Apply various Clippy recommendations (#603)

bytes/src/lib.rs

@@ -96,7 +96,7 @@ pub mod arc {
                 sequestered: self.sequestered.clone(),
             };
 
-            unsafe { self.ptr = self.ptr.offset(index as isize); }
+            unsafe { self.ptr = self.ptr.add(index); }
             self.len -= index;
 
             result
@@ -161,7 +161,7 @@ pub mod arc {
         /// shared4.try_merge(shared2).ok().expect("Failed to merge 4 and 231");
         /// ```
         pub fn try_merge(&mut self, other: Bytes) -> Result<(), Bytes> {
-            if Arc::ptr_eq(&self.sequestered, &other.sequestered) && ::std::ptr::eq(unsafe { self.ptr.offset(self.len as isize) }, other.ptr) {
+            if Arc::ptr_eq(&self.sequestered, &other.sequestered) && ::std::ptr::eq(unsafe { self.ptr.add(self.len) }, other.ptr) {
                 self.len += other.len;
                 Ok(())
             }

communication/src/allocator/process.rs

@@ -35,7 +35,7 @@ impl AllocateBuilder for ProcessBuilder {
 
         // Initialize buzzers; send first, then recv.
         for worker in self.buzzers_send.iter() {
-            let buzzer = Buzzer::new();
+            let buzzer = Buzzer::default();
             worker.send(buzzer).expect("Failed to send buzzer");
         }
         let mut buzzers = Vec::with_capacity(self.buzzers_recv.len());
@@ -88,8 +88,8 @@ impl Process {
 
         counters_recv
             .into_iter()
-            .zip(buzzers_send.into_iter())
-            .zip(buzzers_recv.into_iter())
+            .zip(buzzers_send)
+            .zip(buzzers_recv)
             .enumerate()
             .map(|(index, ((recv, bsend), brecv))| {
                 ProcessBuilder {

communication/src/allocator/thread.rs

@@ -15,11 +15,12 @@ pub struct ThreadBuilder;
 
 impl AllocateBuilder for ThreadBuilder {
     type Allocator = Thread;
-    fn build(self) -> Self::Allocator { Thread::new() }
+    fn build(self) -> Self::Allocator { Thread::default() }
 }
 
 
 /// An allocator for intra-thread communication.
+#[derive(Default)]
 pub struct Thread {
     /// Shared counts of messages in channels.
     events: Rc<RefCell<Vec<usize>>>,
@@ -53,13 +54,6 @@ pub type ThreadPusher<T> = CountPusher<T, Pusher<T>>;
 pub type ThreadPuller<T> = CountPuller<T, Puller<T>>;
 
 impl Thread {
-    /// Allocates a new thread-local channel allocator.
-    pub fn new() -> Self {
-        Thread {
-            events: Rc::new(RefCell::new(Default::default())),
-        }
-    }
-
     /// Creates a new thread-local channel from an identifier and shared counts.
     pub fn new_from<T: 'static>(identifier: usize, events: Rc<RefCell<Vec<usize>>>)
         -> (ThreadPusher<T>, ThreadPuller<T>)

communication/src/allocator/zero_copy/allocator.rs

@@ -82,7 +82,7 @@ impl<A: AllocateBuilder> TcpBuilder<A> {
         // Fulfill puller obligations.
         let mut recvs = Vec::with_capacity(self.peers);
         for promise in self.promises.into_iter() {
-            let buzzer = crate::buzzer::Buzzer::new();
+            let buzzer = crate::buzzer::Buzzer::default();
             let queue = MergeQueue::new(buzzer);
             promise.send(queue.clone()).expect("Failed to send MergeQueue");
             recvs.push(queue.clone());

communication/src/allocator/zero_copy/allocator_process.rs

@@ -60,7 +60,7 @@ impl ProcessBuilder {
         // Fulfill puller obligations.
         let mut recvs = Vec::with_capacity(self.peers);
         for puller in self.pullers.into_iter() {
-            let buzzer = crate::buzzer::Buzzer::new();
+            let buzzer = crate::buzzer::Buzzer::default();
             let queue = MergeQueue::new(buzzer);
             puller.send(queue.clone()).expect("Failed to send MergeQueue");
             recvs.push(queue.clone());

communication/src/allocator/zero_copy/initialize.rs

@@ -63,10 +63,8 @@ pub fn initialize_networking_from_sockets<S: Stream + 'static>(
 -> ::std::io::Result<(Vec<TcpBuilder<ProcessBuilder>>, CommsGuard)>
 {
     // Sockets are expected to be blocking,
-    for socket in sockets.iter_mut() {
-        if let Some(socket) = socket {
-            socket.set_nonblocking(false).expect("failed to set socket to blocking");
-        }
+    for socket in sockets.iter_mut().flatten() {
+        socket.set_nonblocking(false).expect("failed to set socket to blocking");
     }
 
     let processes = sockets.len();

communication/src/allocator/zero_copy/tcp.rs

@@ -1,4 +1,4 @@
-//!
+//! Methods related to reading from and writing to TCP connections
 
 use std::io::{self, Write};
 use crossbeam_channel::{Sender, Receiver};
@@ -67,9 +67,9 @@ where
         assert!(!buffer.empty().is_empty());
 
         // Attempt to read some more bytes into self.buffer.
-        let read = match reader.read(&mut buffer.empty()) {
+        let read = match reader.read(buffer.empty()) {
             Err(x) => tcp_panic("reading data", x),
-            Ok(n) if n == 0 => {
+            Ok(0) => {
                 tcp_panic(
                     "reading data",
                     std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "socket closed"),
@@ -102,7 +102,7 @@ where
                     panic!("Clean shutdown followed by data.");
                 }
                 buffer.ensure_capacity(1);
-                if reader.read(&mut buffer.empty()).unwrap_or_else(|e| tcp_panic("reading EOF", e)) > 0 {
+                if reader.read(buffer.empty()).unwrap_or_else(|e| tcp_panic("reading EOF", e)) > 0 {
                     panic!("Clean shutdown followed by data.");
                 }
             }
@@ -141,7 +141,7 @@ pub fn send_loop<S: Stream>(
     logger.as_mut().map(|l| l.log(StateEvent { send: true, process, remote, start: true, }));
 
     let mut sources: Vec<MergeQueue> = sources.into_iter().map(|x| {
-        let buzzer = crate::buzzer::Buzzer::new();
+        let buzzer = crate::buzzer::Buzzer::default();
         let queue = MergeQueue::new(buzzer);
         x.send(queue.clone()).expect("failed to send MergeQueue");
         queue

communication/src/buzzer.rs

@@ -8,13 +8,11 @@ pub struct Buzzer {
     thread: Thread,
 }
 
+impl Default for Buzzer {
+    fn default() -> Self { Self { thread: std::thread::current() } }
+}
+
 impl Buzzer {
-    /// Creates a new buzzer for the current thread.
-    pub fn new() -> Self {
-        Self {
-            thread: std::thread::current()
-        }
-    }
     /// Unparks the target thread.
     pub fn buzz(&self) {
         self.thread.unpark()

communication/src/initialize.rs

@@ -155,15 +155,15 @@ impl Config {
                 Ok((vec![GenericBuilder::Thread(ThreadBuilder)], Box::new(())))
             },
             Config::Process(threads) => {
-                Ok((Process::new_vector(threads).into_iter().map(|x| GenericBuilder::Process(x)).collect(), Box::new(())))
+                Ok((Process::new_vector(threads).into_iter().map(GenericBuilder::Process).collect(), Box::new(())))
             },
             Config::ProcessBinary(threads) => {
-                Ok((ProcessBuilder::new_vector(threads).into_iter().map(|x| GenericBuilder::ProcessBinary(x)).collect(), Box::new(())))
+                Ok((ProcessBuilder::new_vector(threads).into_iter().map(GenericBuilder::ProcessBinary).collect(), Box::new(())))
             },
             Config::Cluster { threads, process, addresses, report, log_fn } => {
                 match initialize_networking(addresses, process, threads, report, log_fn) {
                     Ok((stuff, guard)) => {
-                        Ok((stuff.into_iter().map(|x| GenericBuilder::ZeroCopy(x)).collect(), Box::new(guard)))
+                        Ok((stuff.into_iter().map(GenericBuilder::ZeroCopy).collect(), Box::new(guard)))
                     },
                     Err(err) => Err(format!("failed to initialize networking: {}", err))
                 }

communication/src/lib.rs

@@ -181,11 +181,11 @@ fn promise_futures<T>(sends: usize, recvs: usize) -> (Vec<Vec<Sender<T>>>, Vec<V
     let mut senders: Vec<_> = (0 .. sends).map(|_| Vec::with_capacity(recvs)).collect();
     let mut recvers: Vec<_> = (0 .. recvs).map(|_| Vec::with_capacity(sends)).collect();
 
-    for sender in 0 .. sends {
-        for recver in 0 .. recvs {
+    for sender in senders.iter_mut() {
+        for recver in recvers.iter_mut() {
             let (send, recv) = crossbeam_channel::unbounded();
-            senders[sender].push(send);
-            recvers[recver].push(recv);
+            sender.push(send);
+            recver.push(recv);
         }
     }
 

communication/src/networking.rs

@@ -100,7 +100,7 @@ pub fn create_sockets(addresses: Vec<String>, my_index: usize, noisy: bool) -> R
     let mut results = start_task.join().unwrap()?;
     results.push(None);
     let to_extend = await_task.join().unwrap()?;
-    results.extend(to_extend.into_iter());
+    results.extend(to_extend);
 
     if noisy { println!("worker {}:\tinitialization complete", my_index) }
 

container/src/columnation.rs

@@ -200,9 +200,9 @@ impl<T: Columnation> Default for TimelyStack<T> {
 
 impl<'a, A: 'a + Columnation> FromIterator<&'a A> for TimelyStack<A> {
     fn from_iter<T: IntoIterator<Item = &'a A>>(iter: T) -> Self {
-        let mut iter = iter.into_iter();
+        let iter = iter.into_iter();
         let mut c = TimelyStack::<A>::with_capacity(iter.size_hint().0);
-        while let Some(element) = iter.next() {
+        for element in iter {
             c.copy(element);
         }
 

container/src/flatcontainer.rs

@@ -17,13 +17,13 @@ impl<R: Region + Clone + 'static> Container for FlatStack<R> {
 
     type Iter<'a> = <&'a Self as IntoIterator>::IntoIter;
 
-    fn iter<'a>(&'a self) -> Self::Iter<'a> {
+    fn iter(&self) -> Self::Iter<'_> {
         IntoIterator::into_iter(self)
     }
 
     type DrainIter<'a> = Self::Iter<'a>;
 
-    fn drain<'a>(&'a mut self) -> Self::DrainIter<'a> {
+    fn drain(&mut self) -> Self::DrainIter<'_> {
         IntoIterator::into_iter(&*self)
     }
 }

mdbook/src/chapter_2/chapter_2_4.md

@@ -184,7 +184,7 @@ fn main() {
 
         in1.binary_frontier(&in2, Pipeline, Pipeline, "concat_buffer", |capability, info| {
 
-            let mut notificator = FrontierNotificator::new();
+            let mut notificator = FrontierNotificator::default();
             let mut stash = HashMap::new();
 
             move |input1, input2, output| {

timely/examples/threadless.rs

@@ -5,7 +5,7 @@ use timely::WorkerConfig;
 fn main() {
 
     // create a naked single-threaded worker.
-    let allocator = timely::communication::allocator::Thread::new();
+    let allocator = timely::communication::allocator::Thread::default();
     let mut worker = timely::worker::Worker::new(WorkerConfig::default(), allocator);
 
     // create input and probe handles.

timely/src/dataflow/channels/pullers/counter.rs

@@ -24,7 +24,7 @@ pub struct ConsumedGuard<T: Ord + Clone + 'static> {
 
 impl<T:Ord+Clone+'static> ConsumedGuard<T> {
     pub(crate) fn time(&self) -> &T {
-        &self.time.as_ref().unwrap()
+        self.time.as_ref().unwrap()
     }
 }
 

timely/src/dataflow/channels/pushers/exchange.rs

@@ -71,7 +71,7 @@ where
             let hash_func = &mut self.hash_func;
 
             // if the number of pushers is a power of two, use a mask
-            if (self.pushers.len() & (self.pushers.len() - 1)) == 0 {
+            if self.pushers.len().is_power_of_two() {
                 let mask = (self.pushers.len() - 1) as u64;
                 let pushers = &mut self.pushers;
                 data.push_partitioned(

timely/src/dataflow/operators/aggregation/aggregate.rs

@@ -76,7 +76,7 @@ impl<S: Scope, K: ExchangeData+Hash+Eq, V: ExchangeData> Aggregate<S, K, V> for
         hash: H) -> Stream<S, R> where S::Timestamp: Eq {
 
         let mut aggregates = HashMap::new();
-        self.unary_notify(Exchange::new(move |&(ref k, _)| hash(k)), "Aggregate", vec![], move |input, output, notificator| {
+        self.unary_notify(Exchange::new(move |(k, _)| hash(k)), "Aggregate", vec![], move |input, output, notificator| {
 
             // read each input, fold into aggregates
             input.for_each(|time, data| {

timely/src/dataflow/operators/aggregation/state_machine.rs

@@ -7,6 +7,8 @@ use crate::dataflow::{Stream, Scope};
 use crate::dataflow::operators::generic::operator::Operator;
 use crate::dataflow::channels::pact::Exchange;
 
+/// Provides the `state_machine` method.
+///
 /// Generic state-transition machinery: each key has a state, and receives a sequence of events.
 /// Events are applied in time-order, but no other promises are made. Each state transition can
 /// produce output, which is sent.
@@ -15,8 +17,6 @@ use crate::dataflow::channels::pact::Exchange;
 /// updates for the current time reflected in the notificator, though. In the case of partially
 /// ordered times, the only guarantee is that updates are not applied out of order, not that there
 /// is some total order on times respecting the total order (updates may be interleaved).
-
-/// Provides the `state_machine` method.
 pub trait StateMachine<S: Scope, K: ExchangeData+Hash+Eq, V: ExchangeData> {
     /// Tracks a state for each presented key, using user-supplied state transition logic.
     ///
@@ -66,7 +66,7 @@ impl<S: Scope, K: ExchangeData+Hash+Eq, V: ExchangeData> StateMachine<S, K, V> f
         let mut pending: HashMap<_, Vec<(K, V)>> = HashMap::new();   // times -> (keys -> state)
         let mut states = HashMap::new();    // keys -> state
 
-        self.unary_notify(Exchange::new(move |&(ref k, _)| hash(k)), "StateMachine", vec![], move |input, output, notificator| {
+        self.unary_notify(Exchange::new(move |(k, _)| hash(k)), "StateMachine", vec![], move |input, output, notificator| {
 
             // go through each time with data, process each (key, val) pair.
             notificator.for_each(|time,_,_| {
@@ -88,7 +88,7 @@ impl<S: Scope, K: ExchangeData+Hash+Eq, V: ExchangeData> StateMachine<S, K, V> f
 
                 // stash if not time yet
                 if notificator.frontier(0).less_than(time.time()) {
-                    pending.entry(time.time().clone()).or_insert_with(Vec::new).extend(data.drain(..));
+                    pending.entry(time.time().clone()).or_insert_with(Vec::new).append(data);
                     notificator.notify_at(time.retain());
                 }
                 else {

timely/src/dataflow/operators/branch.rs

@@ -54,7 +54,7 @@ impl<S: Scope, D: Data> Branch<S, D> for Stream<S, D> {
                     let mut out1 = output1_handle.session(&time);
                     let mut out2 = output2_handle.session(&time);
                     for datum in data.drain(..) {
-                        if condition(&time.time(), &datum) {
+                        if condition(time.time(), &datum) {
                             out2.give(datum);
                         } else {
                             out1.give(datum);
@@ -107,7 +107,7 @@ impl<S: Scope, C: Container> BranchWhen<S::Timestamp> for StreamCore<S, C> {
                 let mut output2_handle = output2.activate();
 
                 input.for_each(|time, data| {
-                    let mut out = if condition(&time.time()) {
+                    let mut out = if condition(time.time()) {
                         output2_handle.session(&time)
                     } else {
                         output1_handle.session(&time)

timely/src/dataflow/operators/capability.rs

@@ -40,13 +40,13 @@ pub trait CapabilityTrait<T: Timestamp> {
     fn valid_for_output(&self, query_buffer: &Rc<RefCell<ChangeBatch<T>>>) -> bool;
 }
 
-impl<'a, T: Timestamp, C: CapabilityTrait<T>> CapabilityTrait<T> for &'a C {
+impl<T: Timestamp, C: CapabilityTrait<T>> CapabilityTrait<T> for &C {
     fn time(&self) -> &T { (**self).time() }
     fn valid_for_output(&self, query_buffer: &Rc<RefCell<ChangeBatch<T>>>) -> bool {
         (**self).valid_for_output(query_buffer)
     }
 }
-impl<'a, T: Timestamp, C: CapabilityTrait<T>> CapabilityTrait<T> for &'a mut C {
+impl<T: Timestamp, C: CapabilityTrait<T>> CapabilityTrait<T> for &mut C {
     fn time(&self) -> &T { (**self).time() }
     fn valid_for_output(&self, query_buffer: &Rc<RefCell<ChangeBatch<T>>>) -> bool {
         (**self).valid_for_output(query_buffer)
@@ -227,9 +227,10 @@ impl Error for DowngradeError {}
 /// A shared list of shared output capability buffers.
 type CapabilityUpdates<T> = Rc<RefCell<Vec<Rc<RefCell<ChangeBatch<T>>>>>>;
 
-/// An capability of an input port. Holding onto this capability will implicitly holds onto a
-/// capability for all the outputs ports this input is connected to, after the connection summaries
-/// have been applied.
+/// An capability of an input port. 
+///
+/// Holding onto this capability will implicitly holds onto a capability for all the outputs 
+/// ports this input is connected to, after the connection summaries have been applied.
 ///
 /// This input capability supplies a `retain_for_output(self)` method which consumes the input
 /// capability and turns it into a [Capability] for a specific output port.

timely/src/dataflow/operators/core/enterleave.rs

@@ -103,7 +103,7 @@ pub trait Leave<G: Scope, C: Container> {
     fn leave(&self) -> StreamCore<G, C>;
 }
 
-impl<'a, G: Scope, C: Clone+Container, T: Timestamp+Refines<G::Timestamp>> Leave<G, C> for StreamCore<Child<'a, G, T>, C> {
+impl<G: Scope, C: Clone+Container, T: Timestamp+Refines<G::Timestamp>> Leave<G, C> for StreamCore<Child<'_, G, T>, C> {
     fn leave(&self) -> StreamCore<G, C> {
 
         let scope = self.scope();

timely/src/dataflow/operators/core/exchange.rs

@@ -23,18 +23,18 @@ pub trait Exchange<C: PushPartitioned> {
     ///            .inspect(|x| println!("seen: {:?}", x));
     /// });
     /// ```
-    fn exchange<F: 'static>(&self, route: F) -> Self
+    fn exchange<F>(&self, route: F) -> Self
     where
-        for<'a> F: FnMut(&C::Item<'a>) -> u64;
+        for<'a> F: FnMut(&C::Item<'a>) -> u64 + 'static;
 }
 
 impl<G: Scope, C> Exchange<C> for StreamCore<G, C>
 where
     C: PushPartitioned + ExchangeData,
 {
-    fn exchange<F: 'static>(&self, route: F) -> StreamCore<G, C>
+    fn exchange<F>(&self, route: F) -> StreamCore<G, C>
     where
-        for<'a> F: FnMut(&C::Item<'a>) -> u64,
+        for<'a> F: FnMut(&C::Item<'a>) -> u64 + 'static,
     {
         self.unary(ExchangeCore::new(route), "Exchange", |_, _| {
             move |input, output| {