} // end _PruneLogFiles()
private static void _PruneFilesNotInUse(string dir, string pattern, long cbMaxSize)
{
const int MIN_LOG_BYTES = 1024 * 1024;
if (cbMaxSize < MIN_LOG_BYTES)
{
Util.Fail("should not happen"); // safe to use Util.Fail here
cbMaxSize = MIN_LOG_BYTES;
}
using (ExceptionGuard disposer = new ExceptionGuard())
{
DirectoryInfo di = new DirectoryInfo(dir);
FileSystemInfo[] fsis = di.GetFileSystemInfos(pattern);
List <FileInfo> files = new List <FileInfo>(fsis.Length);
List <FileStream> fileLocks = new List <FileStream>(fsis.Length);
disposer.ProtectAll(fileLocks); // it does not make a copy of the list, so it's okay that we haven't put anything in yet.
long totalSize = 0;
foreach (FileSystemInfo fsi in fsis)
{
FileInfo fi = fsi as FileInfo;
if (null != fi)
{
// We only count not-in-use files against our disk limit. If the
// file is not in use, this will "lock" it (making it appear
// in-use to anybody else) and put the resulting FileStream in the
// fileLocks list.
if (_FileNotInUse(fi, fileLocks))
{
#if DEBUG_LOG_PRUNING
Trace("File \"{0}\" is NOT in use. (it will be considered for pruning)", fi.FullName);
#endif
fi.Refresh(); // in case _FileNotInUse finalized it.
totalSize += fi.Length;
files.Add(fi);
}
#if DEBUG_LOG_PRUNING
else
{
Trace("File \"{0}\" is in use.", fi.FullName);
}
#endif
}
}
if (totalSize <= cbMaxSize)
{
// Don't need to prune anything.
return;
}
// Sort by age: oldest first.
files.Sort((x, y) => x.CreationTime.CompareTo(y.CreationTime));
long cbDeletedSoFar = 0;
long cbNeedToDelete = totalSize - cbMaxSize;
int idxCandidate = 0;
while ((idxCandidate < files.Count) &&
(cbDeletedSoFar < cbNeedToDelete))
{
if (_TryDeleteOldFile(files[idxCandidate].FullName))
{
cbDeletedSoFar += files[idxCandidate].Length;
}
idxCandidate++;
}
if (cbDeletedSoFar < cbNeedToDelete)
{
Trace("Warning: could not delete enough log files matching \"{0}\" from \"{1}\" to get under the limit of {2}.",
pattern,
dir,
Util.FormatByteSize(cbMaxSize));
}
} // end using( disposer ) <-- the files will actually get deleted here when we close the FileStream handles.
} // end _PruneFilesNotInUse()