97 lines
3.4 KiB
Go
97 lines
3.4 KiB
Go
// VulcanizeDB
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// Copyright © 2020 Vulcanize
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Affero General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Affero General Public License for more details.
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// You should have received a copy of the GNU Affero General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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package ipfsethdb
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import (
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"context"
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"github.com/ethereum/go-ethereum/ethdb"
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"github.com/ipfs/go-blockservice"
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)
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var _ ethdb.Iterator = &Iterator{}
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// Iterator is the type that satisfies the ethdb.Iterator interface for IPFS Ethereum data
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// Iteratee interface is used in Geth for various tests, trie/sync_bloom.go (for fast sync),
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// rawdb.InspectDatabase, and the new core/state/snapshot features.
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// This should not be confused with trie.NodeIterator or state.NodeIteraor (which can be constructed
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// from the ethdb.KeyValueStoreand ethdb.Database interfaces)
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type Iterator struct {
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blockService blockservice.BlockService
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currentKey, prefix []byte
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err error
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}
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// NewIterator returns an ethdb.Iterator interface for PG-IPFS
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func NewIterator(start, prefix []byte, bs blockservice.BlockService) ethdb.Iterator {
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return &Iterator{
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blockService: bs,
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prefix: prefix,
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currentKey: start,
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}
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}
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// Next satisfies the ethdb.Iterator interface
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// Next moves the iterator to the next key/value pair
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// It returns whether the iterator is exhausted
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func (i *Iterator) Next() bool {
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// this is complicated by the ipfs db keys not being the keccak256 hashes
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// go-ethereum usage of this method expects the iteration to occur over keccak256 keys
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panic("implement me: Next")
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}
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// Error satisfies the ethdb.Iterator interface
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// Error returns any accumulated error
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// Exhausting all the key/value pairs is not considered to be an error
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func (i *Iterator) Error() error {
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return i.err
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}
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// Key satisfies the ethdb.Iterator interface
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// Key returns the key of the current key/value pair, or nil if done
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// The caller should not modify the contents of the returned slice
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// and its contents may change on the next call to Next
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func (i *Iterator) Key() []byte {
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return i.currentKey
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}
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// Value satisfies the ethdb.Iterator interface
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// Value returns the value of the current key/value pair, or nil if done
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// The caller should not modify the contents of the returned slice
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// and its contents may change on the next call to Next
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func (i *Iterator) Value() []byte {
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// we are using state codec because we don't know the codec and at this level the codec doesn't matter, the datastore key is multihash-only derived
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c, err := Keccak256ToCid(i.currentKey, stateTrieCodec)
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if err != nil {
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i.err = err
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return nil
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}
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block, err := i.blockService.GetBlock(context.Background(), c)
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if err != nil {
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i.err = err
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return nil
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}
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return block.RawData()
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}
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// Release satisfies the ethdb.Iterator interface
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// Release releases associated resources
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// Release should always succeed and can be called multiple times without causing error
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func (i *Iterator) Release() {
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i.blockService.Close()
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}
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