// 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 rawdb import ( "github.com/ethereum/go-ethereum/ethdb" ) // table is a wrapper around a database that prefixes each key access with a pre- // configured string. type table struct { db ethdb.Database prefix string } // NewTable returns a database object that prefixes all keys with a given string. func NewTable(db ethdb.Database, prefix string) ethdb.Database { return &table{ db: db, prefix: prefix, } } // Close is a noop to implement the Database interface. func (t *table) Close() error { return nil } // Has retrieves if a prefixed version of a key is present in the database. func (t *table) Has(key []byte) (bool, error) { return t.db.Has(append([]byte(t.prefix), key...)) } // Get retrieves the given prefixed key if it's present in the database. func (t *table) Get(key []byte) ([]byte, error) { return t.db.Get(append([]byte(t.prefix), key...)) } // HasAncient is a noop passthrough that just forwards the request to the underlying // database. func (t *table) HasAncient(kind string, number uint64) (bool, error) { return t.db.HasAncient(kind, number) } // Ancient is a noop passthrough that just forwards the request to the underlying // database. func (t *table) Ancient(kind string, number uint64) ([]byte, error) { return t.db.Ancient(kind, number) } // AncientRange is a noop passthrough that just forwards the request to the underlying // database. func (t *table) AncientRange(kind string, start, count, maxBytes uint64) ([][]byte, error) { return t.db.AncientRange(kind, start, count, maxBytes) } // Ancients is a noop passthrough that just forwards the request to the underlying // database. func (t *table) Ancients() (uint64, error) { return t.db.Ancients() } // Tail is a noop passthrough that just forwards the request to the underlying // database. func (t *table) Tail() (uint64, error) { return t.db.Tail() } // AncientSize is a noop passthrough that just forwards the request to the underlying // database. func (t *table) AncientSize(kind string) (uint64, error) { return t.db.AncientSize(kind) } // ModifyAncients runs an ancient write operation on the underlying database. func (t *table) ModifyAncients(fn func(ethdb.AncientWriteOp) error) (int64, error) { return t.db.ModifyAncients(fn) } func (t *table) ReadAncients(fn func(reader ethdb.AncientReaderOp) error) (err error) { return t.db.ReadAncients(fn) } // TruncateHead is a noop passthrough that just forwards the request to the underlying // database. func (t *table) TruncateHead(items uint64) (uint64, error) { return t.db.TruncateHead(items) } // TruncateTail is a noop passthrough that just forwards the request to the underlying // database. func (t *table) TruncateTail(items uint64) (uint64, error) { return t.db.TruncateTail(items) } // Sync is a noop passthrough that just forwards the request to the underlying // database. func (t *table) Sync() error { return t.db.Sync() } // MigrateTable processes the entries in a given table in sequence // converting them to a new format if they're of an old format. func (t *table) MigrateTable(kind string, convert convertLegacyFn) error { return t.db.MigrateTable(kind, convert) } // AncientDatadir returns the ancient datadir of the underlying database. func (t *table) AncientDatadir() (string, error) { return t.db.AncientDatadir() } // Put inserts the given value into the database at a prefixed version of the // provided key. func (t *table) Put(key []byte, value []byte) error { return t.db.Put(append([]byte(t.prefix), key...), value) } // Delete removes the given prefixed key from the database. func (t *table) Delete(key []byte) error { return t.db.Delete(append([]byte(t.prefix), key...)) } // NewIterator creates a binary-alphabetical iterator over a subset // of database content with a particular key prefix, starting at a particular // initial key (or after, if it does not exist). func (t *table) NewIterator(prefix []byte, start []byte) ethdb.Iterator { innerPrefix := append([]byte(t.prefix), prefix...) iter := t.db.NewIterator(innerPrefix, start) return &tableIterator{ iter: iter, prefix: t.prefix, } } // Stat returns a particular internal stat of the database. func (t *table) Stat(property string) (string, error) { return t.db.Stat(property) } // Compact flattens the underlying data store for the given key range. In essence, // deleted and overwritten versions are discarded, and the data is rearranged to // reduce the cost of operations needed to access them. // // A nil start is treated as a key before all keys in the data store; a nil limit // is treated as a key after all keys in the data store. If both is nil then it // will compact entire data store. func (t *table) Compact(start []byte, limit []byte) error { // If no start was specified, use the table prefix as the first value if start == nil { start = []byte(t.prefix) } else { start = append([]byte(t.prefix), start...) } // If no limit was specified, use the first element not matching the prefix // as the limit if limit == nil { limit = []byte(t.prefix) for i := len(limit) - 1; i >= 0; i-- { // Bump the current character, stopping if it doesn't overflow limit[i]++ if limit[i] > 0 { break } // Character overflown, proceed to the next or nil if the last if i == 0 { limit = nil } } } else { limit = append([]byte(t.prefix), limit...) } // Range correctly calculated based on table prefix, delegate down return t.db.Compact(start, limit) } // NewBatch creates a write-only database that buffers changes to its host db // until a final write is called, each operation prefixing all keys with the // pre-configured string. func (t *table) NewBatch() ethdb.Batch { return &tableBatch{t.db.NewBatch(), t.prefix} } // NewBatchWithSize creates a write-only database batch with pre-allocated buffer. func (t *table) NewBatchWithSize(size int) ethdb.Batch { return &tableBatch{t.db.NewBatchWithSize(size), t.prefix} } // NewSnapshot creates a database snapshot based on the current state. // The created snapshot will not be affected by all following mutations // happened on the database. func (t *table) NewSnapshot() (ethdb.Snapshot, error) { return t.db.NewSnapshot() } // tableBatch is a wrapper around a database batch that prefixes each key access // with a pre-configured string. type tableBatch struct { batch ethdb.Batch prefix string } // Put inserts the given value into the batch for later committing. func (b *tableBatch) Put(key, value []byte) error { return b.batch.Put(append([]byte(b.prefix), key...), value) } // Delete inserts the a key removal into the batch for later committing. func (b *tableBatch) Delete(key []byte) error { return b.batch.Delete(append([]byte(b.prefix), key...)) } // ValueSize retrieves the amount of data queued up for writing. func (b *tableBatch) ValueSize() int { return b.batch.ValueSize() } // Write flushes any accumulated data to disk. func (b *tableBatch) Write() error { return b.batch.Write() } // Reset resets the batch for reuse. func (b *tableBatch) Reset() { b.batch.Reset() } // tableReplayer is a wrapper around a batch replayer which truncates // the added prefix. type tableReplayer struct { w ethdb.KeyValueWriter prefix string } // Put implements the interface KeyValueWriter. func (r *tableReplayer) Put(key []byte, value []byte) error { trimmed := key[len(r.prefix):] return r.w.Put(trimmed, value) } // Delete implements the interface KeyValueWriter. func (r *tableReplayer) Delete(key []byte) error { trimmed := key[len(r.prefix):] return r.w.Delete(trimmed) } // Replay replays the batch contents. func (b *tableBatch) Replay(w ethdb.KeyValueWriter) error { return b.batch.Replay(&tableReplayer{w: w, prefix: b.prefix}) } // tableIterator is a wrapper around a database iterator that prefixes each key access // with a pre-configured string. type tableIterator struct { iter ethdb.Iterator prefix string } // Next moves the iterator to the next key/value pair. It returns whether the // iterator is exhausted. func (iter *tableIterator) Next() bool { return iter.iter.Next() } // Error returns any accumulated error. Exhausting all the key/value pairs // is not considered to be an error. func (iter *tableIterator) Error() error { return iter.iter.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. func (iter *tableIterator) Key() []byte { key := iter.iter.Key() if key == nil { return nil } return key[len(iter.prefix):] } // 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 (iter *tableIterator) Value() []byte { return iter.iter.Value() } // Release releases associated resources. Release should always succeed and can // be called multiple times without causing error. func (iter *tableIterator) Release() { iter.iter.Release() }