Esempio n. 1
0
func (v *version) getIterators(slice *util.Range, ro *opt.ReadOptions) (its []iterator.Iterator) {
	strict := opt.GetStrict(v.s.o.Options, ro, opt.StrictReader)
	for level, tables := range v.levels {
		if level == 0 {
			// Merge all level zero files together since they may overlap.
			for _, t := range tables {
				its = append(its, v.s.tops.newIterator(t, slice, ro))
			}
		} else if len(tables) != 0 {
			its = append(its, iterator.NewIndexedIterator(tables.newIndexIterator(v.s.tops, v.s.icmp, slice, ro), strict))
		}
	}
	return
}
Esempio n. 2
0
// NewIterator creates an iterator from the table.
//
// Slice allows slicing the iterator to only contains keys in the given
// range. A nil Range.Start is treated as a key before all keys in the
// table. And a nil Range.Limit is treated as a key after all keys in
// the table.
//
// The returned iterator is not goroutine-safe and should be released
// when not used.
//
// Also read Iterator documentation of the leveldb/iterator package.
func (r *Reader) NewIterator(slice *util.Range, ro *opt.ReadOptions) iterator.Iterator {
	r.mu.RLock()
	defer r.mu.RUnlock()

	if r.err != nil {
		return iterator.NewEmptyIterator(r.err)
	}

	fillCache := !ro.GetDontFillCache()
	indexBlock, rel, err := r.getIndexBlock(fillCache)
	if err != nil {
		return iterator.NewEmptyIterator(err)
	}
	index := &indexIter{
		blockIter: r.newBlockIter(indexBlock, rel, slice, true),
		tr:        r,
		slice:     slice,
		fillCache: !ro.GetDontFillCache(),
	}
	return iterator.NewIndexedIterator(index, opt.GetStrict(r.o, ro, opt.StrictReader))
}
// Creates an iterator.
func (c *compaction) newIterator() iterator.Iterator {
	// Creates iterator slice.
	icap := len(c.levels)
	if c.sourceLevel == 0 {
		// Special case for level-0.
		icap = len(c.levels[0]) + 1
	}
	its := make([]iterator.Iterator, 0, icap)

	// Options.
	ro := &opt.ReadOptions{
		DontFillCache: true,
		Strict:        opt.StrictOverride,
	}
	strict := c.s.o.GetStrict(opt.StrictCompaction)
	if strict {
		ro.Strict |= opt.StrictReader
	}

	for i, tables := range c.levels {
		if len(tables) == 0 {
			continue
		}

		// Level-0 is not sorted and may overlaps each other.
		if c.sourceLevel+i == 0 {
			for _, t := range tables {
				its = append(its, c.s.tops.newIterator(t, nil, ro))
			}
		} else {
			it := iterator.NewIndexedIterator(tables.newIndexIterator(c.s.tops, c.s.icmp, nil, ro), strict)
			its = append(its, it)
		}
	}

	return iterator.NewMergedIterator(its, c.s.icmp, strict)
}