private IEnumerable <KeyValuePair <Key, Value> > InternalEnumerateFromKey(byte[] startingKey)
{
if (startingKey == null)
{
yield break;
}
var enumerators = new List <IEnumerable <KeyValuePair <Key, Value> > >();
Key key = new Key(startingKey, 0);
// Capture copy of the rotated table if there is one
var rotatedMemTable = _rotatedJournaledMemTable;
// Select main MemTable
enumerators.Add(_currentJournaledMemTable.EnumerateSnapshotFromKey(key));
if (rotatedMemTable != null)
{
enumerators.Add(rotatedMemTable.EnumerateSnapshotFromKey(key));
}
// Now check the files on disk
using (var manifestSnapshot = _manifest.GetLatestManifest()) {
List <SortedBlockTable> pages = new List <SortedBlockTable>();
try {
pages.AddRange(manifestSnapshot.GetPagesAtLevel(0)
.OrderByDescending(page => page.Version)
.Select(page => {
PerformanceCounters.SBTEnumerateFromKey.Increment();
return(new SortedBlockTable(_cache, _manifest.BaseFileName, page.Level, page.Version));
}));
pages.ForEach(p => enumerators.Add(p.EnumerateFromKey(_cache, key)));
for (int i = 1; i < manifestSnapshot.NumLevels; i++)
{
enumerators.Add(TableEnumerator.Enumerate(i, _cache, _manifest.BaseFileName, manifestSnapshot, key));
}
foreach (var pair in MergeEnumerator.Merge(enumerators, t => t.Key))
{
yield return(pair);
}
} finally {
// make sure all the tables get closed
pages.ForEach(table => table.Close());
}
}
}
public static IEnumerable <KeyValuePair <Key, Value> > EnumerateMergedTablesPreCached(RazorCache cache, string baseFileName, IEnumerable <PageRef> tableSpecs, ExceptionHandling exceptionHandling, Action <string> logger)
{
PerformanceCounters.SBTEnumerateMergedTablesPrecached.Increment();
var tables = tableSpecs
.Select(pageRef => new SortedBlockTable(cache, baseFileName, pageRef.Level, pageRef.Version))
.ToList();
try {
foreach (var pair in MergeEnumerator.Merge(tables.Select(t => t.Enumerate().ToList().AsEnumerable()), t => t.Key))
{
yield return(pair);
}
} finally {
tables.ForEach(t => t.Close());
}
}