Example #1
0
func (db *DB) newRawIterator(auxm *memDB, auxt tFiles, slice *util.Range, ro *opt.ReadOptions) iterator.Iterator {
	strict := opt.GetStrict(db.s.o.Options, ro, opt.StrictReader)
	em, fm := db.getMems()
	v := db.s.version()

	tableIts := v.getIterators(slice, ro)
	n := len(tableIts) + len(auxt) + 3
	its := make([]iterator.Iterator, 0, n)

	if auxm != nil {
		ami := auxm.NewIterator(slice)
		ami.SetReleaser(&memdbReleaser{m: auxm})
		its = append(its, ami)
	}
	for _, t := range auxt {
		its = append(its, v.s.tops.newIterator(t, slice, ro))
	}

	emi := em.NewIterator(slice)
	emi.SetReleaser(&memdbReleaser{m: em})
	its = append(its, emi)
	if fm != nil {
		fmi := fm.NewIterator(slice)
		fmi.SetReleaser(&memdbReleaser{m: fm})
		its = append(its, fmi)
	}
	its = append(its, tableIts...)
	mi := iterator.NewMergedIterator(its, db.s.icmp, strict)
	mi.SetReleaser(&versionReleaser{v: v})
	return mi
}
// 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)
}