Merge pull request #20298 from mpashchenkov:mp/python-desync

G-API: Python. Desync.

* Desync. GMat.

* Alignment

modules/gapi/src/executor/gstreamingexecutor.cpp

@@ -1017,6 +1017,49 @@ void check_DesyncObjectConsumedByMultipleIslands(const cv::gimpl::GIslandModel::
     } // for(nodes)
 }
 
+// NB: Construct GRunArgsP based on passed info and store the memory in passed cv::GRunArgs.
+// Needed for python bridge, because in case python user doesn't pass output arguments to apply.
+void constructOptGraphOutputs(const cv::GTypesInfo &out_info,
+                                    cv::GOptRunArgs &args,
+                                    cv::GOptRunArgsP &outs)
+{
+    for (auto&& info : out_info)
+    {
+        switch (info.shape)
+        {
+            case cv::GShape::GMAT:
+            {
+                args.emplace_back(cv::optional<cv::Mat>{});
+                outs.emplace_back(&cv::util::get<cv::optional<cv::Mat>>(args.back()));
+                break;
+            }
+            case cv::GShape::GSCALAR:
+            {
+                args.emplace_back(cv::optional<cv::Scalar>{});
+                outs.emplace_back(&cv::util::get<cv::optional<cv::Scalar>>(args.back()));
+                break;
+            }
+            case cv::GShape::GARRAY:
+            {
+                cv::detail::VectorRef ref;
+                cv::util::get<cv::detail::ConstructVec>(info.ctor)(ref);
+                args.emplace_back(cv::util::make_optional(std::move(ref)));
+                outs.emplace_back(wrap_opt_arg(cv::util::get<cv::optional<cv::detail::VectorRef>>(args.back())));
+                break;
+            }
+            case cv::GShape::GOPAQUE:
+            {
+                cv::detail::OpaqueRef ref;
+                cv::util::get<cv::detail::ConstructOpaque>(info.ctor)(ref);
+                args.emplace_back(cv::util::make_optional(std::move(ref)));
+                outs.emplace_back(wrap_opt_arg(cv::util::get<cv::optional<cv::detail::OpaqueRef>>(args.back())));
+                break;
+            }
+            default:
+                cv::util::throw_error(std::logic_error("Unsupported optional output shape for Python"));
+        }
+    }
+}
 } // anonymous namespace
 
 class cv::gimpl::GStreamingExecutor::Synchronizer final {
@@ -1320,6 +1363,16 @@ cv::gimpl::GStreamingExecutor::GStreamingExecutor(std::unique_ptr<ade::Graph> &&
     // per the same input frame, so the output traffic multiplies)
     GAPI_Assert(m_collector_map.size() > 0u);
     m_out_queue.set_capacity(queue_capacity * m_collector_map.size());
+
+    // FIXME: The code duplicates logic of collectGraphInfo()
+    cv::gimpl::GModel::ConstGraph cgr(*m_orig_graph);
+    auto meta = cgr.metadata().get<cv::gimpl::Protocol>().out_nhs;
+    out_info.reserve(meta.size());
+
+    ade::util::transform(meta, std::back_inserter(out_info), [&cgr](const ade::NodeHandle& nh) {
+        const auto& data = cgr.metadata(nh).get<cv::gimpl::Data>();
+        return cv::GTypeInfo{data.shape, data.kind, data.ctor};
+    });
 }
 
 cv::gimpl::GStreamingExecutor::~GStreamingExecutor()
@@ -1653,6 +1706,31 @@ bool cv::gimpl::GStreamingExecutor::pull(cv::GOptRunArgsP &&outs)
     return true;
 }
 
+std::tuple<bool, cv::util::variant<cv::GRunArgs, cv::GOptRunArgs>> cv::gimpl::GStreamingExecutor::pull()
+{
+    using RunArgs = cv::util::variant<cv::GRunArgs, cv::GOptRunArgs>;
+    bool is_over = false;
+
+    if (m_desync) {
+        GOptRunArgs opt_run_args;
+        GOptRunArgsP opt_outs;
+        opt_outs.reserve(out_info.size());
+        opt_run_args.reserve(out_info.size());
+
+        constructOptGraphOutputs(out_info, opt_run_args, opt_outs);
+        is_over = pull(std::move(opt_outs));
+        return std::make_tuple(is_over, RunArgs(opt_run_args));
+    }
+
+    GRunArgs run_args;
+    GRunArgsP outs;
+    run_args.reserve(out_info.size());
+    outs.reserve(out_info.size());
+
+    constructGraphOutputs(out_info, run_args, outs);
+    is_over = pull(std::move(outs));
+    return std::make_tuple(is_over, RunArgs(run_args));
+}
 
 bool cv::gimpl::GStreamingExecutor::try_pull(cv::GRunArgsP &&outs)
 {

modules/gapi/src/executor/gstreamingexecutor.hpp

@@ -195,6 +195,8 @@ protected:
 
     void wait_shutdown();
 
+    cv::GTypesInfo out_info;
+
 public:
     explicit GStreamingExecutor(std::unique_ptr<ade::Graph> &&g_model,
                                 const cv::GCompileArgs &comp_args);
@@ -203,6 +205,7 @@ public:
     void start();
     bool pull(cv::GRunArgsP &&outs);
     bool pull(cv::GOptRunArgsP &&outs);
+    std::tuple<bool, cv::util::variant<cv::GRunArgs, cv::GOptRunArgs>> pull();
     bool try_pull(cv::GRunArgsP &&outs);
     void stop();
     bool running() const;