// Creates an iterator.
func (c *compaction) newIterator() iterator.Iterator {
// Creates iterator slice.
icap := len(c.tables)
if c.level == 0 {
// Special case for level-0
icap = len(c.tables[0]) + 1
}
its := make([]iterator.Iterator, 0, icap)
// Options.
ro := &opt.ReadOptions{
DontFillCache: true,
}
strict := c.s.o.GetStrict(opt.StrictIterator)
for i, tables := range c.tables {
if len(tables) == 0 {
continue
}
// Level-0 is not sorted and may overlaps each other.
if c.level+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, true)
its = append(its, it)
}
}
return iterator.NewMergedIterator(its, c.s.icmp, true)
}
func (db *DB) newRawIterator(slice *util.Range, ro *opt.ReadOptions) iterator.Iterator {
em, fm := db.getMems()
v := db.s.version()
ti := v.getIterators(slice, ro)
n := len(ti) + 2
i := make([]iterator.Iterator, 0, n)
emi := em.mdb.NewIterator(slice)
emi.SetReleaser(&memdbReleaser{m: em})
i = append(i, emi)
if fm != nil {
fmi := fm.mdb.NewIterator(slice)
fmi.SetReleaser(&memdbReleaser{m: fm})
i = append(i, fmi)
}
i = append(i, ti...)
strict := db.s.o.GetStrict(opt.StrictIterator) || ro.GetStrict(opt.StrictIterator)
mi := iterator.NewMergedIterator(i, db.s.icmp, strict)
mi.SetReleaser(&versionReleaser{v: v})
return mi
}