OpenForRead(long streamPosition, string traceType)
{
// Combine the metadata and page-align IoBuffers
uint mdBufferSize;
uint paBufferSize;
this._MetadataKIoBuffer.QuerySize(out mdBufferSize);
this._PageAlignedKIoBuffer.QuerySize(out paBufferSize);
this._AllocationReportedToGC = mdBufferSize + paBufferSize;
AddGCMemoryPressure(this._AllocationReportedToGC);
this._CombinedKIoBuffer.Clear();
this._CombinedKIoBuffer.AddIoBufferReference(this._MetadataKIoBuffer, 0, mdBufferSize);
this._CombinedKIoBuffer.AddIoBufferReference(this._PageAlignedKIoBuffer, 0, paBufferSize);
this._CombinedBufferStream.Reuse(this._CombinedKIoBuffer, this._MetadataSize);
// Parse the log stream physical record
unsafe
{
KLogicalLogInformation.MetadataBlockHeader *mdHdr = null;
mdHdr = (KLogicalLogInformation.MetadataBlockHeader *) this._CombinedBufferStream.GetBufferPointer();
ReleaseAssert.AssertIfNot(
this._CombinedBufferStream.PositionTo(mdHdr->OffsetToStreamHeader),
"Unexpected PositionTo failure");
this._StreamBlockHeader = (KLogicalLogInformation.StreamBlockHeader *) this._CombinedBufferStream.GetBufferPointer();
// Position the stream at 1st byte of user record
ReleaseAssert.AssertIfNot(
this._CombinedBufferStream.Skip((uint)sizeof(KLogicalLogInformation.StreamBlockHeader)),
"Unexpected Skip failure");
this._OffsetToData = mdHdr->OffsetToStreamHeader + (uint)sizeof(KLogicalLogInformation.StreamBlockHeader);
#if false
// TODO: Start: DebugOnly
UInt64 savedCrc = _StreamBlockHeader->HeaderCRC64;
_StreamBlockHeader->HeaderCRC64 = 0;
if (NativeLog.KCrc64(_StreamBlockHeader, (uint)sizeof(KLogicalLogInformation.StreamBlockHeader), 0) != savedCrc)
{
throw new InvalidDataException();
}
_StreamBlockHeader->HeaderCRC64 = 0; // NOTE: Leave HeaderCRC64 0 - this is the unsealed condition
if ((_OffsetToData + _StreamBlockHeader->DataSize) > mdBufferSize)
{
savedCrc = 0;
KIoBufferStream.InterationCallback LocalHashFunc = ((
byte *ioBufferFragment,
ref UInt32 fragmentSize) =>
{
savedCrc = NativeLog.KCrc64(ioBufferFragment, fragmentSize, savedCrc);
return(0);
});
ReleaseAssert.AssertIfNot(
_CombinedBufferStream.Iterate(LocalHashFunc, _StreamBlockHeader->DataSize) == 0,
"Unexpected Iterate failure");
if (_StreamBlockHeader->DataCRC64 != savedCrc)
{
throw new InvalidDataException();
}
}
// TODO: END: DebugOnly
#endif
// Compute position and limits of the KIoBufferStream
System.Diagnostics.Debug.Assert(this._StreamBlockHeader->StreamOffsetPlusOne > 0);
var recordOffsetToDesiredPosition = streamPosition - (this._StreamBlockHeader->StreamOffsetPlusOne - 1);
if ((recordOffsetToDesiredPosition < 0) || (recordOffsetToDesiredPosition >= this._StreamBlockHeader->DataSize))
{
var s =
string.Format(
CultureInfo.InvariantCulture,
"OpenForRead: streamPosition {0}, StreamOffsetPlusOne {1}, DataSize {2}, recordOffsetToDesiredPosition {3}, HeadTruncationPoint {4}, HighestOperationId {5} ",
streamPosition,
this._StreamBlockHeader->StreamOffsetPlusOne,
this._StreamBlockHeader->DataSize,
recordOffsetToDesiredPosition,
this._StreamBlockHeader->HeadTruncationPoint,
this._StreamBlockHeader->HighestOperationId);
AppTrace.TraceSource.WriteInfo(
traceType,
s
);
}
System.Diagnostics.Debug.Assert(recordOffsetToDesiredPosition <= uint.MaxValue);
this._CombinedBufferStream.Reuse(
this._CombinedKIoBuffer,
(uint)recordOffsetToDesiredPosition + this._OffsetToData,
this._OffsetToData + this._StreamBlockHeader->DataSize);
}
}
SealForWrite(
long currentHeadTruncationPoint,
bool IsBarrier,
out NativeLog.IKIoBuffer metadataBuffer,
out uint metadataSize,
out NativeLog.IKIoBuffer pageAlignedBuffer,
out long userSizeOfStreamData,
out long AsnOfRecord,
out long OpOfRecord)
{
unsafe
{
uint trimSize = 0;
uint dataResidingOutsideMetadata = 0;
UInt64 dataCrc = 0;
this._MetadataBlockHeader->Flags = IsBarrier ? (uint)KLogicalLogInformation.MetadatBlockHeaderFlags.IsEndOfLogicalRecord : 0;
this._StreamBlockHeader->DataSize = this._CombinedBufferStream.GetPosition() - this._OffsetToData;
this._StreamBlockHeader->HeadTruncationPoint = currentHeadTruncationPoint;
this._PageAlignedKIoBufferView.Clear();
// Compute CRC64 for record data
if ((this._OffsetToData < KLogicalLogInformation.FixedMetadataSize) &&
((this._OffsetToData + this._StreamBlockHeader->DataSize) <= KLogicalLogInformation.FixedMetadataSize))
{
// no data outside the metadata buffer
metadataSize = this._OffsetToData + this._StreamBlockHeader->DataSize;
}
else
{
//
// Compute how much of the metadata is being used. It should be the entire 4K block minus the
// space reserved by the physical logger
//
metadataSize = (uint)KLogicalLogInformation.FixedMetadataSize - this._MetadataSize;
ReleaseAssert.AssertIfNot(this._CombinedBufferStream.PositionTo(this._OffsetToData), "Unexpected PositionTo failure");
KIoBufferStream.InterationCallback LocalHashFunc = ((
byte *ioBufferFragment,
ref UInt32 fragmentSize) =>
{
dataCrc = NativeLog.KCrc64(ioBufferFragment, fragmentSize, dataCrc);
return(0);
});
ReleaseAssert.AssertIfNot(
this._CombinedBufferStream.Iterate(LocalHashFunc, this._StreamBlockHeader->DataSize) == 0,
"Unexpected Iterate failure");
//
// Compute the number of data blocks that are needed to hold the data that is within the payload
// data buffer. This excludes the payload data in the metadata portion
//
ReleaseAssert.AssertIf(this._OffsetToData > MetadataBlockSize, "Unexpected size for _OffsetToData");
dataResidingOutsideMetadata = this._StreamBlockHeader->DataSize - (MetadataBlockSize - this._OffsetToData);
trimSize = ((((dataResidingOutsideMetadata) + (MetadataBlockSize - 1)) / MetadataBlockSize) * MetadataBlockSize);
this._PageAlignedKIoBufferView.AddIoBufferReference(
this._PageAlignedKIoBuffer,
0,
(uint)trimSize);
}
this._StreamBlockHeader->DataCRC64 = dataCrc;
// Now compute block header CRC
this._StreamBlockHeader->HeaderCRC64 = NativeLog.KCrc64(
this._StreamBlockHeader,
(uint)sizeof(KLogicalLogInformation.StreamBlockHeader),
0);
// Build results
metadataBuffer = this._MetadataKIoBuffer;
pageAlignedBuffer = this._PageAlignedKIoBufferView;
userSizeOfStreamData = this._StreamBlockHeader->DataSize;
AsnOfRecord = this._StreamBlockHeader->StreamOffsetPlusOne;
OpOfRecord = this._StreamBlockHeader->HighestOperationId;
}
}
