private long WriteSkip()
{
long skipPointer = freqOutput.GetFilePointer();
skipBuffer.WriteTo(freqOutput);
return(skipPointer);
}
// Writes the contents of buffer into the fields stream
// and adds a new entry for this document into the index
// stream. This assumes the buffer was already written
// in the correct fields format.
internal void FlushDocument(int numStoredFields, RAMOutputStream buffer)
{
indexStream.WriteLong(fieldsStream.GetFilePointer());
fieldsStream.WriteVInt(numStoredFields);
buffer.WriteTo(fieldsStream);
}
// Writes the contents of buffer into the fields stream
// and adds a new entry for this document into the index
// stream. This assumes the buffer was already written
// in the correct fields format.
internal void FlushDocument(int numStoredFields, RAMOutputStream buffer)
{
indexStream.WriteLong(fieldsStream.GetFilePointer());
fieldsStream.WriteVInt(numStoredFields);
buffer.WriteTo(fieldsStream);
}
/// <summary>
/// expert: writes a value dictionary for a sorted/sortedset field </summary>
protected internal virtual void AddTermsDict(FieldInfo field, IEnumerable<BytesRef> values)
{
// first check if its a "fixed-length" terms dict
int minLength = int.MaxValue;
int maxLength = int.MinValue;
foreach (BytesRef v in values)
{
minLength = Math.Min(minLength, v.Length);
maxLength = Math.Max(maxLength, v.Length);
}
if (minLength == maxLength)
{
// no index needed: direct addressing by mult
AddBinaryField(field, values);
}
else
{
// header
Meta.WriteVInt(field.Number);
Meta.WriteByte((byte)Lucene45DocValuesFormat.BINARY);
Meta.WriteVInt(BINARY_PREFIX_COMPRESSED);
Meta.WriteLong(-1L);
// now write the bytes: sharing prefixes within a block
long startFP = Data.FilePointer;
// currently, we have to store the delta from expected for every 1/nth term
// we could avoid this, but its not much and less overall RAM than the previous approach!
RAMOutputStream addressBuffer = new RAMOutputStream();
MonotonicBlockPackedWriter termAddresses = new MonotonicBlockPackedWriter(addressBuffer, BLOCK_SIZE);
BytesRef lastTerm = new BytesRef();
long count = 0;
foreach (BytesRef v in values)
{
if (count % ADDRESS_INTERVAL == 0)
{
termAddresses.Add(Data.FilePointer - startFP);
// force the first term in a block to be abs-encoded
lastTerm.Length = 0;
}
// prefix-code
int sharedPrefix = StringHelper.BytesDifference(lastTerm, v);
Data.WriteVInt(sharedPrefix);
Data.WriteVInt(v.Length - sharedPrefix);
Data.WriteBytes(v.Bytes, v.Offset + sharedPrefix, v.Length - sharedPrefix);
lastTerm.CopyBytes(v);
count++;
}
long indexStartFP = Data.FilePointer;
// write addresses of indexed terms
termAddresses.Finish();
addressBuffer.WriteTo(Data);
addressBuffer = null;
termAddresses = null;
Meta.WriteVInt(minLength);
Meta.WriteVInt(maxLength);
Meta.WriteVLong(count);
Meta.WriteLong(startFP);
Meta.WriteVInt(ADDRESS_INTERVAL);
Meta.WriteLong(indexStartFP);
Meta.WriteVInt(PackedInts.VERSION_CURRENT);
Meta.WriteVInt(BLOCK_SIZE);
}
}