forked from cerc-io/plugeth
67 lines
1.9 KiB
Go
67 lines
1.9 KiB
Go
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// Copyright 2018 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser 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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//
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// The go-ethereum library 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 Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package shed
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import (
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"github.com/syndtr/goleveldb/leveldb"
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)
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// StringField is the most simple field implementation
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// that stores an arbitrary string under a specific LevelDB key.
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type StringField struct {
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db *DB
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key []byte
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}
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// NewStringField retruns a new Instance of StringField.
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// It validates its name and type against the database schema.
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func (db *DB) NewStringField(name string) (f StringField, err error) {
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key, err := db.schemaFieldKey(name, "string")
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if err != nil {
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return f, err
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}
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return StringField{
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db: db,
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key: key,
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}, nil
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}
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// Get returns a string value from database.
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// If the value is not found, an empty string is returned
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// an no error.
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func (f StringField) Get() (val string, err error) {
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b, err := f.db.Get(f.key)
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if err != nil {
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if err == leveldb.ErrNotFound {
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return "", nil
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}
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return "", err
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}
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return string(b), nil
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}
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// Put stores a string in the database.
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func (f StringField) Put(val string) (err error) {
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return f.db.Put(f.key, []byte(val))
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}
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// PutInBatch stores a string in a batch that can be
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// saved later in database.
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func (f StringField) PutInBatch(batch *leveldb.Batch, val string) {
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batch.Put(f.key, []byte(val))
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}
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