intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 85 insertions, 0 deletions

diff --git a/library/cpp/lwtrace/example3/my_action.h b/library/cpp/lwtrace/example3/my_action.h
new file mode 100644
index 0000000000..9a04293ba2
--- /dev/null
+++ b/library/cpp/lwtrace/example3/my_action.h
@@ -0,0 +1,85 @@
+#pragma once
+
+#include <library/cpp/lwtrace/all.h>
+#include <util/stream/file.h>
+
+// Example of custom state for custom executors
+// Holds file for output from TMyActionExecutor
+class TMyFile: public NLWTrace::IResource {
+private:
+    TMutex Mutex;
+    THolder<TUnbufferedFileOutput> File;
+
+public:
+    // Note that this class must have default ctor (it's declared here just for clearness)
+    TMyFile() {
+    }
+
+    // Note that dtor will be called by TManager::Delete() after detachment and destruction of all executors
+    ~TMyFile() {
+    }
+
+    // Some kind of state initialization
+    // Can be called only from executor constructor, and should not be thread-safe
+    void Open(const TString& path) {
+        if (File) {
+            // We must avoid double open because each executor will call Open() on the same object
+            // if the same file was specified in Opts
+            return;
+        }
+        File.Reset(new TUnbufferedFileOutput(path));
+    }
+
+    // Outputs a line to opened file
+    // Can be called from DoExecute() and must be thread-safe
+    void Output(const TString& line) {
+        Y_VERIFY(File);
+        TGuard<TMutex> g(Mutex); // Because DoExecute() call can come from any thread
+        *File << line << Endl;
+    }
+};
+
+// Action that prints events to specified file
+class TMyActionExecutor: public NLWTrace::TCustomActionExecutor {
+private:
+    TMyFile& File;
+
+public:
+    TMyActionExecutor(NLWTrace::TProbe* probe, const NLWTrace::TCustomAction& action, NLWTrace::TSession* session)
+        : NLWTrace::TCustomActionExecutor(probe, false /* not destructive */)
+        , File(session->Resources().Get<TMyFile>("FileHolder/" + action.GetOpts(0))) // unique state id must include your d
+    {
+        if (action.GetOpts().size() != 1) {
+            yexception() << "wrong number of Opts in MyAction";
+        }
+        File.Open(action.GetOpts(0));
+    }
+
+    static const char* GetActionName() {
+        static const char name[] = "MyAction";
+        return name;
+    }
+
+private:
+    virtual bool DoExecute(NLWTrace::TOrbit&, const NLWTrace::TParams& params) {
+        // Serialize param values to strings
+        TString paramValues[LWTRACE_MAX_PARAMS];
+        Probe->Event.Signature.SerializeParams(params, paramValues);
+
+        // Generate output line
+        TStringStream ss;
+        ss << "TMyActionExecutor>>> ";
+        ss << Probe->Event.Name;
+        for (ui32 i = 0; i < Probe->Event.Signature.ParamCount; ++i) {
+            ss << " " << Probe->Event.Signature.ParamNames[i] << "=" << paramValues[i];
+        }
+
+        // Write line to file
+        File.Output(ss.Str());
+
+        // Executors can chain if you specify multiple actions in one block (in trace query).
+        // So return true to continue execution of actions for given trace query block (on current triggered event)
+        // or return false if this action is the last for this block
+        return true;
+    }
+};