Merge 'Expose some HTTP functionality useful for websocket code' from Povilas Kanapickas

This PR exposes some HTTP functionality that will useful for websocket code. The PR essentially takes two commits from #2552 so that it's easier to review and land the PR.

Closes #2579

* https://github.com/scylladb/seastar:
  http: Make request writing functions public
  http: Expose connection_factory implementations

Author: xemul

include/seastar/http/client.hh

@@ -25,6 +25,7 @@
 #include <boost/intrusive/list.hpp>
 #endif
 #include <seastar/net/api.hh>
+#include <seastar/http/connection_factory.hh>
 #include <seastar/http/reply.hh>
 #include <seastar/core/condition-variable.hh>
 #include <seastar/core/iostream.hh>
@@ -136,26 +137,6 @@ private:
     void shutdown() noexcept;
 };
 
-/**
- * \brief Factory that provides transport for \ref client
- *
- * This customization point allows callers provide its own transport for client. The
- * client code calls factory when it needs more connections to the server and maintains
- * the pool of re-usable sockets internally
- */
-
-class connection_factory {
-public:
-    /**
-     * \brief Make a \ref connected_socket
-     *
-     * The implementations of this method should return ready-to-use socket that will
-     * be used by \ref client as transport for its http connections
-     */
-    virtual future<connected_socket> make(abort_source*) = 0;
-    virtual ~connection_factory() {}
-};
-
 /**
  * \brief Class client wraps communications using HTTP protocol
  *

include/seastar/http/connection_factory.hh

@@ -0,0 +1,74 @@
+/*
+ * This file is open source software, licensed to you under the terms
+ * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
+ * distributed with this work for additional information regarding copyright
+ * ownership.  You may not use this file except in compliance with the License.
+ *
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#pragma once
+
+#include <seastar/core/seastar.hh>
+#include <seastar/net/api.hh>
+#include <seastar/net/tls.hh>
+
+namespace seastar::http::experimental {
+
+/**
+ * \brief Factory that provides transport for \ref client
+ *
+ * This customization point allows callers provide its own transport for client. The
+ * client code calls factory when it needs more connections to the server.
+ */
+
+class connection_factory {
+public:
+    /**
+     * \brief Make a \ref connected_socket
+     *
+     * The implementations of this method should return ready-to-use socket that will
+     * be used by \ref client as transport for its http connections
+     */
+    virtual future<connected_socket> make(abort_source*) = 0;
+    virtual ~connection_factory() {}
+};
+
+class basic_connection_factory : public connection_factory {
+    socket_address _addr;
+public:
+    explicit basic_connection_factory(socket_address addr)
+        : _addr(std::move(addr))
+    {
+    }
+    virtual future<connected_socket> make(abort_source* as) override {
+        return seastar::connect(_addr, {}, transport::TCP);
+    }
+};
+
+class tls_connection_factory : public connection_factory {
+    socket_address _addr;
+    shared_ptr<tls::certificate_credentials> _creds;
+    sstring _host;
+public:
+    tls_connection_factory(socket_address addr, shared_ptr<tls::certificate_credentials> creds, sstring host)
+        : _addr(std::move(addr))
+        , _creds(std::move(creds))
+        , _host(std::move(host))
+    {
+    }
+    virtual future<connected_socket> make(abort_source* as) override {
+        return tls::connect(_creds, _addr, tls::tls_options{.server_name = _host});
+    }
+};
+
+}

include/seastar/http/request.hh

@@ -313,10 +313,10 @@ struct request {
      */
     static request make(httpd::operation_type type, sstring host, sstring path);
 
-private:
-    void add_query_param(std::string_view param);
     sstring request_line() const;
     future<> write_request_headers(output_stream<char>& out) const;
+private:
+    void add_query_param(std::string_view param);
     friend class experimental::connection;
 };
 

src/http/client.cc

@@ -35,7 +35,6 @@ module seastar;
 #include <seastar/core/loop.hh>
 #include <seastar/core/when_all.hh>
 #include <seastar/core/reactor.hh>
-#include <seastar/net/tls.hh>
 #include <seastar/http/client.hh>
 #include <seastar/http/request.hh>
 #include <seastar/http/reply.hh>
@@ -203,39 +202,11 @@ future<> connection::close() {
     });
 }
 
-class basic_connection_factory : public connection_factory {
-    socket_address _addr;
-public:
-    explicit basic_connection_factory(socket_address addr)
-            : _addr(std::move(addr))
-    {
-    }
-    virtual future<connected_socket> make(abort_source* as) override {
-        return seastar::connect(_addr, {}, transport::TCP);
-    }
-};
-
 client::client(socket_address addr)
         : client(std::make_unique<basic_connection_factory>(std::move(addr)))
 {
 }
 
-class tls_connection_factory : public connection_factory {
-    socket_address _addr;
-    shared_ptr<tls::certificate_credentials> _creds;
-    sstring _host;
-public:
-    tls_connection_factory(socket_address addr, shared_ptr<tls::certificate_credentials> creds, sstring host)
-            : _addr(std::move(addr))
-            , _creds(std::move(creds))
-            , _host(std::move(host))
-    {
-    }
-    virtual future<connected_socket> make(abort_source* as) override {
-        return tls::connect(_creds, _addr, tls::tls_options{.server_name = _host});
-    }
-};
-
 client::client(socket_address addr, shared_ptr<tls::certificate_credentials> creds, sstring host)
         : client(std::make_unique<tls_connection_factory>(std::move(addr), std::move(creds), std::move(host)))
 {