/// <summary>
/// Get a new cursor for the record. There must NOT be a cached
/// tableid for the record.
/// </summary>
/// <param name="recordId">The id of the record.</param>
/// <returns>The cursor for the record.</returns>
public TCursor GetNewCursor(RecordId recordId)
{
Debug.Assert(!this.HasCachedCursor(recordId), "There is already a cached cusor for the record");
CachedCursor victim = this.cachedCursors.OrderBy(x => x.Timestamp).First();
victim.Timestamp = this.timestamp++;
victim.Id = recordId;
this.Tracer.TraceVerbose("returned new cusor {0} for {1}", victim.Cursor, recordId);
return(victim.Cursor);
}
/// <summary>
/// Initializes a new instance of the CursorCache class.
/// </summary>
/// <param name="openFunc">Delegate used to open a new cursor.</param>
/// <param name="closeFunc">Delegate used to close a cursor opened by openFunc.</param>
/// <param name="tablename">The name of the table.</param>
/// <param name="maxCursors">The number of Cursors to open.</param>
public CursorCache(Func <TCursor> openFunc, Action <TCursor> closeFunc, string tablename, int maxCursors)
{
this.Tracer = new Tracer("CursorCache", "Esent cursor cache", String.Format("CursorCache ({0})", tablename));
this.openFunc = openFunc;
this.closeFunc = closeFunc;
this.cachedCursors = new List <CachedCursor>(maxCursors);
for (int i = 0; i < maxCursors; ++i)
{
TCursor cursor = this.openFunc();
var cachedtableid = new CachedCursor
{
Id = 0,
Cursor = cursor,
Timestamp = 0,
};
this.cachedCursors.Add(cachedtableid);
this.Tracer.TraceInfo("cached cursor {0}", cachedtableid.Cursor);
}
}
