/
memiterator.go
85 lines (71 loc) · 1.6 KB
/
memiterator.go
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package store
import (
"bytes"
"errors"
abci "github.com/tendermint/tendermint/abci/types"
dbm "github.com/tendermint/tm-db"
)
// Iterates over iterKVCache items.
// if types is nil, means it was deleted.
// Implements Iterator.
type memIterator struct {
start, end []byte
items []abci.EventAttribute
}
func (mi *memIterator) Error() error {
return errors.New("memIterator error")
}
func newMemIterator(start, end []byte, items []abci.EventAttribute) *memIterator {
itemsInDomain := make([]abci.EventAttribute, 0)
for _, item := range items {
if dbm.IsKeyInDomain(item.Key, start, end) {
itemsInDomain = append(itemsInDomain, item)
}
}
return &memIterator{
start: start,
end: end,
items: itemsInDomain,
}
}
func (mi *memIterator) Domain() ([]byte, []byte) {
return mi.start, mi.end
}
func (mi *memIterator) Valid() bool {
return len(mi.items) > 0
}
func (mi *memIterator) assertValid() {
if !mi.Valid() {
panic("memIterator is invalid")
}
}
func (mi *memIterator) Next() {
mi.assertValid()
mi.items = mi.items[1:]
}
func (mi *memIterator) Key() []byte {
mi.assertValid()
return mi.items[0].Key
}
func (mi *memIterator) Value() []byte {
mi.assertValid()
return mi.items[0].Value
}
func (mi *memIterator) Close() error {
mi.start = nil
mi.end = nil
mi.items = nil
return nil
}
//----------------------------------------
// Misc.
// bytes.Compare but bounded on both sides by nil.
// both (k1, nil) and (nil, k2) return -1
func keyCompare(k1, k2 []byte) int {
if k1 == nil && k2 == nil {
return 0
} else if k1 == nil || k2 == nil {
return -1
}
return bytes.Compare(k1, k2)
}