Method initialize

kv/table/reader.go:122–154

initialize store reader, reads index block(keys,offset etc.), then caches it.

()

// initialize store reader, reads index block(keys,offset etc.), then caches it.
func (r *storeMMapReader) initialize() error {
	// decode footer
	footerStart := len(r.fullBlock) - sstFileFooterSize
	// validate magic-number
	if uint64Func(r.fullBlock[footerStart+magicNumberAtFooter:]) != magicNumberOffsetFile {
		return fmt.Errorf("verify magic-number of sstfile:%s failure", r.path)
	}
	posOfOffset := int(binary.LittleEndian.Uint32(r.fullBlock[footerStart : footerStart+4]))
	posOfKeys := int(binary.LittleEndian.Uint32(r.fullBlock[footerStart+4 : footerStart+8]))
	if !intsAreSortedFunc([]int{
		0, posOfOffset, posOfKeys, footerStart,
	}) {
		return fmt.Errorf("bad footer data, posOfOffsets: %d posOfKeys: %d,"+
			" footerStart: %d", posOfOffset, posOfKeys, footerStart)
	}
	// decode offsets
	offsetsBlock := r.fullBlock[posOfOffset:posOfKeys]
	r.offsets = encoding.NewFixedOffsetDecoder()
	if err := unmarshalFixedOffsetFunc(r.offsets, offsetsBlock); err != nil {
		return fmt.Errorf("unmarshal fixed-offsets decoder with error: %s", err)
	}
	// decode keys
	if _, err := encoding.BitmapUnmarshal(r.keys, r.fullBlock[posOfKeys:]); err != nil {
		return fmt.Errorf("unmarshal keys data from file[%s] error:%s", r.path, err)
	}
	// validate keys and offsets
	if r.offsets.Size() != int(r.keys.GetCardinality()) {
		return fmt.Errorf("num. of keys != num. of offsets in file[%s]", r.path)
	}
	// read entries block
	r.entriesBlock = r.fullBlock[:posOfOffset]
	return nil
}

func unmarshalFixedOffset(decoder *encoding.FixedOffsetDecoder, data []byte) error {
	_, err := decoder.Unmarshal(data)