/*++

Copyright (c) 2006, Intel Corporation                                                         
All rights reserved. This program and the accompanying materials                          
are licensed and made available under the terms and conditions of the BSD License         
which accompanies this distribution.  The full text of the license may be found at        
http://opensource.org/licenses/bsd-license.php                                            
                                                                                          
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

Module Name:

  DxePerformanceLib.c

Abstract:

  Performance Library

--*/

STATIC PERFORMANCE_PROTOCOL    *mPerformance = NULL;

/**
  The constructor function caches the pointer to Performance protocol.
  
  The constructor function locates Performance protocol from protocol database.
  It will ASSERT() if that operation fails and it will always return EFI_SUCCESS. 

  @param  ImageHandle   The firmware allocated handle for the EFI image.
  @param  SystemTable   A pointer to the EFI System Table.
  
  @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.

**/
EFI_STATUS
EFIAPI
PerformanceLibConstructor (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS            Status;

  Status = gBS->LocateProtocol (&gPerformanceProtocolGuid, NULL, (VOID **) &mPerformance);
  ASSERT_EFI_ERROR (Status);
  ASSERT (mPerformance != NULL);

  return Status;
}

/**
  Creates a record for the beginning of a performance measurement. 
  
  Creates a record that contains the Handle, Token, and Module.
  If TimeStamp is not zero, then TimeStamp is added to the record as the start time.
  If TimeStamp is zero, then this function reads the current time stamp
  and adds that time stamp value to the record as the start time.

  @param  Handle                  Pointer to environment specific context used
                                  to identify the component being measured.
  @param  Token                   Pointer to a Null-terminated ASCII string
                                  that identifies the component being measured.
  @param  Module                  Pointer to a Null-terminated ASCII string
                                  that identifies the module being measured.
  @param  TimeStamp               64-bit time stamp.

  @retval RETURN_SUCCESS          The start of the measurement was recorded.
  @retval RETURN_OUT_OF_RESOURCES There are not enough resources to record the measurement.

**/
RETURN_STATUS
EFIAPI
StartPerformanceMeasurement (
  IN CONST VOID   *Handle,  OPTIONAL
  IN CONST CHAR8  *Token,   OPTIONAL
  IN CONST CHAR8  *Module,  OPTIONAL
  IN UINT64       TimeStamp
  )
{
  EFI_STATUS  Status;
  
  Status = mPerformance->StartGauge (Handle, Token, Module, TimeStamp);

  return (RETURN_STATUS) Status;
}

/**
  Fills in the end time of a performance measurement. 
  
  Looks up the record that matches Handle, Token, and Module.
  If the record can not be found then return RETURN_NOT_FOUND.
  If the record is found and TimeStamp is not zero,
  then TimeStamp is added to the record as the end time.
  If the record is found and TimeStamp is zero, then this function reads
  the current time stamp and adds that time stamp value to the record as the end time.
  If this function is called multiple times for the same record, then the end time is overwritten.

  @param  Handle                  Pointer to environment specific context used
                                  to identify the component being measured.
  @param  Token                   Pointer to a Null-terminated ASCII string
                                  that identifies the component being measured.
  @param  Module                  Pointer to a Null-terminated ASCII string
                                  that identifies the module being measured.
  @param  TimeStamp               64-bit time stamp.

  @retval RETURN_SUCCESS          The end of  the measurement was recorded.
  @retval RETURN_NOT_FOUND        The specified measurement record could not be found.

**/
RETURN_STATUS
EFIAPI
EndPerformanceMeasurement (
  IN CONST VOID   *Handle,  OPTIONAL
  IN CONST CHAR8  *Token,   OPTIONAL
  IN CONST CHAR8  *Module,  OPTIONAL
  IN UINT64       TimeStamp
  )
{
  EFI_STATUS  Status;

  Status = mPerformance->EndGauge (Handle, Token, Module, TimeStamp);

  return (RETURN_STATUS) Status;
}

/**
  Retrieves a previously logged performance measurement. 
  
  Looks up the record that matches Handle, Token, and Module.
  If the record can not be found then return RETURN_NOT_FOUND.
  If the record is found then the start of the measurement is returned in StartTimeStamp,
  and the end of the measurement is returned in EndTimeStamp.

  @param  LogEntryKey             The key for the previous performance measurement log entry.
                                  If 0, then the first performance measurement log entry is retrieved.
  @param  Handle                  Pointer to environment specific context used
                                  to identify the component being measured.
  @param  Token                   Pointer to a Null-terminated ASCII string
                                  that identifies the component being measured.
  @param  Module                  Pointer to a Null-terminated ASCII string
                                  that identifies the module being measured.
  @param  StartTimeStamp          The 64-bit time stamp that was recorded when the measurement was started.
  @param  EndTimeStamp            The 64-bit time stamp that was recorded when the measurement was ended.

  @return The key for the current performance log entry.

**/
UINTN
EFIAPI
GetPerformanceMeasurement (
  UINTN           LogEntryKey, 
  OUT CONST VOID  **Handle,
  OUT CONST CHAR8 **Token,
  OUT CONST CHAR8 **Module,
  OUT UINT64      *StartTimeStamp,
  OUT UINT64      *EndTimeStamp
  )
{
  EFI_STATUS        Status;
  GAUGE_DATA_ENTRY  *GaugeData;

  ASSERT (Handle != NULL);
  ASSERT (Token != NULL);
  ASSERT (Module != NULL);
  ASSERT (StartTimeStamp != NULL);
  ASSERT (EndTimeStamp != NULL);

  Status = mPerformance->GetGauge (LogEntryKey++, &GaugeData);
  
  //
  // Make sure that LogEntryKey is a valid log entry key,
  //
  ASSERT (Status != EFI_INVALID_PARAMETER);

  if (EFI_ERROR (Status)) {
    //
    // The LogEntryKey is the last entry (equals to the total entry number).
    //
    return 0;
  }

  ASSERT (GaugeData != NULL);

  *Handle         = (VOID *) (UINTN) GaugeData->Handle;
  *Token          = GaugeData->Token;
  *Module         = GaugeData->Module;
  *StartTimeStamp = GaugeData->StartTimeStamp;
  *EndTimeStamp   = GaugeData->EndTimeStamp;

  return LogEntryKey;  
}

/**
  Returns TRUE if the performance measurement macros are enabled. 
  
  This function returns TRUE if the PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
  PcdPerformanceLibraryPropertyMask is set.  Otherwise FALSE is returned.

  @retval TRUE                    The PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
                                  PcdPerformanceLibraryPropertyMask is set.
  @retval FALSE                   The PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
                                  PcdPerformanceLibraryPropertyMask is clear.

**/
BOOLEAN
EFIAPI
PerformanceMeasurementEnabled (
  VOID
  )
{
  return ((PcdGet8(PcdPerformanceLibraryPropertyMask) & PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED) != 0);
}