examples: add vanilla_http_server - a fast, multi-threaded, non-blocking, port and host reuse, thread-safe, epoll server (#23094)

Author: enghitalo

cmd/tools/modules/testing/common.v

@@ -242,6 +242,7 @@ pub fn new_test_session(_vargs string, will_compile bool) TestSession {
 			skip_files << 'examples/database/psql/customer.v'
 		}
 		$if windows {
+			skip_files << 'examples/vanilla_http_server' // requires epoll
 			skip_files << 'examples/1brc/solution/main.v' // requires mmap
 			skip_files << 'examples/database/mysql.v'
 			skip_files << 'examples/database/orm.v'

cmd/tools/vbuild-examples.v

@@ -10,6 +10,7 @@ const efolders = [
 	'examples/viewer',
 	'examples/vweb_orm_jwt',
 	'examples/vweb_fullstack',
+	'examples/vanilla_http_server',
 ]
 
 pub fn normalised_vroot_path(path string) string {

examples/vanilla_http_server/.editorconfig

@@ -0,0 +1,8 @@
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.v]
+indent_style = tab

examples/vanilla_http_server/.gitattributes

@@ -0,0 +1,8 @@
+* text=auto eol=lf
+*.bat eol=crlf
+
+*.v linguist-language=V
+*.vv linguist-language=V
+*.vsh linguist-language=V
+v.mod linguist-language=V
+.vdocignore linguist-language=ignore

examples/vanilla_http_server/.gitignore

@@ -0,0 +1,23 @@
+# Binaries for programs and plugins
+main
+*.exe
+*.exe~
+*.so
+*.dylib
+*.dll
+
+# Ignore binary output folders
+bin/
+
+# Ignore common editor/system specific metadata
+.DS_Store
+.idea/
+.vscode/
+*.iml
+
+# ENV
+.env
+
+# vweb and database
+*.db
+*.js

examples/vanilla_http_server/README.md

@@ -0,0 +1,101 @@
+# Vanilla
+
+Vanilla is a raw V server.
+
+## Description
+
+This project is a simple server written in the V programming language.
+It aims to provide a minimalistic and efficient server implementation.
+
+## Features
+
+- Lightweight and fast
+- Minimal dependencies
+- Easy to understand and extend
+
+## Installation
+
+To install Vanilla, you need to have the V compiler installed.
+You can download it from the [official V website](https://vlang.io).
+
+## Usage
+
+To run the server, use the following command:
+
+```sh
+v -prod crun .
+```
+
+This will start the server, and you can access it at `http://localhost:3000`.
+
+## Code Overview
+
+### Main Server
+
+The main server logic is implemented in [src/main.v](v/vanilla/src/main.v).
+The server is initialized and started in the `main` function:
+
+```v ignore
+module main
+
+const port = 3000
+
+fn main() {
+	mut server := Server{
+		router: setup_router()
+	}
+
+	server.socket_fd = create_server_socket(port)
+	if server.socket_fd < 0 {
+		return
+	}
+	server.epoll_fd = C.epoll_create1(0)
+	if server.epoll_fd < 0 {
+		C.perror('epoll_create1 failed'.str)
+		C.close(server.socket_fd)
+		return
+	}
+
+	server.lock_flag.lock()
+	if add_fd_to_epoll(server.epoll_fd, server.socket_fd, u32(C.EPOLLIN)) == -1 {
+		C.close(server.socket_fd)
+		C.close(server.epoll_fd)
+
+		server.lock_flag.unlock()
+		return
+	}
+
+	server.lock_flag.unlock()
+
+	server.lock_flag.init()
+	for i := 0; i < 16; i++ {
+		server.threads[i] = spawn process_events(&server)
+	}
+	println('listening on http://localhost:${port}/')
+	event_loop(&server)
+}
+```
+
+## Test
+
+### CURL
+
+```sh
+curl -X GET --verbose http://localhost:3000/ &&
+curl -X POST --verbose http://localhost:3000/user &&
+curl -X GET --verbose http://localhost:3000/user/1
+
+```
+
+### WRK
+
+```sh
+wrk --connection 512 --threads 16 --duration 10s http://localhost:3000
+```
+
+### Valgrind
+```sh
+# Race condition check
+v -prod -gc none . 
+valgrind --tool=helgrind ./vanilla_http_server
+```

examples/vanilla_http_server/src/controllers.v

@@ -0,0 +1,42 @@
+module main
+
+import strings
+
+const http_ok_response = 'HTTP/1.1 200 OK\r\nContent-Type: application/json\r\nContent-Length: 0\r\nConnection: keep-alive\r\n\r\n'.bytes()
+
+const http_created_response = 'HTTP/1.1 201 Created\r\nContent-Type: application/json\r\nContent-Length: 0\r\nConnection: keep-alive\r\n\r\n'.bytes()
+
+fn home_controller(params []string) ![]u8 {
+	return http_ok_response
+}
+
+fn get_users_controller(params []string) ![]u8 {
+	return http_ok_response
+}
+
+@[direct_array_access; manualfree]
+fn get_user_controller(params []string) ![]u8 {
+	if params.len == 0 {
+		return tiny_bad_request_response
+	}
+	id := params[0]
+	response_body := id
+
+	mut sb := strings.new_builder(200)
+	sb.write_string('HTTP/1.1 200 OK\r\nContent-Type: text/plain\r\nContent-Length: ')
+	sb.write_string(response_body.len.str())
+	sb.write_string('\r\nConnection: keep-alive\r\n\r\n')
+	sb.write_string(response_body)
+
+	defer {
+		unsafe {
+			response_body.free()
+			params.free()
+		}
+	}
+	return sb
+}
+
+fn create_user_controller(params []string) ![]u8 {
+	return http_created_response
+}

examples/vanilla_http_server/src/main.c.v

@@ -0,0 +1,32 @@
+module main
+
+// handle_request finds and executes the handler for a given route.
+// It takes an HttpRequest object as an argument and returns the response as a byte array.
+fn handle_request(req HttpRequest) ![]u8 {
+	method := unsafe { tos(&req.buffer[req.method.start], req.method.len) }
+	path := unsafe { tos(&req.buffer[req.path.start], req.path.len) }
+
+	if method == 'GET' {
+		if path == '/' {
+			return home_controller([])
+		} else if path.starts_with('/user/') {
+			id := path[6..]
+			return get_user_controller([id])
+		}
+	} else if method == 'POST' {
+		if path == '/user' {
+			return create_user_controller([])
+		}
+	}
+
+	return tiny_bad_request_response
+}
+
+fn main() {
+	mut server := Server{
+		request_handler: handle_request
+		port:            3001
+	}
+
+	server.run()
+}

examples/vanilla_http_server/src/request_parser.v

@@ -0,0 +1,71 @@
+module main
+
+struct Slice {
+	start int
+	len   int
+}
+
+struct HttpRequest {
+mut:
+	buffer  []u8
+	method  Slice
+	path    Slice
+	version Slice
+}
+
+@[direct_array_access]
+fn parse_request_line(mut req HttpRequest) ! {
+	mut i := 0
+	// Parse HTTP method
+	for i < req.buffer.len && req.buffer[i] != ` ` {
+		i++
+	}
+	req.method = Slice{
+		start: 0
+		len:   i
+	}
+	i++
+
+	// Parse path
+	mut path_start := i
+	for i < req.buffer.len && req.buffer[i] != ` ` {
+		i++
+	}
+	req.path = Slice{
+		start: path_start
+		len:   i - path_start
+	}
+	i++
+
+	// Parse HTTP version
+	mut version_start := i
+	for i < req.buffer.len && req.buffer[i] != `\r` {
+		i++
+	}
+	req.version = Slice{
+		start: version_start
+		len:   i - version_start
+	}
+
+	// Move to the end of the request line
+	if i + 1 < req.buffer.len && req.buffer[i] == `\r` && req.buffer[i + 1] == `\n` {
+		i += 2
+	} else {
+		return error('Invalid HTTP request line')
+	}
+}
+
+fn decode_http_request(buffer []u8) !HttpRequest {
+	mut req := HttpRequest{
+		buffer: buffer
+	}
+
+	parse_request_line(mut req)!
+
+	return req
+}
+
+// Helper function to convert Slice to string for debugging
+fn slice_to_string(buffer []u8, s Slice) string {
+	return buffer[s.start..s.start + s.len].bytestr()
+}