Beispiel #1
0
 internal virtual void  addTerm(System.String term, TermVectorOffsetInfo info)
 {
     terms.Add(term);
     if (offsets != null)
     {
         offsets.Add(info);
     }
 }
        /// <summary> </summary>
        /// <param name="term">The term to map
        /// </param>
        /// <param name="frequency">The frequency of the term
        /// </param>
        /// <param name="offsets">Offset information, may be null
        /// </param>
        /// <param name="positions">Position information, may be null
        /// </param>
        //We need to combine any previous mentions of the term
        public override void  Map(System.String term, int frequency, TermVectorOffsetInfo[] offsets, int[] positions)
        {
            TermVectorEntry entry = termToTVE[term];

            if (entry == null)
            {
                entry           = new TermVectorEntry(ALL, term, frequency, storeOffsets == true?offsets:null, storePositions == true?positions:null);
                termToTVE[term] = entry;
                currentSet.Add(entry);
            }
            else
            {
                entry.Frequency = entry.Frequency + frequency;
                if (storeOffsets)
                {
                    TermVectorOffsetInfo[] existingOffsets = entry.GetOffsets();
                    //A few diff. cases here:  offsets is null, existing offsets is null, both are null, same for positions
                    if (existingOffsets != null && offsets != null && offsets.Length > 0)
                    {
                        //copy over the existing offsets
                        TermVectorOffsetInfo[] newOffsets = new TermVectorOffsetInfo[existingOffsets.Length + offsets.Length];
                        Array.Copy(existingOffsets, 0, newOffsets, 0, existingOffsets.Length);
                        Array.Copy(offsets, 0, newOffsets, existingOffsets.Length, offsets.Length);
                        entry.SetOffsets(newOffsets);
                    }
                    else if (existingOffsets == null && offsets != null && offsets.Length > 0)
                    {
                        entry.SetOffsets(offsets);
                    }
                    //else leave it alone
                }
                if (storePositions)
                {
                    int[] existingPositions = entry.GetPositions();
                    if (existingPositions != null && positions != null && positions.Length > 0)
                    {
                        int[] newPositions = new int[existingPositions.Length + positions.Length];
                        Array.Copy(existingPositions, 0, newPositions, 0, existingPositions.Length);
                        Array.Copy(positions, 0, newPositions, existingPositions.Length, positions.Length);
                        entry.SetPositions(newPositions);
                    }
                    else if (existingPositions == null && positions != null && positions.Length > 0)
                    {
                        entry.SetPositions(positions);
                    }
                }
            }
        }
        /// <summary> </summary>
        /// <param name="field">The field to read in
        /// </param>
        /// <param name="tvfPointer">The pointer within the tvf file where we should start reading
        /// </param>
        /// <param name="mapper">The mapper used to map the TermVector
        /// </param>
        /// <throws>  IOException </throws>
        private void  ReadTermVector(System.String field, long tvfPointer, TermVectorMapper mapper)
        {
            // Now read the data from specified position
            //We don't need to offset by the FORMAT here since the pointer already includes the offset
            tvf.Seek(tvfPointer);

            int numTerms = tvf.ReadVInt();

            //System.out.println("Num Terms: " + numTerms);
            // If no terms - return a constant empty termvector. However, this should never occur!
            if (numTerms == 0)
            {
                return;
            }

            bool storePositions;
            bool storeOffsets;

            if (format >= FORMAT_VERSION)
            {
                byte bits = tvf.ReadByte();
                storePositions = (bits & STORE_POSITIONS_WITH_TERMVECTOR) != 0;
                storeOffsets   = (bits & STORE_OFFSET_WITH_TERMVECTOR) != 0;
            }
            else
            {
                tvf.ReadVInt();
                storePositions = false;
                storeOffsets   = false;
            }
            mapper.SetExpectations(field, numTerms, storeOffsets, storePositions);
            int start       = 0;
            int deltaLength = 0;
            int totalLength = 0;

            byte[] byteBuffer;
            char[] charBuffer;
            bool   preUTF8 = format < FORMAT_UTF8_LENGTH_IN_BYTES;

            // init the buffers
            if (preUTF8)
            {
                charBuffer = new char[10];
                byteBuffer = null;
            }
            else
            {
                charBuffer = null;
                byteBuffer = new byte[20];
            }

            for (int i = 0; i < numTerms; i++)
            {
                start       = tvf.ReadVInt();
                deltaLength = tvf.ReadVInt();
                totalLength = start + deltaLength;

                System.String term;

                if (preUTF8)
                {
                    // Term stored as java chars
                    if (charBuffer.Length < totalLength)
                    {
                        char[] newCharBuffer = new char[(int)(1.5 * totalLength)];
                        Array.Copy(charBuffer, 0, newCharBuffer, 0, start);
                        charBuffer = newCharBuffer;
                    }
                    tvf.ReadChars(charBuffer, start, deltaLength);
                    term = new System.String(charBuffer, 0, totalLength);
                }
                else
                {
                    // Term stored as utf8 bytes
                    if (byteBuffer.Length < totalLength)
                    {
                        byte[] newByteBuffer = new byte[(int)(1.5 * totalLength)];
                        Array.Copy(byteBuffer, 0, newByteBuffer, 0, start);
                        byteBuffer = newByteBuffer;
                    }
                    tvf.ReadBytes(byteBuffer, start, deltaLength);
                    term = System.Text.Encoding.UTF8.GetString(byteBuffer, 0, totalLength);
                }
                int   freq      = tvf.ReadVInt();
                int[] positions = null;
                if (storePositions)
                {
                    //read in the positions
                    //does the mapper even care about positions?
                    if (mapper.IsIgnoringPositions == false)
                    {
                        positions = new int[freq];
                        int prevPosition = 0;
                        for (int j = 0; j < freq; j++)
                        {
                            positions[j] = prevPosition + tvf.ReadVInt();
                            prevPosition = positions[j];
                        }
                    }
                    else
                    {
                        //we need to skip over the positions.  Since these are VInts, I don't believe there is anyway to know for sure how far to skip
                        //
                        for (int j = 0; j < freq; j++)
                        {
                            tvf.ReadVInt();
                        }
                    }
                }
                TermVectorOffsetInfo[] offsets = null;
                if (storeOffsets)
                {
                    //does the mapper even care about offsets?
                    if (mapper.IsIgnoringOffsets == false)
                    {
                        offsets = new TermVectorOffsetInfo[freq];
                        int prevOffset = 0;
                        for (int j = 0; j < freq; j++)
                        {
                            int startOffset = prevOffset + tvf.ReadVInt();
                            int endOffset   = startOffset + tvf.ReadVInt();
                            offsets[j] = new TermVectorOffsetInfo(startOffset, endOffset);
                            prevOffset = endOffset;
                        }
                    }
                    else
                    {
                        for (int j = 0; j < freq; j++)
                        {
                            tvf.ReadVInt();
                            tvf.ReadVInt();
                        }
                    }
                }
                mapper.Map(term, freq, offsets, positions);
            }
        }