Support coroutine filter. (#1352)

lib/inc/drogon/HttpAppFramework.h

@@ -19,8 +19,7 @@
 #include <drogon/CacheMap.h>
 #include <drogon/DrObject.h>
 #include <drogon/HttpBinder.h>
-#include <drogon/IntranetIpFilter.h>
-#include <drogon/LocalHostFilter.h>
+#include <drogon/HttpFilter.h>
 #include <drogon/MultiPart.h>
 #include <drogon/NotFound.h>
 #include <drogon/drogon_callbacks.h>

lib/inc/drogon/HttpFilter.h

@@ -20,6 +20,10 @@
 #include <drogon/HttpResponse.h>
 #include <memory>
 
+#ifdef __cpp_impl_coroutine
+#include <drogon/utils/coroutine.h>
+#endif
+
 namespace drogon
 {
 /**
@@ -43,9 +47,7 @@ class DROGON_EXPORT HttpFilterBase : public virtual DrObjectBase
     virtual void doFilter(const HttpRequestPtr &req,
                           FilterCallback &&fcb,
                           FilterChainCallback &&fccb) = 0;
-    virtual ~HttpFilterBase()
-    {
-    }
+    ~HttpFilterBase() override = default;
 };
 
 /**
@@ -60,8 +62,61 @@ class HttpFilter : public DrObject<T>, public HttpFilterBase
 {
   public:
     static constexpr bool isAutoCreation{AutoCreation};
-    virtual ~HttpFilter()
-    {
-    }
+    ~HttpFilter() override = default;
 };
+
+namespace internal
+{
+DROGON_EXPORT void handleException(
+    const std::exception &,
+    const HttpRequestPtr &,
+    std::function<void(const HttpResponsePtr &)> &&);
+}
+
+#ifdef __cpp_impl_coroutine
+template <typename T, bool AutoCreation = true>
+class HttpCoroFilter : public DrObject<T>, public HttpFilterBase
+{
+  public:
+    static constexpr bool isAutoCreation{AutoCreation};
+    ~HttpCoroFilter() override = default;
+    void doFilter(const HttpRequestPtr &req,
+                  FilterCallback &&fcb,
+                  FilterChainCallback &&fccb) final
+    {
+        drogon::async_run([this,
+                           req,
+                           fcb = std::move(fcb),
+                           fccb = std::move(fccb)]() mutable -> drogon::Task<> {
+            HttpResponsePtr resp;
+            try
+            {
+                resp = co_await doFilter(req);
+            }
+            catch (const std::exception &ex)
+            {
+                internal::handleException(ex, req, std::move(fcb));
+                co_return;
+            }
+            catch (...)
+            {
+                LOG_ERROR << "Exception not derived from std::exception";
+                co_return;
+            }
+
+            if (resp)
+            {
+                fcb(resp);
+            }
+            else
+            {
+                fccb();
+            }
+        });
+    }
+
+    virtual Task<HttpResponsePtr> doFilter(const HttpRequestPtr &req) = 0;
+};
+#endif
+
 }  // namespace drogon

lib/tests/CMakeLists.txt

@@ -72,6 +72,7 @@ if (BUILD_CTL)
   if(DROGON_CXX_STANDARD GREATER_EQUAL 20 AND HAS_COROUTINE)
     set(INTEGRATION_TEST_SERVER_SOURCES
         ${INTEGRATION_TEST_SERVER_SOURCES}
+        integration_test/server/CoroFilter.cpp
         integration_test/server/api_v1_CoroTest.cc)
     set(CMAKE_CXX_STANDARD 20)
     set(CMAKE_CXX_STANDARD_REQUIRED TRUE)

lib/tests/integration_test/client/main.cc

@@ -24,6 +24,7 @@
 #include <mutex>
 #include <algorithm>
 #include <atomic>
+#include <chrono>
 
 #ifndef _WIN32
 #include <unistd.h>
@@ -1011,6 +1012,7 @@ void doTest(const HttpClientPtr &client, std::shared_ptr<test::Case> TEST_CTX)
                             CHECK(resp->getStatusCode() == k200OK);
                             CHECK(resp->body() == largeString);
                         });
+
 #ifdef USE_BROTLI
     // Post compressed data
     req = HttpRequest::newHttpRequest();
@@ -1093,6 +1095,23 @@ void doTest(const HttpClientPtr &client, std::shared_ptr<test::Case> TEST_CTX)
         {
             FAIL("Unexpected exception, what()" + std::string(e.what()));
         }
+
+        // Test coroutine filter
+        try
+        {
+            auto req = HttpRequest::newHttpRequest();
+            auto start = std::chrono::system_clock::now();
+            req->setPath("/api/v1/corotest/delay?secs=2");
+            auto resp = co_await client->sendRequestCoro(req);
+            CHECK(resp->getStatusCode() == k200OK);
+            auto end = std::chrono::system_clock::now();
+            std::chrono::duration<double, std::milli> duration = end - start;
+            CHECK(duration.count() >= 2000);
+        }
+        catch (const std::exception &e)
+        {
+            FAIL("Unexpected exception, what()" + std::string(e.what()));
+        }
     }());
 #endif
 }

lib/tests/integration_test/server/CoroFilter.cpp

@@ -0,0 +1,12 @@
+//
+// Created by wanchen.he on 2022/8/16.
+//
+
+#include "CoroFilter.h"
+
+Task<HttpResponsePtr> CoroFilter::doFilter(const HttpRequestPtr& req)
+{
+    int secs = std::stoi(req->getParameter("secs"));
+    co_await sleepCoro(trantor::EventLoop::getEventLoopOfCurrentThread(), secs);
+    co_return {};
+}

lib/tests/integration_test/server/CoroFilter.h

@@ -0,0 +1,17 @@
+//
+// Created by wanchen.he on 2022/8/16.
+//
+#pragma once
+
+#include <drogon/HttpFilter.h>
+using namespace drogon;
+
+class CoroFilter : public drogon::HttpCoroFilter<CoroFilter>
+{
+  public:
+    Task<HttpResponsePtr> doFilter(const HttpRequestPtr &req) override;
+    CoroFilter()
+    {
+        LOG_DEBUG << "CoroFilter constructor";
+    }
+};

lib/tests/integration_test/server/api_v1_CoroTest.h

@@ -11,6 +11,7 @@ class CoroTest : public drogon::HttpController<CoroTest>
     METHOD_LIST_BEGIN
     METHOD_ADD(CoroTest::get, "/get", Get);
     METHOD_ADD(CoroTest::get2, "/get2", Get);
+    METHOD_ADD(CoroTest::get2, "/delay", Get, "CoroFilter");
     METHOD_ADD(CoroTest::this_will_fail, "/this_will_fail", Get);
     METHOD_ADD(CoroTest::this_will_fail2, "/this_will_fail2", Get);
     METHOD_LIST_END