Reduce Transient Allocations during Bulk Text Output

src/buffer/out/AttrRow.cpp

@@ -185,14 +185,14 @@ size_t ATTR_ROW::FindAttrIndex(const size_t index, size_t* const pApplies) const
 // - Finds the hyperlink IDs present in this row and returns them
 // Return value:
 // - An unordered set containing the hyperlink IDs present in this row
-std::unordered_set<uint16_t> ATTR_ROW::GetHyperlinks()
+std::vector<uint16_t> ATTR_ROW::GetHyperlinks()
 {
-    std::unordered_set<uint16_t> ids;
+    std::vector<uint16_t> ids;
     for (const auto& run : _list)
     {
         if (run.GetAttributes().IsHyperlink())
         {
-            ids.emplace(run.GetAttributes().GetHyperlinkId());
+            ids.emplace_back(run.GetAttributes().GetHyperlinkId());
         }
     }
     return ids;

src/buffer/out/AttrRow.hpp

@@ -20,7 +20,6 @@ Revision History:
 
 #pragma once
 
-#include "boost/container/small_vector.hpp"
 #include "TextAttributeRun.hpp"
 #include "AttrRowIterator.hpp"
 
@@ -51,7 +50,7 @@ class ATTR_ROW final
     size_t FindAttrIndex(const size_t index,
                          size_t* const pApplies) const;
 
-    std::unordered_set<uint16_t> GetHyperlinks();
+    std::vector<uint16_t> GetHyperlinks();
 
     bool SetAttrToEnd(const UINT iStart, const TextAttribute attr);
     void ReplaceAttrs(const TextAttribute& toBeReplacedAttr, const TextAttribute& replaceWith) noexcept;

src/buffer/out/AttrRowIterator.hpp

@@ -15,7 +15,6 @@ Author(s):
 
 #pragma once
 
-#include "boost/container/small_vector.hpp"
 #include "TextAttribute.hpp"
 #include "TextAttributeRun.hpp"
 

src/buffer/out/CharRow.hpp

@@ -24,7 +24,6 @@ Revision History:
 #include "CharRowCellReference.hpp"
 #include "CharRowCell.hpp"
 #include "UnicodeStorage.hpp"
-#include "boost/container/small_vector.hpp"
 
 class ROW;
 

src/buffer/out/textBuffer.cpp

@@ -1230,9 +1230,15 @@ void TextBuffer::_PruneHyperlinks()
     // If the buffer does not contain the same reference, we can remove that hyperlink from our map
     // This way, obsolete hyperlink references are cleared from our hyperlink map instead of hanging around
     // Get all the hyperlink references in the row we're erasing
-    auto firstRowRefs = _storage.at(_firstRow).GetAttrRow().GetHyperlinks();
-    if (!firstRowRefs.empty())
+    const auto hyperlinks = _storage.at(_firstRow).GetAttrRow().GetHyperlinks();
+
+    if (!hyperlinks.empty())
     {
+        // Move to unordered set so we can use hashed lookup of IDs instead of linear search.
+        // Only make it an unordered set now because set always heap allocates but vector
+        // doesn't when the set is empty (saving an allocation in the common case of no links.)
+        std::unordered_set<uint16_t> firstRowRefs{ hyperlinks.cbegin(), hyperlinks.cend() };
+
         const auto total = TotalRowCount();
         // Loop through all the rows in the buffer except the first row -
         // we have found all hyperlink references in the first row and put them in refs,
@@ -1254,12 +1260,12 @@ void TextBuffer::_PruneHyperlinks()
                 break;
             }
         }
-    }
 
-    // Now delete obsolete references from our map
-    for (auto hyperlinkReference : firstRowRefs)
-    {
-        RemoveHyperlinkFromMap(hyperlinkReference);
+        // Now delete obsolete references from our map
+        for (auto hyperlinkReference : firstRowRefs)
+        {
+            RemoveHyperlinkFromMap(hyperlinkReference);
+        }
     }
 }
 

src/host/precomp.h

@@ -88,8 +88,6 @@ TRACELOGGING_DECLARE_PROVIDER(g_hConhostV2EventTraceProvider);
 #include "../inc/operators.hpp"
 #include "../inc/conattrs.hpp"
 
-#include "boost/container/small_vector.hpp"
-
 // TODO: MSFT 9355094 Find a better way of doing this. http://osgvsowi/9355094
 [[nodiscard]] inline NTSTATUS NTSTATUS_FROM_HRESULT(HRESULT hr)
 {

src/host/tracing.cpp

@@ -210,13 +210,13 @@ void Tracing::s_TraceApi(const CONSOLE_SCREENBUFFERINFO_MSG* const a)
     static_assert(sizeof(UINT32) == sizeof(*a->ColorTable), "a->ColorTable");
 }
 
-void Tracing::s_TraceApi(const CONSOLE_MODE_MSG* const a, const std::wstring& handleType)
+void Tracing::s_TraceApi(const CONSOLE_MODE_MSG* const a, const std::wstring_view handleType)
 {
     TraceLoggingWrite(
         g_hConhostV2EventTraceProvider,
         "API_GetConsoleMode",
         TraceLoggingHexUInt32(a->Mode, "Mode"),
-        TraceLoggingWideString(handleType.c_str(), "Handle type"),
+        TraceLoggingCountedWideString(handleType.data(), gsl::narrow_cast<ULONG>(handleType.size()), "Handle type"),
         TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE),
         TraceLoggingKeyword(TraceKeywords::API));
 }

src/host/tracing.hpp

@@ -50,7 +50,7 @@ class Tracing
     static void s_TraceApi(_In_ const void* const buffer, const CONSOLE_WRITECONSOLE_MSG* const a);
 
     static void s_TraceApi(const CONSOLE_SCREENBUFFERINFO_MSG* const a);
-    static void s_TraceApi(const CONSOLE_MODE_MSG* const a, const std::wstring& handleType);
+    static void s_TraceApi(const CONSOLE_MODE_MSG* const a, const std::wstring_view handleType);
     static void s_TraceApi(const CONSOLE_SETTEXTATTRIBUTE_MSG* const a);
     static void s_TraceApi(const CONSOLE_WRITECONSOLEOUTPUTSTRING_MSG* const a);
 

src/inc/LibraryIncludes.h

@@ -74,6 +74,9 @@
 #include <base/numerics/safe_math.h>
 #pragma warning(pop)
 
+// Boost
+#include "boost/container/small_vector.hpp"
+
 // IntSafe
 #define ENABLE_INTSAFE_SIGNED_FUNCTIONS
 #include <intsafe.h>

src/server/ApiDispatchers.cpp

@@ -35,7 +35,7 @@
 {
     Telemetry::Instance().LogApiCall(Telemetry::ApiCall::GetConsoleMode);
     CONSOLE_MODE_MSG* const a = &m->u.consoleMsgL1.GetConsoleMode;
-    std::wstring handleType = L"unknown";
+    std::wstring_view handleType = L"unknown";
 
     TraceLoggingWrite(g_hConhostV2EventTraceProvider,
                       "API_GetConsoleMode",
@@ -54,14 +54,14 @@
     RETURN_HR_IF_NULL(E_HANDLE, pObjectHandle);
     if (pObjectHandle->IsInputHandle())
     {
-        handleType = L"input handle";
+        handleType = L"input";
         InputBuffer* pObj;
         RETURN_IF_FAILED(pObjectHandle->GetInputBuffer(GENERIC_READ, &pObj));
         m->_pApiRoutines->GetConsoleInputModeImpl(*pObj, a->Mode);
     }
     else
     {
-        handleType = L"output handle";
+        handleType = L"output";
         SCREEN_INFORMATION* pObj;
         RETURN_IF_FAILED(pObjectHandle->GetScreenBuffer(GENERIC_READ, &pObj));
         m->_pApiRoutines->GetConsoleOutputModeImpl(*pObj, a->Mode);

src/server/ApiMessage.cpp

@@ -9,10 +9,18 @@
 #include "DeviceComm.h"
 
 _CONSOLE_API_MSG::_CONSOLE_API_MSG() :
+    Complete{ 0 },
+    State{ 0 },
     _pDeviceComm(nullptr),
-    _pApiRoutines(nullptr)
+    _pApiRoutines(nullptr),
+    _inputBuffer{},
+    _outputBuffer{},
+    Descriptor{ 0 },
+    CreateObject{ 0 },
+    CreateScreenBuffer{ 0 },
+    msgHeader{ 0 }
 {
-    ZeroMemory(this, sizeof(_CONSOLE_API_MSG));
+
 }
 
 ConsoleProcessHandle* _CONSOLE_API_MSG::GetProcessHandle() const
@@ -57,6 +65,7 @@ ConsoleHandleData* _CONSOLE_API_MSG::GetObjectHandle() const
 // -  HRESULT indicating if the input buffer was successfully retrieved.
 [[nodiscard]] HRESULT _CONSOLE_API_MSG::GetInputBuffer(_Outptr_result_bytebuffer_(*pcbSize) void** const ppvBuffer,
                                                        _Out_ ULONG* const pcbSize)
+try
 {
     // Initialize the buffer if it hasn't been initialized yet.
     if (State.InputBuffer == nullptr)
@@ -65,12 +74,11 @@ ConsoleHandleData* _CONSOLE_API_MSG::GetObjectHandle() const
 
         ULONG const cbReadSize = Descriptor.InputSize - State.ReadOffset;
 
-        wistd::unique_ptr<BYTE[]> pPayload = wil::make_unique_nothrow<BYTE[]>(cbReadSize);
-        RETURN_IF_NULL_ALLOC(pPayload);
+        _inputBuffer.resize(cbReadSize);
 
-        RETURN_IF_FAILED(ReadMessageInput(0, pPayload.get(), cbReadSize));
+        RETURN_IF_FAILED(ReadMessageInput(0, _inputBuffer.data(), cbReadSize));
 
-        State.InputBuffer = pPayload.release(); // TODO: MSFT: 9565140 - don't release, maintain as smart pointer.
+        State.InputBuffer = _inputBuffer.data();
         State.InputBufferSize = cbReadSize;
     }
 
@@ -80,6 +88,7 @@ ConsoleHandleData* _CONSOLE_API_MSG::GetObjectHandle() const
 
     return S_OK;
 }
+CATCH_RETURN();
 
 // Routine Description:
 // - This routine retrieves the output buffer associated with this message. It will allocate one if needed.
@@ -94,6 +103,7 @@ ConsoleHandleData* _CONSOLE_API_MSG::GetObjectHandle() const
 [[nodiscard]] HRESULT _CONSOLE_API_MSG::GetAugmentedOutputBuffer(const ULONG cbFactor,
                                                                  _Outptr_result_bytebuffer_(*pcbSize) PVOID* const ppvBuffer,
                                                                  _Out_ PULONG pcbSize)
+try
 {
     // Initialize the buffer if it hasn't been initialized yet.
     if (State.OutputBuffer == nullptr)
@@ -103,11 +113,12 @@ ConsoleHandleData* _CONSOLE_API_MSG::GetObjectHandle() const
         ULONG cbWriteSize = Descriptor.OutputSize - State.WriteOffset;
         RETURN_IF_FAILED(ULongMult(cbWriteSize, cbFactor, &cbWriteSize));
 
-        BYTE* pPayload = new (std::nothrow) BYTE[cbWriteSize];
-        RETURN_IF_NULL_ALLOC(pPayload);
-        ZeroMemory(pPayload, sizeof(BYTE) * cbWriteSize);
+        _outputBuffer.resize(cbWriteSize);
 
-        State.OutputBuffer = pPayload; // TODO: MSFT: 9565140 - maintain as smart pointer.
+        // 0 it out.
+        std::fill(_outputBuffer.begin(), _outputBuffer.end(), (BYTE)0);
+
+        State.OutputBuffer = _outputBuffer.data();
         State.OutputBufferSize = cbWriteSize;
     }
 
@@ -117,6 +128,7 @@ ConsoleHandleData* _CONSOLE_API_MSG::GetObjectHandle() const
 
     return S_OK;
 }
+CATCH_RETURN();
 
 // Routine Description:
 // - This routine retrieves the output buffer associated with this message. It will allocate one if needed.
@@ -148,8 +160,9 @@ ConsoleHandleData* _CONSOLE_API_MSG::GetObjectHandle() const
 
     if (State.InputBuffer != nullptr)
     {
-        delete[] static_cast<BYTE*>(State.InputBuffer);
+        _inputBuffer.clear();
         State.InputBuffer = nullptr;
+        State.InputBufferSize = 0;
     }
 
     if (State.OutputBuffer != nullptr)
@@ -165,8 +178,9 @@ ConsoleHandleData* _CONSOLE_API_MSG::GetObjectHandle() const
             LOG_IF_FAILED(_pDeviceComm->WriteOutput(&IoOperation));
         }
 
-        delete[] static_cast<BYTE*>(State.OutputBuffer);
+        _outputBuffer.clear();
         State.OutputBuffer = nullptr;
+        State.OutputBufferSize = 0;
     }
 
     return hr;

src/server/ApiMessage.h

@@ -35,6 +35,12 @@ typedef struct _CONSOLE_API_MSG
     IDeviceComm* _pDeviceComm;
     IApiRoutines* _pApiRoutines;
 
+private:
+    boost::container::small_vector<BYTE, 128> _inputBuffer;
+    boost::container::small_vector<BYTE, 128> _outputBuffer;
+
+public:
+
     // From here down is the actual packet data sent/received.
     CD_IO_DESCRIPTOR Descriptor;
     union
@@ -58,6 +64,8 @@ typedef struct _CONSOLE_API_MSG
     // End packet data
 
 public:
+    // DO NOT PUT MORE FIELDS DOWN HERE. They will be stomped by driver fills.
+
     ConsoleProcessHandle* GetProcessHandle() const;
     ConsoleHandleData* GetObjectHandle() const;
 
@@ -73,4 +81,6 @@ typedef struct _CONSOLE_API_MSG
     void SetReplyStatus(const NTSTATUS Status);
     void SetReplyInformation(const ULONG_PTR pInformation);
 
+    // DO NOT PUT MORE FIELDS DOWN HERE. They will be stomped by driver fills.
+
 } CONSOLE_API_MSG, *PCONSOLE_API_MSG, * const PCCONSOLE_API_MSG;