Plugins/PluginPerfMon/PerfSnap.cpp

@@ -0,0 +1,166 @@
+//============================================================================
+// File: PERFSNAP.CPP
+// Author: Matt Pietrek
+// From: Microsoft Systems Journal, "Under the Hood", March 1996
+//============================================================================
+#pragma warning(disable: 4996)
+
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+
+#include <windows.h>
+#include <winperf.h>
+#include <stdlib.h>
+#include <tchar.h>
+#pragma hdrstop
+#include "titledb.h"
+#include "perfsnap.h"
+#include "makeptr.h"
+
+PBYTE CPerfSnapshot::c_pBuffer = NULL;
+DWORD CPerfSnapshot::c_cbBufferSize = 0;
+
+CPerfSnapshot::CPerfSnapshot(
+    CPerfTitleDatabase * pCounterTitles )
+{
+    m_pPerfDataHeader = 0;
+    m_pCounterTitles = pCounterTitles;
+}
+
+CPerfSnapshot::~CPerfSnapshot( void )
+{
+    DisposeSnapshot();
+}
+
+BOOL
+CPerfSnapshot::TakeSnapshot( PCTSTR pszSnapshotItems )
+{
+    DisposeSnapshot();  // Clear out any current snapshot
+
+    // Convert the input string (e.g., "Process") into the form required
+    // by the HKEY_PERFORMANCE_DATA key (e.g., "232")
+
+    TCHAR szConvertedItemNames[ 256 ];
+    if ( !ConvertSnapshotItemName( pszSnapshotItems, szConvertedItemNames,
+                                   sizeof(szConvertedItemNames) ) )
+        return FALSE;
+
+    DWORD cbAllocSize = 0;
+    LONG retValue;
+        
+    while ( 1 ) // Loop until we get the data, or we fail unexpectedly
+    {
+        retValue = RegQueryValueEx( HKEY_PERFORMANCE_DATA,
+                                    szConvertedItemNames, 0, 0,
+                                    c_pBuffer, &c_cbBufferSize );
+
+        if ( retValue == ERROR_SUCCESS )    // We apparently got the snapshot
+        {
+			m_pPerfDataHeader = (PPERF_DATA_BLOCK)c_pBuffer;
+
+            // Verify that the signature is a unicode "PERF"
+            if ( memcmp( m_pPerfDataHeader->Signature, L"PERF", 8 ) )
+                break;
+
+            return TRUE;
+        }
+        else if ( retValue != ERROR_MORE_DATA ) // Anything other failure
+            break;                              // code means something
+                                                // bad happened, so bail out.
+
+        // If we get here, our buffer wasn't big enough.  Delete it and
+        // try again with a bigger buffer.
+        delete [] c_pBuffer;
+        
+        // The new buffer size will be 4096 bytes bigger than the larger
+        // of: 1) The previous allocation size, or 2) The size that the
+        // RegQueryValueEx call said was necessary.
+        if ( c_cbBufferSize > cbAllocSize )
+            cbAllocSize = c_cbBufferSize + 4096;
+        else
+            cbAllocSize += 4096;
+
+        // Allocate a new, larger buffer in preparation to try again.
+        c_pBuffer = new BYTE[ cbAllocSize ];
+        if ( !c_pBuffer )
+            break;
+
+        c_cbBufferSize = cbAllocSize;
+    }
+
+    // If we get here, the RegQueryValueEx failed unexpectedly.
+    return FALSE;
+}
+
+void
+CPerfSnapshot::DisposeSnapshot( void )
+{
+    m_pPerfDataHeader = 0;
+}
+
+void
+CPerfSnapshot::CleanUp( void )
+{
+    delete [] c_pBuffer;
+    c_pBuffer = 0;
+	c_cbBufferSize = 0;
+}
+
+DWORD
+CPerfSnapshot::GetNumObjectTypes( void )
+{
+    return m_pPerfDataHeader ? m_pPerfDataHeader->NumObjectTypes: 0;
+}
+
+BOOL
+CPerfSnapshot::GetSystemName( PTSTR pszSystemName, DWORD nSize )
+{
+    if ( !m_pPerfDataHeader )   // If no snapshot data, bail out.
+        return FALSE;
+
+    // Make sure the input buffer size is big enough
+    if ( nSize < m_pPerfDataHeader->SystemNameLength )
+        return FALSE;
+
+    // Make a unicode string point to the system name string
+    // that's stored in the PERF_DATA_BLOCK
+    LPWSTR lpwszName = MakePtr( LPWSTR, m_pPerfDataHeader,
+                                m_pPerfDataHeader->SystemNameOffset );
+
+    #ifdef UNICODE  // Copy the PERF_DATA_BLOCK string to the input buffer
+    lstrcpy( pszSystemName, lpwszName );
+    #else
+    wcstombs( pszSystemName, lpwszName, nSize );
+    #endif
+        
+    return TRUE;
+}
+
+PVOID
+CPerfSnapshot::GetPostHeaderPointer( void )
+{
+    // Returns a header to the first byte following the PERF_DATA_BLOCK
+    // (including the variable length system name string at the end)
+    return m_pPerfDataHeader ?
+            MakePtr(PVOID, m_pPerfDataHeader,m_pPerfDataHeader->HeaderLength)
+            : 0;
+}
+
+BOOL
+CPerfSnapshot::ConvertSnapshotItemName( PCTSTR pszIn,
+                                        PTSTR pszOut, DWORD nSize )
+{
+    if ( IsBadStringPtr( pszIn, 0xFFFFFFFF ) )
+        return FALSE;
+
+
+	DWORD objectID = m_pCounterTitles->GetIndexFromTitleString(pszIn);
+
+    if ( objectID )
+        pszOut += wsprintf( pszOut, TEXT("%u "), objectID );
+    else
+        pszOut += wsprintf( pszOut, TEXT("%s "), pszIn );
+
+    return TRUE;
+}