// Initializes a new instance of the KeyValueStore.
public KeyValueStore(string baseFileName, RazorCache cache)
{
if (!Directory.Exists (baseFileName))
Directory.CreateDirectory (baseFileName);
_manifest = new Manifest (baseFileName);
_manifest.Logger = RazorDBx.C5.Logger.Log;
int memTableVersion = _manifest.CurrentVersion (0);
CheckForIncompleteJournalRotation (baseFileName, memTableVersion); // Check for a previously aborted journal rotation.
_currentJournaledMemTable = new JournaledMemTable (_manifest.BaseFileName, memTableVersion); // Create new journal for this run (and potentially load from disk, if there was data loaded previously).
_cache = cache == null ? new RazorCache () : cache;
}
void CheckForIncompleteJournalRotation(string baseFileName, int currentMemTableVersion)
{
int previousMemTableVersion = currentMemTableVersion - 1;
if (File.Exists (Config.JournalFile (baseFileName, previousMemTableVersion))) { // Is there a left-over journal from a previous rotation that was aborted while in rotation?
var memTable = new JournaledMemTable (baseFileName, previousMemTableVersion);
memTable.WriteToSortedBlockTable (_manifest);
memTable.Close ();
}
}
// Rotates the mem table.
public void RotateMemTable()
{
lock (memTableRotationLock) {
if (_currentJournaledMemTable.Full) { // Double check the flag in case we have multiple threads that make it into this routine.
_rotationSemaphore.WaitOne (); // Wait for the rotation gate to be open, and automatically reset once a single thread gets through.
_rotatedJournaledMemTable = Interlocked.Exchange<JournaledMemTable> (ref _currentJournaledMemTable, new JournaledMemTable (_manifest.BaseFileName, _manifest.NextVersion (0)));
ThreadPool.QueueUserWorkItem ((o) => {
try {
_rotatedJournaledMemTable.WriteToSortedBlockTable (_manifest);
_rotatedJournaledMemTable = null;
} finally {
_rotationSemaphore.Release (); // Open the gate for the next rotation.
}
});
}
}
}
// Truncates a current database.
public void Truncate()
{
_currentJournaledMemTable.Close ();
TableManager.Default.Close (this);
foreach (var pair in _secondaryIndexes)
pair.Value.Close (FastClose);
string basePath = Path.GetFullPath (Manifest.BaseFileName);
foreach (string file in Directory.GetFiles(basePath, "*.*", SearchOption.AllDirectories))
File.Delete (file);
foreach (string dir in Directory.GetDirectories(basePath, "*.*", SearchOption.AllDirectories))
Directory.Delete (dir, true);
_manifest = new Manifest (basePath);
_currentJournaledMemTable = new JournaledMemTable (_manifest.BaseFileName, _manifest.CurrentVersion (0));
_cache = new RazorCache ();
_secondaryIndexes = new Dictionary<string, KeyValueStore> (StringComparer.OrdinalIgnoreCase);
Manifest.LogMessage ("Database Truncated.");
}
// Close a specified value.
public void Close(bool fast = false)
{
// Make sure any inflight rotations have occurred before shutting down.
if (!_rotationSemaphore.WaitOne (30000))
throw new TimeoutException ("Timed out waiting for table rotation to complete.");
_rotationSemaphore.Release (); // Release again in case another thread tries to close it again.
if (!finalizing && !fast)
TableManager.Default.Close (this);
if (_currentJournaledMemTable != null) {
_currentJournaledMemTable.Close ();
_currentJournaledMemTable = null;
}
if (_secondaryIndexes != null)
foreach (var idx in _secondaryIndexes)
idx.Value.Close (fast);
GC.SuppressFinalize (this); // Don't finalize since we already closed it.
}