From 9a25bdea37f0438209432d6e6d6cf640ff72acf8 Mon Sep 17 00:00:00 2001
From: Andrew Phillips <andrew.phillips2@canada.ca>
Date: Tue, 2 Sep 2025 11:27:50 -0300
Subject: [PATCH] refactor: Optimize filter plugins to read in chunks of
 PIPESIZE

Co-authored-by: aider (openai/andrew/openrouter/deepseek/deepseek-chat-v3.1) <aider@aider.chat>
---
 src/filter_plugin/head.rs       | 12 ++++++++----
 src/filter_plugin/skip.rs       | 28 +++++++++++++---------------
 src/filter_plugin/strip_ansi.rs | 16 +++++++++++++---
 src/filter_plugin/tail.rs       |  3 ++-
 4 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/src/filter_plugin/head.rs b/src/filter_plugin/head.rs
index c6b20f1..27d1893 100644
--- a/src/filter_plugin/head.rs
+++ b/src/filter_plugin/head.rs
@@ -1,5 +1,6 @@
 use super::FilterPlugin;
 use std::io::{Result, Read, Write, BufRead};
+use crate::common::PIPESIZE;
 
 pub struct HeadBytesFilter {
     remaining: usize,
@@ -19,10 +20,13 @@ impl FilterPlugin for HeadBytesFilter {
             return Ok(());
         }
         
-        // Read only up to remaining bytes
-        let mut buffer = vec![0; self.remaining];
-        let bytes_read = reader.read(&mut buffer)?;
-        if bytes_read > 0 {
+        let mut buffer = vec![0; PIPESIZE];
+        while self.remaining > 0 {
+            let to_read = std::cmp::min(self.remaining, PIPESIZE);
+            let bytes_read = reader.read(&mut buffer[..to_read])?;
+            if bytes_read == 0 {
+                break;
+            }
             writer.write_all(&buffer[..bytes_read])?;
             self.remaining -= bytes_read;
         }
diff --git a/src/filter_plugin/skip.rs b/src/filter_plugin/skip.rs
index 2de1537..a83b195 100644
--- a/src/filter_plugin/skip.rs
+++ b/src/filter_plugin/skip.rs
@@ -1,5 +1,6 @@
 use super::FilterPlugin;
 use std::io::{Result, Read, Write, BufRead, Seek};
+use crate::common::PIPESIZE;
 
 pub struct SkipBytesFilter {
     remaining: usize,
@@ -15,22 +16,12 @@ impl SkipBytesFilter {
 
 impl FilterPlugin for SkipBytesFilter {
     fn filter<R: Read, W: Write>(&mut self, reader: &mut R, writer: &mut W) -> Result<()> {
-        // Try to use seek if the reader supports it
+        // Skip bytes in chunks
         if self.remaining > 0 {
-            // Create a mutable reference that we can try to cast to &mut dyn Seek
-            let any_reader: &mut dyn std::io::Read = reader;
-            // We need to use unsafe code to perform the cast, but let's find a safer way
-            
-            // Instead, we can use a helper function that uses a trait object
-            // For now, we'll use a different approach: check if the concrete type implements Seek
-            // Since we can't easily do that at runtime, we'll use a different strategy
-            
-            // Let's read a small buffer at a time to be efficient
-            const BUFFER_SIZE: usize = 8192;
+            let mut buffer = vec![0; PIPESIZE];
             while self.remaining > 0 {
-                let to_read = std::cmp::min(self.remaining, BUFFER_SIZE);
-                let mut buffer = vec![0; to_read];
-                let bytes_read = reader.read(&mut buffer)?;
+                let to_read = std::cmp::min(self.remaining, PIPESIZE);
+                let bytes_read = reader.read(&mut buffer[..to_read])?;
                 if bytes_read == 0 {
                     break;
                 }
@@ -39,7 +30,14 @@ impl FilterPlugin for SkipBytesFilter {
         }
         
         // Copy the remaining data
-        std::io::copy(reader, writer)?;
+        let mut buffer = vec![0; PIPESIZE];
+        loop {
+            let bytes_read = reader.read(&mut buffer)?;
+            if bytes_read == 0 {
+                break;
+            }
+            writer.write_all(&buffer[..bytes_read])?;
+        }
         Ok(())
     }
 }
diff --git a/src/filter_plugin/strip_ansi.rs b/src/filter_plugin/strip_ansi.rs
index 3acb52a..8aa6dc7 100644
--- a/src/filter_plugin/strip_ansi.rs
+++ b/src/filter_plugin/strip_ansi.rs
@@ -1,5 +1,6 @@
 use std::io::{Result, Read, Write};
 use strip_ansi_escapes::strip as strip_ansi_escapes;
+use crate::common::PIPESIZE;
 
 use super::FilterPlugin;
 
@@ -13,9 +14,18 @@ impl StripAnsiFilter {
 
 impl FilterPlugin for StripAnsiFilter {
     fn filter<R: Read, W: Write>(&mut self, reader: &mut R, writer: &mut W) -> Result<()> {
-        let mut data = Vec::new();
-        reader.read_to_end(&mut data)?;
-        let stripped = strip_ansi_escapes(&data);
+        let mut buffer = vec![0; PIPESIZE];
+        let mut processed_data = Vec::new();
+        
+        loop {
+            let bytes_read = reader.read(&mut buffer)?;
+            if bytes_read == 0 {
+                break;
+            }
+            processed_data.extend_from_slice(&buffer[..bytes_read]);
+        }
+        
+        let stripped = strip_ansi_escapes(&processed_data);
         writer.write_all(&stripped)?;
         Ok(())
     }
diff --git a/src/filter_plugin/tail.rs b/src/filter_plugin/tail.rs
index 0e5b6f2..8927107 100644
--- a/src/filter_plugin/tail.rs
+++ b/src/filter_plugin/tail.rs
@@ -1,6 +1,7 @@
 use super::FilterPlugin;
 use std::io::{Result, Read, Write, BufRead};
 use std::collections::VecDeque;
+use crate::common::PIPESIZE;
 
 pub struct TailBytesFilter {
     buffer: VecDeque<u8>,
@@ -18,7 +19,7 @@ impl TailBytesFilter {
 
 impl FilterPlugin for TailBytesFilter {
     fn filter<R: Read, W: Write>(&mut self, reader: &mut R, writer: &mut W) -> Result<()> {
-        let mut temp_buffer = vec![0; 8192];
+        let mut temp_buffer = vec![0; PIPESIZE];
         loop {
             let bytes_read = reader.read(&mut temp_buffer)?;
             if bytes_read == 0 {