forked from TrueCloudLab/neoneo-go
ddd1d92ff1
The idea here is to preserve the history of `dev` branch development and its code when merging with the `master`. Later this code could be moved into the masters code where appropriate.
114 lines
2.6 KiB
Go
114 lines
2.6 KiB
Go
package database
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import (
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"github.com/syndtr/goleveldb/leveldb"
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"github.com/syndtr/goleveldb/leveldb/errors"
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ldbutil "github.com/syndtr/goleveldb/leveldb/util"
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)
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//DbDir is the folder which all database files will be put under
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// Structure /DbDir/net
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const DbDir = "db/"
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// LDB represents a leveldb object
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type LDB struct {
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db *leveldb.DB
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Path string
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}
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// ErrNotFound means that the value was not found in the db
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var ErrNotFound = errors.New("value not found for that key")
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// Database contains all methods needed for an object to be a database
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type Database interface {
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// Has checks whether the key is in the database
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Has(key []byte) (bool, error)
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// Put adds the key value pair into the pair
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Put(key []byte, value []byte) error
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// Get returns the value for the given key
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Get(key []byte) ([]byte, error)
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// Delete deletes the given value for the key from the database
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Delete(key []byte) error
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//Prefix returns all values that start with key
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Prefix(key []byte) ([][]byte, error)
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// Close closes the underlying db object
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Close() error
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}
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// New will return a new leveldb instance
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func New(path string) (*LDB, error) {
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dbPath := DbDir + path
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db, err := leveldb.OpenFile(dbPath, nil)
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if err != nil {
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return nil, err
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}
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if _, corrupted := err.(*errors.ErrCorrupted); corrupted {
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db, err = leveldb.RecoverFile(path, nil)
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if err != nil {
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return nil, err
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}
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}
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return &LDB{
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db,
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dbPath,
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}, nil
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}
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// Has implements the database interface
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func (l *LDB) Has(key []byte) (bool, error) {
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return l.db.Has(key, nil)
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}
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// Put implements the database interface
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func (l *LDB) Put(key []byte, value []byte) error {
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return l.db.Put(key, value, nil)
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}
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// Get implements the database interface
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func (l *LDB) Get(key []byte) ([]byte, error) {
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val, err := l.db.Get(key, nil)
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if err == nil {
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return val, nil
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}
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if err == leveldb.ErrNotFound {
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return val, ErrNotFound
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}
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return val, err
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}
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// Delete implements the database interface
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func (l *LDB) Delete(key []byte) error {
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return l.db.Delete(key, nil)
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}
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// Close implements the database interface
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func (l *LDB) Close() error {
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return l.db.Close()
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}
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// Prefix implements the database interface
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func (l *LDB) Prefix(key []byte) ([][]byte, error) {
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var results [][]byte
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iter := l.db.NewIterator(ldbutil.BytesPrefix(key), nil)
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for iter.Next() {
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value := iter.Value()
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// Copy the data, as we cannot modify it
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// Once the iter has been released
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deref := make([]byte, len(value))
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copy(deref, value)
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// Append result
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results = append(results, deref)
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}
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iter.Release()
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err := iter.Error()
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return results, err
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}
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