public IEnumerable <IndexEntry> GetRange(ulong stream, long startNumber, long endNumber, int?limit = null)
{
Ensure.Nonnegative(startNumber, "startNumber");
Ensure.Nonnegative(endNumber, "endNumber");
ulong hash = GetHash(stream);
var result = new List <IndexEntry>();
var startKey = BuildKey(hash, startNumber);
var endKey = BuildKey(hash, endNumber);
if (startKey.GreaterThan(_maxEntry) || endKey.SmallerThan(_minEntry))
{
return(result);
}
var workItem = GetWorkItem();
try {
IndexEntryKey lowBoundsCheck, highBoundsCheck;
var recordRange = LocateRecordRange(endKey, out lowBoundsCheck, out highBoundsCheck);
long low = recordRange.Lower;
long high = recordRange.Upper;
while (low < high)
{
var mid = low + (high - low) / 2;
IndexEntry midpoint = ReadEntry(_indexEntrySize, mid, workItem, _version);
var midpointKey = new IndexEntryKey(midpoint.Stream, midpoint.Version);
if (midpointKey.GreaterThan(lowBoundsCheck))
{
throw new MaybeCorruptIndexException(String.Format(
"Midpoint key (stream: {0}, version: {1}) > low bounds check key (stream: {2}, version: {3})",
midpointKey.Stream, midpointKey.Version, lowBoundsCheck.Stream, lowBoundsCheck.Version));
}
else if (!midpointKey.GreaterEqualsThan(highBoundsCheck))
{
throw new MaybeCorruptIndexException(String.Format(
"Midpoint key (stream: {0}, version: {1}) < high bounds check key (stream: {2}, version: {3})",
midpointKey.Stream, midpointKey.Version, highBoundsCheck.Stream, highBoundsCheck.Version));
}
if (midpointKey.SmallerEqualsThan(endKey))
{
high = mid;
highBoundsCheck = midpointKey;
}
else
{
low = mid + 1;
lowBoundsCheck = midpointKey;
}
}
PositionAtEntry(_indexEntrySize, high, workItem);
for (long i = high, n = Count; i < n; ++i)
{
IndexEntry entry = ReadNextNoSeek(workItem, _version);
var candidateKey = new IndexEntryKey(entry.Stream, entry.Version);
if (candidateKey.GreaterThan(endKey))
{
throw new MaybeCorruptIndexException(string.Format(
"entry ({0}@{1}) > endKey {2}, stream {3}, startNum {4}, endNum {5}, PTable: {6}.",
entry.Stream, entry.Version, startKey, stream, startNumber, endNumber, Filename));
}
if (candidateKey.SmallerThan(startKey))
{
return(result);
}
result.Add(entry);
if (result.Count == limit)
{
break;
}
}
return(result);
} finally {
ReturnWorkItem(workItem);
}
}
private bool TryGetSmallestEntry(ulong stream, long startNumber, long endNumber, out IndexEntry entry)
{
Ensure.Nonnegative(startNumber, "startNumber");
Ensure.Nonnegative(endNumber, "endNumber");
entry = TableIndex.InvalidIndexEntry;
var startKey = BuildKey(stream, startNumber);
var endKey = BuildKey(stream, endNumber);
if (startKey.GreaterThan(_maxEntry) || endKey.SmallerThan(_minEntry))
{
return(false);
}
var workItem = GetWorkItem();
try {
IndexEntryKey lowBoundsCheck, highBoundsCheck;
var recordRange = LocateRecordRange(startKey, out lowBoundsCheck, out highBoundsCheck);
long low = recordRange.Lower;
long high = recordRange.Upper;
while (low < high)
{
var mid = low + (high - low + 1) / 2;
var midpoint = ReadEntry(_indexEntrySize, mid, workItem, _version);
var midpointKey = new IndexEntryKey(midpoint.Stream, midpoint.Version);
if (midpointKey.GreaterThan(lowBoundsCheck))
{
throw new MaybeCorruptIndexException(String.Format(
"Midpoint key (stream: {0}, version: {1}) > low bounds check key (stream: {2}, version: {3})",
midpointKey.Stream, midpointKey.Version, lowBoundsCheck.Stream, lowBoundsCheck.Version));
}
else if (!midpointKey.GreaterEqualsThan(highBoundsCheck))
{
throw new MaybeCorruptIndexException(String.Format(
"Midpoint key (stream: {0}, version: {1}) < high bounds check key (stream: {2}, version: {3})",
midpointKey.Stream, midpointKey.Version, highBoundsCheck.Stream, highBoundsCheck.Version));
}
if (midpointKey.SmallerThan(startKey))
{
high = mid - 1;
highBoundsCheck = midpointKey;
}
else
{
low = mid;
lowBoundsCheck = midpointKey;
}
}
var candEntry = ReadEntry(_indexEntrySize, high, workItem, _version);
var candidateKey = new IndexEntryKey(candEntry.Stream, candEntry.Version);
if (candidateKey.SmallerThan(startKey))
{
throw new MaybeCorruptIndexException(string.Format(
"candEntry ({0}@{1}) < startKey {2}, stream {3}, startNum {4}, endNum {5}, PTable: {6}.",
candEntry.Stream, candEntry.Version, startKey, stream, startNumber, endNumber, Filename));
}
if (candidateKey.GreaterThan(endKey))
{
return(false);
}
entry = candEntry;
return(true);
} finally {
ReturnWorkItem(workItem);
}
}