RequestServer+LibHTTP+LibGemini: Cache connections to the same host

This makes connections (particularly TLS-based ones) do the handshaking
stuff only once.
Currently the cache is configured to keep at most two connections evenly
balanced in queue size, and with a grace period of 10s after the last
queued job has finished (after which the connection will be dropped).

3 files changed, 22 insertions, 15 deletions

diff --git a/Userland/Libraries/LibGemini/GeminiJob.cpp b/Userland/Libraries/LibGemini/GeminiJob.cpp
index 6ab80ae571..340d470644 100644
--- a/Userland/Libraries/LibGemini/GeminiJob.cpp
+++ b/Userland/Libraries/LibGemini/GeminiJob.cpp
@@ -14,15 +14,11 @@
 
 namespace Gemini {
 
-void GeminiJob::start()
+void GeminiJob::start(NonnullRefPtr<Core::Socket> socket)
 {
     VERIFY(!m_socket);
-    m_socket = TLS::TLSv12::construct(this);
-    m_socket->set_root_certificates(m_override_ca_certificates ? *m_override_ca_certificates : DefaultRootCACertificates::the().certificates());
-    m_socket->on_tls_connected = [this] {
-        dbgln_if(GEMINIJOB_DEBUG, "GeminiJob: on_connected callback");
-        on_socket_connected();
-    };
+    VERIFY(is<TLS::TLSv12>(*socket));
+    m_socket = static_ptr_cast<TLS::TLSv12>(socket);
     m_socket->on_tls_error = [this](TLS::AlertDescription error) {
         if (error == TLS::AlertDescription::HandshakeFailure) {
             deferred_invoke([this] {
@@ -45,11 +41,20 @@ void GeminiJob::start()
         if (on_certificate_requested)
             on_certificate_requested(*this);
     };
-    bool success = ((TLS::TLSv12&)*m_socket).connect(m_request.url().host(), m_request.url().port_or_default());
-    if (!success) {
-        deferred_invoke([this] {
-            return did_fail(Core::NetworkJob::Error::ConnectionFailed);
-        });
+
+    if (m_socket->is_established()) {
+        deferred_invoke([this] { on_socket_connected(); });
+    } else {
+        m_socket->set_root_certificates(m_override_ca_certificates ? *m_override_ca_certificates : DefaultRootCACertificates::the().certificates());
+        m_socket->on_tls_connected = [this] {
+            on_socket_connected();
+        };
+        bool success = ((TLS::TLSv12&)*m_socket).connect(m_request.url().host(), m_request.url().port_or_default());
+        if (!success) {
+            deferred_invoke([this] {
+                return did_fail(Core::NetworkJob::Error::ConnectionFailed);
+            });
+        }
     }
 }
 
@@ -59,7 +64,6 @@ void GeminiJob::shutdown()
         return;
     m_socket->on_tls_ready_to_read = nullptr;
     m_socket->on_tls_connected = nullptr;
-    remove_child(*m_socket);
     m_socket = nullptr;
 }
 
diff --git a/Userland/Libraries/LibGemini/GeminiJob.h b/Userland/Libraries/LibGemini/GeminiJob.h
index 2407d2cca5..20cc8afcf9 100644
--- a/Userland/Libraries/LibGemini/GeminiJob.h
+++ b/Userland/Libraries/LibGemini/GeminiJob.h
@@ -27,10 +27,13 @@ public:
     {
     }
 
-    virtual void start() override;
+    virtual void start(NonnullRefPtr<Core::Socket>) override;
     virtual void shutdown() override;
     void set_certificate(String certificate, String key);
 
+    Core::Socket const* socket() const { return m_socket; }
+    URL url() const { return m_request.url(); }
+
     Function<void(GeminiJob&)> on_certificate_requested;
 
 protected:
diff --git a/Userland/Libraries/LibGemini/Job.h b/Userland/Libraries/LibGemini/Job.h
index 01eac13e11..5bc50216f7 100644
--- a/Userland/Libraries/LibGemini/Job.h
+++ b/Userland/Libraries/LibGemini/Job.h
@@ -19,7 +19,7 @@ public:
     explicit Job(const GeminiRequest&, OutputStream&);
     virtual ~Job() override;
 
-    virtual void start() override = 0;
+    virtual void start(NonnullRefPtr<Core::Socket>) override = 0;
     virtual void shutdown() override = 0;
 
     GeminiResponse* response() { return static_cast<GeminiResponse*>(Core::NetworkJob::response()); }