refactor: Simplify Parse trait by using Vec<u8> instead of AyncWriteE…

…xt (#30)

breakwater-parser/Cargo.toml

@@ -16,9 +16,6 @@ breakwater-core.workspace = true
 
 enum_dispatch.workspace = true
 memchr.workspace = true
-snafu.workspace = true
-tokio.workspace = true
-trait-variant.workspace = true
 
 [dev-dependencies]
 criterion.workspace = true

breakwater-parser/benches/parsing.rs

@@ -1,6 +1,6 @@
 use std::{sync::Arc, time::Duration};
 
-use breakwater_core::{framebuffer::FrameBuffer, test_helpers::DevNullTcpStream};
+use breakwater_core::framebuffer::FrameBuffer;
 #[cfg(target_arch = "x86_64")]
 use breakwater_parser::assembler::AssemblerParser;
 use breakwater_parser::{
@@ -80,26 +80,20 @@ fn invoke_benchmark(
 
     for parse_name in parser_names {
         c_group.bench_with_input(parse_name, &commands, |b, input| {
-            b.to_async(tokio::runtime::Runtime::new().expect("Failed to start tokio runtime"))
-                .iter(|| async {
-                    let mut parser = match parse_name {
-                        "original" => {
-                            ParserImplementation::Original(OriginalParser::new(fb.clone()))
-                        }
-                        "refactored" => {
-                            ParserImplementation::Refactored(RefactoredParser::new(fb.clone()))
-                        }
-                        "memchr" => ParserImplementation::Naive(MemchrParser::new(fb.clone())),
-                        #[cfg(target_arch = "x86_64")]
-                        "assembler" => ParserImplementation::Assembler(AssemblerParser::default()),
-                        _ => panic!("Parser implementation {parse_name} not known"),
-                    };
+            b.iter(|| {
+                let mut parser = match parse_name {
+                    "original" => ParserImplementation::Original(OriginalParser::new(fb.clone())),
+                    "refactored" => {
+                        ParserImplementation::Refactored(RefactoredParser::new(fb.clone()))
+                    }
+                    "memchr" => ParserImplementation::Naive(MemchrParser::new(fb.clone())),
+                    #[cfg(target_arch = "x86_64")]
+                    "assembler" => ParserImplementation::Assembler(AssemblerParser::default()),
+                    _ => panic!("Parser implementation {parse_name} not known"),
+                };
 
-                    parser
-                        .parse(input, DevNullTcpStream::default())
-                        .await
-                        .expect("Failed to parse commands");
-                });
+                parser.parse(input, &mut Vec::new());
+            });
         });
     }
 }

breakwater-parser/src/assembler.rs

@@ -1,20 +1,14 @@
 use std::arch::asm;
 
-use tokio::io::AsyncWriteExt;
-
-use crate::{Parser, ParserError};
+use crate::Parser;
 
 const PARSER_LOOKAHEAD: usize = "PX 1234 1234 rrggbbaa\n".len(); // Longest possible command
 
 #[derive(Default)]
 pub struct AssemblerParser {}
 
 impl Parser for AssemblerParser {
-    async fn parse(
-        &mut self,
-        buffer: &[u8],
-        _stream: impl AsyncWriteExt + Send + Unpin,
-    ) -> Result<usize, ParserError> {
+    fn parse(&mut self, buffer: &[u8], _response: &mut Vec<u8>) -> usize {
         let mut last_byte_parsed = 0;
 
         // This loop does nothing and should be seen as a placeholder
@@ -33,7 +27,7 @@ impl Parser for AssemblerParser {
             )
         }
 
-        Ok(last_byte_parsed)
+        last_byte_parsed
     }
 
     fn parser_lookahead(&self) -> usize {

breakwater-parser/src/lib.rs

@@ -2,30 +2,17 @@
 #![feature(portable_simd)]
 
 use enum_dispatch::enum_dispatch;
-use snafu::Snafu;
-use tokio::io::AsyncWriteExt;
 
 #[cfg(target_arch = "x86_64")]
 pub mod assembler;
 pub mod memchr;
 pub mod original;
 pub mod refactored;
 
-#[derive(Debug, Snafu)]
-pub enum ParserError {
-    #[snafu(display("Failed to write to TCP socket"))]
-    WriteToTcpSocket { source: std::io::Error },
-}
-
 #[enum_dispatch(ParserImplementation)]
-// According to https://blog.rust-lang.org/2023/12/21/async-fn-rpit-in-traits.html
-#[trait_variant::make(SendParser: Send)]
 pub trait Parser {
-    async fn parse(
-        &mut self,
-        buffer: &[u8],
-        stream: impl AsyncWriteExt + Send + Unpin,
-    ) -> Result<usize, ParserError>;
+    /// Returns the last byte parsed. The next parsing loop will again contain all data that was not parsed.
+    fn parse(&mut self, buffer: &[u8], response: &mut Vec<u8>) -> usize;
 
     // Sadly this cant be const (yet?) (https://github.com/rust-lang/rust/issues/71971 and https://github.com/rust-lang/rfcs/pull/2632)
     fn parser_lookahead(&self) -> usize;

breakwater-parser/src/memchr.rs

@@ -1,9 +1,8 @@
 use std::sync::Arc;
 
 use breakwater_core::framebuffer::FrameBuffer;
-use tokio::io::AsyncWriteExt;
 
-use crate::{Parser, ParserError};
+use crate::Parser;
 
 pub struct MemchrParser {
     fb: Arc<FrameBuffer>,
@@ -16,11 +15,7 @@ impl MemchrParser {
 }
 
 impl Parser for MemchrParser {
-    async fn parse(
-        &mut self,
-        buffer: &[u8],
-        _stream: impl AsyncWriteExt + Send + Unpin,
-    ) -> Result<usize, ParserError> {
+    fn parse(&mut self, buffer: &[u8], _response: &mut Vec<u8>) -> usize {
         let mut last_char_after_newline = 0;
         for newline in memchr::memchr_iter(b'\n', buffer) {
             // TODO Use get_unchecked everywhere
@@ -68,7 +63,7 @@ impl Parser for MemchrParser {
             }
         }
 
-        Ok(last_char_after_newline.saturating_sub(1))
+        last_char_after_newline.saturating_sub(1)
     }
 
     fn parser_lookahead(&self) -> usize {

breakwater-parser/src/original.rs

@@ -4,9 +4,8 @@ use std::{
 };
 
 use breakwater_core::{framebuffer::FrameBuffer, ALT_HELP_TEXT, HELP_TEXT};
-use tokio::io::AsyncWriteExt;
 
-use crate::{Parser, ParserError};
+use crate::Parser;
 
 pub const PARSER_LOOKAHEAD: usize = "PX 1234 1234 rrggbbaa\n".len(); // Longest possible command
 
@@ -32,11 +31,7 @@ impl OriginalParser {
 }
 
 impl Parser for OriginalParser {
-    async fn parse(
-        &mut self,
-        buffer: &[u8],
-        mut stream: impl AsyncWriteExt + Send + Unpin,
-    ) -> Result<usize, ParserError> {
+    fn parse(&mut self, buffer: &[u8], response: &mut Vec<u8>) -> usize {
         let mut last_byte_parsed = 0;
         let mut help_count = 0;
 
@@ -131,22 +126,16 @@ impl Parser for OriginalParser {
                         last_byte_parsed = i;
                         i += 1;
                         if let Some(rgb) = self.fb.get(x, y) {
-                            match stream
-                                .write_all(
-                                    format!(
-                                        "PX {} {} {:06x}\n",
-                                        // We don't want to return the actual (absolute) coordinates, the client should also get the result offseted
-                                        x - self.connection_x_offset,
-                                        y - self.connection_y_offset,
-                                        rgb.to_be() >> 8
-                                    )
-                                    .as_bytes(),
+                            response.extend_from_slice(
+                                format!(
+                                    "PX {} {} {:06x}\n",
+                                    // We don't want to return the actual (absolute) coordinates, the client should also get the result offseted
+                                    x - self.connection_x_offset,
+                                    y - self.connection_y_offset,
+                                    rgb.to_be() >> 8
                                 )
-                                .await
-                            {
-                                Ok(_) => (),
-                                Err(_) => continue,
-                            }
+                                .as_bytes(),
+                            );
                         }
                         continue;
                     }
@@ -167,39 +156,34 @@ impl Parser for OriginalParser {
                 i += 4;
                 last_byte_parsed = i - 1;
 
-                stream
-                    .write_all(
-                        format!("SIZE {} {}\n", self.fb.get_width(), self.fb.get_height())
-                            .as_bytes(),
-                    )
-                    .await
-                    .expect("Failed to write bytes to tcp socket");
+                response.extend_from_slice(
+                    format!("SIZE {} {}\n", self.fb.get_width(), self.fb.get_height()).as_bytes(),
+                );
                 continue;
             } else if current_command & 0xffff_ffff == HELP_PATTERN {
                 i += 4;
                 last_byte_parsed = i - 1;
 
-                #[allow(clippy::comparison_chain)]
-                if help_count < 3 {
-                    stream
-                        .write_all(HELP_TEXT)
-                        .await
-                        .expect("Failed to write bytes to tcp socket");
-                    help_count += 1;
-                } else if help_count == 3 {
-                    stream
-                        .write_all(ALT_HELP_TEXT)
-                        .await
-                        .expect("Failed to write bytes to tcp socket");
-                    help_count += 1;
+                match help_count {
+                    0..=2 => {
+                        response.extend_from_slice(HELP_TEXT);
+                        help_count += 1;
+                    }
+                    3 => {
+                        response.extend_from_slice(ALT_HELP_TEXT);
+                        help_count += 1;
+                    }
+                    _ => {
+                        // The client has requested the help to often, let's just ignore it
+                    }
                 }
                 continue;
             }
 
             i += 1;
         }
 
-        Ok(last_byte_parsed.wrapping_sub(1))
+        last_byte_parsed.wrapping_sub(1)
     }
 
     fn parser_lookahead(&self) -> usize {