Initial http implementation

CMakeLists.txt

@@ -128,13 +128,14 @@ set(SOURCES
     src/connection.cpp
     src/server.cpp
     src/json_commit_request_parser.cpp
+    src/http_handler.cpp
     src/arena_allocator.cpp
     ${CMAKE_BINARY_DIR}/json_tokens.cpp)
 
 add_executable(weaseldb ${SOURCES})
 add_dependencies(weaseldb generate_json_tokens)
 target_link_libraries(weaseldb Threads::Threads toml11::toml11 weaseljson
-                      simdutf::simdutf)
+                      simdutf::simdutf llhttp_static)
 
 enable_testing()
 
@@ -158,6 +159,15 @@ target_link_libraries(test_commit_request doctest::doctest weaseljson test_data
                       nlohmann_json::nlohmann_json simdutf::simdutf)
 target_include_directories(test_commit_request PRIVATE src tests)
 
+add_executable(
+  test_http_handler tests/test_http_handler.cpp src/http_handler.cpp
+                    src/arena_allocator.cpp src/connection.cpp)
+target_link_libraries(test_http_handler doctest::doctest llhttp_static
+                      Threads::Threads)
+target_include_directories(test_http_handler PRIVATE src)
+target_compile_definitions(test_http_handler
+                           PRIVATE DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN)
+
 add_executable(bench_arena_allocator benchmarks/bench_arena_allocator.cpp
                                      src/arena_allocator.cpp)
 target_link_libraries(bench_arena_allocator nanobench)
@@ -192,6 +202,7 @@ target_include_directories(debug_arena PRIVATE src)
 
 add_test(NAME arena_allocator_tests COMMAND test_arena_allocator)
 add_test(NAME commit_request_tests COMMAND test_commit_request)
+add_test(NAME http_handler_tests COMMAND test_http_handler)
 add_test(NAME arena_allocator_benchmarks COMMAND bench_arena_allocator)
 add_test(NAME commit_request_benchmarks COMMAND bench_commit_request)
 add_test(NAME parser_comparison_benchmarks COMMAND bench_parser_comparison)

src/http_handler.cpp

@@ -0,0 +1,309 @@
+#include "http_handler.hpp"
+#include "arena_allocator.hpp"
+#include <cstring>
+#include <string>
+
+// HttpConnectionState implementation
+HttpConnectionState::HttpConnectionState(
+    [[maybe_unused]] ArenaAllocator &arena) {
+  llhttp_settings_init(&settings);
+
+  // Set up llhttp callbacks
+  settings.on_url = HttpHandler::onUrl;
+  settings.on_header_field = HttpHandler::onHeaderField;
+  settings.on_header_value = HttpHandler::onHeaderValue;
+  settings.on_headers_complete = HttpHandler::onHeadersComplete;
+  settings.on_body = HttpHandler::onBody;
+  settings.on_message_complete = HttpHandler::onMessageComplete;
+
+  llhttp_init(&parser, HTTP_REQUEST, &settings);
+  parser.data = this;
+}
+
+// HttpHandler implementation
+void HttpHandler::on_connection_established(Connection &conn) {
+  // Allocate HTTP state in connection's arena
+  ArenaAllocator &arena = conn.getArena();
+  auto *state = arena.construct<HttpConnectionState>(arena);
+  conn.user_data = state;
+}
+
+void HttpHandler::on_connection_closed(Connection &conn) {
+  // Arena cleanup happens automatically when connection is destroyed
+  conn.user_data = nullptr;
+}
+
+void HttpHandler::on_write_progress(std::unique_ptr<Connection> &conn_ptr) {
+  // Reset arena after all messages have been written for the next request
+  if (conn_ptr->outgoingBytesQueued() == 0) {
+    conn_ptr->reset();
+    on_connection_established(*conn_ptr);
+  }
+}
+
+void HttpHandler::on_data_arrived(std::string_view data,
+                                  std::unique_ptr<Connection> &conn_ptr) {
+  auto *state = static_cast<HttpConnectionState *>(conn_ptr->user_data);
+  if (!state) {
+    sendErrorResponse(*conn_ptr, 500, "Internal server error");
+    return;
+  }
+
+  // Parse HTTP data with llhttp
+  enum llhttp_errno err =
+      llhttp_execute(&state->parser, data.data(), data.size());
+
+  if (err != HPE_OK) {
+    sendErrorResponse(*conn_ptr, 400, "Bad request");
+    return;
+  }
+
+  // If message is complete, route and handle the request
+  if (state->message_complete) {
+    // Parse route from method and URL
+    state->route = parseRoute(state->method, state->url);
+
+    // Route to appropriate handler
+    switch (state->route) {
+    case HttpRoute::GET_version:
+      handleGetVersion(*conn_ptr, *state);
+      break;
+    case HttpRoute::POST_commit:
+      handlePostCommit(*conn_ptr, *state);
+      break;
+    case HttpRoute::GET_subscribe:
+      handleGetSubscribe(*conn_ptr, *state);
+      break;
+    case HttpRoute::GET_status:
+      handleGetStatus(*conn_ptr, *state);
+      break;
+    case HttpRoute::PUT_retention:
+      handlePutRetention(*conn_ptr, *state);
+      break;
+    case HttpRoute::GET_retention:
+      handleGetRetention(*conn_ptr, *state);
+      break;
+    case HttpRoute::DELETE_retention:
+      handleDeleteRetention(*conn_ptr, *state);
+      break;
+    case HttpRoute::GET_metrics:
+      handleGetMetrics(*conn_ptr, *state);
+      break;
+    case HttpRoute::NotFound:
+    default:
+      handleNotFound(*conn_ptr, *state);
+      break;
+    }
+
+    // Connection state will be reset when appropriate by the server
+    // For now, we don't reset immediately since messages may still be queued
+  }
+}
+
+HttpRoute HttpHandler::parseRoute(std::string_view method,
+                                  std::string_view url) {
+  // Strip query parameters if present
+  size_t query_pos = url.find('?');
+  if (query_pos != std::string_view::npos) {
+    url = url.substr(0, query_pos);
+  }
+
+  // Route based on method and path
+  if (method == "GET") {
+    if (url == "/v1/version")
+      return HttpRoute::GET_version;
+    if (url == "/v1/subscribe")
+      return HttpRoute::GET_subscribe;
+    if (url.starts_with("/v1/status"))
+      return HttpRoute::GET_status;
+    if (url.starts_with("/v1/retention")) {
+      // Check if it's a specific retention policy or list all
+      return HttpRoute::GET_retention;
+    }
+    if (url == "/metrics")
+      return HttpRoute::GET_metrics;
+  } else if (method == "POST") {
+    if (url == "/v1/commit")
+      return HttpRoute::POST_commit;
+  } else if (method == "PUT") {
+    if (url.starts_with("/v1/retention/"))
+      return HttpRoute::PUT_retention;
+  } else if (method == "DELETE") {
+    if (url.starts_with("/v1/retention/"))
+      return HttpRoute::DELETE_retention;
+  }
+
+  return HttpRoute::NotFound;
+}
+
+// Route handlers (basic implementations)
+void HttpHandler::handleGetVersion(
+    Connection &conn, [[maybe_unused]] const HttpConnectionState &state) {
+  sendJsonResponse(
+      conn, 200,
+      R"({"version":"0.0.1","leader":"node-1","committed_version":42})");
+}
+
+void HttpHandler::handlePostCommit(
+    Connection &conn, [[maybe_unused]] const HttpConnectionState &state) {
+  // TODO: Parse commit request from state.body and process
+  sendJsonResponse(
+      conn, 200,
+      R"({"request_id":"example","status":"committed","version":43})");
+}
+
+void HttpHandler::handleGetSubscribe(
+    Connection &conn, [[maybe_unused]] const HttpConnectionState &state) {
+  // TODO: Implement subscription streaming
+  sendJsonResponse(
+      conn, 200,
+      R"({"message":"Subscription endpoint - streaming not yet implemented"})");
+}
+
+void HttpHandler::handleGetStatus(
+    Connection &conn, [[maybe_unused]] const HttpConnectionState &state) {
+  // TODO: Extract request_id from URL and check status
+  sendJsonResponse(
+      conn, 200,
+      R"({"request_id":"example","status":"committed","version":43})");
+}
+
+void HttpHandler::handlePutRetention(
+    Connection &conn, [[maybe_unused]] const HttpConnectionState &state) {
+  // TODO: Parse retention policy from body and store
+  sendJsonResponse(conn, 200, R"({"policy_id":"example","status":"created"})");
+}
+
+void HttpHandler::handleGetRetention(
+    Connection &conn, [[maybe_unused]] const HttpConnectionState &state) {
+  // TODO: Extract policy_id from URL or return all policies
+  sendJsonResponse(conn, 200, R"({"policies":[]})");
+}
+
+void HttpHandler::handleDeleteRetention(
+    Connection &conn, [[maybe_unused]] const HttpConnectionState &state) {
+  // TODO: Extract policy_id from URL and delete
+  sendJsonResponse(conn, 200, R"({"policy_id":"example","status":"deleted"})");
+}
+
+void HttpHandler::handleGetMetrics(
+    Connection &conn, [[maybe_unused]] const HttpConnectionState &state) {
+  // TODO: Implement metrics collection and formatting
+  sendResponse(conn, 200, "text/plain",
+               "# WeaselDB metrics\nweaseldb_requests_total 0\n");
+}
+
+void HttpHandler::handleNotFound(
+    Connection &conn, [[maybe_unused]] const HttpConnectionState &state) {
+  sendErrorResponse(conn, 404, "Not found");
+}
+
+// HTTP utility methods
+void HttpHandler::sendResponse(Connection &conn, int status_code,
+                               std::string_view content_type,
+                               std::string_view body) {
+  [[maybe_unused]] ArenaAllocator &arena = conn.getArena();
+
+  // Build HTTP response using arena
+  std::string response;
+  response.reserve(256 + body.size());
+
+  response += "HTTP/1.1 ";
+  response += std::to_string(status_code);
+  response += " ";
+
+  // Status text
+  switch (status_code) {
+  case 200:
+    response += "OK";
+    break;
+  case 400:
+    response += "Bad Request";
+    break;
+  case 404:
+    response += "Not Found";
+    break;
+  case 500:
+    response += "Internal Server Error";
+    break;
+  default:
+    response += "Unknown";
+    break;
+  }
+
+  response += "\r\n";
+  response += "Content-Type: ";
+  response += content_type;
+  response += "\r\n";
+  response += "Content-Length: ";
+  response += std::to_string(body.size());
+  response += "\r\n";
+  response += "Connection: keep-alive\r\n";
+  response += "\r\n";
+  response += body;
+
+  conn.appendMessage(response);
+}
+
+void HttpHandler::sendJsonResponse(Connection &conn, int status_code,
+                                   std::string_view json) {
+  sendResponse(conn, status_code, "application/json", json);
+}
+
+void HttpHandler::sendErrorResponse(Connection &conn, int status_code,
+                                    std::string_view message) {
+  [[maybe_unused]] ArenaAllocator &arena = conn.getArena();
+
+  std::string json = R"({"error":")";
+  json += message;
+  json += R"("})";
+
+  sendJsonResponse(conn, status_code, json);
+}
+
+// llhttp callbacks
+int HttpHandler::onUrl(llhttp_t *parser, const char *at, size_t length) {
+  auto *state = static_cast<HttpConnectionState *>(parser->data);
+  // Store URL in arena (simplified - would need to accumulate for streaming)
+  state->url = std::string_view(at, length);
+  return 0;
+}
+
+int HttpHandler::onHeaderField([[maybe_unused]] llhttp_t *parser,
+                               [[maybe_unused]] const char *at,
+                               [[maybe_unused]] size_t length) {
+  // TODO: Store headers if needed
+  return 0;
+}
+
+int HttpHandler::onHeaderValue([[maybe_unused]] llhttp_t *parser,
+                               [[maybe_unused]] const char *at,
+                               [[maybe_unused]] size_t length) {
+  // TODO: Store header values if needed
+  return 0;
+}
+
+int HttpHandler::onHeadersComplete(llhttp_t *parser) {
+  auto *state = static_cast<HttpConnectionState *>(parser->data);
+  state->headers_complete = true;
+
+  // Get HTTP method
+  const char *method_str =
+      llhttp_method_name(static_cast<llhttp_method_t>(parser->method));
+  state->method = std::string_view(method_str);
+
+  return 0;
+}
+
+int HttpHandler::onBody(llhttp_t *parser, const char *at, size_t length) {
+  auto *state = static_cast<HttpConnectionState *>(parser->data);
+  // Store body (simplified - would need to accumulate for streaming)
+  state->body = std::string_view(at, length);
+  return 0;
+}
+
+int HttpHandler::onMessageComplete(llhttp_t *parser) {
+  auto *state = static_cast<HttpConnectionState *>(parser->data);
+  state->message_complete = true;
+  return 0;
+}

src/http_handler.hpp

@@ -0,0 +1,92 @@
+#pragma once
+
+#include "connection.hpp"
+#include "connection_handler.hpp"
+#include <llhttp.h>
+#include <memory>
+#include <string_view>
+
+/**
+ * HTTP routes supported by WeaselDB server.
+ * Using enum for efficient switch-based routing.
+ */
+enum class HttpRoute {
+  GET_version,
+  POST_commit,
+  GET_subscribe,
+  GET_status,
+  PUT_retention,
+  GET_retention,
+  DELETE_retention,
+  GET_metrics,
+  NotFound
+};
+
+/**
+ * HTTP connection state stored in Connection::user_data.
+ * Manages llhttp parser state and request data.
+ */
+struct HttpConnectionState {
+  llhttp_t parser;
+  llhttp_settings_t settings;
+
+  // Current request data (arena-allocated)
+  std::string_view method;
+  std::string_view url;
+  std::string_view body;
+
+  // Parse state
+  bool headers_complete = false;
+  bool message_complete = false;
+  HttpRoute route = HttpRoute::NotFound;
+
+  explicit HttpConnectionState(ArenaAllocator &arena);
+};
+
+/**
+ * HTTP/1.1 server implementation using llhttp for parsing.
+ * Supports the WeaselDB REST API endpoints with enum-based routing.
+ */
+class HttpHandler : public ConnectionHandler {
+public:
+  HttpHandler() = default;
+
+  void on_connection_established(Connection &conn) override;
+  void on_connection_closed(Connection &conn) override;
+  void on_data_arrived(std::string_view data,
+                       std::unique_ptr<Connection> &conn_ptr) override;
+  void on_write_progress(std::unique_ptr<Connection> &conn_ptr) override;
+
+  // Route parsing (public for testing)
+  static HttpRoute parseRoute(std::string_view method, std::string_view url);
+
+  // llhttp callbacks (public for HttpConnectionState access)
+  static int onUrl(llhttp_t *parser, const char *at, size_t length);
+  static int onHeaderField(llhttp_t *parser, const char *at, size_t length);
+  static int onHeaderValue(llhttp_t *parser, const char *at, size_t length);
+  static int onHeadersComplete(llhttp_t *parser);
+  static int onBody(llhttp_t *parser, const char *at, size_t length);
+  static int onMessageComplete(llhttp_t *parser);
+
+private:
+  // Route handlers
+  void handleGetVersion(Connection &conn, const HttpConnectionState &state);
+  void handlePostCommit(Connection &conn, const HttpConnectionState &state);
+  void handleGetSubscribe(Connection &conn, const HttpConnectionState &state);
+  void handleGetStatus(Connection &conn, const HttpConnectionState &state);
+  void handlePutRetention(Connection &conn, const HttpConnectionState &state);
+  void handleGetRetention(Connection &conn, const HttpConnectionState &state);
+  void handleDeleteRetention(Connection &conn,
+                             const HttpConnectionState &state);
+  void handleGetMetrics(Connection &conn, const HttpConnectionState &state);
+  void handleNotFound(Connection &conn, const HttpConnectionState &state);
+
+  // HTTP utilities
+  static void sendResponse(Connection &conn, int status_code,
+                           std::string_view content_type,
+                           std::string_view body);
+  static void sendJsonResponse(Connection &conn, int status_code,
+                               std::string_view json);
+  static void sendErrorResponse(Connection &conn, int status_code,
+                                std::string_view message);
+};

src/main.cpp

@@ -1,6 +1,7 @@
 #include "config.hpp"
 #include "connection.hpp"
 #include "connection_handler.hpp"
+#include "http_handler.hpp"
 #include "server.hpp"
 #include <atomic>
 #include <csignal>
@@ -21,21 +22,6 @@ void signal_handler(int sig) {
   }
 }
 
-/**
- * Simple echo handler that mirrors received data back to the client.
- *
- * This implementation preserves the current behavior of the server
- * while demonstrating the ConnectionHandler interface pattern.
- */
-class EchoHandler : public ConnectionHandler {
-public:
-  void on_data_arrived(std::string_view data,
-                       std::unique_ptr<Connection> &conn_ptr) override {
-    // Echo the received data back to the client
-    conn_ptr->appendMessage(data);
-  }
-};
-
 void print_help(const char *program_name) {
   std::cout << "WeaselDB - High-performance write-side database component\n\n";
   std::cout << "Usage: " << program_name << " [OPTIONS]\n\n";
@@ -121,8 +107,8 @@ int main(int argc, char *argv[]) {
             << std::endl;
 
   // Create handler and server
-  EchoHandler echo_handler;
+  HttpHandler http_handler;
-  auto server = Server::create(*config, echo_handler);
+  auto server = Server::create(*config, http_handler);
   g_server = server.get();
 
   // Setup signal handling
@@ -130,7 +116,7 @@ int main(int argc, char *argv[]) {
   signal(SIGTERM, signal_handler);
   signal(SIGINT, signal_handler);
 
-  std::cout << "Starting WeaselDB server..." << std::endl;
+  std::cout << "Starting WeaselDB HTTP server..." << std::endl;
   server->run();
   std::cout << "Server shutdown complete." << std::endl;
 

tests/test_http_handler.cpp

@@ -0,0 +1,85 @@
+#include "arena_allocator.hpp"
+#include "http_handler.hpp"
+#include <atomic>
+#include <doctest/doctest.h>
+
+// Global variable needed by Connection
+std::atomic<int> activeConnections{0};
+
+// Simple test helper since Connection has complex constructor requirements
+struct TestConnectionData {
+  ArenaAllocator arena;
+  std::string message_buffer;
+  void *user_data = nullptr;
+
+  void appendMessage(std::string_view data) { message_buffer += data; }
+
+  ArenaAllocator &getArena() { return arena; }
+  const std::string &getResponse() const { return message_buffer; }
+  void clearResponse() { message_buffer.clear(); }
+  void reset() {
+    arena.reset();
+    message_buffer.clear();
+  }
+};
+
+TEST_CASE("HttpHandler route parsing") {
+  SUBCASE("GET routes") {
+    CHECK(HttpHandler::parseRoute("GET", "/v1/version") ==
+          HttpRoute::GET_version);
+    CHECK(HttpHandler::parseRoute("GET", "/v1/subscribe") ==
+          HttpRoute::GET_subscribe);
+    CHECK(HttpHandler::parseRoute("GET", "/v1/status") ==
+          HttpRoute::GET_status);
+    CHECK(HttpHandler::parseRoute("GET", "/v1/retention") ==
+          HttpRoute::GET_retention);
+    CHECK(HttpHandler::parseRoute("GET", "/metrics") == HttpRoute::GET_metrics);
+  }
+
+  SUBCASE("POST routes") {
+    CHECK(HttpHandler::parseRoute("POST", "/v1/commit") ==
+          HttpRoute::POST_commit);
+  }
+
+  SUBCASE("PUT routes") {
+    CHECK(HttpHandler::parseRoute("PUT", "/v1/retention/policy1") ==
+          HttpRoute::PUT_retention);
+  }
+
+  SUBCASE("DELETE routes") {
+    CHECK(HttpHandler::parseRoute("DELETE", "/v1/retention/policy1") ==
+          HttpRoute::DELETE_retention);
+  }
+
+  SUBCASE("Unknown routes") {
+    CHECK(HttpHandler::parseRoute("GET", "/unknown") == HttpRoute::NotFound);
+    CHECK(HttpHandler::parseRoute("PATCH", "/v1/version") ==
+          HttpRoute::NotFound);
+  }
+
+  SUBCASE("Query parameters stripped") {
+    CHECK(HttpHandler::parseRoute("GET", "/v1/version?foo=bar") ==
+          HttpRoute::GET_version);
+  }
+}
+
+TEST_CASE("HttpHandler route parsing functionality") {
+  // Test just the static route parsing method since full integration testing
+  // would require complex Connection setup with server dependencies
+
+  SUBCASE("Route parsing with query parameters") {
+    CHECK(HttpHandler::parseRoute("GET", "/v1/version?param=value") ==
+          HttpRoute::GET_version);
+    CHECK(HttpHandler::parseRoute("GET", "/v1/subscribe?stream=true") ==
+          HttpRoute::GET_subscribe);
+  }
+
+  SUBCASE("Retention policy routes") {
+    CHECK(HttpHandler::parseRoute("PUT", "/v1/retention/policy123") ==
+          HttpRoute::PUT_retention);
+    CHECK(HttpHandler::parseRoute("DELETE", "/v1/retention/policy456") ==
+          HttpRoute::DELETE_retention);
+    CHECK(HttpHandler::parseRoute("GET", "/v1/retention/policy789") ==
+          HttpRoute::GET_retention);
+  }
+}