http: enclose libevent-dependent code in a namespace

This commit is a no-op to isolate HTTP methods and objects that
depend on libevent. Following commits will add replacement objects
and methods in a new namespace for testing and review before
switching over the server.

src/httprpc.cpp

@@ -26,6 +26,7 @@
 #include <string>
 #include <vector>
 
+using http_libevent::HTTPRequest;
 using util::SplitString;
 using util::TrimStringView;
 

src/httpserver.cpp

@@ -43,6 +43,7 @@
 #include <support/events.h>
 
 using common::InvalidPortErrMsg;
+using http_libevent::HTTPRequest;
 
 /** Maximum size of http request (request line + headers) */
 static const size_t MAX_HEADERS_SIZE = 8192;
@@ -438,6 +439,7 @@ static void libevent_log_cb(int severity, const char *msg)
     LogPrintLevel(BCLog::LIBEVENT, level, "%s\n", msg);
 }
 
+namespace http_libevent {
 bool InitHTTPServer(const util::SignalInterrupt& interrupt)
 {
     if (!InitHTTPAllowList())
@@ -559,6 +561,7 @@ void StopHTTPServer()
     g_work_queue.reset();
     LogDebug(BCLog::HTTP, "Stopped HTTP server\n");
 }
+} // namespace http_libevent
 
 struct event_base* EventBase()
 {
@@ -591,6 +594,8 @@ void HTTPEvent::trigger(struct timeval* tv)
     else
         evtimer_add(ev, tv); // trigger after timeval passed
 }
+
+namespace http_libevent {
 HTTPRequest::HTTPRequest(struct evhttp_request* _req, const util::SignalInterrupt& interrupt, bool _replySent)
     : req(_req), m_interrupt(interrupt), replySent(_replySent)
 {
@@ -753,6 +758,7 @@ std::optional<std::string> GetQueryParameterFromUri(const char* uri, const std::
 
     return result;
 }
+} // namespace http_libevent
 
 void RegisterHTTPHandler(const std::string &prefix, bool exactMatch, const HTTPRequestHandler &handler)
 {

src/httpserver.h

@@ -30,6 +30,8 @@ static const int DEFAULT_HTTP_SERVER_TIMEOUT=30;
 struct evhttp_request;
 struct event_base;
 class CService;
+
+namespace http_libevent {
 class HTTPRequest;
 
 /** Initialize HTTP server.
@@ -48,9 +50,10 @@ void StopHTTPServer();
 
 /** Change logging level for libevent. */
 void UpdateHTTPServerLogging(bool enable);
+} // namespace http_libevent
 
 /** Handler for requests to a certain HTTP path */
-typedef std::function<bool(HTTPRequest* req, const std::string &)> HTTPRequestHandler;
+typedef std::function<bool(http_libevent::HTTPRequest* req, const std::string&)> HTTPRequestHandler;
 /** Register handler for prefix.
  * If multiple handlers match a prefix, the first-registered one will
  * be invoked.
@@ -64,6 +67,7 @@ void UnregisterHTTPHandler(const std::string &prefix, bool exactMatch);
  */
 struct event_base* EventBase();
 
+namespace http_libevent {
 /** In-flight HTTP request.
  * Thin C++ wrapper around evhttp_request.
  */
@@ -145,6 +149,7 @@ public:
     void WriteReply(int nStatus, std::span<const std::byte> reply);
 };
 
+
 /** Get the query parameter value from request uri for a specified key, or std::nullopt if the key
  * is not found.
  *
@@ -158,6 +163,7 @@ public:
  * @param[in] key represents the query parameter of which the value is returned
  */
 std::optional<std::string> GetQueryParameterFromUri(const char* uri, const std::string& key);
+} // namespace http_libevent
 
 /** Event handler closure.
  */

src/init.cpp

@@ -121,6 +121,10 @@ using common::AmountErrMsg;
 using common::InvalidPortErrMsg;
 using common::ResolveErrMsg;
 
+using http_libevent::InitHTTPServer;
+using http_libevent::InterruptHTTPServer;
+using http_libevent::StartHTTPServer;
+using http_libevent::StopHTTPServer;
 using node::ApplyArgsManOptions;
 using node::BlockManager;
 using node::CalculateCacheSizes;

src/rest.cpp

@@ -37,6 +37,7 @@
 
 #include <univalue.h>
 
+using http_libevent::HTTPRequest;
 using node::GetTransaction;
 using node::NodeContext;
 using util::SplitString;

src/rpc/node.cpp

@@ -256,7 +256,7 @@ static RPCHelpMan logging()
 
     // Update libevent logging if BCLog::LIBEVENT has changed.
     if (changed_log_categories & BCLog::LIBEVENT) {
-        UpdateHTTPServerLogging(LogInstance().WillLogCategory(BCLog::LIBEVENT));
+        http_libevent::UpdateHTTPServerLogging(LogInstance().WillLogCategory(BCLog::LIBEVENT));
     }
 
     UniValue result(UniValue::VOBJ);

src/test/fuzz/http_request.cpp

@@ -20,6 +20,8 @@
 #include <string>
 #include <vector>
 
+using http_libevent::HTTPRequest;
+
 extern "C" int evhttp_parse_firstline_(struct evhttp_request*, struct evbuffer*);
 extern "C" int evhttp_parse_headers_(struct evhttp_request*, struct evbuffer*);
 

src/test/httpserver_tests.cpp

@@ -11,6 +11,7 @@ BOOST_FIXTURE_TEST_SUITE(httpserver_tests, BasicTestingSetup)
 
 BOOST_AUTO_TEST_CASE(test_query_parameters)
 {
+    using http_libevent::GetQueryParameterFromUri;
     std::string uri {};
 
     // No parameters