From 4ef92089d5743e896c920d6fa364ff66ab22c346 Mon Sep 17 00:00:00 2001
From: Josh Holmer <jholmer.in@gmail.com>
Date: Wed, 15 Apr 2020 12:37:52 -0400
Subject: [PATCH] Unbreak no-default-features

In order to avoid problems with mutable references,
the approach is to use the eval sender for non-parallel.
Computations will still be done synchronously
with the fake synchronous rayon module.
---
 src/evaluate.rs | 31 +------------------------------
 1 file changed, 1 insertion(+), 30 deletions(-)

diff --git a/src/evaluate.rs b/src/evaluate.rs
index ba58a8f0..f60a6e2f 100644
--- a/src/evaluate.rs
+++ b/src/evaluate.rs
@@ -17,7 +17,6 @@ use rayon;
 use rayon::prelude::*;
 use std::sync::atomic::AtomicUsize;
 use std::sync::atomic::Ordering::SeqCst;
-#[cfg(feature = "parallel")]
 use std::sync::mpsc::*;
 use std::sync::Arc;
 use std::thread;
@@ -47,46 +46,30 @@ pub(crate) struct Evaluator {
     nth: AtomicUsize,
     best_candidate_size: Arc<AtomicMin>,
     /// images are sent to the thread for evaluation
-    #[cfg(feature = "parallel")]
     eval_send: SyncSender<Candidate>,
     // the thread helps evaluate images asynchronously
-    #[cfg(feature = "parallel")]
     eval_thread: thread::JoinHandle<Option<Candidate>>,
-    // in non-parallel mode, images are evaluated synchronously
-    #[cfg(not(feature = "parallel"))]
-    eval_best_candidate: Option<Candidate>,
 }
 
 impl Evaluator {
     pub fn new(deadline: Arc<Deadline>) -> Self {
-        #[cfg(feature = "parallel")]
         let (tx, rx) = sync_channel(4);
         Self {
             deadline,
             best_candidate_size: Arc::new(AtomicMin::new(None)),
             nth: AtomicUsize::new(0),
-            #[cfg(feature = "parallel")]
             eval_send: tx,
-            #[cfg(feature = "parallel")]
             eval_thread: thread::spawn(move || rx.into_iter().min_by_key(Candidate::cmp_key)),
-            #[cfg(not(feature = "parallel"))]
-            eval_best_candidate: None,
         }
     }
 
     /// Wait for all evaluations to finish and return smallest reduction
     /// Or `None` if all reductions were worse than baseline.
-    #[cfg(feature = "parallel")]
     fn get_best_candidate(self) -> Option<Candidate> {
         drop(self.eval_send); // disconnect the sender, breaking the loop in the thread
         self.eval_thread.join().expect("eval thread")
     }
 
-    #[cfg(not(feature = "parallel"))]
-    fn get_best_candidate(self) -> Option<Candidate> {
-        self.eval_best_candidate
-    }
-
     pub fn get_result(self) -> Option<PngData> {
         self.get_best_candidate().map(|candidate| candidate.image)
     }
@@ -108,7 +91,6 @@ impl Evaluator {
         let best_candidate_size = self.best_candidate_size.clone();
         // sends it off asynchronously for compression,
         // but results will be collected via the message queue
-        #[cfg(feature = "parallel")]
         let eval_send = self.eval_send.clone();
         rayon::spawn(move || {
             let filters_iter = STD_FILTERS.par_iter().with_max_len(1);
@@ -144,18 +126,7 @@ impl Evaluator {
                         nth,
                     };
 
-                    #[cfg(feature = "parallel")]
-                    {
-                        eval_send.send(new).expect("send");
-                    }
-
-                    #[cfg(not(feature = "parallel"))]
-                    {
-                        match self.eval_best_candidate {
-                            Some(prev) if prev.cmp_key() < new.cmp_key() => {}
-                            _ => self.eval_best_candidate = Some(new),
-                        }
-                    }
+                    eval_send.send(new).expect("send");
                 }
             });
         });