AmlStream.c

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#include <Stream/AmlStream.h>
 
EFI_STATUS
EFIAPI
AmlStreamInit (
  IN  OUT AML_STREAM             *Stream,
  IN      UINT8                  *Buffer,
  IN      UINT32                 MaxBufferSize,
  IN      EAML_STREAM_DIRECTION  Direction
  )
{
  if ((Stream == NULL)                            ||
      (Buffer == NULL)                            ||
      (MaxBufferSize == 0)                        ||
      ((Direction != EAmlStreamDirectionForward)  &&
       (Direction != EAmlStreamDirectionBackward)))
  {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  Stream->Buffer        = Buffer;
  Stream->MaxBufferSize = MaxBufferSize;
  Stream->Index         = 0;
  Stream->Direction     = Direction;
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
AmlStreamClone (
  IN  CONST AML_STREAM   *Stream,
  OUT        AML_STREAM  *ClonedStream
  )
{
  if (!IS_STREAM (Stream)   ||
      (ClonedStream == NULL))
  {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  ClonedStream->Buffer        = Stream->Buffer;
  ClonedStream->MaxBufferSize = Stream->MaxBufferSize;
  ClonedStream->Index         = Stream->Index;
  ClonedStream->Direction     = Stream->Direction;
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
AmlStreamInitSubStream (
  IN  CONST AML_STREAM  *Stream,
  OUT       AML_STREAM  *SubStream
  )
{
  if (!IS_STREAM (Stream) ||
      (SubStream == NULL))
  {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  if (IS_STREAM_FORWARD (Stream)) {
    SubStream->Buffer = AmlStreamGetCurrPos (Stream);
  } else if (IS_STREAM_BACKWARD (Stream)) {
    SubStream->Buffer = Stream->Buffer;
  } else {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  SubStream->MaxBufferSize = AmlStreamGetFreeSpace (Stream);
  SubStream->Index         = 0;
  SubStream->Direction     = Stream->Direction;
 
  return EFI_SUCCESS;
}
 
UINT8 *
EFIAPI
AmlStreamGetBuffer (
  IN  CONST AML_STREAM  *Stream
  )
{
  if (!IS_STREAM (Stream)) {
    ASSERT (0);
    return NULL;
  }
 
  return Stream->Buffer;
}
 
UINT32
EFIAPI
AmlStreamGetMaxBufferSize (
  IN  CONST AML_STREAM  *Stream
  )
{
  if (!IS_STREAM (Stream)) {
    ASSERT (0);
    return 0;
  }
 
  return Stream->MaxBufferSize;
}
 
EFI_STATUS
EFIAPI
AmlStreamReduceMaxBufferSize (
  IN  AML_STREAM  *Stream,
  IN  UINT32      Diff
  )
{
  if (!IS_STREAM (Stream)       ||
      (Diff == 0)               ||
      ((Stream->MaxBufferSize - Diff) <= Stream->Index))
  {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  Stream->MaxBufferSize -= Diff;
  return EFI_SUCCESS;
}
 
UINT32
EFIAPI
AmlStreamGetIndex (
  IN  CONST AML_STREAM  *Stream
  )
{
  if (!IS_STREAM (Stream)) {
    ASSERT (0);
    return 0;
  }
 
  return Stream->Index;
}
 
EAML_STREAM_DIRECTION
EFIAPI
AmlStreamGetDirection (
  IN  CONST AML_STREAM  *Stream
  )
{
  if (!IS_STREAM (Stream)) {
    ASSERT (0);
    return EAmlStreamDirectionInvalid;
  }
 
  return Stream->Direction;
}
 
UINT8 *
EFIAPI
AmlStreamGetCurrPos (
  IN  CONST AML_STREAM  *Stream
  )
{
  if (!IS_STREAM (Stream)) {
    ASSERT (0);
    return NULL;
  }
 
  if (IS_STREAM_FORWARD (Stream)) {
    return Stream->Buffer + Stream->Index;
  } else if (IS_STREAM_BACKWARD (Stream)) {
    return Stream->Buffer + (Stream->MaxBufferSize - 1) - Stream->Index;
  } else {
    ASSERT (0);
    return NULL;
  }
}
 
UINT32
EFIAPI
AmlStreamGetFreeSpace (
  IN  CONST AML_STREAM  *Stream
  )
{
  if (!IS_STREAM (Stream)) {
    ASSERT (0);
    return 0;
  }
 
  if (Stream->Index > Stream->MaxBufferSize) {
    ASSERT (0);
    return 0;
  }
 
  return Stream->MaxBufferSize - Stream->Index;
}
 
EFI_STATUS
EFIAPI
AmlStreamProgress (
  IN  AML_STREAM  *Stream,
  IN  UINT32      Offset
  )
{
  if (!IS_STREAM (Stream)         ||
      IS_END_OF_STREAM (Stream)  ||
      (Offset == 0))
  {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  if (AmlStreamGetFreeSpace (Stream) < Offset) {
    ASSERT (0);
    return EFI_BUFFER_TOO_SMALL;
  }
 
  Stream->Index += Offset;
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
AmlStreamRewind (
  IN  AML_STREAM  *Stream,
  IN  UINT32      Offset
  )
{
  if (!IS_STREAM (Stream) ||
      (Offset == 0))
  {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  if (AmlStreamGetIndex (Stream) < Offset) {
    ASSERT (0);
    return EFI_BUFFER_TOO_SMALL;
  }
 
  Stream->Index -= Offset;
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
AmlStreamReset (
  IN  AML_STREAM  *Stream
  )
{
  if (!IS_STREAM (Stream)) {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  Stream->Index = 0;
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
AmlStreamPeekByte (
  IN  AML_STREAM  *Stream,
  OUT UINT8       *OutByte
  )
{
  UINT8  *CurPos;
 
  if (!IS_STREAM (Stream)       ||
      IS_END_OF_STREAM (Stream) ||
      (OutByte == NULL))
  {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  CurPos = AmlStreamGetCurrPos (Stream);
  if (CurPos == NULL) {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  *OutByte = *CurPos;
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
AmlStreamReadByte (
  IN  AML_STREAM  *Stream,
  OUT UINT8       *OutByte
  )
{
  EFI_STATUS  Status;
 
  if (!IS_STREAM (Stream)       ||
      IS_END_OF_STREAM (Stream) ||
      (OutByte == NULL))
  {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  // Stream is checked in the function call.
  Status = AmlStreamPeekByte (Stream, OutByte);
  if (EFI_ERROR (Status)) {
    ASSERT (0);
    return Status;
  }
 
  Status = AmlStreamProgress (Stream, 1);
  ASSERT_EFI_ERROR (Status);
  return Status;
}
 
EFI_STATUS
EFIAPI
AmlStreamWrite (
  IN        AML_STREAM  *Stream,
  IN  CONST UINT8       *Buffer,
  IN        UINT32      Size
  )
{
  UINT8  *CurrPos;
 
  if (!IS_STREAM (Stream)       ||
      IS_END_OF_STREAM (Stream) ||
      (Buffer == NULL)          ||
      (Size == 0))
  {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  if (AmlStreamGetFreeSpace (Stream) < Size) {
    ASSERT (0);
    return EFI_BUFFER_TOO_SMALL;
  }
 
  CurrPos = AmlStreamGetCurrPos (Stream);
 
  // If the Stream goes backward, prepare some space to copy the data.
  if (IS_STREAM_BACKWARD (Stream)) {
    CurrPos -= Size;
  }
 
  CopyMem (CurrPos, Buffer, Size);
  Stream->Index += Size;
 
  return EFI_SUCCESS;
}
 
BOOLEAN
EFIAPI
AmlStreamCmp (
  IN  CONST AML_STREAM  *Stream1,
  IN  CONST AML_STREAM  *Stream2,
  IN        UINT32      Size
  )
{
  UINT32  MinSize;
  UINT8   *CurrPosStream1;
  UINT8   *CurrPosStream2;
 
  if (!IS_STREAM (Stream1)                        ||
      IS_END_OF_STREAM (Stream1)                  ||
      !IS_STREAM (Stream2)                        ||
      IS_END_OF_STREAM (Stream2)                  ||
      (Stream1->Direction != Stream2->Direction)  ||
      (Size == 0))
  {
    ASSERT (0);
    return FALSE;
  }
 
  // Check the Size is not longer than the remaining size of
  // Stream1 and Stream2.
  MinSize = MIN (
              AmlStreamGetFreeSpace (Stream1),
              AmlStreamGetFreeSpace (Stream2)
              );
  if (MinSize < Size) {
    ASSERT (0);
    return FALSE;
  }
 
  CurrPosStream1 = AmlStreamGetCurrPos (Stream1);
  if (CurrPosStream1 == NULL) {
    ASSERT (0);
    return FALSE;
  }
 
  CurrPosStream2 = AmlStreamGetCurrPos (Stream2);
  if (CurrPosStream2 == NULL) {
    ASSERT (0);
    return FALSE;
  }
 
  if (Stream1->Direction == EAmlStreamDirectionForward) {
    return (0 == CompareMem (CurrPosStream1, CurrPosStream2, MinSize));
  }
 
  // The stream is already pointing on the last byte, thus the (-1).
  //          +---------------------+
  // BStream  | | | | | | | |M|E|T|0|
  //          +---------------------+
  //                               ^
  //                             CurrPos
  return (0 == CompareMem (
                 CurrPosStream1 - (MinSize - 1),
                 CurrPosStream2 - (MinSize - 1),
                 MinSize
                 ));
}
 
EFI_STATUS
EFIAPI
AmlStreamCpyS (
  OUT CHAR8       *DstBuffer,
  IN  UINT32      MaxDstBufferSize,
  IN  AML_STREAM  *Stream,
  IN  UINT32      Size
  )
{
  CHAR8  *StreamBufferStart;
 
  // Stream is checked in the function call.
  if ((DstBuffer == NULL)       ||
      (MaxDstBufferSize == 0)   ||
      (Size > MaxDstBufferSize) ||
      (Size > AmlStreamGetMaxBufferSize (Stream)))
  {
    ASSERT (0);
    return EFI_INVALID_PARAMETER;
  }
 
  if (Size == 0) {
    return EFI_SUCCESS;
  }
 
  // Find the address at which the data is starting.
  StreamBufferStart = (CHAR8 *)(IS_STREAM_FORWARD (Stream) ?
                                Stream->Buffer :
                                AmlStreamGetCurrPos (Stream));
 
  CopyMem (DstBuffer, StreamBufferStart, Size);
 
  return EFI_SUCCESS;
}