Merge pull request #125 from pamburus/feature/scanner-performance-4

new: Minor performance improvement

Cargo.toml

@@ -4,7 +4,7 @@ categories = ["command-line-utilities"]
 description = "Utility for viewing json-formatted log files."
 keywords = ["cli", "human", "log"]
 name = "hl"
-version = "0.25.1-beta.3"
+version = "0.25.1-beta.4"
 edition = "2021"
 build = "build.rs"
 

src/app.rs

@@ -17,7 +17,7 @@ use std::os::unix::fs::MetadataExt;
 
 // third-party imports
 use closure::closure;
-use crossbeam_channel::{self as channel, Receiver, RecvError, Sender,RecvTimeoutError};
+use crossbeam_channel::{self as channel, Receiver, RecvError, Sender, RecvTimeoutError};
 use crossbeam_utils::thread;
 use itertools::{izip, Itertools};
 use platform_dirs::AppDirs;
@@ -34,7 +34,7 @@ use crate::formatting::{RecordFormatter, RecordWithSourceFormatter, RawRecordFor
 use crate::index::{Indexer, Timestamp};
 use crate::input::{BlockLine, InputHolder, InputReference, Input};
 use crate::model::{Filter, Parser, ParserSettings, RawRecord, Record, RecordFilter, RecordWithSourceConstructor};
-use crate::scanning::{BufFactory, Scanner, Segment, SegmentBufFactory};
+use crate::scanning::{BufFactory, Scanner, Segment, SegmentBuf, SegmentBufFactory};
 use crate::serdex::StreamDeserializerWithOffsets;
 use crate::settings::{Fields, Formatting};
 use crate::theme::{Element, StylingPush, Theme};
@@ -132,7 +132,7 @@ impl App {
             // prepare receive/transmit channels for input data
             let (txi, rxi): (Vec<_>, Vec<_>) = (0..n).map(|_| channel::bounded(1)).unzip();
             // prepare receive/transmit channels for output data
-            let (txo, rxo): (Vec<_>, Vec<_>) = (0..n).into_iter().map(|_| channel::bounded::<(usize, Vec<u8>)>(1)).unzip();
+            let (txo, rxo): (Vec<_>, Vec<_>) = (0..n).into_iter().map(|_| channel::bounded::<(usize, SegmentBuf)>(1)).unzip();
             // spawn reader thread
             let reader = scope.spawn(closure!(clone sfi, |_| -> Result<()> {
                 let mut tx = StripedSender::new(txi);
@@ -157,12 +157,12 @@ impl App {
                                 let mut buf = bfo.new_buf();
                                 processor.process(segment.data(), &mut buf, prefix, &mut RecordIgnorer{});
                                 sfi.recycle(segment);
-                                if let Err(_) = txo.send((i, buf)) {
+                                if let Err(_) = txo.send((i, buf.into())) {
                                     break;
                                 };
                             }
                             Segment::Incomplete(segment, _) => {
-                                if let Err(_) = txo.send((i, segment.to_vec())) {
+                                if let Err(_) = txo.send((i, segment)) {
                                     break;
                                 }
                             }
@@ -173,8 +173,8 @@ impl App {
             // spawn writer thread
             let writer = scope.spawn(closure!(ref bfo, |_| -> Result<()> {
                 for (_, buf) in StripedReceiver::new(rxo) {
-                    output.write_all(&buf[..])?;
-                    bfo.recycle(buf);
+                    output.write_all(buf.data())?;
+                    bfo.recycle(buf.into_inner());
                 }
                 Ok(())
             }));

src/scanning.rs

@@ -47,8 +47,7 @@ impl SegmentBuf {
     }
 
     /// Converts the SegmentBuf to a Vec<u8>.
-    pub fn to_vec(mut self) -> Vec<u8> {
-        self.data.resize(self.size, 0);
+    pub fn into_inner(self) -> Vec<u8> {
         self.data
     }
 
@@ -110,7 +109,7 @@ impl<T: AsRef<[u8]>> From<T> for SegmentBuf {
 // ---
 
 /// Segment is an output of Scanner.
-/// Complete segment cantains a whole number of tokens.
+/// Complete segment contains a whole number of tokens.
 /// Incomplete segment contains a part of a token.
 #[derive(Debug, Eq, PartialEq)]
 pub enum Segment {