/// <summary>
/// Gets a log reader capable of reading records between the specified positions
/// </summary>
internal PhysicalLogReader GetPhysicalLogReader(
ulong startingRecordPosition,
ulong endingRecordPosition,
long startingLsn,
string readerName,
LogReaderType readerType)
{
PhysicalLogReader logReader;
do
{
logReader = new PhysicalLogReader(
this,
startingRecordPosition,
endingRecordPosition,
startingLsn,
readerName,
readerType);
if (logReader.IsValid)
{
break;
}
logReader.Dispose();
} while (true);
return(logReader);
}
internal string GetEarliestLogReaderName(out LogReaderType readerType)
{
lock (this.readersLock)
{
readerType = this.earliestLogReader.ReaderType;
return(this.earliestLogReader.ReaderName);
}
}
internal LogReaderRange(
long fullCopyStartingLsn,
ulong startingRecordPosition,
string readerName,
LogReaderType readerType)
{
this.startingRecordPosition = startingRecordPosition;
this.referenceCount = 1;
this.ReaderName = readerName;
this.logReaderType = readerType;
this.fullCopyStartingLsn = fullCopyStartingLsn;
}
internal bool AddLogReader(
long startingLsn,
ulong startingRecordPosition,
ulong endingRecordPosition,
string readerName,
LogReaderType readerType)
{
Utility.Assert(
(startingRecordPosition == 0) || (this.LogHeadRecordPosition <= startingRecordPosition),
"(startingRecordPosition == 0) || (this.CurrentLogHeadPosition <= startingRecordPosition), start record position :{0}. LogHeadRecordPosition: {1}",
startingRecordPosition, this.LogHeadRecordPosition);
FabricEvents.Events.LogManager(
this.Tracer.Type,
"AddLogReader: Adding Log Reader with StartingRecordPosition: " + startingRecordPosition + " EndingRecordPosition: " + endingRecordPosition +
" ReaderName: " + readerName);
lock (this.readersLock)
{
if (this.LogHeadRecordPosition > startingRecordPosition)
{
return(false);
}
int i;
LogReaderRange readerRange;
for (i = 0; i < this.logReaderRanges.Count; i++)
{
readerRange = this.logReaderRanges[i];
if (startingRecordPosition < readerRange.StartingRecordPosition)
{
break;
}
if (readerRange.StartingRecordPosition == startingRecordPosition)
{
readerRange.AddRef();
// If a fullcopy reader comes in at the same position of a non-full copy reader, over-write the type as full-copy reader
// have significance when determining safe LSN to delete state providers
if (readerType == LogReaderType.FullCopy)
{
readerRange.ReaderType = LogReaderType.FullCopy;
}
return(true);
}
}
readerRange = new LogReaderRange(startingLsn, startingRecordPosition, readerName, readerType);
this.logReaderRanges.Insert(i, readerRange);
if (i == 0)
{
this.earliestLogReader = this.logReaderRanges[0];
}
}
Utility.Assert(
(endingRecordPosition == long.MaxValue) || (this.CurrentLogTailPosition >= endingRecordPosition),
@"(endingRecordPosition == Int64.MaxValue) || (this.CurrentLogTailPosition >= endingRecordPosition), EndingRecordPosition: {0}",
endingRecordPosition);
return(true);
}
