iterator

iterator.go

@@ -0,0 +1,82 @@
+// VulcanizeDB
+// Copyright © 2020 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package ipfseth
+
+import (
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/jmoiron/sqlx"
+)
+
+// We don't need these iterator interfaces right now
+// Iteratee interface is only used in Geth for various tests, trie/sync_bloom.go (for fast sync), and rawdb.InspectDatabase
+type Iterator struct {
+	db                 *sqlx.DB
+	currentKey, prefix []byte
+	err                error
+}
+
+func NewIterator(start, prefix []byte, db *sqlx.DB) ethdb.Iterator {
+	return &Iterator{
+		db:         db,
+		prefix:     prefix,
+		currentKey: start,
+	}
+}
+
+// Next satisfies the ethdb.Iterator interface
+// Next moves the iterator to the next key/value pair
+// It returns whether the iterator is exhausted
+func (i *Iterator) Next() bool {
+	panic("implement me: Next")
+}
+
+// Error satisfies the ethdb.Iterator interface
+// Error returns any accumulated error
+// Exhausting all the key/value pairs is not considered to be an error
+func (i *Iterator) Error() error {
+	return i.err
+}
+
+// Key satisfies the ethdb.Iterator interface
+// Key returns the key of the current key/value pair, or nil if done
+// The caller should not modify the contents of the returned slice
+// and its contents may change on the next call to Next
+func (i *Iterator) Key() []byte {
+	return i.currentKey
+}
+
+// Value satisfies the ethdb.Iterator interface
+// Value returns the value of the current key/value pair, or nil if done
+// The caller should not modify the contents of the returned slice
+// and its contents may change on the next call to Next
+func (i *Iterator) Value() []byte {
+	mhKey, err := MultihashKeyFromKeccak256(i.currentKey)
+	if err != nil {
+		i.err = err
+		return nil
+	}
+	var data []byte
+	i.err = i.db.Get(&data, getPgStr, mhKey)
+	return data
+}
+
+// Release satisfies the ethdb.Iterator interface
+// Release releases associated resources
+// Release should always succeed and can be called multiple times without causing error
+func (i *Iterator) Release() {
+	i.db.Close()
+}