Golang IndexInput.ReadVInt方法代码示例

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
}

/* Reads but does not decode the byte[] blob holding
   metadata for the current terms block */
func (r *Lucene41PostingsReader) ReadTermsBlock(termsIn store.IndexInput, fieldInfo 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
}

/*
Lucene42DocValuesProducer.java
Line 126
*/
func (dvp *Lucene42DocValuesProducer) readFields(meta store.IndexInput, infos FieldInfos) (err error) {
	fieldNumber, err := 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 {
				n, err := meta.ReadVInt()
				if err != nil {
					return err
				}
				entry.packedIntsVersion = int(n)
			}
		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 = meta.ReadVInt()
	}
	return err
}

func newCompressingStoredFieldsIndexReader(fieldsIndexIn store.IndexInput, si SegmentInfo) (r *CompressingStoredFieldsIndexReader, err error) {
	r = &CompressingStoredFieldsIndexReader{}
	r.maxDoc = int(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([]util.PackedIntsReader, 0, 16)
	r.startPointersDeltas = make([]util.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 := util.NewPackedReaderNoHeader(fieldsIndexIn, util.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 := util.NewPackedReaderNoHeader(fieldsIndexIn, util.PACKED, packedIntsVersion, numChunks, uint32(bitsPerStartPointer))
			if err != nil {
				return nil, err
			}
			r.startPointersDeltas = append(r.startPointersDeltas, pr)
		}
	}

	return r, nil
}