80 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			80 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
package ethdb
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import (
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	"github.com/ethereum/go-ethereum/compression/rle"
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	"github.com/ethereum/go-ethereum/logger"
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	"github.com/ethereum/go-ethereum/logger/glog"
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	"github.com/syndtr/goleveldb/leveldb"
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	"github.com/syndtr/goleveldb/leveldb/errors"
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	"github.com/syndtr/goleveldb/leveldb/iterator"
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	"github.com/syndtr/goleveldb/leveldb/opt"
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)
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var OpenFileLimit = 64
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type LDBDatabase struct {
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	// filename for reporting
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	fn string
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	// LevelDB instance
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	db *leveldb.DB
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}
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// NewLDBDatabase returns a LevelDB wrapped object. LDBDatabase does not persist data by
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// it self but requires a background poller which syncs every X. `Flush` should be called
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// when data needs to be stored and written to disk.
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func NewLDBDatabase(file string) (*LDBDatabase, error) {
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	// Open the db
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	db, err := leveldb.OpenFile(file, &opt.Options{OpenFilesCacheCapacity: OpenFileLimit})
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	// check for curruption and attempt to recover
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	if _, iscorrupted := err.(*errors.ErrCorrupted); iscorrupted {
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		db, err = leveldb.RecoverFile(file, nil)
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	}
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	// (re) check for errors and abort if opening of the db failed
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	if err != nil {
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		return nil, err
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	}
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	database := &LDBDatabase{
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		fn: file,
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		db: db,
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	}
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	return database, nil
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}
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// Put puts the given key / value to the queue
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func (self *LDBDatabase) Put(key []byte, value []byte) error {
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	return self.db.Put(key, rle.Compress(value), nil)
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}
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// Get returns the given key if it's present.
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func (self *LDBDatabase) Get(key []byte) ([]byte, error) {
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	dat, err := self.db.Get(key, nil)
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	if err != nil {
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		return nil, err
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	}
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	return rle.Decompress(dat)
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}
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// Delete deletes the key from the queue and database
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func (self *LDBDatabase) Delete(key []byte) error {
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	return self.db.Delete(key, nil)
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}
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func (self *LDBDatabase) NewIterator() iterator.Iterator {
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	return self.db.NewIterator(nil, nil)
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}
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// Flush flushes out the queue to leveldb
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func (self *LDBDatabase) Flush() error {
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	return nil
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}
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func (self *LDBDatabase) Close() {
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	if err := self.Flush(); err != nil {
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		glog.V(logger.Error).Infof("error: flush '%s': %v\n", self.fn, err)
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	}
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	self.db.Close()
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	glog.V(logger.Error).Infoln("flushed and closed db:", self.fn)
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}
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