LibWebSocket: Add a new websocket library

This library currently contains a basic WebSocket client that can
handle both standard TCP websockets and TLS websockets.

Userland/Libraries/LibWebSocket/Impl/TCPWebSocketConnectionImpl.cpp

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2021, The SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <LibWebSocket/Impl/TCPWebSocketConnectionImpl.h>
+
+namespace WebSocket {
+
+TCPWebSocketConnectionImpl::TCPWebSocketConnectionImpl(Core::Object* parent)
+    : AbstractWebSocketImpl(parent)
+{
+}
+
+TCPWebSocketConnectionImpl::~TCPWebSocketConnectionImpl()
+{
+    discard_connection();
+}
+
+void TCPWebSocketConnectionImpl::connect(ConnectionInfo const& connection)
+{
+    VERIFY(!m_socket);
+    VERIFY(on_connected);
+    VERIFY(on_connection_error);
+    VERIFY(on_ready_to_read);
+    m_socket = Core::TCPSocket::construct(this);
+
+    m_notifier = Core::Notifier::construct(m_socket->fd(), Core::Notifier::Read);
+    m_notifier->on_ready_to_read = [this] {
+        on_ready_to_read();
+    };
+
+    m_socket->on_connected = [this] {
+        on_connected();
+    };
+    bool success = m_socket->connect(connection.url().host(), connection.url().port());
+    if (!success) {
+        deferred_invoke([this](auto&) {
+            on_connection_error();
+        });
+    }
+}
+
+bool TCPWebSocketConnectionImpl::send(ReadonlyBytes data)
+{
+    return m_socket->write(data);
+}
+
+bool TCPWebSocketConnectionImpl::can_read_line()
+{
+    return m_socket->can_read_line();
+}
+
+String TCPWebSocketConnectionImpl::read_line(size_t size)
+{
+    return m_socket->read_line(size);
+}
+
+bool TCPWebSocketConnectionImpl::can_read()
+{
+    return m_socket->can_read();
+}
+
+ByteBuffer TCPWebSocketConnectionImpl::read(int max_size)
+{
+    return m_socket->read(max_size);
+}
+
+bool TCPWebSocketConnectionImpl::eof()
+{
+    return m_socket->eof();
+}
+
+void TCPWebSocketConnectionImpl::discard_connection()
+{
+    if (!m_socket)
+        return;
+    m_socket->on_ready_to_read = nullptr;
+    remove_child(*m_socket);
+    m_socket = nullptr;
+}
+
+}