public IEnumerable <CommitPoint> GetCommitPoints()
{
using (var inputStream = _persistenceManager.GetInputStream(_masterFilePath))
{
if (inputStream.Length <= HeaderSize)
{
yield break;
}
long recordPos = inputStream.Length - CommitPoint.RecordSize;
while (recordPos >= HeaderSize)
{
inputStream.Seek(recordPos, SeekOrigin.Begin);
CommitPoint commitPoint = null;
try
{
commitPoint = CommitPoint.Load(inputStream);
}
catch (InvalidCommitPointException)
{
Logging.LogError(BrightstarEventId.CommitPointReadError,
"Could not read commit point at offset {0} in master file '{1}'",
inputStream.Position, _masterFilePath);
}
if (commitPoint != null)
{
yield return(commitPoint);
}
recordPos = recordPos - CommitPoint.RecordSize;
}
}
}
public CommitPoint GetCommitPoint(ulong commitPointLocation)
{
if (commitPointLocation < HeaderSize ||
((commitPointLocation - HeaderSize) % (ulong)CommitPoint.RecordSize) != 0)
{
throw new ArgumentException("Invalid commit point offset", "commitPointLocation");
}
using (var inputStream = _persistenceManager.GetInputStream(_masterFilePath))
{
inputStream.Seek((long)commitPointLocation, SeekOrigin.Begin);
return(CommitPoint.Load(inputStream));
}
}
private CommitPoint _GetCommitPoint(long commitPointLocation, Stream stream)
{
CommitPoint ret;
if (_commitPoints.TryGetValue(commitPointLocation, out ret))
{
return(ret);
}
stream.Seek(commitPointLocation, SeekOrigin.Begin);
ret = CommitPoint.Load(stream);
_commitPoints.TryAdd(commitPointLocation, ret);
return(ret);
}
public CommitPoint GetLatestCommitPoint(int skipRecords = 0)
{
try
{
using (var stream = _persistenceManager.GetInputStream(_masterFilePath))
{
if (stream.Length == HeaderSize)
{
if (skipRecords > 0)
{
throw new StoreManagerException(_directoryPath,
"Master file is corrupt and no valid commit point information could be read.");
}
return(null);
}
long recordStart;
if ((stream.Length - HeaderSize) % CommitPoint.RecordSize != 0)
{
recordStart = stream.Length - ((stream.Length - HeaderSize) % CommitPoint.RecordSize) -
((skipRecords + 1) * CommitPoint.RecordSize);
}
else
{
recordStart = stream.Length - ((skipRecords + 1) * CommitPoint.RecordSize);
}
stream.Seek(recordStart, SeekOrigin.Begin);
var commitPoint = CommitPoint.Load(stream);
if (skipRecords > 0)
{
// We skipped over one or more invalid records, so we record a higher next transaction id number in the commit point we return
commitPoint.NextCommitNumber = commitPoint.NextCommitNumber + (ulong)skipRecords;
// Master file is not truncated here like in the old implementation,
// because this could potentially interfere with a master file write operation for a store commit
// instead we will need to just always skip corrupt transactions.
}
return(commitPoint);
}
}
catch (InvalidCommitPointException)
{
Logging.LogWarning(BrightstarEventId.CommitPointReadError,
String.Format(
"Failed to read valid commit point from master file '{0}'. Rewinding to previous commit point",
_masterFilePath));
return(GetLatestCommitPoint(skipRecords + 1));
}
}
