From: Martin Pitt <martin@piware.de>
Date: Sun, 19 Sep 2021 08:38:31 +0000 (+0200)
Subject: simple-http: Add scaffolding for thread pool implementation
X-Git-Url: https://piware.de/gitweb/?p=learn-rust.git;a=commitdiff_plain;h=4d4ba2d5f703969851742798e79e16333fb9ca9a

simple-http: Add scaffolding for thread pool implementation

Turn into library crate. Add ThreadPool stub to src/lib.
---

diff --git a/simple-http/src/bin/main.rs b/simple-http/src/bin/main.rs
new file mode 100644
index 0000000..ff3af27
--- /dev/null
+++ b/simple-http/src/bin/main.rs
@@ -0,0 +1,72 @@
+use std::io::prelude::*;
+
+use std::net::TcpListener;
+use std::net::TcpStream;
+use std::time::Duration;
+use std::{fs, str, thread};
+
+use simple_http::ThreadPool;
+
+fn handle_connection(mut stream: TcpStream) {
+     let mut buffer = [0; 1024];
+
+    stream.read(&mut buffer).unwrap();
+
+    let buffer = match str::from_utf8(&buffer[..]) {
+        Ok(s) => s,
+        Err(e) => {
+            eprintln!("Invalid non-UTF8 request: {}\n{}", e, String::from_utf8_lossy(&buffer[..]));
+            return;
+        }
+    };
+    println!("Request: {}", buffer);
+
+    let path;
+
+    // simple web server, just interested in first line
+    if let Some(line) = buffer.lines().next() {
+        let request: Vec<_> = line.split_whitespace().collect();
+        if request.len() != 3 || request[0] != "GET" || request[2] != "HTTP/1.1" {
+            stream.write(b"HTTP/1.1 501 NOT IMPLEMENTED\r\n").unwrap();
+            stream.flush().unwrap();
+            return;
+        }
+
+        path = request[1];
+    } else {
+        eprintln!("Ignoring empty request: {}", buffer);
+        return;
+    }
+
+    let (code, file) = if path == "/" || path == "/index.html" {
+        ("200 OK", "index.html")
+    } else if path == "/slow" {
+        thread::sleep(Duration::from_secs(5));
+        ("200 OK", "index.html")
+    } else {
+        ("404 NOT FOUND", "404.html")
+    };
+
+    let text = fs::read_to_string(file).unwrap();
+
+    let response = format!(
+        "HTTP/1.1 {}\r\n\
+         Content-Type: text/html\r\n\
+         Content-Length: {}\r\n\r\n{}",
+        code,
+        text.len(),
+        text);
+
+    stream.write(response.as_bytes()).unwrap();
+    stream.flush().unwrap();
+}
+
+fn main() {
+    let listener = TcpListener::bind("127.0.0.1:7878").unwrap();
+    let pool = ThreadPool::new(4);
+
+    for stream in listener.incoming() {
+        let stream = stream.unwrap();
+        pool.execute(|| handle_connection(stream));
+    }
+}
diff --git a/simple-http/src/lib.rs b/simple-http/src/lib.rs
new file mode 100644
index 0000000..ff8bc4f
--- /dev/null
+++ b/simple-http/src/lib.rs
@@ -0,0 +1,40 @@
+use std::thread;
+
+struct Worker {
+    id: usize,
+    thread: thread::JoinHandle<()>,
+}
+
+impl Worker {
+    fn new(id: usize) -> Worker {
+        Worker { id, thread: thread::spawn(|| {}) }
+    }
+}
+
+pub struct ThreadPool {
+    workers: Vec<Worker>,
+}
+
+impl ThreadPool {
+    /// Create a new thread pool.
+    ///
+    /// # Panics
+    ///
+    /// - if size is zero
+    pub fn new(size: usize) -> ThreadPool {
+        assert!(size > 0);
+        let mut workers = Vec::with_capacity(size);
+
+        for id in 0..size {
+            workers.push(Worker::new(id));
+        }
+
+        ThreadPool { workers }
+    }
+
+    pub fn execute<F>(&self, f: F)
+    where F: FnOnce() + Send + 'static
+    {
+        thread::spawn(f);
+    }
+}
diff --git a/simple-http/src/main.rs b/simple-http/src/main.rs
deleted file mode 100644
index 0993075..0000000
--- a/simple-http/src/main.rs
+++ /dev/null
@@ -1,69 +0,0 @@
-use std::io::prelude::*;
-
-use std::net::TcpListener;
-use std::net::TcpStream;
-use std::time::Duration;
-use std::{fs, str, thread};
-
-fn handle_connection(mut stream: TcpStream) {
-     let mut buffer = [0; 1024];
-
-    stream.read(&mut buffer).unwrap();
-
-    let buffer = match str::from_utf8(&buffer[..]) {
-        Ok(s) => s,
-        Err(e) => {
-            eprintln!("Invalid non-UTF8 request: {}\n{}", e, String::from_utf8_lossy(&buffer[..]));
-            return;
-        }
-    };
-    println!("Request: {}", buffer);
-
-    let path;
-
-    // simple web server, just interested in first line
-    if let Some(line) = buffer.lines().next() {
-        let request: Vec<_> = line.split_whitespace().collect();
-        if request.len() != 3 || request[0] != "GET" || request[2] != "HTTP/1.1" {
-            stream.write(b"HTTP/1.1 501 NOT IMPLEMENTED\r\n").unwrap();
-            stream.flush().unwrap();
-            return;
-        }
-
-        path = request[1];
-    } else {
-        eprintln!("Ignoring empty request: {}", buffer);
-        return;
-    }
-
-    let (code, file) = if path == "/" || path == "/index.html" {
-        ("200 OK", "index.html")
-    } else if path == "/slow" {
-        thread::sleep(Duration::from_secs(5));
-        ("200 OK", "index.html")
-    } else {
-        ("404 NOT FOUND", "404.html")
-    };
-
-    let text = fs::read_to_string(file).unwrap();
-
-    let response = format!(
-        "HTTP/1.1 {}\r\n\
-         Content-Type: text/html\r\n\
-         Content-Length: {}\r\n\r\n{}",
-        code,
-        text.len(),
-        text);
-
-    stream.write(response.as_bytes()).unwrap();
-    stream.flush().unwrap();
-}
-
-fn main() {
-    let listener = TcpListener::bind("127.0.0.1:7878").unwrap();
-
-    for stream in listener.incoming() {
-        let stream = stream.unwrap();
-        thread::spawn(|| handle_connection(stream));
-    }
-}