NON-WORKING: can't spawn a thread because the closure would outlive reports.

This commit is contained in:
Richard Newman 2018-03-14 08:18:22 -07:00
parent 349d3d3990
commit a0c52fa425

View file

@ -24,27 +24,30 @@ use types::{
};
pub struct TxObserver {
notify_fn: Arc<Box<Fn(&String, &Vec<Arc<TxReport>>) + Send + Sync>>,
notify_fn: Arc<Box<Fn(&String, &Vec<&TxReport>) + Send + Sync>>,
attributes: AttributeSet,
}
impl TxObserver {
pub fn new<F>(attributes: AttributeSet, notify_fn: F) -> TxObserver where F: Fn(&String, &Vec<Arc<TxReport>>) + 'static + Send + Sync {
pub fn new<F>(attributes: AttributeSet, notify_fn: F) -> TxObserver where F: Fn(&String, &Vec<&TxReport>) + 'static + Send + Sync {
TxObserver {
notify_fn: Arc::new(Box::new(notify_fn)),
attributes,
}
}
pub fn applicable_reports(&self, reports: &Vec<Arc<TxReport>>) -> Vec<Arc<TxReport>> {
reports.into_iter().filter_map( |report| {
self.attributes.intersection(&report.changeset)
.next()
.and_then(|_| Some(Arc::clone(report)))
}).collect()
pub fn applicable_reports<'r>(&self, reports: &'r Vec<TxReport>) -> Vec<&'r TxReport> {
let mut out = Vec::with_capacity(reports.len());
for report in reports {
if self.attributes.intersection(&report.changeset).next().is_none() {
continue;
}
out.push(report);
}
out
}
fn notify(&self, key: &String, reports: &Vec<Arc<TxReport>>) {
fn notify(&self, key: &String, reports: &Vec<&TxReport>) {
(*self.notify_fn)(key, reports);
}
}
@ -53,14 +56,14 @@ pub trait Command {
fn execute(&mut self);
}
pub struct NotifyTxObserver {
pub struct NotifyTxObserver<'r> {
key: String,
reports: Vec<Arc<TxReport>>,
reports: Vec<&'r TxReport>,
observer: Weak<TxObserver>,
}
impl NotifyTxObserver {
pub fn new(key: String, reports: Vec<Arc<TxReport>>, observer: Weak<TxObserver>) -> Self {
impl<'r> NotifyTxObserver<'r> {
pub fn new(key: String, reports: Vec<&'r TxReport>, observer: Weak<TxObserver>) -> Self {
NotifyTxObserver {
key,
reports,
@ -69,17 +72,17 @@ impl NotifyTxObserver {
}
}
impl Command for NotifyTxObserver {
impl<'r> Command for NotifyTxObserver<'r> {
fn execute(&mut self) {
self.observer.upgrade().map(|o| o.notify(&self.key, &self.reports));
}
}
pub struct AsyncBatchExecutor {
commands: Vec<Box<Command + Send>>,
pub struct AsyncBatchExecutor<'r> {
commands: Vec<Box<Command + Send + 'r>>,
}
impl Command for AsyncBatchExecutor {
impl<'r> Command for AsyncBatchExecutor<'r> {
fn execute(&mut self) {
// need to clone to move to a new thread.
let command_queue = ::std::mem::replace(&mut self.commands, Vec::new());
@ -121,8 +124,8 @@ impl TxObservationService {
!self.observers.is_empty()
}
fn command_from_reports(&self, key: &String, reports: &Vec<Arc<TxReport>>, observer: &Arc<TxObserver>) -> Option<Box<Command + Send>> {
let applicable_reports = observer.applicable_reports(reports);
fn command_from_reports<'r>(&self, key: &String, reports: &'r Vec<TxReport>, observer: &Arc<TxObserver>) -> Option<Box<Command + Send + 'r>> {
let applicable_reports: Vec<&'r TxReport> = observer.applicable_reports(reports);
if !applicable_reports.is_empty() {
Some(Box::new(NotifyTxObserver::new(key.clone(), applicable_reports, Arc::downgrade(observer))))
} else {
@ -130,12 +133,13 @@ impl TxObservationService {
}
}
pub fn transaction_did_commit(&mut self, reports: Vec<Arc<TxReport>>) {
// notify all observers about their relevant transactions
let commands: Vec<Box<Command + Send>> = self.observers
.iter()
.filter_map(|(key, observer)| { self.command_from_reports(&key, &reports, &observer) })
.collect();
pub fn transaction_did_commit(&mut self, reports: Vec<TxReport>) {
let mut commands = Vec::with_capacity(self.observers.len());
for (key, observer) in self.observers.iter() {
if let Some(command) = self.command_from_reports(key, &reports, &observer) {
commands.push(command);
}
}
self.command_queue.push(Box::new(AsyncBatchExecutor { commands }));
}