cosmos-sdk/store/cachekv/memiterator.go

51 lines
914 B
Go

package cachekv
import (
dbm "github.com/tendermint/tm-db"
"github.com/cosmos/cosmos-sdk/store/types"
)
// Iterates over iterKVCache items.
// if key is nil, means it was deleted.
// Implements Iterator.
type memIterator struct {
types.Iterator
deleted map[string]struct{}
}
func newMemIterator(start, end []byte, items *dbm.MemDB, deleted map[string]struct{}, ascending bool) *memIterator {
var iter types.Iterator
var err error
if ascending {
iter, err = items.Iterator(start, end)
} else {
iter, err = items.ReverseIterator(start, end)
}
if err != nil {
panic(err)
}
newDeleted := make(map[string]struct{})
for k, v := range deleted {
newDeleted[k] = v
}
return &memIterator{
Iterator: iter,
deleted: newDeleted,
}
}
func (mi *memIterator) Value() []byte {
key := mi.Iterator.Key()
if _, ok := mi.deleted[string(key)]; ok {
return nil
}
return mi.Iterator.Value()
}