsyncType: Future<Output=()> + Send + 'static>
(&self,
concurrency_limit: u32,
futures_timeout: Duration,
pipeline_name: IntoString,
pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> OutStreamType,
on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> CloseVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let (in_stream, in_stream_id) = self.channel.create_stream_for_new_events();
let out_stream = pipeline_builder(in_stream);
self.spawn_futures_executor_from_stream(concurrency_limit, futures_timeout, pipeline_name, in_stream_id, out_stream, on_close_callback).await
}
/// For channels that allow it (like [channels::reference::mmap_log::MmapLog]), spawns two listeners for events sent to this `Multi`:
/// 1) One for past events -- to be processed by the stream returned by `oldies_pipeline_builder()`;
/// 2) Another one for subsequent events -- to be processed by the stream returned by `newies_pipeline_builder()`.
/// By using this method, it is assumed that both pipeline builders returns `Future` events. If this is not so, see one of the sibling methods.\
/// The stream splitting is guaranteed not to drop any events and `sequential_transition` may be used to indicate if old events should be processed first or if both old and new events
/// may be processed simultaneously (in an inevitable out-of-order fashion).
pub async fn spawn_futures_oldies_executor<IntoString: Into<String>,
OutItemType: Send + Debug,
OldiesOutStreamType: Stream<Item=OldiesOutType> + Sync + Send + 'static,
NewiesOutStreamType: Stream<Item=NewiesOutType> + Sync + Send + 'static,
OldiesOutType: Future<Output=OutItemType> + Send,
NewiesOutType: Future<Output=OutItemType> + Send,
OldiesCloseVoidAsyncType: Future<Output=()> + Send + 'static,
NewiesCloseVoidAsyncType: Future<Output=()> + Send + 'static>
(self: &Arc<Self>,
concurrency_limit: u32,
sequential_transition: bool,
futures_timeout: Duration,
oldies_pipeline_name: IntoString,
oldies_pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> OldiesOutStreamType,
oldies_on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> OldiesCloseVoidAsyncType + Send + Sync + 'static,
newies_pipeline_name: IntoString,
newies_pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> NewiesOutStreamType + Send + Sync + 'static,
newies_on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> NewiesCloseVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let ((oldies_in_stream, oldies_in_stream_id),
(newies_in_stream, newies_in_stream_id)) = self.channel.create_streams_for_old_and_new_events();
let cloned_self = Arc::clone(&self);
let oldies_pipeline_name = oldies_pipeline_name.into();
let newies_pipeline_name = Arc::new(newies_pipeline_name.into());
let oldies_out_stream = oldies_pipeline_builder(oldies_in_stream);
let newies_out_stream = newies_pipeline_builder(newies_in_stream);
match sequential_transition {
true => {
self.spawn_futures_executor_from_stream(concurrency_limit, futures_timeout, oldies_pipeline_name, oldies_in_stream_id, oldies_out_stream,
move |executor| {
let cloned_self = Arc::clone(&cloned_self);
let newies_pipeline_name = Arc::clone(&newies_pipeline_name);
async move {
cloned_self.spawn_futures_executor_from_stream(concurrency_limit, futures_timeout, newies_pipeline_name.as_str(), newies_in_stream_id, newies_out_stream,
newies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `newies`/sequential executor: {:?}", err))
.expect("CANNOT SPAWN NEWIES EXECUTOR AFTER OLDIES HAD COMPLETE");
oldies_on_close_callback(executor).await;
}
} ).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `oldies`/sequential executor: {:?}", err))?;
},
false => {
self.spawn_futures_executor_from_stream(concurrency_limit, futures_timeout, oldies_pipeline_name, oldies_in_stream_id, oldies_out_stream,
oldies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `oldies` executor: {:?}", err))?;
self.spawn_futures_executor_from_stream(concurrency_limit, futures_timeout, newies_pipeline_name.as_str(), newies_in_stream_id, newies_out_stream,
newies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `newies` executor: {:?}", err))?;
},
}
Ok(())
}
/// Internal method with common code for [Self::spawn_futures_executor()] & [Self::spawn_futures_oldies_executor()].
async fn spawn_futures_executor_from_stream<IntoString: Into<String>,
OutItemType: Send + Debug,
OutStreamType: Stream<Item=OutType> + Send + 'static,
OutType: Future<Output=OutItemType> + Send,
CloseVoidAsyncType: Future<Output=()> + Send + 'static>
(&self,
concurrency_limit: u32,
futures_timeout: Duration,
pipeline_name: IntoString,
stream_id: u32,
pipelined_stream: OutStreamType,
on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> CloseVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let executor = StreamExecutor::<INSTRUMENTS>::with_futures_timeout(format!("{}: {}", self.name(), pipeline_name.into()), futures_timeout);
self.add_executor(executor.clone(), stream_id).await?;
executor
.spawn_futures_executor::<_, _, _>(
concurrency_limit,
on_close_callback,
pipelined_stream
);
Ok(())
}
/// Spawns a new listener of all subsequent events sent to this `Multi`, processing them through the `Stream` returned by `pipeline_builder()`,
/// which generates events that are Fallible.
pub async fn spawn_fallibles_executor<IntoString: Into<String>,
OutItemType: Send + Debug,
OutStreamType: Stream<Item=Result<OutItemType, Box<dyn std::error::Error + Send + Sync>>> + Send + 'static,
CloseVoidAsyncType: Future<Output=()> + Send + 'static>
(&self,
concurrency_limit: u32,
pipeline_name: IntoString,
pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> OutStreamType,
on_err_callback: impl Fn(Box<dyn std::error::Error + Send + Sync>) + Send + Sync + 'static,
on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> CloseVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let (in_stream, in_stream_id) = self.channel.create_stream_for_new_events();
let out_stream = pipeline_builder(in_stream);
self.spawn_fallibles_executor_from_stream(concurrency_limit, pipeline_name, in_stream_id, out_stream, on_err_callback, on_close_callback).await
}
/// For channels that allow it (like [channels::reference::mmap_log::MmapLog]), spawns two listeners for events sent to this `Multi`:
/// 1) One for past events -- to be processed by the stream returned by `oldies_pipeline_builder()`;
/// 2) Another one for subsequent events -- to be processed by the stream returned by `newies_pipeline_builder()`.
/// By using this method, it is assumed that both pipeline builders returns Fallible events. If this is not so, see one of the sibling methods.\
/// The stream splitting is guaranteed not to drop any events and `sequential_transition` may be used to indicate if old events should be processed first or if both old and new events
/// may be processed simultaneously (in an inevitable out-of-order fashion).
pub async fn spawn_fallibles_oldies_executor<IntoString: Into<String>,
OutItemType: Send + Debug,
OldiesOutStreamType: Stream<Item=Result<OutItemType, Box<dyn std::error::Error + Send + Sync>>> + Sync + Send + 'static,
NewiesOutStreamType: Stream<Item=Result<OutItemType, Box<dyn std::error::Error + Send + Sync>>> + Sync + Send + 'static,
OldiesCloseVoidAsyncType: Future<Output=()> + Send + 'static,
NewiesCloseVoidAsyncType: Future<Output=()> + Send + 'static>
(self: &Arc<Self>,
concurrency_limit: u32,
sequential_transition: bool,
oldies_pipeline_name: IntoString,
oldies_pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> OldiesOutStreamType,
oldies_on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> OldiesCloseVoidAsyncType + Send + Sync + 'static,
newies_pipeline_name: IntoString,
newies_pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> NewiesOutStreamType + Send + Sync + 'static,
newies_on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> NewiesCloseVoidAsyncType + Send + Sync + 'static,
on_err_callback: impl Fn(Box<dyn std::error::Error + Send + Sync>) + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let ((oldies_in_stream, oldies_in_stream_id),
(newies_in_stream, newies_in_stream_id)) = self.channel.create_streams_for_old_and_new_events();
let cloned_self = Arc::clone(self);
let oldies_pipeline_name = oldies_pipeline_name.into();
let newies_pipeline_name = Arc::new(newies_pipeline_name.into());
let on_err_callback_ref1 = Arc::new(on_err_callback);
let on_err_callback_ref2 = Arc::clone(&on_err_callback_ref1);
let oldies_out_stream = oldies_pipeline_builder(oldies_in_stream);
let newies_out_stream = newies_pipeline_builder(newies_in_stream);
match sequential_transition {
true => {
self.spawn_fallibles_executor_from_stream(concurrency_limit, oldies_pipeline_name, oldies_in_stream_id, oldies_out_stream,
move |err| on_err_callback_ref1(err),
move |executor| {
let cloned_self = Arc::clone(&cloned_self);
let on_err_callback_ref2 = Arc::clone(&on_err_callback_ref2);
let newies_pipeline_name = Arc::clone(&newies_pipeline_name);
async move {
cloned_self.spawn_fallibles_executor_from_stream(concurrency_limit, newies_pipeline_name.as_str(), newies_in_stream_id, newies_out_stream,
move |err| on_err_callback_ref2(err),
newies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `newies`/sequential executor: {:?}", err))
.expect("CANNOT SPAWN NEWIES EXECUTOR AFTER OLDIES HAD COMPLETE");
oldies_on_close_callback(executor).await;
}
} ).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `oldies`/sequential executor: {:?}", err))?;
},
false => {
self.spawn_fallibles_executor_from_stream(concurrency_limit, oldies_pipeline_name, oldies_in_stream_id, oldies_out_stream,
move |err| on_err_callback_ref1(err),
oldies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `oldies` executor: {:?}", err))?;
self.spawn_fallibles_executor_from_stream(concurrency_limit, newies_pipeline_name.as_str(), newies_in_stream_id, newies_out_stream,
move |err| on_err_callback_ref2(err),
newies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_oldies_executor(): could not start `newies` executor: {:?}", err))?;
},
}
Ok(())
}
/// Internal method with common code for [Self::spawn_fallibles_executor()] & [Self::spawn_oldies_fallibles_executor()].
async fn spawn_fallibles_executor_from_stream<IntoString: Into<String>,
OutItemType: Send + Debug,
OutStreamType: Stream<Item=Result<OutItemType, Box<dyn std::error::Error + Send + Sync>>> + Send + 'static,
CloseVoidAsyncType: Future<Output=()> + Send + 'static>
(&self,
concurrency_limit: u32,
pipeline_name: IntoString,
stream_id: u32,
pipelined_stream: OutStreamType,
on_err_callback: impl Fn(Box<dyn std::error::Error + Send + Sync>) + Send + Sync + 'static,
on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> CloseVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let executor = StreamExecutor::<INSTRUMENTS>::new(format!("{}: {}", self.name(), pipeline_name.into()));
self.add_executor(executor.clone(), stream_id).await?;
executor
.spawn_fallibles_executor::<_, _>(
concurrency_limit,
on_err_callback,
on_close_callback,
pipelined_stream
);
Ok(())
}
/// Spawns a new listener of all subsequent events sent to this `Multi`, processing them through the `Stream` returned by `pipeline_builder()`,
/// which generates events that are Non-Futures & Non-Fallible.
pub async fn spawn_non_futures_non_fallible_executor<IntoString: Into<String>,
OutItemType: Send + Debug,
OutStreamType: Stream<Item=OutItemType> + Send + 'static,
CloseVoidAsyncType: Future<Output=()> + Send + 'static>
(&self,
concurrency_limit: u32,
pipeline_name: IntoString,
pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> OutStreamType,
on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> CloseVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let (in_stream, in_stream_id) = self.channel.create_stream_for_new_events();
let out_stream = pipeline_builder(in_stream);
self.spawn_non_futures_non_fallible_executor_from_stream(concurrency_limit, pipeline_name, in_stream_id, out_stream, on_close_callback).await
}
/// For channels that allow it (like [channels::reference::mmap_log::MmapLog]), spawns two listeners for events sent to this `Multi`:
/// 1) One for past events -- to be processed by the stream returned by `oldies_pipeline_builder()`;
/// 2) Another one for subsequent events -- to be processed by the stream returned by `newies_pipeline_builder()`.
/// By using this method, it is assumed that both pipeline builders returns non-Futures & non-Fallible events. If this is not so, see [spawn_oldies_executor].\
/// The stream splitting is guaranteed not to drop any events and `sequential_transition` may be used to indicate if old events should be processed first or if both old and new events
/// may be processed simultaneously (in an inevitable out-of-order fashion).
pub async fn spawn_non_futures_non_fallible_oldies_executor<IntoString: Into<String>,
OldiesOutItemType: Send + Debug,
NewiesOutItemType: Send + Debug,
OldiesOutStreamType: Stream<Item=OldiesOutItemType> + Sync + Send + 'static,
NewiesOutStreamType: Stream<Item=NewiesOutItemType> + Sync + Send + 'static,
OldiesCloseVoidAsyncType: Future<Output=()> + Send + 'static,
NewiesCloseVoidAsyncType: Future<Output=()> + Send + 'static>
(self: &Arc<Self>,
concurrency_limit: u32,
sequential_transition: bool,
oldies_pipeline_name: IntoString,
oldies_pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> OldiesOutStreamType,
oldies_on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> OldiesCloseVoidAsyncType + Send + Sync + 'static,
newies_pipeline_name: IntoString,
newies_pipeline_builder: impl FnOnce(MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>) -> NewiesOutStreamType,
newies_on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> NewiesCloseVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let ((oldies_in_stream, oldies_in_stream_id),
(newies_in_stream, newies_in_stream_id)) = self.channel.create_streams_for_old_and_new_events();
let cloned_self = Arc::clone(self);
let oldies_pipeline_name = oldies_pipeline_name.into();
let newies_pipeline_name = Arc::new(newies_pipeline_name.into());
let oldies_out_stream = oldies_pipeline_builder(oldies_in_stream);
let newies_out_stream = newies_pipeline_builder(newies_in_stream);
match sequential_transition {
true => {
self.spawn_non_futures_non_fallible_executor_from_stream(concurrency_limit, oldies_pipeline_name, oldies_in_stream_id, oldies_out_stream,
move |executor| {
let cloned_self = Arc::clone(&cloned_self);
let newies_pipeline_name = Arc::clone(&newies_pipeline_name);
async move {
cloned_self.spawn_non_futures_non_fallible_executor_from_stream(concurrency_limit, newies_pipeline_name.as_str(), newies_in_stream_id, newies_out_stream,
move |executor| newies_on_close_callback(executor)).await
.map_err(|err| format!("Multi::spawn_non_futures_non_fallible_oldies_executor(): could not start `newies` executor: {:?}", err))
.expect("CANNOT SPAWN NEWIES EXECUTOR AFTER OLDIES HAD COMPLETE");
oldies_on_close_callback(executor).await;
}
}).await
.map_err(|err| format!("Multi::spawn_non_futures_non_fallible_oldies_executor(): could not start `oldies`/sequential executor: {:?}", err))?;
},
false => {
self.spawn_non_futures_non_fallible_executor_from_stream(concurrency_limit, oldies_pipeline_name, oldies_in_stream_id, oldies_out_stream,
oldies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_non_futures_non_fallible_oldies_executor(): could not start `oldies` executor: {:?}", err))?;
self.spawn_non_futures_non_fallible_executor_from_stream(concurrency_limit, newies_pipeline_name.as_str(), newies_in_stream_id, newies_out_stream,
newies_on_close_callback).await
.map_err(|err| format!("Multi::spawn_non_futures_non_fallible_oldies_executor(): could not start `newies` executor: {:?}", err))?;
},
}
Ok(())
}
/// Internal method with common code for [spawn_non_futures_non_fallible_executor()] & [spawn_non_futures_non_fallible_oldies_executor()].
async fn spawn_non_futures_non_fallible_executor_from_stream<IntoString: Into<String>,
OutItemType: Send + Debug,
OutStreamType: Stream<Item=OutItemType> + Send + 'static,
CloseVoidAsyncType: Future<Output=()> + Send + 'static>
(&self,
concurrency_limit: u32,
pipeline_name: IntoString,
stream_id: u32,
pipelined_stream: OutStreamType,
on_close_callback: impl FnOnce(Arc<dyn StreamExecutorStats + Send + Sync>) -> CloseVoidAsyncType + Send + Sync + 'static)
-> Result<(), Box<dyn std::error::Error>> {
let executor = StreamExecutor::<INSTRUMENTS>::new(format!("{}: {}", self.name(), pipeline_name.into()));
self.add_executor(executor.clone(), stream_id).await?;
executor
.spawn_non_futures_non_fallibles_executor::<_, _>(
concurrency_limit,
on_close_callback,
pipelined_stream
);
Ok(())
}
/// Closes this `Multi`, in isolation -- flushing pending events, closing the producers,
/// waiting for all events to be fully processed and calling all executor's "on close" callbacks.\
/// If this `Multi` share resources with another one (which will get dumped by the "on close"
/// callback), most probably you want to close them atomically -- see [multis_close_async!()].\
/// Returns `true` if all events could be flushed within the given `timeout`.
pub async fn close(&self, timeout: Duration) -> bool {
self.channel.gracefully_end_all_streams(timeout).await == 0
}
/// Asynchronously blocks until all resources associated with the executor responsible for `pipeline_name` are freed:
/// 1) immediately causes `pipeline_name` to cease receiving new elements by removing it from the active list
/// 2) wait for all pending elements to be processed
/// 3) remove the queue/channel and wake the Stream to see that it has ended
/// 4) waits for the executor to inform it ceased its execution
/// 5) return, dropping all resources\
/// Note it might make sense to spawn this operation by a `Tokio task`, for it may block indefinitely if the Stream has no timeout.\
/// Also note that timing out this operation is not advisable, for resources won't be freed until it reaches the last step.\
/// Returns false if there was no executor associated with `pipeline_name`.
#[must_use = "futures do nothing unless you `.await` or poll them"]
pub async fn flush_and_cancel_executor<IntoString: Into<String>>
(&self,
pipeline_name: IntoString,
timeout: Duration) -> bool {
let executor_name = format!("{}: {}", self.multi_name, pipeline_name.into());
// remove the pipeline from the active list
let mut executor_infos = self.executor_infos.write().await;
let executor_info = match executor_infos.remove(&executor_name) {
Some(executor) => executor,
None => return false,
};
drop(executor_infos);
// wait until all elements are taken out from the queue
executor_info.executor_stats.report_scheduled_to_finish();
self.channel.gracefully_end_stream(executor_info.stream_id, timeout).await;
true
}
/// Registers an executor within this `Multi` so it can be managed -- closed, inquired for stats, etc
async fn add_executor(&self, stream_executor: Arc<dyn StreamExecutorStats + Send + Sync>, stream_id: u32) -> Result<(), Box<dyn std::error::Error>> {
let mut internal_multis = self.executor_infos.write().await;
if internal_multis.contains_key(stream_executor.executor_name()) {
Err(Box::from(format!("an executor with the same name is already present: '{}'", stream_executor.executor_name())))
} else {
internal_multis.insert(stream_executor.executor_name().to_owned(), ExecutorInfo { executor_stats: stream_executor, stream_id });
Ok(())
}
}
}
/// This trait exists to allow simplifying generic declarations of concrete [Multi] types.
/// See also [GenericUni].\
/// Usage:
/// ```nocompile
/// struct MyGenericStruct<T: GenericMulti> { the_multi: T }
/// let the_multi = Multi<Lots,And,Lots<Of,Generic,Arguments>>::new();
/// let my_struct = MyGenericStruct { the_multi };
pub trait GenericMulti<const INSTRUMENTS: usize> {
/// The instruments this Multi will collect/report
const INSTRUMENTS: usize;
/// The payload type this Multi's producers will receive
type ItemType: Debug + Sync + Send + 'static;
/// The payload type this [Multi]'s `Stream`s will yield
type DerivedItemType: Debug + Sync + Send + 'static;
/// The channel through which payloads will travel from producers to listeners (see [Multi] for more info)
type MultiChannelType: FullDuplexMultiChannel<ItemType=Self::ItemType, DerivedItemType=Self::DerivedItemType> + Sync + Send;
/// Defined as `MutinyStream<'static, ItemType, MultiChannelType, DerivedItemType>`,\
/// the concrete type for the `Stream` of `DerivedItemType`s to be given to listeners
type MutinyStreamType;
/// See [Multi::new()]
fn new<IntoString: Into<String>>(multi_name: IntoString) -> Self;
fn to_multi(self) -> Multi<Self::ItemType, Self::MultiChannelType, INSTRUMENTS, Self::DerivedItemType>;
}
/// Macro to close, atomically-ish, all [Multi]s passed in as parameters
#[macro_export]
macro_rules! multis_close_async {
($timeout: expr,
$($multi: expr),+) => {
{
tokio::join!( $( $multi.channel.flush($timeout), )+ );
tokio::join!( $( $multi.channel.gracefully_end_all_streams($timeout), )+ );
}
}
}
pub use multis_close_async;
use crate::stream_executor::StreamExecutorStats;
pub use crate::types::ChannelCommon;
/// Keeps track of the `stream_executor` associated to each `stream_id`
pub struct ExecutorInfo {
pub executor_stats: Arc<dyn StreamExecutorStats + Send + Sync>,
pub stream_id: u32,
}