// NewLDBDatabase returns a LevelDB wrapped object.
func NewLDBDatabase(file string, cache int) (*LDBDatabase, error) {
// Calculate the cache allowance for this particular database
cache = int(float64(cache) * cacheRatio[filepath.Base(file)])
if cache < 16 {
cache = 16
}
glog.V(logger.Info).Infof("Alloted %dMB cache to %s", cache, file)
// Open the db and recover any potential corruptions
db, err := leveldb.OpenFile(file, &opt.Options{
OpenFilesCacheCapacity: OpenFileLimit,
BlockCacheCapacity: cache / 2 * opt.MiB,
WriteBuffer: cache / 4 * opt.MiB, // Two of these are used internally
})
if _, corrupted := err.(*errors.ErrCorrupted); corrupted {
db, err = leveldb.RecoverFile(file, nil)
}
// (Re)check for errors and abort if opening of the db failed
if err != nil {
return nil, err
}
return &LDBDatabase{
fn: file,
db: db,
}, nil
}
// newPersistentNodeDB creates/opens a leveldb backed persistent node database,
// also flushing its contents in case of a version mismatch.
func newPersistentNodeDB(path string, version int, self NodeID) (*nodeDB, error) {
opts := &opt.Options{OpenFilesCacheCapacity: 5}
db, err := leveldb.OpenFile(path, opts)
if _, iscorrupted := err.(*errors.ErrCorrupted); iscorrupted {
db, err = leveldb.RecoverFile(path, nil)
}
if err != nil {
return nil, err
}
// The nodes contained in the cache correspond to a certain protocol version.
// Flush all nodes if the version doesn't match.
currentVer := make([]byte, binary.MaxVarintLen64)
currentVer = currentVer[:binary.PutVarint(currentVer, int64(version))]
blob, err := db.Get(nodeDBVersionKey, nil)
switch err {
case leveldb.ErrNotFound:
// Version not found (i.e. empty cache), insert it
if err := db.Put(nodeDBVersionKey, currentVer, nil); err != nil {
db.Close()
return nil, err
}
case nil:
// Version present, flush if different
if !bytes.Equal(blob, currentVer) {
db.Close()
if err = os.RemoveAll(path); err != nil {
return nil, err
}
return newPersistentNodeDB(path, version, self)
}
}
return &nodeDB{
lvl: db,
self: self,
quit: make(chan struct{}),
}, nil
}