ladybird/Userland/Services/RequestServer/ConnectionCache.cpp

/*
 * Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include "ConnectionCache.h"
#include <AK/Debug.h>
#include <LibCore/EventLoop.h>

namespace RequestServer::ConnectionCache {

HashMap<ConnectionKey, NonnullOwnPtr<NonnullOwnPtrVector<Connection<Core::TCPSocket>>>> g_tcp_connection_cache {};
HashMap<ConnectionKey, NonnullOwnPtr<NonnullOwnPtrVector<Connection<TLS::TLSv12>>>> g_tls_connection_cache {};

void request_did_finish(URL const& url, Core::Socket const* socket)
{
    if (!socket) {
        dbgln("Request with a null socket finished for URL {}", url);
        return;
    }

    dbgln_if(REQUESTSERVER_DEBUG, "Request for {} finished", url);

    ConnectionKey key { url.host(), url.port_or_default() };
    auto fire_off_next_job = [&](auto& cache) {
        auto it = cache.find(key);
        if (it == cache.end()) {
            dbgln("Request for URL {} finished, but we don't own that!", url);
            return;
        }
        auto connection_it = it->value->find_if([&](auto& connection) { return connection->socket == socket; });
        if (connection_it.is_end()) {
            dbgln("Request for URL {} finished, but we don't have a socket for that!", url);
            return;
        }

        auto& connection = *connection_it;
        if (connection->request_queue.is_empty()) {
            connection->has_started = false;
            connection->current_url = {};
            connection->removal_timer->on_timeout = [ptr = connection.ptr(), &cache_entry = *it->value, key = it->key, &cache]() mutable {
                Core::deferred_invoke([&, key = move(key), ptr] {
                    dbgln_if(REQUESTSERVER_DEBUG, "Removing no-longer-used connection {} (socket {})", ptr, ptr->socket);
                    auto did_remove = cache_entry.remove_first_matching([&](auto& entry) { return entry == ptr; });
                    VERIFY(did_remove);
                    if (cache_entry.is_empty())
                        cache.remove(key);
                });
            };
            connection->removal_timer->start();
        } else {
            using SocketType = RemoveCVReference<decltype(*connection->socket)>;
            bool is_connected;
            if constexpr (IsSame<SocketType, TLS::TLSv12>)
                is_connected = connection->socket->is_established();
            else
                is_connected = connection->socket->is_connected();
            if (!is_connected) {
                // Create another socket for the connection.
                connection->socket = SocketType::construct(nullptr);
                dbgln_if(REQUESTSERVER_DEBUG, "Creating a new socket for {} -> {}", url, connection->socket);
            }
            dbgln_if(REQUESTSERVER_DEBUG, "Running next job in queue for connection {} @{}", &connection, connection->socket);
            auto request = connection->request_queue.take_first();
            connection->timer.start();
            connection->current_url = url;
            request(connection->socket);
        }
    };

    if (is<TLS::TLSv12>(socket))
        fire_off_next_job(g_tls_connection_cache);
    else if (is<Core::TCPSocket>(socket))
        fire_off_next_job(g_tcp_connection_cache);
    else
        dbgln("Unknown socket {} finished for URL {}", *socket, url);
}

void dump_jobs()
{
    dbgln("=========== TLS Connection Cache ==========");
    for (auto& connection : g_tls_connection_cache) {
        dbgln(" - {}:{}", connection.key.hostname, connection.key.port);
        for (auto& entry : *connection.value) {
            dbgln("  - Connection {} (started={}) (socket={})", &entry, entry.has_started, entry.socket);
            dbgln("    Currently loading {} ({} elapsed)", entry.current_url, entry.timer.elapsed());
            dbgln("    Request Queue:");
            for (auto& job : entry.request_queue)
                dbgln("    - {}", &job);
        }
    }
    dbgln("=========== TCP Connection Cache ==========");
    for (auto& connection : g_tcp_connection_cache) {
        dbgln(" - {}:{}", connection.key.hostname, connection.key.port);
        for (auto& entry : *connection.value) {
            dbgln("  - Connection {} (started={}) (socket={})", &entry, entry.has_started, entry.socket);
            dbgln("    Currently loading {} ({} elapsed)", entry.current_url, entry.timer.elapsed());
            dbgln("    Request Queue:");
            for (auto& job : entry.request_queue)
                dbgln("    - {}", &job);
        }
    }
}

}