/// <summary>
/// Pad a length of the term buffer with a padding record.
/// </summary>
/// <param name="termId"> for the current term.</param>
/// <param name="termOffset"> in the term at which to append.</param>
/// <param name="header"> for writing the default header.</param>
/// <param name="length"> of the padding to be written.</param>
/// <returns> the resulting offset of the term after success otherwise <see cref="TRIPPED"/>.</returns>
public int AppendPadding(
int termId,
int termOffset,
HeaderWriter header,
int length)
{
int frameLength = length + DataHeaderFlyweight.HEADER_LENGTH;
int alignedLength = BitUtil.Align(frameLength, FrameDescriptor.FRAME_ALIGNMENT);
UnsafeBuffer termBuffer = _termBuffer;
int termLength = termBuffer.Capacity;
int resultingOffset = termOffset + alignedLength;
PutRawTailOrdered(termId, resultingOffset);
if (resultingOffset > termLength)
{
resultingOffset = HandleEndOfLogCondition(termBuffer, termOffset, header, termLength, termId);
}
else
{
header.Write(termBuffer, termOffset, frameLength, termId);
FrameDescriptor.FrameType(termBuffer, termOffset, FrameDescriptor.PADDING_FRAME_TYPE);
FrameDescriptor.FrameLengthOrdered(termBuffer, termOffset, frameLength);
}
return(resultingOffset);
}
private long HandleEndOfLogCondition(UnsafeBuffer termBuffer, long termOffset, HeaderWriter header,
int termLength, int termId)
{
if (termOffset < termLength)
{
int offset = (int)termOffset;
int paddingLength = termLength - offset;
header.Write(termBuffer, offset, paddingLength, termId);
FrameDescriptor.FrameType(termBuffer, offset, FrameDescriptor.PADDING_FRAME_TYPE);
FrameDescriptor.FrameLengthOrdered(termBuffer, offset, paddingLength);
}
return(FAILED);
}
private long HandleEndOfLogCondition(UnsafeBuffer termBuffer, long termOffset, HeaderWriter header,
int termLength, int termId)
{
int resultingOffset = FAILED;
if (termOffset <= termLength)
{
resultingOffset = TRIPPED;
if (termOffset < termLength)
{
int offset = (int)termOffset;
int paddingLength = termLength - offset;
header.Write(termBuffer, offset, paddingLength, termId);
FrameDescriptor.FrameType(termBuffer, offset, FrameDescriptor.PADDING_FRAME_TYPE);
FrameDescriptor.FrameLengthOrdered(termBuffer, offset, paddingLength);
}
}
return(LogBufferDescriptor.PackTail(termId, resultingOffset));
}
/// <summary>
/// Try to gap fill the current term at a given offset if the gap contains no data.
///
/// Note: the gap offset plus gap length must end on a <seealso cref="FrameDescriptor.FRAME_ALIGNMENT"/> boundary.
/// </summary>
/// <param name="logMetaDataBuffer"> containing the default headers </param>
/// <param name="termBuffer"> to gap fill </param>
/// <param name="termId"> for the current term. </param>
/// <param name="gapOffset"> to fill from </param>
/// <param name="gapLength"> to length of the gap. </param>
/// <returns> true if the gap has been filled with a padding record or false if data found. </returns>
public static bool TryFillGap(UnsafeBuffer logMetaDataBuffer, UnsafeBuffer termBuffer, int termId, int gapOffset, int gapLength)
{
int offset = gapOffset + gapLength - FrameDescriptor.FRAME_ALIGNMENT;
while (offset >= gapOffset)
{
if (0 != termBuffer.GetInt(offset))
{
return(false);
}
offset -= FrameDescriptor.FRAME_ALIGNMENT;
}
LogBufferDescriptor.ApplyDefaultHeader(logMetaDataBuffer, termBuffer, gapOffset);
FrameDescriptor.FrameType(termBuffer, gapOffset, HeaderFlyweight.HDR_TYPE_PAD);
FrameDescriptor.FrameTermOffset(termBuffer, gapOffset);
FrameDescriptor.FrameTermId(termBuffer, gapOffset, termId);
FrameDescriptor.FrameLengthOrdered(termBuffer, gapOffset, gapLength);
return(true);
}