public ulong GetCounterValue(Counter counter, Span <byte> index)
{
using var _ = RocksDbEncoder.EncodeCounter(counter, index, out var key);
var result = Database.Get(key);
return(result != null?BinaryPrimitives.ReadUInt64LittleEndian(result) : 0);
}
internal void IncrementCounterValue(WriteBatch batch, Counter counter, Span <byte> index)
{
using var _ = RocksDbEncoder.EncodeCounter(counter, index, out var key);
byte[] newValueBytes = new byte[8];
BinaryPrimitives.WriteUInt64LittleEndian(newValueBytes, 1);
// Todo: Allocation
batch.Merge(key.ToArray(), (ulong)key.Length, newValueBytes, (ulong)newValueBytes.Length);
}
public unsafe bool SeekCeil(ReadOnlyMemory <byte> data)
{
using var _ = RocksDbEncoder.EncodeInvertedIndexTerm(data.Span, out var bytes);
fixed(byte *b = &MemoryMarshal.GetReference(bytes))
{
RocksDbIterator.Seek(b, (ulong)bytes.Length);
}
UpdateIteratorState();
return(RocksIteratorValid);
}
internal RocksDbDocsIdSetEnumerator(RocksDbStorage storage, int termId, int?propertyId)
{
Storage = storage;
TermId = termId;
PropertyId = propertyId;
RocksDbIterator = storage.Database.NewIterator();
RocksIteratorKey = Array.Empty <byte>();
Prefix = RocksDbEncoder.EncodeInvertedIndexPostingPrefix(termId, propertyId);
// Todo: Create encoder instead of slicing or create a special method
Cost = propertyId != null
? (long)Storage.GetCounterValue(RocksDbStorage.Counter.TermFrequencyByTermAndProperty, Prefix.AsSpan().Slice(1))
: (long)Storage.GetCounterValue(RocksDbStorage.Counter.TermFrequencyByTerm, Prefix.AsSpan().Slice(1));
}
protected void AddInvertedIndexTerm(WriteBatch batch, ReadOnlySpan <byte> property, ReadOnlySpan <byte> term,
int docId)
{
var propertyId = AliasStore.GetOrCreate(property);
var termId = AliasStore.GetOrCreate(term);
using (RocksDbEncoder.EncodeInt32(termId, out var termIdBytes))
{
using (RocksDbEncoder.EncodeInvertedIndexTerm(term, out var array))
{
batch.Put(array, termIdBytes);
AddInvertedIndexPosting(batch, propertyId, termId, docId);
}
}
}
protected void AddInvertedIndexPosting(WriteBatch batch, int propertyId, int termId, int docId)
{
using var posting1 = RocksDbEncoder.EncodeInvertedIndexPostingWithProperty(termId, propertyId, docId, out var span1);
using var posting2 = RocksDbEncoder.EncodeInvertedIndexPosting(termId, docId, out var span2);
batch.Put(span1, ReadOnlySpan <byte> .Empty);
IncrementCounterValue(batch, Counter.TermFrequencyByTermAndProperty, span1.Slice(1, 8));
batch.Put(span2, ReadOnlySpan <byte> .Empty);
//Todo: Slow
if (Database.Get(span2) == null)
{
IncrementCounterValue(batch, Counter.TermFrequencyByTerm, span2.Slice(1, 4));
}
}
public bool Advance(int target)
{
if (!PropertyId.HasValue)
{
using var _ = RocksDbEncoder.EncodeInvertedIndexPosting(TermId, target, out var prefix);
RocksDbIterator.Seek(prefix.ToArray());
}
else
{
using var _ = RocksDbEncoder.EncodeInvertedIndexPostingWithProperty(TermId, PropertyId.Value, target, out var prefix);
RocksDbIterator.Seek(prefix.ToArray());
}
Positioned = true;
UpdateIteratorState();
return(RocksIteratorValid);
}
protected void UpdateIteratorState()
{
var iteratorValid = RocksDbIterator.Valid();
if (!iteratorValid)
{
RocksIteratorValid = false;
return;
}
// Todo: Allocating, stackalloc here if rocksdb support span
RocksIteratorKey = RocksDbIterator.Key();
RocksIteratorValid = RocksIteratorKey.AsSpan().StartsWith(Prefix.AsSpan());
if (RocksIteratorValid)
{
CurrentDocId = RocksDbEncoder.ReadPostingDocId(RocksIteratorKey.AsSpan());
}
}