Reference commit

src/tools/scratch/README.md

@@ -0,0 +1,5 @@
+## Narrator Buddy
+
+This is a sample of how we might implement Narrator Buddy. This was an internal tool for taking what narrator would read aloud, and logging it to the console.
+
+Currently this builds as a scratch project in the Terminal solution. It's provided as a reference implementation for how a real narrator buddy might be implemented in the future.

src/tools/scratch/Scratch.vcxproj

@@ -9,6 +9,7 @@
     <ConfigurationType>Application</ConfigurationType>
   </PropertyGroup>
   <Import Project="..\..\common.build.pre.props" />
+  <Import Project="..\..\common.nugetversions.props" />
   <ItemGroup>
     <ClCompile Include="main.cpp" />
   </ItemGroup>
@@ -32,4 +33,5 @@
   <!-- Careful reordering these. Some default props (contained in these files) are order sensitive. -->
   <Import Project="..\..\common.build.post.props" />
   <Import Project="..\..\common.build.tests.props" />
+  <Import Project="..\..\common.nugetversions.targets" />
 </Project>

src/tools/scratch/main.cpp

@@ -2,9 +2,141 @@
 // Licensed under the MIT license.
 
 #include <windows.h>
+#include <iostream>
+#include <string>
+#include <vector>
+#include <array>
+#include <thread>
+#include <sstream>
 
-// This wmain exists for help in writing scratch programs while debugging.
-int __cdecl wmain(int /*argc*/, WCHAR* /*argv[]*/)
+#include <wil\result.h>
+#include <wil\resource.h>
+#include <wil\com.h>
+
+#include <evntcons.h>
+#include <evntrace.h>
+
+namespace
+{
+    wil::unique_event g_stopEvent{ wil::EventOptions::None };
+
+} // namespace anonymous
+
+void WINAPI ProcessEtwEvent(_In_ PEVENT_RECORD rawEvent)
+{
+    // This is the task id from srh.man (with the same name).
+    constexpr auto InitiateSpeaking = 5;
+
+    auto data = rawEvent->UserData;
+    auto dataLen = rawEvent->UserDataLength;
+    auto processId = rawEvent->EventHeader.ProcessId;
+    auto task = rawEvent->EventHeader.EventDescriptor.Task;
+
+    if (task == InitiateSpeaking)
+    {
+        // The payload first has an int32 representing the channel we're writing to. This is basically always writing to the
+        // default channel, so just skip over those bytes... the rest is the string payload we want to speak,
+        // as a null terminated string.
+        if (dataLen <= 4)
+        {
+            return;
+        }
+
+        const auto stringPayloadSize = (dataLen - 4) / sizeof(wchar_t);
+        // We don't need the null terminator, because wstring intends to handle that on its own.
+        const auto stringLen = stringPayloadSize - 1;
+        const auto payload = std::wstring(reinterpret_cast<wchar_t*>(static_cast<char*>(data) + 4), stringLen);
+
+        wprintf(L"[Narrator pid=%d]: %s\n", processId, payload.c_str());
+        fflush(stdout);
+
+        if (payload == L"Exiting Narrator")
+        {
+            g_stopEvent.SetEvent();
+        }
+    }
+}
+
+int __cdecl wmain(int argc, wchar_t* argv[])
 {
+    const bool runForever = (argc == 2) &&
+                            std::wstring{ argv[1] } == L"-forever";
+
+    GUID sessionGuid;
+    FAIL_FAST_IF_FAILED(::CoCreateGuid(&sessionGuid));
+
+    std::array<wchar_t, 64> traceSessionName{};
+    FAIL_FAST_IF_FAILED(StringCchPrintf(traceSessionName.data(), static_cast<DWORD>(traceSessionName.size()), L"NarratorTraceSession_%d", ::GetCurrentProcessId()));
+
+    unsigned int traceSessionNameBytes = static_cast<unsigned int>((wcslen(traceSessionName.data()) + 1) * sizeof(wchar_t));
+
+    // Now, to get tracing. Most settings below are defaults from MSDN, except where noted.
+    // First, set up a session (StartTrace) - which requires a PROPERTIES struct. This has to have
+    // the session name after it in the same block of memory...
+    const unsigned int propertiesByteSize = sizeof(EVENT_TRACE_PROPERTIES) + traceSessionNameBytes;
+    std::vector<char> eventTracePropertiesBuffer(propertiesByteSize);
+    auto properties = reinterpret_cast<EVENT_TRACE_PROPERTIES*>(eventTracePropertiesBuffer.data());
+
+    // Set up properties struct for a real-time session...
+    properties->Wnode.BufferSize = propertiesByteSize;
+    properties->Wnode.Guid = sessionGuid;
+    properties->Wnode.ClientContext = 1;
+    properties->Wnode.Flags = WNODE_FLAG_TRACED_GUID;
+    properties->LogFileMode = EVENT_TRACE_REAL_TIME_MODE | EVENT_TRACE_USE_PAGED_MEMORY;
+    properties->LoggerNameOffset = sizeof(EVENT_TRACE_PROPERTIES);
+    properties->FlushTimer = 1;
+    // Finally, copy the session name...
+    memcpy(properties + 1, traceSessionName.data(), traceSessionNameBytes);
+
+    std::thread traceThread;
+    auto joinTraceThread = wil::scope_exit([&]() {
+        if (traceThread.joinable())
+        {
+            traceThread.join();
+        }
+    });
+
+    TRACEHANDLE session{};
+    const auto rc = ::StartTrace(&session, traceSessionName.data(), properties);
+    FAIL_FAST_IF(rc != ERROR_SUCCESS);
+    auto stopTrace = wil::scope_exit([&]() {
+        EVENT_TRACE_PROPERTIES properties{};
+        properties.Wnode.BufferSize = sizeof(properties);
+        properties.Wnode.Guid = sessionGuid;
+        properties.Wnode.Flags = WNODE_FLAG_TRACED_GUID;
+
+        ::ControlTrace(session, nullptr, &properties, EVENT_TRACE_CONTROL_STOP);
+    });
+
+    constexpr GUID narratorProviderGuid = { 0x835b79e2, 0xe76a, 0x44c4, 0x98, 0x85, 0x26, 0xad, 0x12, 0x2d, 0x3b, 0x4d };
+    FAIL_FAST_IF(ERROR_SUCCESS != ::EnableTrace(TRUE /* enable */, 0 /* enableFlag */, TRACE_LEVEL_VERBOSE, &narratorProviderGuid, session));
+    auto disableTrace = wil::scope_exit([&]() {
+        ::EnableTrace(FALSE /* enable */, 0 /* enableFlag */, TRACE_LEVEL_VERBOSE, &narratorProviderGuid, session);
+    });
+
+    // Finally, start listening (OpenTrace/ProcessTrace/CloseTrace)...
+    EVENT_TRACE_LOGFILE trace{};
+    trace.LoggerName = traceSessionName.data();
+    trace.ProcessTraceMode = PROCESS_TRACE_MODE_EVENT_RECORD | PROCESS_TRACE_MODE_REAL_TIME;
+    trace.EventRecordCallback = ProcessEtwEvent;
+
+    using unique_tracehandle = wil::unique_any<TRACEHANDLE, decltype(::CloseTrace), ::CloseTrace>;
+    unique_tracehandle traceHandle{ ::OpenTrace(&trace) };
+
+    // Since the actual call to ProcessTrace blocks while it's working,
+    // we spin up a separate thread to do that.
+    traceThread = std::thread([traceHandle(std::move(traceHandle))]() mutable {
+        ::ProcessTrace(traceHandle.addressof(), 1 /* handleCount */, nullptr /* startTime */, nullptr /* endTime */);
+    });
+
+    if (runForever)
+    {
+        ::Sleep(INFINITE);
+    }
+    else
+    {
+        g_stopEvent.wait(INFINITE);
+    }
+
     return 0;
 }