62 lines
2.5 KiB
Go
62 lines
2.5 KiB
Go
|
// Copyright 2018 The go-ethereum Authors
|
||
|
|
// This file is part of the go-ethereum library.
|
||
|
|
//
|
||
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
||
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
||
|
|
// the Free Software Foundation, either version 3 of the License, or
|
||
|
|
// (at your option) any later version.
|
||
|
|
//
|
||
|
|
// The go-ethereum library 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 Lesser General Public License for more details.
|
||
|
|
//
|
||
|
|
// You should have received a copy of the GNU Lesser General Public License
|
||
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
|
||
|
|
package ethdb
|
||
|
|
|
||
|
|
// Iterator iterates over a database's key/value pairs in ascending key order.
|
||
|
|
//
|
||
|
|
// When it encounters an error any seek will return false and will yield no key/
|
||
|
|
// value pairs. The error can be queried by calling the Error method. Calling
|
||
|
|
// Release is still necessary.
|
||
|
|
//
|
||
|
|
// An iterator must be released after use, but it is not necessary to read an
|
||
|
|
// iterator until exhaustion. An iterator is not safe for concurrent use, but it
|
||
|
|
// is safe to use multiple iterators concurrently.
|
||
|
|
type Iterator interface {
|
||
|
|
// Next moves the iterator to the next key/value pair. It returns whether the
|
||
|
|
// iterator is exhausted.
|
||
|
|
Next() bool
|
||
|
|
|
||
|
|
// Error returns any accumulated error. Exhausting all the key/value pairs
|
||
|
|
// is not considered to be an error.
|
||
|
|
Error() error
|
||
|
|
|
||
|
|
// 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.
|
||
|
|
Key() []byte
|
||
|
|
|
||
|
|
// 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.
|
||
|
|
Value() []byte
|
||
|
|
|
||
|
|
// Release releases associated resources. Release should always succeed and can
|
||
|
|
// be called multiple times without causing error.
|
||
|
|
Release()
|
||
|
|
}
|
||
|
|
|
||
|
|
// Iteratee wraps the NewIterator methods of a backing data store.
|
||
|
|
type Iteratee interface {
|
||
|
|
// NewIterator creates a binary-alphabetical iterator over the entire keyspace
|
||
|
|
// contained within the key-value database.
|
||
|
|
NewIterator() Iterator
|
||
|
|
|
||
|
|
// NewIteratorWithPrefix creates a binary-alphabetical iterator over a subset
|
||
|
|
// of database content with a particular key prefix.
|
||
|
|
NewIteratorWithPrefix(prefix []byte) Iterator
|
||
|
|
}
|