/// <summary>Delete old OIV fsimages.</summary>
/// <remarks>
/// Delete old OIV fsimages. Since the target dir is not a full blown
/// storage directory, we simply list and keep the latest ones. For the
/// same reason, no storage inspector is used.
/// </remarks>
internal virtual void PurgeOldLegacyOIVImages(string dir, long txid)
{
FilePath oivImageDir = new FilePath(dir);
string oivImagePrefix = NNStorage.NameNodeFile.ImageLegacyOiv.GetName();
string[] filesInStorage;
// Get the listing
filesInStorage = oivImageDir.List(new _FilenameFilter_250(oivImagePrefix));
// Check whether there is any work to do.
if (filesInStorage.Length <= numCheckpointsToRetain)
{
return;
}
// Create a sorted list of txids from the file names.
TreeSet <long> sortedTxIds = new TreeSet <long>();
foreach (string fName in filesInStorage)
{
// Extract the transaction id from the file name.
long fTxId;
try
{
fTxId = long.Parse(Sharpen.Runtime.Substring(fName, oivImagePrefix.Length + 1));
}
catch (FormatException)
{
// This should not happen since we have already filtered it.
// Log and continue.
Log.Warn("Invalid file name. Skipping " + fName);
continue;
}
sortedTxIds.AddItem(Sharpen.Extensions.ValueOf(fTxId));
}
int numFilesToDelete = sortedTxIds.Count - numCheckpointsToRetain;
IEnumerator <long> iter = sortedTxIds.GetEnumerator();
while (numFilesToDelete > 0 && iter.HasNext())
{
long txIdVal = iter.Next();
string fileName = NNStorage.GetLegacyOIVImageFileName(txIdVal);
Log.Info("Deleting " + fileName);
FilePath fileToDelete = new FilePath(oivImageDir, fileName);
if (!fileToDelete.Delete())
{
// deletion failed.
Log.Warn("Failed to delete image file: " + fileToDelete);
}
numFilesToDelete--;
}
}