예제 #1
0
// NewWriter create new initialized table writer.
func NewWriter(w desc.Writer, o opt.OptionsGetter) *Writer {
	t := &Writer{w: w, o: o, cmp: o.GetComparer()}
	// Creating blocks
	t.data = block.NewWriter(o.GetBlockRestartInterval())
	t.index = block.NewWriter(1)
	filter := o.GetFilter()
	if filter != nil {
		t.filter = block.NewFilterWriter(filter)
		t.filter.Generate(0)
	}
	t.lblock = new(bInfo)
	return t
}
예제 #2
0
// NewReader create new initialized table reader.
func NewReader(r desc.Reader, size uint64, o opt.OptionsGetter, cache cache.Namespace) (p *Reader, err error) {
	mb, ib, err := readFooter(r, size)
	if err != nil {
		return
	}

	t := &Reader{r: r, o: o, dataEnd: mb.offset, cache: cache}

	// index block
	buf, err := ib.readAll(r, true)
	if err != nil {
		return
	}
	t.index, err = block.NewReader(buf, o.GetComparer())
	if err != nil {
		return
	}

	// filter block
	filter := o.GetFilter()
	if filter != nil {
		// we will ignore any errors at meta/filter block
		// since it is not essential for operation

		// meta block
		buf, err = mb.readAll(r, true)
		if err != nil {
			goto out
		}
		var meta *block.Reader
		meta, err = block.NewReader(buf, comparer.BytesComparer{})
		if err != nil {

			goto out
		}

		// check for filter name
		iter := meta.NewIterator()
		key := "filter." + filter.Name()
		if iter.Seek([]byte(key)) && string(iter.Key()) == key {
			fb := new(bInfo)
			_, err = fb.decodeFrom(iter.Value())
			if err != nil {
				return
			}

			// now the data end before filter block start offset
			t.dataEnd = fb.offset

			// filter block
			buf, err = fb.readAll(r, true)
			if err != nil {
				goto out
			}
			t.filter, err = block.NewFilterReader(buf, filter)
			if err != nil {
				goto out
			}
		}
	}

out:
	return t, nil
}