Golang IndexInput.ReadVInt方法代碼示例

func (np *NormsProducer) readFields(meta store.IndexInput, infos FieldInfos) (err error) {
	var fieldNumber int32
	if fieldNumber, err = meta.ReadVInt(); err != nil {
		return err
	}
	for fieldNumber != -1 {
		info := infos.FieldInfoByNumber(int(fieldNumber))
		if info == nil {
			return errors.New(fmt.Sprintf("Invalid field number: %v (resource=%v)", fieldNumber, meta))
		} else if !info.HasNorms() {
			return errors.New(fmt.Sprintf("Invalid field: %v (resource=%v)", info.Name, meta))
		}
		var format byte
		if format, err = meta.ReadByte(); err != nil {
			return err
		}
		var offset int64
		if offset, err = meta.ReadLong(); err != nil {
			return err
		}
		entry := &NormsEntry{
			format: format,
			offset: offset,
		}
		if format > UNCOMPRESSED {
			return errors.New(fmt.Sprintf("Unknown format: %v, input=%v", format, meta))
		}
		np.norms[int(fieldNumber)] = entry
		if fieldNumber, err = meta.ReadVInt(); err != nil {
			return err
		}
	}
	return nil
}

/* Reads but does not decode the byte[] blob holding
   metadata for the current terms block */
func (r *Lucene41PostingsReader) ReadTermsBlock(termsIn store.IndexInput,
	fieldInfo model.FieldInfo, _termState *BlockTermState) (err error) {

	termState := _termState.Self.(*intBlockTermState)
	numBytes, err := asInt(termsIn.ReadVInt())
	if err != nil {
		return err
	}

	if termState.bytes == nil {
		// TODO over-allocate
		termState.bytes = make([]byte, numBytes)
		termState.bytesReader = store.NewEmptyByteArrayDataInput()
	} else if len(termState.bytes) < numBytes {
		// TODO over-allocate
		termState.bytes = make([]byte, numBytes)
	}

	err = termsIn.ReadBytes(termState.bytes)
	if err != nil {
		return err
	}
	termState.bytesReader.Reset(termState.bytes)
	return nil
}

func readBytesRef(in store.IndexInput) ([]byte, error) {
	length, err := asInt(in.ReadVInt())
	if err != nil {
		return nil, err
	}
	bytes := make([]byte, length)
	if err = in.ReadBytes(bytes); err != nil {
		return nil, err
	}
	return bytes, nil
}

func (r *Lucene41PostingsReader) Init(termsIn store.IndexInput) error {
	log.Printf("Initializing from: %v", termsIn)
	// Make sure we are talking to the matching postings writer
	_, err := codec.CheckHeader(termsIn, LUCENE41_TERMS_CODEC, LUCENE41_VERSION_START, LUCENE41_VERSION_CURRENT)
	if err != nil {
		return err
	}
	indexBlockSize, err := termsIn.ReadVInt()
	if err != nil {
		return err
	}
	log.Printf("Index block size: %v", indexBlockSize)
	if indexBlockSize != LUCENE41_BLOCK_SIZE {
		panic(fmt.Sprintf("index-time BLOCK_SIZE (%v) != read-time BLOCK_SIZE (%v)", indexBlockSize, LUCENE41_BLOCK_SIZE))
	}
	return nil
}

/**
 * Read values that have been written using variable-length encoding instead of bit-packing.
 */
func readVIntBlock(docIn store.IndexInput, docBuffer []int,
	freqBuffer []int, num int, indexHasFreq bool) (err error) {
	if indexHasFreq {
		for i := 0; i < num; i++ {
			code, err := asInt(docIn.ReadVInt())
			if err != nil {
				return err
			}
			docBuffer[i] = int(uint(code) >> 1)
			if (code & 1) != 0 {
				freqBuffer[i] = 1
			} else {
				freqBuffer[i], err = asInt(docIn.ReadVInt())
				if err != nil {
					return err
				}
			}
		}
	} else {
		for i := 0; i < num; i++ {
			docBuffer[i], err = asInt(docIn.ReadVInt())
			if err != nil {
				return err
			}
		}
	}
	return nil
}

/*
Lucene42DocValuesProducer.java/4.5.1/L138
*/
func (dvp *Lucene42DocValuesProducer) readFields(meta store.IndexInput) (err error) {
	var fieldNumber int
	var fieldType byte
	fieldNumber, err = asInt(meta.ReadVInt())
	for fieldNumber != -1 && err == nil {
		fieldType, err = meta.ReadByte()
		if err != nil {
			break
		}
		switch fieldType {
		case LUCENE42_DV_NUMBER:
			entry := NumericEntry{}
			entry.offset, err = meta.ReadLong()
			if err != nil {
				return err
			}
			entry.format, err = meta.ReadByte()
			if err != nil {
				return err
			}
			switch entry.format {
			case LUCENE42_DV_DELTA_COMPRESSED:
			case LUCENE42_DV_TABLE_COMPRESSED:
			case LUCENE42_DV_GCD_COMPRESSED:
			case LUCENE42_DV_UNCOMPRESSED:
			default:
				return errors.New(fmt.Sprintf("Unknown format: %v, input=%v", entry.format, meta))
			}
			if entry.format != LUCENE42_DV_UNCOMPRESSED {
				entry.packedIntsVersion, err = asInt(meta.ReadVInt())
				if err != nil {
					return err
				}
			}
			dvp.numerics[fieldNumber] = entry
		case LUCENE42_DV_BYTES:
			panic("not implemented yet")
		case LUCENE42_DV_FST:
			panic("not implemented yet")
		default:
			return errors.New(fmt.Sprintf("invalid entry type: %v, input=%v", fieldType, meta))
		}
		fieldNumber, err = asInt(meta.ReadVInt())
	}
	return
}

func newCompressingStoredFieldsIndexReader(fieldsIndexIn store.IndexInput,
	si *model.SegmentInfo) (r *CompressingStoredFieldsIndexReader, err error) {

	r = &CompressingStoredFieldsIndexReader{}
	r.maxDoc = si.DocCount()
	r.docBases = make([]int, 0, 16)
	r.startPointers = make([]int64, 0, 16)
	r.avgChunkDocs = make([]int, 0, 16)
	r.avgChunkSizes = make([]int64, 0, 16)
	r.docBasesDeltas = make([]packed.PackedIntsReader, 0, 16)
	r.startPointersDeltas = make([]packed.PackedIntsReader, 0, 16)

	packedIntsVersion, err := fieldsIndexIn.ReadVInt()
	if err != nil {
		return nil, err
	}

	for blockCount := 0; ; blockCount++ {
		numChunks, err := fieldsIndexIn.ReadVInt()
		if err != nil {
			return nil, err
		}
		if numChunks == 0 {
			break
		}

		{ // doc bases
			n, err := fieldsIndexIn.ReadVInt()
			if err != nil {
				return nil, err
			}
			r.docBases = append(r.docBases, int(n))
			n, err = fieldsIndexIn.ReadVInt()
			if err != nil {
				return nil, err
			}
			r.avgChunkDocs = append(r.avgChunkDocs, int(n))
			bitsPerDocBase, err := fieldsIndexIn.ReadVInt()
			if err != nil {
				return nil, err
			}
			if bitsPerDocBase > 32 {
				return nil, errors.New(fmt.Sprintf("Corrupted bitsPerDocBase (resource=%v)", fieldsIndexIn))
			}
			pr, err := packed.NewPackedReaderNoHeader(fieldsIndexIn, packed.PACKED, packedIntsVersion, numChunks, uint32(bitsPerDocBase))
			if err != nil {
				return nil, err
			}
			r.docBasesDeltas = append(r.docBasesDeltas, pr)
		}

		{ // start pointers
			n, err := fieldsIndexIn.ReadVLong()
			if err != nil {
				return nil, err
			}
			r.startPointers = append(r.startPointers, n)
			n, err = fieldsIndexIn.ReadVLong()
			if err != nil {
				return nil, err
			}
			r.avgChunkSizes = append(r.avgChunkSizes, n)
			bitsPerStartPointer, err := fieldsIndexIn.ReadVInt()
			if err != nil {
				return nil, err
			}
			if bitsPerStartPointer > 64 {
				return nil, errors.New(fmt.Sprintf("Corrupted bitsPerStartPonter (resource=%v)", fieldsIndexIn))
			}
			pr, err := packed.NewPackedReaderNoHeader(fieldsIndexIn, packed.PACKED, packedIntsVersion, numChunks, uint32(bitsPerStartPointer))
			if err != nil {
				return nil, err
			}
			r.startPointersDeltas = append(r.startPointersDeltas, pr)
		}
	}

	return r, nil
}