// Delete removes a value with given key.
func (db *LevelDB) Delete(ctx storage.Context, tk storage.TKey) error {
if db == nil {
return fmt.Errorf("Can't call Delete on nil LevelDB")
}
if ctx == nil {
return fmt.Errorf("Received nil context in Delete()")
}
wo := db.options.WriteOptions
var err error
key := ctx.ConstructKey(tk)
if !ctx.Versioned() {
dvid.StartCgo()
err = db.ldb.Delete(wo, key)
dvid.StopCgo()
} else {
vctx, ok := ctx.(storage.VersionedCtx)
if !ok {
return fmt.Errorf("Non-versioned context that says it's versioned received in Delete(): %v", ctx)
}
tombstoneKey := vctx.TombstoneKey(tk)
batch := db.NewBatch(vctx).(*goBatch)
batch.WriteBatch.Delete(key)
batch.WriteBatch.Put(tombstoneKey, dvid.EmptyValue())
if err = batch.Commit(); err != nil {
dvid.Criticalf("Error on batch commit of Delete: %v\n", err)
err = fmt.Errorf("Error on batch commit of Delete: %v", err)
}
}
return err
}
// Put writes a value with given key.
func (db *LevelDB) Put(ctx storage.Context, tk storage.TKey, v []byte) error {
if ctx == nil {
return fmt.Errorf("Received nil context in Put()")
}
wo := db.options.WriteOptions
var err error
key := ctx.ConstructKey(tk)
if !ctx.Versioned() {
dvid.StartCgo()
err = db.ldb.Put(wo, key, v)
dvid.StopCgo()
} else {
vctx, ok := ctx.(storage.VersionedCtx)
if !ok {
return fmt.Errorf("Non-versioned context that says it's versioned received in Put(): %v", ctx)
}
tombstoneKey := vctx.TombstoneKey(tk)
batch := db.NewBatch(vctx).(*goBatch)
batch.WriteBatch.Delete(tombstoneKey)
batch.WriteBatch.Put(key, v)
if err = batch.Commit(); err != nil {
batch.Close()
err = fmt.Errorf("Error on PUT: %v\n", err)
}
}
storage.StoreKeyBytesWritten <- len(key)
storage.StoreValueBytesWritten <- len(v)
return err
}
// PutRange puts key-value pairs that have been sorted in sequential key order.
func (db *LMDB) PutRange(values []KeyValue) error {
if db == nil || db.env == nil {
return fmt.Errorf("Cannot run PutRange() on invalid database.")
}
dvid.StartCgo()
defer dvid.StopCgo()
txn, err := db.env.BeginTxn(nil, 0)
if err != nil {
return err
}
defer txn.Commit()
for _, kv := range values {
kBytes := kv.K.Bytes()
v := kv.V
if v == nil || len(v) == 0 {
v = []byte{0}
}
if err := txn.Put(db.dbi, kBytes, v, 0); err != nil {
return err
}
StoreKeyBytesRead <- len(kBytes)
StoreValueBytesRead <- len(v)
}
return nil
}
// Get returns a value given a key.
func (db *LevelDB) Get(ctx storage.Context, tk storage.TKey) ([]byte, error) {
if ctx == nil {
return nil, fmt.Errorf("Received nil context in Get()")
}
if ctx.Versioned() {
vctx, ok := ctx.(storage.VersionedCtx)
if !ok {
return nil, fmt.Errorf("Bad Get(): context is versioned but doesn't fulfill interface: %v", ctx)
}
// Get all versions of this key and return the most recent
// log.Printf(" basholeveldb versioned get of key %v\n", k)
values, err := db.getSingleKeyVersions(vctx, tk)
// log.Printf(" got back %v\n", values)
if err != nil {
return nil, err
}
kv, err := vctx.VersionedKeyValue(values)
// log.Printf(" after deversioning: %v\n", kv)
if kv != nil {
return kv.V, err
}
return nil, err
} else {
key := ctx.ConstructKey(tk)
ro := db.options.ReadOptions
// log.Printf(" basholeveldb unversioned get of key %v\n", key)
dvid.StartCgo()
v, err := db.ldb.Get(ro, key)
dvid.StopCgo()
storage.StoreValueBytesRead <- len(v)
return v, err
}
}
func (db *LevelDB) metadataExists() (bool, error) {
var ctx storage.MetadataContext
keyBeg, keyEnd := ctx.KeyRange()
dvid.StartCgo()
ro := levigo.NewReadOptions()
it := db.ldb.NewIterator(ro)
defer func() {
it.Close()
dvid.StopCgo()
}()
it.Seek(keyBeg)
for {
if it.Valid() {
// Did we pass the final key?
if bytes.Compare(it.Key(), keyEnd) > 0 {
break
}
return true, nil
}
break
}
if err := it.GetError(); err != nil {
return false, err
}
dvid.Infof("No metadata found for %s...\n", db)
return false, nil
}
func (batch *goBatch) Commit() error {
dvid.StartCgo()
defer dvid.StopCgo()
err := batch.ldb.Write(batch.wo, batch.WriteBatch)
batch.WriteBatch.Close()
return err
}
func (b *batch) Commit() error {
if b == nil {
return fmt.Errorf("Illegal Commit() on a nil batch")
}
dvid.StartCgo()
defer dvid.StopCgo()
return b.txn.Commit()
}
// RawDelete is a low-level function. It deletes a key-value pair using full keys
// without any context. This can be used in conjunction with RawRangeQuery.
func (db *LevelDB) RawDelete(k storage.Key) error {
if db == nil {
return fmt.Errorf("Can't call RawDelete on nil LevelDB")
}
wo := db.options.WriteOptions
dvid.StartCgo()
defer dvid.StopCgo()
return db.ldb.Delete(wo, k)
}
func (b *batch) Delete(k Key) {
if b != nil {
dvid.StartCgo()
defer dvid.StopCgo()
if err := b.txn.Del(b.dbi, k.Bytes(), nil); err != nil {
dvid.Error("Error in batch Delete: %s", err.Error())
}
}
}
// newLevelDB returns a leveldb backend, creating leveldb
// at the path if it doesn't already exist.
func (e Engine) newLevelDB(config dvid.StoreConfig) (*LevelDB, bool, error) {
path, _, err := parseConfig(config)
if err != nil {
return nil, false, err
}
// Is there a database already at this path? If not, create.
var created bool
if _, err := os.Stat(path); os.IsNotExist(err) {
dvid.Infof("Database not already at path (%s). Creating directory...\n", path)
created = true
// Make a directory at the path.
if err := os.MkdirAll(path, 0744); err != nil {
return nil, true, fmt.Errorf("Can't make directory at %s: %v", path, err)
}
} else {
dvid.Infof("Found directory at %s (err = %v)\n", path, err)
}
// Open the database
dvid.StartCgo()
defer dvid.StopCgo()
opt, err := getOptions(config.Config)
if err != nil {
return nil, false, err
}
leveldb := &LevelDB{
directory: path,
config: config,
options: opt,
}
dvid.Infof("Opening basholeveldb @ path %s\n", path)
ldb, err := levigo.Open(path, opt.Options)
if err != nil {
return nil, false, err
}
leveldb.ldb = ldb
// if we know it's newly created, just return.
if created {
return leveldb, created, nil
}
// otherwise, check if there's been any metadata or we need to initialize it.
metadataExists, err := leveldb.metadataExists()
if err != nil {
leveldb.Close()
return nil, false, err
}
return leveldb, !metadataExists, nil
}
func (batch *goBatch) Commit() error {
if batch == nil {
return fmt.Errorf("Received nil batch in batch.Commit()\n")
}
dvid.StartCgo()
defer dvid.StopCgo()
err := batch.ldb.Write(batch.wo, batch.WriteBatch)
batch.WriteBatch.Close()
return err
}
// OpenFUSE mounts the given directory as a FUSE file system.
// The FUSE system is a singleton with only one FUSE server operable.
func OpenFUSE(dir string, data Mountable, vinfo VersionInfo) error {
fuseServer.mutex.Lock()
defer fuseServer.mutex.Unlock()
// Make sure we haven't switched mount directory.
if len(fuseServer.dir) > 0 {
if fuseServer.dir != dir {
return fmt.Errorf("Cannot open more than one FUSE directory. Currently open: %s\n",
fuseServer.dir)
}
}
// Make sure our mount directory is present and a directory.
finfo, err := os.Stat(dir)
if err != nil {
if os.IsNotExist(err) {
if err = os.MkdirAll(dir, 0744); err != nil {
return fmt.Errorf("Cannot create mount directory: %s (%s)\n",
dir, err.Error())
}
} else {
return fmt.Errorf("Cannot access given mount directory: %s\n", dir)
}
} else if !finfo.IsDir() {
return fmt.Errorf("Given mount point (%s) is not a directory\n", dir)
}
// Check if data is already mounted at this version.
mount, found := fuseServer.mounts[vinfo.uuid]
if found {
mount.AddData(data, vinfo)
return nil
}
fuseServer.mounts[vinfo.uuid] = Mount{Data{data}, vinfo}
// Mount and serve if not already served.
if fuseServer.dir == "" {
fuseServer.dir = dir
conn, err := fuse.Mount(dir)
if err != nil {
return err
}
// Run FUSE system in gothread.
go func() {
dvid.StartCgo()
fs.Serve(conn, fuseServer)
dvid.StopCgo()
}()
}
return nil
}
// unversionedRange sends a range of key-value pairs down a channel.
func (db *LevelDB) unversionedRange(ctx storage.Context, begTKey, endTKey storage.TKey, ch chan errorableKV, done <-chan struct{}, keysOnly bool) {
dvid.StartCgo()
ro := levigo.NewReadOptions()
it := db.ldb.NewIterator(ro)
defer func() {
it.Close()
dvid.StopCgo()
}()
// Apply context if applicable
begKey := ctx.ConstructKey(begTKey)
endKey := ctx.ConstructKey(endTKey)
// fmt.Printf("unversionedRange():\n")
// fmt.Printf(" index beg: %v\n", kStart)
// fmt.Printf(" index end: %v\n", kEnd)
// fmt.Printf(" key start: %v\n", keyBeg)
// fmt.Printf(" key end: %v\n", keyEnd)
var itValue []byte
it.Seek(begKey)
for {
if it.Valid() {
// fmt.Printf("unversioned found key %v, %d bytes value\n", it.Key(), len(it.Value()))
if !keysOnly {
itValue = it.Value()
storage.StoreValueBytesRead <- len(itValue)
}
itKey := it.Key()
storage.StoreKeyBytesRead <- len(itKey)
// Did we pass the final key?
if bytes.Compare(itKey, endKey) > 0 {
break
}
select {
case <-done:
ch <- errorableKV{nil, nil}
return
case ch <- errorableKV{&storage.KeyValue{K: itKey, V: itValue}, nil}:
it.Next()
}
} else {
break
}
}
if err := it.GetError(); err != nil {
ch <- errorableKV{nil, err}
} else {
ch <- errorableKV{nil, nil}
}
return
}
// RawPut is a low-level function that puts a key-value pair using full keys.
// This can be used in conjunction with RawRangeQuery.
func (db *LevelDB) RawPut(k storage.Key, v []byte) error {
wo := db.options.WriteOptions
dvid.StartCgo()
defer dvid.StopCgo()
if err := db.ldb.Put(wo, k, v); err != nil {
return err
}
storage.StoreKeyBytesWritten <- len(k)
storage.StoreValueBytesWritten <- len(v)
return nil
}
// ProcessRange sends a range of key-value pairs to chunk handlers.
func (db *LMDB) ProcessRange(kStart, kEnd Key, op *ChunkOp, f func(*Chunk)) error {
if db == nil || db.env == nil {
return fmt.Errorf("Cannot ProcessRange() on invalid database.")
}
dvid.StartCgo()
defer dvid.StopCgo()
txn, err := db.env.BeginTxn(nil, lmdb.RDONLY)
if err != nil {
return err
}
defer txn.Abort()
cursor, err := txn.CursorOpen(db.dbi)
if err != nil {
return err
}
defer cursor.Close()
seekKey := kStart.Bytes()
endBytes := kEnd.Bytes()
var cursorOp uint = lmdb.SET_RANGE
for {
k, v, rc := cursor.Get(seekKey, cursorOp)
if rc != nil {
break
}
seekKey = nil
cursorOp = lmdb.NEXT
StoreKeyBytesRead <- len(k)
StoreValueBytesRead <- len(v)
if k == nil || bytes.Compare(k, endBytes) > 0 {
break
}
// Convert byte representation of key to storage.Key
var key Key
key, err = kStart.BytesToKey(k)
if err != nil {
return err
}
if op.Wg != nil {
op.Wg.Add(1)
}
chunk := &Chunk{
op,
KeyValue{key, v},
}
f(chunk)
}
return nil
}
// Delete removes a value with given key.
// If the key does not exist, it returns without error.
func (db *LMDB) Delete(k Key) error {
if db == nil || db.env == nil {
return fmt.Errorf("Cannot GetRange() on invalid database.")
}
dvid.StartCgo()
defer dvid.StopCgo()
txn, err := db.env.BeginTxn(nil, 0)
if err != nil {
return err
}
defer txn.Commit()
return txn.Del(db.dbi, k.Bytes(), nil)
}
// NewKeyValueStore returns a lmdb backend.
func NewKeyValueStore(path string, create bool, config dvid.Config) (Engine, error) {
// Create the directory if it doesn't exist.
if _, err := os.Stat(path); os.IsNotExist(err) {
if err = os.MkdirAll(path, 0770); err != nil {
return nil, fmt.Errorf("Datastore (%s) doesn't exist and couldn't be created: %s", err.Error())
}
}
dvid.StartCgo()
defer dvid.StopCgo()
opt, err := GetOptions(create, config)
if err != nil {
return nil, err
}
env, err := lmdb.NewEnv()
if err != nil {
return nil, err
}
if err = env.SetMapSize(uint64(opt.GBytes * dvid.Giga)); err != nil {
return nil, err
}
if err = env.Open(path, lmdb.NOSYNC|lmdb.WRITEMAP, 0664); err != nil {
return nil, err
}
txn, err := env.BeginTxn(nil, 0)
if err != nil {
return nil, fmt.Errorf("Cannot begin transaction: %s", err.Error())
}
dbi, err := txn.DBIOpen(nil, 0)
if err != nil {
return nil, fmt.Errorf("Cannot create DBI: %s", err.Error())
}
db := &LMDB{
path: path,
config: config,
options: opt,
env: env,
dbi: dbi,
}
txn.Abort()
return db, nil
}
// RepairStore tries to repair a damaged leveldb
func RepairStore(path string, config dvid.Config) error {
dvid.StartCgo()
defer dvid.StopCgo()
opt, err := GetOptions(false, config)
if err != nil {
return err
}
err = levigo.RepairDatabase(path, opt.Options)
if err != nil {
return err
}
return nil
}
func (batch *goBatch) Delete(tk storage.TKey) {
if batch == nil || batch.ctx == nil {
dvid.Criticalf("Received nil batch or nil batch context in batch.Delete()\n")
return
}
dvid.StartCgo()
defer dvid.StopCgo()
key := batch.ctx.ConstructKey(tk)
if batch.vctx != nil {
tombstone := batch.vctx.TombstoneKey(tk) // This will now have current version
batch.WriteBatch.Put(tombstone, dvid.EmptyValue())
}
batch.WriteBatch.Delete(key)
}
// Repair tries to repair a damaged leveldb. Requires "path" string. Implements
// the RepairableEngine interface.
func (e Engine) Repair(path string) error {
dvid.StartCgo()
defer dvid.StopCgo()
opt, err := getOptions(dvid.Config{})
if err != nil {
return err
}
err = levigo.RepairDatabase(path, opt.Options)
if err != nil {
return err
}
return nil
}
func (b *batch) Put(k Key, v []byte) {
if b != nil {
dvid.StartCgo()
defer dvid.StopCgo()
kBytes := k.Bytes()
if v == nil || len(v) == 0 {
v = []byte{0}
}
if err := b.txn.Put(b.dbi, kBytes, v, 0); err != nil {
dvid.Error("Error in batch Put: %s", err.Error())
return
}
StoreKeyBytesWritten <- len(kBytes)
StoreValueBytesWritten <- len(v)
}
}
// NewBatch returns an implementation that allows batch writes
func (db *LevelDB) NewBatch(ctx storage.Context) storage.Batch {
if ctx == nil {
dvid.Criticalf("Received nil context in NewBatch()")
return nil
}
dvid.StartCgo()
defer dvid.StopCgo()
var vctx storage.VersionedCtx
var ok bool
vctx, ok = ctx.(storage.VersionedCtx)
if !ok {
vctx = nil
}
return &goBatch{ctx, vctx, levigo.NewWriteBatch(), db.options.WriteOptions, db.ldb}
}
func (batch *goBatch) Put(tk storage.TKey, v []byte) {
if batch == nil || batch.ctx == nil {
dvid.Criticalf("Received nil batch or nil batch context in batch.Put()\n")
return
}
dvid.StartCgo()
defer dvid.StopCgo()
key := batch.ctx.ConstructKey(tk)
if batch.vctx != nil {
tombstone := batch.vctx.TombstoneKey(tk) // This will now have current version
batch.WriteBatch.Delete(tombstone)
}
storage.StoreKeyBytesWritten <- len(key)
storage.StoreValueBytesWritten <- len(v)
batch.WriteBatch.Put(key, v)
}
// KeysInRange returns a range of present keys spanning (kStart, kEnd).
// For lmdb database, values are read but not returned.
func (db *LMDB) KeysInRange(kStart, kEnd Key) ([]Key, error) {
if db == nil || db.env == nil {
return nil, fmt.Errorf("Cannot run KeysInRange() on invalid database.")
}
dvid.StartCgo()
defer dvid.StopCgo()
txn, err := db.env.BeginTxn(nil, lmdb.RDONLY)
if err != nil {
return nil, err
}
defer txn.Abort()
cursor, err := txn.CursorOpen(db.dbi)
if err != nil {
return nil, err
}
defer cursor.Close()
seekKey := kStart.Bytes()
endBytes := kEnd.Bytes()
keys := []Key{}
var cursorOp uint = lmdb.SET_RANGE
for {
k, v, rc := cursor.Get(seekKey, cursorOp)
if rc != nil {
break
}
seekKey = nil
cursorOp = lmdb.NEXT
StoreKeyBytesRead <- len(k)
StoreValueBytesRead <- len(v)
if k == nil || bytes.Compare(k, endBytes) > 0 {
break
}
// Convert byte representation of key to storage.Key
var key Key
key, err = kStart.BytesToKey(k)
if err != nil {
return nil, err
}
keys = append(keys, key)
}
return keys, nil
}
// RawRangeQuery sends a range of full keys. This is to be used for low-level data
// retrieval like DVID-to-DVID communication and should not be used by data type
// implementations if possible. A nil is sent down the channel when the
// range is complete.
func (db *LevelDB) RawRangeQuery(kStart, kEnd storage.Key, keysOnly bool, out chan *storage.KeyValue, cancel <-chan struct{}) error {
if db == nil {
return fmt.Errorf("Can't call RawRangeQuery on nil LevelDB")
}
dvid.StartCgo()
ro := levigo.NewReadOptions()
it := db.ldb.NewIterator(ro)
defer func() {
it.Close()
dvid.StopCgo()
}()
var itValue []byte
it.Seek(kStart)
for {
if it.Valid() {
if !keysOnly {
itValue = it.Value()
storage.StoreValueBytesRead <- len(itValue)
}
itKey := it.Key()
storage.StoreKeyBytesRead <- len(itKey)
// Did we pass the final key?
if bytes.Compare(itKey, kEnd) > 0 {
break
}
kv := storage.KeyValue{itKey, itValue}
select {
case out <- &kv:
case <-cancel:
return nil
}
//out <- &kv
it.Next()
} else {
break
}
}
out <- nil
if err := it.GetError(); err != nil {
return err
}
return nil
}
// newLevelDB returns a leveldb backend. If create is true, the leveldb
// will be created at the path if it doesn't already exist.
func (e Engine) newLevelDB(config dvid.EngineConfig) (*LevelDB, bool, error) {
// Create path depending on whether it is testing database or not.
path := config.Path
if config.Testing {
path = filepath.Join(os.TempDir(), config.Path)
}
// Is there a database already at this path? If not, create.
var created bool
if _, err := os.Stat(path); os.IsNotExist(err) {
dvid.Infof("Database not already at path (%s). Creating directory...\n", path)
created = true
// Make a directory at the path.
if err := os.MkdirAll(path, 0744); err != nil {
return nil, true, fmt.Errorf("Can't make directory at %s: %v", path, err)
}
} else {
dvid.Infof("Found directory at %s (err = %v)\n", path, err)
}
// Open the database
dvid.StartCgo()
defer dvid.StopCgo()
opt, err := getOptions(config.Config)
if err != nil {
return nil, false, err
}
leveldb := &LevelDB{
directory: path,
config: config,
options: opt,
}
ldb, err := levigo.Open(path, opt.Options)
if err != nil {
return nil, false, err
}
leveldb.ldb = ldb
return leveldb, created, nil
}
// Get returns a value given a key.
func (db *LMDB) Get(k Key) ([]byte, error) {
if db == nil || db.env == nil {
return nil, fmt.Errorf("Cannot Get() on invalid database.")
}
dvid.StartCgo()
defer dvid.StopCgo()
txn, err := db.env.BeginTxn(nil, lmdb.RDONLY)
if err != nil {
return nil, err
}
defer txn.Abort()
value, err := txn.Get(db.dbi, k.Bytes())
if err != nil {
return nil, err
}
return value, nil
}
// getSingleKeyVersions returns all versions of a key. These key-value pairs will be sorted
// in ascending key order and could include a tombstone key.
func (db *LevelDB) getSingleKeyVersions(vctx storage.VersionedCtx, tk []byte) ([]*storage.KeyValue, error) {
dvid.StartCgo()
ro := levigo.NewReadOptions()
it := db.ldb.NewIterator(ro)
defer func() {
it.Close()
dvid.StopCgo()
}()
values := []*storage.KeyValue{}
begKey, err := vctx.MinVersionKey(tk)
if err != nil {
return nil, err
}
endKey, err := vctx.MaxVersionKey(tk)
if err != nil {
return nil, err
}
it.Seek(begKey)
for {
if it.Valid() {
itKey := it.Key()
storage.StoreKeyBytesRead <- len(itKey)
if bytes.Compare(itKey, endKey) > 0 {
// log.Printf("key past %v\n", kEnd)
return values, nil
}
itValue := it.Value()
// log.Printf("got value of length %d\n", len(itValue))
storage.StoreValueBytesRead <- len(itValue)
values = append(values, &storage.KeyValue{itKey, itValue})
it.Next()
} else {
err = it.GetError()
// log.Printf("iteration done, err = %v\n", err)
if err == nil {
return values, nil
}
return nil, err
}
}
}
// NewBatch returns an implementation that allows batch writes. This lmdb implementation
// uses a transaction for the batch.
func (db *LMDB) NewBatch() Batch {
if db == nil || db.env == nil {
dvid.Error("Cannot do NewBatch() of lmdb with nil database")
return nil
}
b := new(batch)
b.env = db.env
b.dbi = db.dbi
dvid.StartCgo()
defer dvid.StopCgo()
txn, err := db.env.BeginTxn(nil, 0)
if err != nil {
dvid.Error("Error in BeginTxn() for NewBatch() of lmdb")
return nil
}
b.txn = txn
return b
}
// Put writes a value with given key.
func (db *LMDB) Put(k Key, v []byte) error {
if db == nil || db.env == nil {
return fmt.Errorf("Cannot Put() on invalid database.")
}
dvid.StartCgo()
defer dvid.StopCgo()
txn, err := db.env.BeginTxn(nil, 0)
if err != nil {
return err
}
defer txn.Commit()
kBytes := k.Bytes()
if v == nil || len(v) == 0 {
v = []byte{0}
}
if err := txn.Put(db.dbi, kBytes, v, 0); err != nil {
return err
}
StoreKeyBytesWritten <- len(kBytes)
StoreValueBytesWritten <- len(v)
return nil
}
