From: Markus Triska <triska@metalevel.at>
Date: Fri, 12 Jun 2020 19:07:18 +0000 (+0200)
Subject: use take() for extra fast processing of binary files
X-Git-Tag: v0.8.127~34^2
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=f910e013a6aa65d3138fae3a585cdaab322e1fae;p=scryer-prolog.git

use take() for extra fast processing of binary files

Suggested by @notoria in #589. Many thanks!
---

diff --git a/src/machine/system_calls.rs b/src/machine/system_calls.rs
index 28339acd..e18da09b 100644
--- a/src/machine/system_calls.rs
+++ b/src/machine/system_calls.rs
@@ -2277,18 +2277,11 @@ impl MachineState {
                 let mut string = String::new();
 
                 if stream.options.stream_type == StreamType::Binary {
-                    let mut mstream = stream.clone();
-                    for _ in 0..num {
-                        let mut b = [0u8; 1];
-
-                        match mstream.read(&mut b) {
-                            Ok(1) => {
-                                string.push(b[0] as char);
-                            }
-                            _ => {
-                                break;
-                            }
-                        }
+                    let mut buf = vec![];
+                    let mut chunk = stream.take(num as u64);
+                    chunk.read_to_end(&mut buf).ok();
+                    for c in buf {
+                        string.push(c as char);
                     }
                 } else {
                     let mut iter = self.open_parsing_stream(stream.clone(),