intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 75 insertions, 0 deletions

diff --git a/library/cpp/lwtrace/custom_action.h b/library/cpp/lwtrace/custom_action.h
new file mode 100644
index 0000000000..92a3c66b84
--- /dev/null
+++ b/library/cpp/lwtrace/custom_action.h
@@ -0,0 +1,75 @@
+#pragma once
+
+#include "probe.h"
+
+#include <library/cpp/lwtrace/protos/lwtrace.pb.h>
+
+#include <util/generic/hash.h>
+
+#include <functional>
+
+namespace NLWTrace {
+    class TSession;
+
+    // Custom action can save any stuff (derived from IResource) in TSession object
+    // IMPORTANT: Derived class will be used from multiple threads! (see example3)
+    class IResource: public TAtomicRefCount<IResource> {
+    public:
+        virtual ~IResource() {
+        }
+    };
+    using TResourcePtr = TIntrusivePtr<IResource>;
+
+    // Trace resources that is used to hold/get/create any stuff
+    class TTraceResources: public THashMap<TString, TResourcePtr> {
+    public:
+        template <class T>
+        T& Get(const TString& name) {
+            auto iter = find(name);
+            if (iter == end()) {
+                iter = insert(value_type(name, TResourcePtr(new T()))).first;
+            }
+            return *static_cast<T*>(iter->second.Get());
+        }
+
+        template <class T>
+        const T* GetOrNull(const TString& name) const {
+            auto iter = find(name);
+            if (iter == end()) {
+                return nullptr;
+            }
+            return *iter->second;
+        }
+    };
+
+    // Base class of all custom actions
+    class TCustomActionExecutor: public IExecutor {
+    protected:
+        TProbe* const Probe;
+        bool Destructive;
+
+    public:
+        TCustomActionExecutor(TProbe* probe, bool destructive)
+            : IExecutor()
+            , Probe(probe)
+            , Destructive(destructive)
+        {
+        }
+
+        bool IsDestructive() {
+            return Destructive;
+        }
+    };
+
+    // Factory to produce custom action executors
+    class TCustomActionFactory {
+    public:
+        using TCallback = std::function<TCustomActionExecutor*(TProbe* probe, const TCustomAction& action, TSession* trace)>;
+        TCustomActionExecutor* Create(TProbe* probe, const TCustomAction& action, TSession* trace) const;
+        void Register(const TString& name, const TCallback& callback);
+
+    private:
+        THashMap<TString, TCallback> Callbacks;
+    };
+
+}