Dependency update

Godeps/Godeps.json

@@ -7,7 +7,7 @@
 	"Deps": [
 		{
 			"ImportPath": "github.com/bkaradzic/go-lz4",
-			"Rev": "93a831dcee242be64a9cc9803dda84af25932de7"
+			"Rev": "4f7c2045dbd17b802370e2e6022200468abf02ba"
 		},
 		{
 			"ImportPath": "github.com/calmh/logger",
@@ -21,13 +21,17 @@
 			"ImportPath": "github.com/calmh/xdr",
 			"Rev": "5f7208e86762911861c94f1849eddbfc0a60cbf0"
 		},
+		{
+			"ImportPath": "github.com/google/go-snappy/snappy",
+			"Rev": "eaa750b9bf4dcb7cb20454be850613b66cda3273"
+		},
 		{
 			"ImportPath": "github.com/juju/ratelimit",
-			"Rev": "c5abe513796336ee2869745bff0638508450e9c5"
+			"Rev": "faa59ce93750e747b2997635e8b7daf30024b1ac"
 		},
 		{
 			"ImportPath": "github.com/kardianos/osext",
-			"Rev": "efacde03154693404c65e7aa7d461ac9014acd0c"
+			"Rev": "6e7f843663477789fac7c02def0d0909e969b4e5"
 		},
 		{
 			"ImportPath": "github.com/syncthing/protocol",
@@ -35,11 +39,7 @@
 		},
 		{
 			"ImportPath": "github.com/syndtr/goleveldb/leveldb",
-			"Rev": "87e4e645d80ae9c537e8f2dee52b28036a5dd75e"
+			"Rev": "a06509502ca32565bdf74afc1e573050023f261c"
-		},
-		{
-			"ImportPath": "github.com/syndtr/gosnappy/snappy",
-			"Rev": "156a073208e131d7d2e212cb749feae7c339e846"
 		},
 		{
 			"ImportPath": "github.com/thejerf/suture",
@@ -59,19 +59,19 @@
 		},
 		{
 			"ImportPath": "golang.org/x/crypto/bcrypt",
-			"Rev": "c57d4a71915a248dbad846d60825145062b4c18e"
+			"Rev": "1e856cbfdf9bc25eefca75f83f25d55e35ae72e0"
 		},
 		{
 			"ImportPath": "golang.org/x/crypto/blowfish",
-			"Rev": "c57d4a71915a248dbad846d60825145062b4c18e"
+			"Rev": "1e856cbfdf9bc25eefca75f83f25d55e35ae72e0"
 		},
 		{
 			"ImportPath": "golang.org/x/text/transform",
-			"Rev": "2076e9cab4147459c82bc81169e46c139d358547"
+			"Rev": "df923bbb63f8ea3a26bb743e2a497abd0ab585f7"
 		},
 		{
 			"ImportPath": "golang.org/x/text/unicode/norm",
-			"Rev": "2076e9cab4147459c82bc81169e46c139d358547"
+			"Rev": "df923bbb63f8ea3a26bb743e2a497abd0ab585f7"
 		}
 	]
 }

Godeps/_workspace/src/github.com/bkaradzic/go-lz4/fuzz.go

@@ -0,0 +1,23 @@
+// +build gofuzz
+
+package lz4
+
+import "encoding/binary"
+
+func Fuzz(data []byte) int {
+
+	if len(data) < 4 {
+		return 0
+	}
+
+	ln := binary.LittleEndian.Uint32(data)
+	if ln > (1 << 21) {
+		return 0
+	}
+
+	if _, err := Decode(nil, data); err != nil {
+		return 0
+	}
+
+	return 1
+}

Godeps/_workspace/src/github.com/bkaradzic/go-lz4/reader.go

@@ -141,7 +141,7 @@ func Decode(dst, src []byte) ([]byte, error) {
 			length += ln
 		}
 
-		if int(d.spos+length) > len(d.src) {
+		if int(d.spos+length) > len(d.src) || int(d.dpos+length) > len(d.dst) {
 			return nil, ErrCorrupt
 		}
 
@@ -179,7 +179,12 @@ func Decode(dst, src []byte) ([]byte, error) {
 		}
 
 		literal := d.dpos - d.ref
+
 		if literal < 4 {
+			if int(d.dpos+4) > len(d.dst) {
+				return nil, ErrCorrupt
+			}
+
 			d.cp(4, decr[literal])
 		} else {
 			length += 4

Godeps/_workspace/src/github.com/bkaradzic/go-lz4/writer.go

@@ -25,8 +25,10 @@
 
 package lz4
 
-import "encoding/binary"
+import (
-import "errors"
+	"encoding/binary"
+	"errors"
+)
 
 const (
 	minMatch              = 4

Godeps/_workspace/src/github.com/juju/ratelimit/LICENSE

@@ -1,5 +1,8 @@
-This package contains an efficient token-bucket-based rate limiter.
+All files in this repository are licensed as follows. If you contribute
-Copyright (C) 2015 Canonical Ltd.
+to this repository, it is assumed that you license your contribution
+under the same license unless you state otherwise.
+
+All files Copyright (C) 2015 Canonical Ltd. unless otherwise specified in the file.
 
 This software is licensed under the LGPLv3, included below.
 

Godeps/_workspace/src/github.com/juju/ratelimit/ratelimit.go

@@ -7,6 +7,7 @@
 package ratelimit
 
 import (
+	"math"
 	"strconv"
 	"sync"
 	"time"
@@ -55,7 +56,7 @@ func NewBucketWithRate(rate float64, capacity int64) *Bucket {
 			continue
 		}
 		tb := NewBucketWithQuantum(fillInterval, capacity, quantum)
-		if diff := abs(tb.Rate() - rate); diff/rate <= rateMargin {
+		if diff := math.Abs(tb.Rate() - rate); diff/rate <= rateMargin {
 			return tb
 		}
 	}
@@ -217,10 +218,3 @@ func (tb *Bucket) adjust(now time.Time) (currentTick int64) {
 	tb.availTick = currentTick
 	return
 }
-
-func abs(f float64) float64 {
-	if f < 0 {
-		return -f
-	}
-	return f
-}

Godeps/_workspace/src/github.com/kardianos/osext/README.md

@@ -4,7 +4,9 @@
 
 There is sometimes utility in finding the current executable file
 that is running. This can be used for upgrading the current executable
-or finding resources located relative to the executable file.
+or finding resources located relative to the executable file. Both
+working directory and the os.Args[0] value are arbitrary and cannot
+be relied on; os.Args[0] can be "faked".
 
 Multi-platform and supports:
  * Linux

Godeps/_workspace/src/github.com/kardianos/osext/osext.go

@@ -16,12 +16,12 @@ func Executable() (string, error) {
 }
 
 // Returns same path as Executable, returns just the folder
-// path. Excludes the executable name.
+// path. Excludes the executable name and any trailing slash.
 func ExecutableFolder() (string, error) {
 	p, err := Executable()
 	if err != nil {
 		return "", err
 	}
-	folder, _ := filepath.Split(p)
+
-	return folder, nil
+	return filepath.Dir(p), nil
 }

Godeps/_workspace/src/github.com/kardianos/osext/osext_procfs.go

@@ -17,12 +17,14 @@ import (
 func executable() (string, error) {
 	switch runtime.GOOS {
 	case "linux":
-		const deletedSuffix = " (deleted)"
+		const deletedTag = " (deleted)"
 		execpath, err := os.Readlink("/proc/self/exe")
 		if err != nil {
 			return execpath, err
 		}
-		return strings.TrimSuffix(execpath, deletedSuffix), nil
+		execpath = strings.TrimSuffix(execpath, deletedTag)
+		execpath = strings.TrimPrefix(execpath, deletedTag)
+		return execpath, nil
 	case "netbsd":
 		return os.Readlink("/proc/curproc/exe")
 	case "openbsd", "dragonfly":

Godeps/_workspace/src/github.com/kardianos/osext/osext_test.go

@@ -24,6 +24,29 @@ const (
 	executableEnvValueDelete = "delete"
 )
 
+func TestPrintExecutable(t *testing.T) {
+	ef, err := Executable()
+	if err != nil {
+		t.Fatalf("Executable failed: %v", err)
+	}
+	t.Log("Executable:", ef)
+}
+func TestPrintExecutableFolder(t *testing.T) {
+	ef, err := ExecutableFolder()
+	if err != nil {
+		t.Fatalf("ExecutableFolder failed: %v", err)
+	}
+	t.Log("Executable Folder:", ef)
+}
+func TestExecutableFolder(t *testing.T) {
+	ef, err := ExecutableFolder()
+	if err != nil {
+		t.Fatalf("ExecutableFolder failed: %v", err)
+	}
+	if ef[len(ef)-1] == filepath.Separator {
+		t.Fatal("ExecutableFolder ends with a trailing slash.")
+	}
+}
 func TestExecutableMatch(t *testing.T) {
 	ep, err := Executable()
 	if err != nil {

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/db.go

@@ -69,6 +69,7 @@ type DB struct {
 	compErrC         chan error
 	compPerErrC      chan error
 	compErrSetC      chan error
+	compWriteLocking bool
 	compStats        []cStats
 
 	// Close.
@@ -108,6 +109,16 @@ func openDB(s *session) (*DB, error) {
 		closeC: make(chan struct{}),
 	}
 
+	// Read-only mode.
+	readOnly := s.o.GetReadOnly()
+
+	if readOnly {
+		// Recover journals (read-only mode).
+		if err := db.recoverJournalRO(); err != nil {
+			return nil, err
+		}
+	} else {
+		// Recover journals.
 		if err := db.recoverJournal(); err != nil {
 			return nil, err
 		}
@@ -122,14 +133,20 @@ func openDB(s *session) (*DB, error) {
 			return nil, err
 		}
 
+	}
+
 	// Doesn't need to be included in the wait group.
 	go db.compactionError()
 	go db.mpoolDrain()
 
+	if readOnly {
+		db.SetReadOnly()
+	} else {
 		db.closeW.Add(3)
 		go db.tCompaction()
 		go db.mCompaction()
 		go db.jWriter()
+	}
 
 	s.logf("db@open done T·%v", time.Since(start))
 
@@ -275,7 +292,7 @@ func recoverTable(s *session, o *opt.Options) error {
 		// We will drop corrupted table.
 		strict = o.GetStrict(opt.StrictRecovery)
 
-		rec   = &sessionRecord{numLevel: o.GetNumLevel()}
+		rec   = &sessionRecord{}
 		bpool = util.NewBufferPool(o.GetBlockSize() + 5)
 	)
 	buildTable := func(iter iterator.Iterator) (tmp storage.File, size int64, err error) {
@@ -450,78 +467,92 @@ func recoverTable(s *session, o *opt.Options) error {
 }
 
 func (db *DB) recoverJournal() error {
-	// Get all tables and sort it by file number.
+	// Get all journals and sort it by file number.
-	journalFiles_, err := db.s.getFiles(storage.TypeJournal)
+	allJournalFiles, err := db.s.getFiles(storage.TypeJournal)
 	if err != nil {
 		return err
 	}
-	journalFiles := files(journalFiles_)
+	files(allJournalFiles).sort()
-	journalFiles.sort()
 
-	// Discard older journal.
+	// Journals that will be recovered.
-	prev := -1
+	var recJournalFiles []storage.File
-	for i, file := range journalFiles {
+	for _, jf := range allJournalFiles {
-		if file.Num() >= db.s.stJournalNum {
+		if jf.Num() >= db.s.stJournalNum || jf.Num() == db.s.stPrevJournalNum {
-			if prev >= 0 {
+			recJournalFiles = append(recJournalFiles, jf)
-				i--
-				journalFiles[i] = journalFiles[prev]
-			}
-			journalFiles = journalFiles[i:]
-			break
-		} else if file.Num() == db.s.stPrevJournalNum {
-			prev = i
 		}
 	}
 
-	var jr *journal.Reader
+	var (
-	var of storage.File
+		of  storage.File // Obsolete file.
-	var mem *memdb.DB
+		rec = &sessionRecord{}
-	batch := new(Batch)
+	)
-	cm := newCMem(db.s)
+
-	buf := new(util.Buffer)
+	// Recover journals.
+	if len(recJournalFiles) > 0 {
+		db.logf("journal@recovery F·%d", len(recJournalFiles))
+
+		// Mark file number as used.
+		db.s.markFileNum(recJournalFiles[len(recJournalFiles)-1].Num())
+
+		var (
 			// Options.
-	strict := db.s.o.GetStrict(opt.StrictJournal)
+			strict      = db.s.o.GetStrict(opt.StrictJournal)
-	checksum := db.s.o.GetStrict(opt.StrictJournalChecksum)
+			checksum    = db.s.o.GetStrict(opt.StrictJournalChecksum)
-	writeBuffer := db.s.o.GetWriteBuffer()
+			writeBuffer = db.s.o.GetWriteBuffer()
-	recoverJournal := func(file storage.File) error {
+
-		db.logf("journal@recovery recovering @%d", file.Num())
+			jr    *journal.Reader
-		reader, err := file.Open()
+			mdb   = memdb.New(db.s.icmp, writeBuffer)
+			buf   = &util.Buffer{}
+			batch = &Batch{}
+		)
+
+		for _, jf := range recJournalFiles {
+			db.logf("journal@recovery recovering @%d", jf.Num())
+
+			fr, err := jf.Open()
 			if err != nil {
 				return err
 			}
-		defer reader.Close()
 
-		// Create/reset journal reader instance.
+			// Create or reset journal reader instance.
 			if jr == nil {
-			jr = journal.NewReader(reader, dropper{db.s, file}, strict, checksum)
+				jr = journal.NewReader(fr, dropper{db.s, jf}, strict, checksum)
 			} else {
-			jr.Reset(reader, dropper{db.s, file}, strict, checksum)
+				jr.Reset(fr, dropper{db.s, jf}, strict, checksum)
 			}
 
 			// Flush memdb and remove obsolete journal file.
 			if of != nil {
-			if mem.Len() > 0 {
+				if mdb.Len() > 0 {
-				if err := cm.flush(mem, 0); err != nil {
+					if _, err := db.s.flushMemdb(rec, mdb, -1); err != nil {
+						fr.Close()
 						return err
 					}
 				}
-			if err := cm.commit(file.Num(), db.seq); err != nil {
+
+				rec.setJournalNum(jf.Num())
+				rec.setSeqNum(db.seq)
+				if err := db.s.commit(rec); err != nil {
+					fr.Close()
 					return err
 				}
-			cm.reset()
+				rec.resetAddedTables()
+
 				of.Remove()
 				of = nil
 			}
 
 			// Replay journal to memdb.
-		mem.Reset()
+			mdb.Reset()
 			for {
 				r, err := jr.Next()
 				if err != nil {
 					if err == io.EOF {
 						break
 					}
-				return errors.SetFile(err, file)
+
+					fr.Close()
+					return errors.SetFile(err, jf)
 				}
 
 				buf.Reset()
@@ -529,53 +560,43 @@ func (db *DB) recoverJournal() error {
 					if err == io.ErrUnexpectedEOF {
 						// This is error returned due to corruption, with strict == false.
 						continue
-				} else {
-					return errors.SetFile(err, file)
 					}
+
+					fr.Close()
+					return errors.SetFile(err, jf)
 				}
-			if err := batch.memDecodeAndReplay(db.seq, buf.Bytes(), mem); err != nil {
+				if err := batch.memDecodeAndReplay(db.seq, buf.Bytes(), mdb); err != nil {
-				if strict || !errors.IsCorrupted(err) {
+					if !strict && errors.IsCorrupted(err) {
-					return errors.SetFile(err, file)
-				} else {
 						db.s.logf("journal error: %v (skipped)", err)
 						// We won't apply sequence number as it might be corrupted.
 						continue
 					}
+
+					fr.Close()
+					return errors.SetFile(err, jf)
 				}
 
 				// Save sequence number.
 				db.seq = batch.seq + uint64(batch.Len())
 
 				// Flush it if large enough.
-			if mem.Size() >= writeBuffer {
+				if mdb.Size() >= writeBuffer {
-				if err := cm.flush(mem, 0); err != nil {
+					if _, err := db.s.flushMemdb(rec, mdb, 0); err != nil {
+						fr.Close()
 						return err
 					}
-				mem.Reset()
+
+					mdb.Reset()
 				}
 			}
 
-		of = file
+			fr.Close()
-		return nil
+			of = jf
 		}
 
-	// Recover all journals.
+		// Flush the last memdb.
-	if len(journalFiles) > 0 {
+		if mdb.Len() > 0 {
-		db.logf("journal@recovery F·%d", len(journalFiles))
+			if _, err := db.s.flushMemdb(rec, mdb, 0); err != nil {
-
-		// Mark file number as used.
-		db.s.markFileNum(journalFiles[len(journalFiles)-1].Num())
-
-		mem = memdb.New(db.s.icmp, writeBuffer)
-		for _, file := range journalFiles {
-			if err := recoverJournal(file); err != nil {
-				return err
-			}
-		}
-
-		// Flush the last journal.
-		if mem.Len() > 0 {
-			if err := cm.flush(mem, 0); err != nil {
 				return err
 			}
 		}
@@ -587,8 +608,10 @@ func (db *DB) recoverJournal() error {
 	}
 
 	// Commit.
-	if err := cm.commit(db.journalFile.Num(), db.seq); err != nil {
+	rec.setJournalNum(db.journalFile.Num())
-		// Close journal.
+	rec.setSeqNum(db.seq)
+	if err := db.s.commit(rec); err != nil {
+		// Close journal on error.
 		if db.journal != nil {
 			db.journal.Close()
 			db.journalWriter.Close()
@@ -604,6 +627,103 @@ func (db *DB) recoverJournal() error {
 	return nil
 }
 
+func (db *DB) recoverJournalRO() error {
+	// Get all journals and sort it by file number.
+	allJournalFiles, err := db.s.getFiles(storage.TypeJournal)
+	if err != nil {
+		return err
+	}
+	files(allJournalFiles).sort()
+
+	// Journals that will be recovered.
+	var recJournalFiles []storage.File
+	for _, jf := range allJournalFiles {
+		if jf.Num() >= db.s.stJournalNum || jf.Num() == db.s.stPrevJournalNum {
+			recJournalFiles = append(recJournalFiles, jf)
+		}
+	}
+
+	var (
+		// Options.
+		strict      = db.s.o.GetStrict(opt.StrictJournal)
+		checksum    = db.s.o.GetStrict(opt.StrictJournalChecksum)
+		writeBuffer = db.s.o.GetWriteBuffer()
+
+		mdb = memdb.New(db.s.icmp, writeBuffer)
+	)
+
+	// Recover journals.
+	if len(recJournalFiles) > 0 {
+		db.logf("journal@recovery RO·Mode F·%d", len(recJournalFiles))
+
+		var (
+			jr    *journal.Reader
+			buf   = &util.Buffer{}
+			batch = &Batch{}
+		)
+
+		for _, jf := range recJournalFiles {
+			db.logf("journal@recovery recovering @%d", jf.Num())
+
+			fr, err := jf.Open()
+			if err != nil {
+				return err
+			}
+
+			// Create or reset journal reader instance.
+			if jr == nil {
+				jr = journal.NewReader(fr, dropper{db.s, jf}, strict, checksum)
+			} else {
+				jr.Reset(fr, dropper{db.s, jf}, strict, checksum)
+			}
+
+			// Replay journal to memdb.
+			for {
+				r, err := jr.Next()
+				if err != nil {
+					if err == io.EOF {
+						break
+					}
+
+					fr.Close()
+					return errors.SetFile(err, jf)
+				}
+
+				buf.Reset()
+				if _, err := buf.ReadFrom(r); err != nil {
+					if err == io.ErrUnexpectedEOF {
+						// This is error returned due to corruption, with strict == false.
+						continue
+					}
+
+					fr.Close()
+					return errors.SetFile(err, jf)
+				}
+				if err := batch.memDecodeAndReplay(db.seq, buf.Bytes(), mdb); err != nil {
+					if !strict && errors.IsCorrupted(err) {
+						db.s.logf("journal error: %v (skipped)", err)
+						// We won't apply sequence number as it might be corrupted.
+						continue
+					}
+
+					fr.Close()
+					return errors.SetFile(err, jf)
+				}
+
+				// Save sequence number.
+				db.seq = batch.seq + uint64(batch.Len())
+			}
+
+			fr.Close()
+		}
+	}
+
+	// Set memDB.
+	db.mem = &memDB{db: db, DB: mdb, ref: 1}
+
+	return nil
+}
+
 func (db *DB) get(key []byte, seq uint64, ro *opt.ReadOptions) (value []byte, err error) {
 	ikey := newIkey(key, seq, ktSeek)
 
@@ -614,7 +734,7 @@ func (db *DB) get(key []byte, seq uint64, ro *opt.ReadOptions) (value []byte, er
 		}
 		defer m.decref()
 
-		mk, mv, me := m.mdb.Find(ikey)
+		mk, mv, me := m.Find(ikey)
 		if me == nil {
 			ukey, _, kt, kerr := parseIkey(mk)
 			if kerr != nil {
@@ -652,7 +772,7 @@ func (db *DB) has(key []byte, seq uint64, ro *opt.ReadOptions) (ret bool, err er
 		}
 		defer m.decref()
 
-		mk, _, me := m.mdb.Find(ikey)
+		mk, _, me := m.Find(ikey)
 		if me == nil {
 			ukey, _, kt, kerr := parseIkey(mk)
 			if kerr != nil {
@@ -784,7 +904,7 @@ func (db *DB) GetProperty(name string) (value string, err error) {
 
 	const prefix = "leveldb."
 	if !strings.HasPrefix(name, prefix) {
-		return "", errors.New("leveldb: GetProperty: unknown property: " + name)
+		return "", ErrNotFound
 	}
 	p := name[len(prefix):]
 
@@ -798,7 +918,7 @@ func (db *DB) GetProperty(name string) (value string, err error) {
 		var rest string
 		n, _ := fmt.Sscanf(p[len(numFilesPrefix):], "%d%s", &level, &rest)
 		if n != 1 || int(level) >= db.s.o.GetNumLevel() {
-			err = errors.New("leveldb: GetProperty: invalid property: " + name)
+			err = ErrNotFound
 		} else {
 			value = fmt.Sprint(v.tLen(int(level)))
 		}
@@ -837,7 +957,7 @@ func (db *DB) GetProperty(name string) (value string, err error) {
 	case p == "aliveiters":
 		value = fmt.Sprintf("%d", atomic.LoadInt32(&db.aliveIters))
 	default:
-		err = errors.New("leveldb: GetProperty: unknown property: " + name)
+		err = ErrNotFound
 	}
 
 	return
@@ -900,6 +1020,9 @@ func (db *DB) Close() error {
 	var err error
 	select {
 	case err = <-db.compErrC:
+		if err == ErrReadOnly {
+			err = nil
+		}
 	default:
 	}
 

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/db_compaction.go

@@ -11,7 +11,6 @@ import (
 	"time"
 
 	"github.com/syndtr/goleveldb/leveldb/errors"
-	"github.com/syndtr/goleveldb/leveldb/memdb"
 	"github.com/syndtr/goleveldb/leveldb/opt"
 )
 
@@ -62,58 +61,8 @@ func (p *cStatsStaging) stopTimer() {
 	}
 }
 
-type cMem struct {
-	s     *session
-	level int
-	rec   *sessionRecord
-}
-
-func newCMem(s *session) *cMem {
-	return &cMem{s: s, rec: &sessionRecord{numLevel: s.o.GetNumLevel()}}
-}
-
-func (c *cMem) flush(mem *memdb.DB, level int) error {
-	s := c.s
-
-	// Write memdb to table.
-	iter := mem.NewIterator(nil)
-	defer iter.Release()
-	t, n, err := s.tops.createFrom(iter)
-	if err != nil {
-		return err
-	}
-
-	// Pick level.
-	if level < 0 {
-		v := s.version()
-		level = v.pickLevel(t.imin.ukey(), t.imax.ukey())
-		v.release()
-	}
-	c.rec.addTableFile(level, t)
-
-	s.logf("mem@flush created L%d@%d N·%d S·%s %q:%q", level, t.file.Num(), n, shortenb(int(t.size)), t.imin, t.imax)
-
-	c.level = level
-	return nil
-}
-
-func (c *cMem) reset() {
-	c.rec = &sessionRecord{numLevel: c.s.o.GetNumLevel()}
-}
-
-func (c *cMem) commit(journal, seq uint64) error {
-	c.rec.setJournalNum(journal)
-	c.rec.setSeqNum(seq)
-
-	// Commit changes.
-	return c.s.commit(c.rec)
-}
-
 func (db *DB) compactionError() {
-	var (
+	var err error
-		err     error
-		wlocked bool
-	)
 noerr:
 	// No error.
 	for {
@@ -121,7 +70,7 @@ noerr:
 		case err = <-db.compErrSetC:
 			switch {
 			case err == nil:
-			case errors.IsCorrupted(err):
+			case err == ErrReadOnly, errors.IsCorrupted(err):
 				goto hasperr
 			default:
 				goto haserr
@@ -139,7 +88,7 @@ haserr:
 			switch {
 			case err == nil:
 				goto noerr
-			case errors.IsCorrupted(err):
+			case err == ErrReadOnly, errors.IsCorrupted(err):
 				goto hasperr
 			default:
 			}
@@ -155,9 +104,9 @@ hasperr:
 		case db.compPerErrC <- err:
 		case db.writeLockC <- struct{}{}:
 			// Hold write lock, so that write won't pass-through.
-			wlocked = true
+			db.compWriteLocking = true
 		case _, _ = <-db.closeC:
-			if wlocked {
+			if db.compWriteLocking {
 				// We should release the lock or Close will hang.
 				<-db.writeLockC
 			}
@@ -287,21 +236,18 @@ func (db *DB) compactionExitTransact() {
 }
 
 func (db *DB) memCompaction() {
-	mem := db.getFrozenMem()
+	mdb := db.getFrozenMem()
-	if mem == nil {
+	if mdb == nil {
 		return
 	}
-	defer mem.decref()
+	defer mdb.decref()
 
-	c := newCMem(db.s)
+	db.logf("memdb@flush N·%d S·%s", mdb.Len(), shortenb(mdb.Size()))
-	stats := new(cStatsStaging)
-
-	db.logf("mem@flush N·%d S·%s", mem.mdb.Len(), shortenb(mem.mdb.Size()))
 
 	// Don't compact empty memdb.
-	if mem.mdb.Len() == 0 {
+	if mdb.Len() == 0 {
-		db.logf("mem@flush skipping")
+		db.logf("memdb@flush skipping")
-		// drop frozen mem
+		// drop frozen memdb
 		db.dropFrozenMem()
 		return
 	}
@@ -317,13 +263,20 @@ func (db *DB) memCompaction() {
 		return
 	}
 
-	db.compactionTransactFunc("mem@flush", func(cnt *compactionTransactCounter) (err error) {
+	var (
+		rec        = &sessionRecord{}
+		stats      = &cStatsStaging{}
+		flushLevel int
+	)
+
+	db.compactionTransactFunc("memdb@flush", func(cnt *compactionTransactCounter) (err error) {
 		stats.startTimer()
-		defer stats.stopTimer()
+		flushLevel, err = db.s.flushMemdb(rec, mdb.DB, -1)
-		return c.flush(mem.mdb, -1)
+		stats.stopTimer()
+		return
 	}, func() error {
-		for _, r := range c.rec.addedTables {
+		for _, r := range rec.addedTables {
-			db.logf("mem@flush revert @%d", r.num)
+			db.logf("memdb@flush revert @%d", r.num)
 			f := db.s.getTableFile(r.num)
 			if err := f.Remove(); err != nil {
 				return err
@@ -332,20 +285,23 @@ func (db *DB) memCompaction() {
 		return nil
 	})
 
-	db.compactionTransactFunc("mem@commit", func(cnt *compactionTransactCounter) (err error) {
+	db.compactionTransactFunc("memdb@commit", func(cnt *compactionTransactCounter) (err error) {
 		stats.startTimer()
-		defer stats.stopTimer()
+		rec.setJournalNum(db.journalFile.Num())
-		return c.commit(db.journalFile.Num(), db.frozenSeq)
+		rec.setSeqNum(db.frozenSeq)
+		err = db.s.commit(rec)
+		stats.stopTimer()
+		return
 	}, nil)
 
-	db.logf("mem@flush committed F·%d T·%v", len(c.rec.addedTables), stats.duration)
+	db.logf("memdb@flush committed F·%d T·%v", len(rec.addedTables), stats.duration)
 
-	for _, r := range c.rec.addedTables {
+	for _, r := range rec.addedTables {
 		stats.write += r.size
 	}
-	db.compStats[c.level].add(stats)
+	db.compStats[flushLevel].add(stats)
 
-	// Drop frozen mem.
+	// Drop frozen memdb.
 	db.dropFrozenMem()
 
 	// Resume table compaction.
@@ -557,7 +513,7 @@ func (b *tableCompactionBuilder) revert() error {
 func (db *DB) tableCompaction(c *compaction, noTrivial bool) {
 	defer c.release()
 
-	rec := &sessionRecord{numLevel: db.s.o.GetNumLevel()}
+	rec := &sessionRecord{}
 	rec.addCompPtr(c.level, c.imax)
 
 	if !noTrivial && c.trivial() {

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/db_iter.go

@@ -8,6 +8,7 @@ package leveldb
 
 import (
 	"errors"
+	"math/rand"
 	"runtime"
 	"sync"
 	"sync/atomic"
@@ -39,11 +40,11 @@ func (db *DB) newRawIterator(slice *util.Range, ro *opt.ReadOptions) iterator.It
 	ti := v.getIterators(slice, ro)
 	n := len(ti) + 2
 	i := make([]iterator.Iterator, 0, n)
-	emi := em.mdb.NewIterator(slice)
+	emi := em.NewIterator(slice)
 	emi.SetReleaser(&memdbReleaser{m: em})
 	i = append(i, emi)
 	if fm != nil {
-		fmi := fm.mdb.NewIterator(slice)
+		fmi := fm.NewIterator(slice)
 		fmi.SetReleaser(&memdbReleaser{m: fm})
 		i = append(i, fmi)
 	}
@@ -80,6 +81,10 @@ func (db *DB) newIterator(seq uint64, slice *util.Range, ro *opt.ReadOptions) *d
 	return iter
 }
 
+func (db *DB) iterSamplingRate() int {
+	return rand.Intn(2 * db.s.o.GetIteratorSamplingRate())
+}
+
 type dir int
 
 const (
@@ -98,6 +103,7 @@ type dbIter struct {
 	seq    uint64
 	strict bool
 
+	smaplingGap int
 	dir         dir
 	key         []byte
 	value       []byte
@@ -105,6 +111,15 @@ type dbIter struct {
 	releaser    util.Releaser
 }
 
+func (i *dbIter) sampleSeek() {
+	ikey := i.iter.Key()
+	i.smaplingGap -= len(ikey) + len(i.iter.Value())
+	for i.smaplingGap < 0 {
+		i.smaplingGap += i.db.iterSamplingRate()
+		i.db.sampleSeek(ikey)
+	}
+}
+
 func (i *dbIter) setErr(err error) {
 	i.err = err
 	i.key = nil
@@ -175,6 +190,7 @@ func (i *dbIter) Seek(key []byte) bool {
 func (i *dbIter) next() bool {
 	for {
 		if ukey, seq, kt, kerr := parseIkey(i.iter.Key()); kerr == nil {
+			i.sampleSeek()
 			if seq <= i.seq {
 				switch kt {
 				case ktDel:
@@ -225,6 +241,7 @@ func (i *dbIter) prev() bool {
 	if i.iter.Valid() {
 		for {
 			if ukey, seq, kt, kerr := parseIkey(i.iter.Key()); kerr == nil {
+				i.sampleSeek()
 				if seq <= i.seq {
 					if !del && i.icmp.uCompare(ukey, i.key) < 0 {
 						return true
@@ -266,6 +283,7 @@ func (i *dbIter) Prev() bool {
 	case dirForward:
 		for i.iter.Prev() {
 			if ukey, _, _, kerr := parseIkey(i.iter.Key()); kerr == nil {
+				i.sampleSeek()
 				if i.icmp.uCompare(ukey, i.key) < 0 {
 					goto cont
 				}

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/db_state.go

@@ -16,7 +16,7 @@ import (
 
 type memDB struct {
 	db *DB
-	mdb *memdb.DB
+	*memdb.DB
 	ref int32
 }
 
@@ -27,12 +27,12 @@ func (m *memDB) incref() {
 func (m *memDB) decref() {
 	if ref := atomic.AddInt32(&m.ref, -1); ref == 0 {
 		// Only put back memdb with std capacity.
-		if m.mdb.Capacity() == m.db.s.o.GetWriteBuffer() {
+		if m.Capacity() == m.db.s.o.GetWriteBuffer() {
-			m.mdb.Reset()
+			m.Reset()
-			m.db.mpoolPut(m.mdb)
+			m.db.mpoolPut(m.DB)
 		}
 		m.db = nil
-		m.mdb = nil
+		m.DB = nil
 	} else if ref < 0 {
 		panic("negative memdb ref")
 	}
@@ -48,6 +48,15 @@ func (db *DB) addSeq(delta uint64) {
 	atomic.AddUint64(&db.seq, delta)
 }
 
+func (db *DB) sampleSeek(ikey iKey) {
+	v := db.s.version()
+	if v.sampleSeek(ikey) {
+		// Trigger table compaction.
+		db.compSendTrigger(db.tcompCmdC)
+	}
+	v.release()
+}
+
 func (db *DB) mpoolPut(mem *memdb.DB) {
 	defer func() {
 		recover()
@@ -117,7 +126,7 @@ func (db *DB) newMem(n int) (mem *memDB, err error) {
 	}
 	mem = &memDB{
 		db:  db,
-		mdb: mdb,
+		DB:  mdb,
 		ref: 2,
 	}
 	db.mem = mem

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/db_test.go

@@ -405,19 +405,21 @@ func (h *dbHarness) compactRange(min, max string) {
 	t.Log("DB range compaction done")
 }
 
-func (h *dbHarness) sizeAssert(start, limit string, low, hi uint64) {
+func (h *dbHarness) sizeOf(start, limit string) uint64 {
-	t := h.t
+	sz, err := h.db.SizeOf([]util.Range{
-	db := h.db
-
-	s, err := db.SizeOf([]util.Range{
 		{[]byte(start), []byte(limit)},
 	})
 	if err != nil {
-		t.Error("SizeOf: got error: ", err)
+		h.t.Error("SizeOf: got error: ", err)
 	}
-	if s.Sum() < low || s.Sum() > hi {
+	return sz.Sum()
-		t.Errorf("sizeof %q to %q not in range, want %d - %d, got %d",
+}
-			shorten(start), shorten(limit), low, hi, s.Sum())
+
+func (h *dbHarness) sizeAssert(start, limit string, low, hi uint64) {
+	sz := h.sizeOf(start, limit)
+	if sz < low || sz > hi {
+		h.t.Errorf("sizeOf %q to %q not in range, want %d - %d, got %d",
+			shorten(start), shorten(limit), low, hi, sz)
 	}
 }
 
@@ -2443,7 +2445,7 @@ func TestDB_TableCompactionBuilder(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		rec := &sessionRecord{numLevel: s.o.GetNumLevel()}
+		rec := &sessionRecord{}
 		rec.addTableFile(i, tf)
 		if err := s.commit(rec); err != nil {
 			t.Fatal(err)
@@ -2453,7 +2455,7 @@ func TestDB_TableCompactionBuilder(t *testing.T) {
 	// Build grandparent.
 	v := s.version()
 	c := newCompaction(s, v, 1, append(tFiles{}, v.tables[1]...))
-	rec := &sessionRecord{numLevel: s.o.GetNumLevel()}
+	rec := &sessionRecord{}
 	b := &tableCompactionBuilder{
 		s:         s,
 		c:         c,
@@ -2477,7 +2479,7 @@ func TestDB_TableCompactionBuilder(t *testing.T) {
 	// Build level-1.
 	v = s.version()
 	c = newCompaction(s, v, 0, append(tFiles{}, v.tables[0]...))
-	rec = &sessionRecord{numLevel: s.o.GetNumLevel()}
+	rec = &sessionRecord{}
 	b = &tableCompactionBuilder{
 		s:         s,
 		c:         c,
@@ -2521,7 +2523,7 @@ func TestDB_TableCompactionBuilder(t *testing.T) {
 	// Compaction with transient error.
 	v = s.version()
 	c = newCompaction(s, v, 1, append(tFiles{}, v.tables[1]...))
-	rec = &sessionRecord{numLevel: s.o.GetNumLevel()}
+	rec = &sessionRecord{}
 	b = &tableCompactionBuilder{
 		s:         s,
 		c:         c,
@@ -2577,3 +2579,123 @@ func TestDB_TableCompactionBuilder(t *testing.T) {
 	}
 	v.release()
 }
+
+func testDB_IterTriggeredCompaction(t *testing.T, limitDiv int) {
+	const (
+		vSize = 200 * opt.KiB
+		tSize = 100 * opt.MiB
+		mIter = 100
+		n     = tSize / vSize
+	)
+
+	h := newDbHarnessWopt(t, &opt.Options{
+		Compression:       opt.NoCompression,
+		DisableBlockCache: true,
+	})
+	defer h.close()
+
+	key := func(x int) string {
+		return fmt.Sprintf("v%06d", x)
+	}
+
+	// Fill.
+	value := strings.Repeat("x", vSize)
+	for i := 0; i < n; i++ {
+		h.put(key(i), value)
+	}
+	h.compactMem()
+
+	// Delete all.
+	for i := 0; i < n; i++ {
+		h.delete(key(i))
+	}
+	h.compactMem()
+
+	var (
+		limit = n / limitDiv
+
+		startKey = key(0)
+		limitKey = key(limit)
+		maxKey   = key(n)
+		slice    = &util.Range{Limit: []byte(limitKey)}
+
+		initialSize0 = h.sizeOf(startKey, limitKey)
+		initialSize1 = h.sizeOf(limitKey, maxKey)
+	)
+
+	t.Logf("inital size %s [rest %s]", shortenb(int(initialSize0)), shortenb(int(initialSize1)))
+
+	for r := 0; true; r++ {
+		if r >= mIter {
+			t.Fatal("taking too long to compact")
+		}
+
+		// Iterates.
+		iter := h.db.NewIterator(slice, h.ro)
+		for iter.Next() {
+		}
+		if err := iter.Error(); err != nil {
+			t.Fatalf("Iter err: %v", err)
+		}
+		iter.Release()
+
+		// Wait compaction.
+		h.waitCompaction()
+
+		// Check size.
+		size0 := h.sizeOf(startKey, limitKey)
+		size1 := h.sizeOf(limitKey, maxKey)
+		t.Logf("#%03d size %s [rest %s]", r, shortenb(int(size0)), shortenb(int(size1)))
+		if size0 < initialSize0/10 {
+			break
+		}
+	}
+
+	if initialSize1 > 0 {
+		h.sizeAssert(limitKey, maxKey, initialSize1/4-opt.MiB, initialSize1+opt.MiB)
+	}
+}
+
+func TestDB_IterTriggeredCompaction(t *testing.T) {
+	testDB_IterTriggeredCompaction(t, 1)
+}
+
+func TestDB_IterTriggeredCompactionHalf(t *testing.T) {
+	testDB_IterTriggeredCompaction(t, 2)
+}
+
+func TestDB_ReadOnly(t *testing.T) {
+	h := newDbHarness(t)
+	defer h.close()
+
+	h.put("foo", "v1")
+	h.put("bar", "v2")
+	h.compactMem()
+
+	h.put("xfoo", "v1")
+	h.put("xbar", "v2")
+
+	t.Log("Trigger read-only")
+	if err := h.db.SetReadOnly(); err != nil {
+		h.close()
+		t.Fatalf("SetReadOnly error: %v", err)
+	}
+
+	h.stor.SetEmuErr(storage.TypeAll, tsOpCreate, tsOpReplace, tsOpRemove, tsOpWrite, tsOpWrite, tsOpSync)
+
+	ro := func(key, value, wantValue string) {
+		if err := h.db.Put([]byte(key), []byte(value), h.wo); err != ErrReadOnly {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		h.getVal(key, wantValue)
+	}
+
+	ro("foo", "vx", "v1")
+
+	h.o.ReadOnly = true
+	h.reopenDB()
+
+	ro("foo", "vx", "v1")
+	ro("bar", "vx", "v2")
+	h.assertNumKeys(4)
+}

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/db_write.go

@@ -63,24 +63,24 @@ func (db *DB) rotateMem(n int) (mem *memDB, err error) {
 	return
 }
 
-func (db *DB) flush(n int) (mem *memDB, nn int, err error) {
+func (db *DB) flush(n int) (mdb *memDB, mdbFree int, err error) {
 	delayed := false
 	flush := func() (retry bool) {
 		v := db.s.version()
 		defer v.release()
-		mem = db.getEffectiveMem()
+		mdb = db.getEffectiveMem()
 		defer func() {
 			if retry {
-				mem.decref()
+				mdb.decref()
-				mem = nil
+				mdb = nil
 			}
 		}()
-		nn = mem.mdb.Free()
+		mdbFree = mdb.Free()
 		switch {
 		case v.tLen(0) >= db.s.o.GetWriteL0SlowdownTrigger() && !delayed:
 			delayed = true
 			time.Sleep(time.Millisecond)
-		case nn >= n:
+		case mdbFree >= n:
 			return false
 		case v.tLen(0) >= db.s.o.GetWriteL0PauseTrigger():
 			delayed = true
@@ -90,15 +90,15 @@ func (db *DB) flush(n int) (mem *memDB, nn int, err error) {
 			}
 		default:
 			// Allow memdb to grow if it has no entry.
-			if mem.mdb.Len() == 0 {
+			if mdb.Len() == 0 {
-				nn = n
+				mdbFree = n
 			} else {
-				mem.decref()
+				mdb.decref()
-				mem, err = db.rotateMem(n)
+				mdb, err = db.rotateMem(n)
 				if err == nil {
-					nn = mem.mdb.Free()
+					mdbFree = mdb.Free()
 				} else {
-					nn = 0
+					mdbFree = 0
 				}
 			}
 			return false
@@ -157,18 +157,18 @@ func (db *DB) Write(b *Batch, wo *opt.WriteOptions) (err error) {
 		}
 	}()
 
-	mem, memFree, err := db.flush(b.size())
+	mdb, mdbFree, err := db.flush(b.size())
 	if err != nil {
 		return
 	}
-	defer mem.decref()
+	defer mdb.decref()
 
 	// Calculate maximum size of the batch.
 	m := 1 << 20
 	if x := b.size(); x <= 128<<10 {
 		m = x + (128 << 10)
 	}
-	m = minInt(m, memFree)
+	m = minInt(m, mdbFree)
 
 	// Merge with other batch.
 drain:
@@ -197,7 +197,7 @@ drain:
 		select {
 		case db.journalC <- b:
 			// Write into memdb
-			if berr := b.memReplay(mem.mdb); berr != nil {
+			if berr := b.memReplay(mdb.DB); berr != nil {
 				panic(berr)
 			}
 		case err = <-db.compPerErrC:
@@ -211,7 +211,7 @@ drain:
 		case err = <-db.journalAckC:
 			if err != nil {
 				// Revert memdb if error detected
-				if berr := b.revertMemReplay(mem.mdb); berr != nil {
+				if berr := b.revertMemReplay(mdb.DB); berr != nil {
 					panic(berr)
 				}
 				return
@@ -225,7 +225,7 @@ drain:
 		if err != nil {
 			return
 		}
-		if berr := b.memReplay(mem.mdb); berr != nil {
+		if berr := b.memReplay(mdb.DB); berr != nil {
 			panic(berr)
 		}
 	}
@@ -233,7 +233,7 @@ drain:
 	// Set last seq number.
 	db.addSeq(uint64(b.Len()))
 
-	if b.size() >= memFree {
+	if b.size() >= mdbFree {
 		db.rotateMem(0)
 	}
 	return
@@ -249,8 +249,7 @@ func (db *DB) Put(key, value []byte, wo *opt.WriteOptions) error {
 	return db.Write(b, wo)
 }
 
-// Delete deletes the value for the given key. It returns ErrNotFound if
+// Delete deletes the value for the given key.
-// the DB does not contain the key.
 //
 // It is safe to modify the contents of the arguments after Delete returns.
 func (db *DB) Delete(key []byte, wo *opt.WriteOptions) error {
@@ -290,9 +289,9 @@ func (db *DB) CompactRange(r util.Range) error {
 	}
 
 	// Check for overlaps in memdb.
-	mem := db.getEffectiveMem()
+	mdb := db.getEffectiveMem()
-	defer mem.decref()
+	defer mdb.decref()
-	if isMemOverlaps(db.s.icmp, mem.mdb, r.Start, r.Limit) {
+	if isMemOverlaps(db.s.icmp, mdb.DB, r.Start, r.Limit) {
 		// Memdb compaction.
 		if _, err := db.rotateMem(0); err != nil {
 			<-db.writeLockC
@@ -309,3 +308,31 @@ func (db *DB) CompactRange(r util.Range) error {
 	// Table compaction.
 	return db.compSendRange(db.tcompCmdC, -1, r.Start, r.Limit)
 }
+
+// SetReadOnly makes DB read-only. It will stay read-only until reopened.
+func (db *DB) SetReadOnly() error {
+	if err := db.ok(); err != nil {
+		return err
+	}
+
+	// Lock writer.
+	select {
+	case db.writeLockC <- struct{}{}:
+		db.compWriteLocking = true
+	case err := <-db.compPerErrC:
+		return err
+	case _, _ = <-db.closeC:
+		return ErrClosed
+	}
+
+	// Set compaction read-only.
+	select {
+	case db.compErrSetC <- ErrReadOnly:
+	case perr := <-db.compPerErrC:
+		return perr
+	case _, _ = <-db.closeC:
+		return ErrClosed
+	}
+
+	return nil
+}

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/errors.go

@@ -12,6 +12,7 @@ import (
 
 var (
 	ErrNotFound         = errors.ErrNotFound
+	ErrReadOnly         = errors.New("leveldb: read-only mode")
 	ErrSnapshotReleased = errors.New("leveldb: snapshot released")
 	ErrIterReleased     = errors.New("leveldb: iterator released")
 	ErrClosed           = errors.New("leveldb: closed")

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/memdb/memdb.go

@@ -206,6 +206,7 @@ func (p *DB) randHeight() (h int) {
 	return
 }
 
+// Must hold RW-lock if prev == true, as it use shared prevNode slice.
 func (p *DB) findGE(key []byte, prev bool) (int, bool) {
 	node := 0
 	h := p.maxHeight - 1
@@ -302,7 +303,7 @@ func (p *DB) Put(key []byte, value []byte) error {
 	node := len(p.nodeData)
 	p.nodeData = append(p.nodeData, kvOffset, len(key), len(value), h)
 	for i, n := range p.prevNode[:h] {
-		m := n + 4 + i
+		m := n + nNext + i
 		p.nodeData = append(p.nodeData, p.nodeData[m])
 		p.nodeData[m] = node
 	}
@@ -434,20 +435,22 @@ func (p *DB) Len() int {
 
 // Reset resets the DB to initial empty state. Allows reuse the buffer.
 func (p *DB) Reset() {
+	p.mu.Lock()
 	p.rnd = rand.New(rand.NewSource(0xdeadbeef))
 	p.maxHeight = 1
 	p.n = 0
 	p.kvSize = 0
 	p.kvData = p.kvData[:0]
-	p.nodeData = p.nodeData[:4+tMaxHeight]
+	p.nodeData = p.nodeData[:nNext+tMaxHeight]
 	p.nodeData[nKV] = 0
 	p.nodeData[nKey] = 0
 	p.nodeData[nVal] = 0
 	p.nodeData[nHeight] = tMaxHeight
 	for n := 0; n < tMaxHeight; n++ {
-		p.nodeData[4+n] = 0
+		p.nodeData[nNext+n] = 0
 		p.prevNode[n] = 0
 	}
+	p.mu.Unlock()
 }
 
 // New creates a new initalized in-memory key/value DB. The capacity

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/opt/options.go

@@ -34,10 +34,11 @@ var (
 	DefaultCompactionTotalSize           = 10 * MiB
 	DefaultCompactionTotalSizeMultiplier = 10.0
 	DefaultCompressionType               = SnappyCompression
-	DefaultOpenFilesCacher               = LRUCacher
+	DefaultIteratorSamplingRate          = 1 * MiB
-	DefaultOpenFilesCacheCapacity        = 500
 	DefaultMaxMemCompationLevel          = 2
 	DefaultNumLevel                      = 7
+	DefaultOpenFilesCacher               = LRUCacher
+	DefaultOpenFilesCacheCapacity        = 500
 	DefaultWriteBuffer                   = 4 * MiB
 	DefaultWriteL0PauseTrigger           = 12
 	DefaultWriteL0SlowdownTrigger        = 8
@@ -249,6 +250,11 @@ type Options struct {
 	// The default value (DefaultCompression) uses snappy compression.
 	Compression Compression
 
+	// DisableBufferPool allows disable use of util.BufferPool functionality.
+	//
+	// The default value is false.
+	DisableBufferPool bool
+
 	// DisableBlockCache allows disable use of cache.Cache functionality on
 	// 'sorted table' block.
 	//
@@ -288,6 +294,13 @@ type Options struct {
 	// The default value is nil.
 	Filter filter.Filter
 
+	// IteratorSamplingRate defines approximate gap (in bytes) between read
+	// sampling of an iterator. The samples will be used to determine when
+	// compaction should be triggered.
+	//
+	// The default is 1MiB.
+	IteratorSamplingRate int
+
 	// MaxMemCompationLevel defines maximum level a newly compacted 'memdb'
 	// will be pushed into if doesn't creates overlap. This should less than
 	// NumLevel. Use -1 for level-0.
@@ -313,6 +326,11 @@ type Options struct {
 	// The default value is 500.
 	OpenFilesCacheCapacity int
 
+	// If true then opens DB in read-only mode.
+	//
+	// The default value is false.
+	ReadOnly bool
+
 	// Strict defines the DB strict level.
 	Strict Strict
 
@@ -464,6 +482,20 @@ func (o *Options) GetCompression() Compression {
 	return o.Compression
 }
 
+func (o *Options) GetDisableBufferPool() bool {
+	if o == nil {
+		return false
+	}
+	return o.DisableBufferPool
+}
+
+func (o *Options) GetDisableBlockCache() bool {
+	if o == nil {
+		return false
+	}
+	return o.DisableBlockCache
+}
+
 func (o *Options) GetDisableCompactionBackoff() bool {
 	if o == nil {
 		return false
@@ -492,6 +524,13 @@ func (o *Options) GetFilter() filter.Filter {
 	return o.Filter
 }
 
+func (o *Options) GetIteratorSamplingRate() int {
+	if o == nil || o.IteratorSamplingRate <= 0 {
+		return DefaultIteratorSamplingRate
+	}
+	return o.IteratorSamplingRate
+}
+
 func (o *Options) GetMaxMemCompationLevel() int {
 	level := DefaultMaxMemCompationLevel
 	if o != nil {
@@ -533,6 +572,13 @@ func (o *Options) GetOpenFilesCacheCapacity() int {
 	return o.OpenFilesCacheCapacity
 }
 
+func (o *Options) GetReadOnly() bool {
+	if o == nil {
+		return false
+	}
+	return o.ReadOnly
+}
+
 func (o *Options) GetStrict(strict Strict) bool {
 	if o == nil || o.Strict == 0 {
 		return DefaultStrict&strict != 0

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/session.go

@@ -11,10 +11,8 @@ import (
 	"io"
 	"os"
 	"sync"
-	"sync/atomic"
 
 	"github.com/syndtr/goleveldb/leveldb/errors"
-	"github.com/syndtr/goleveldb/leveldb/iterator"
 	"github.com/syndtr/goleveldb/leveldb/journal"
 	"github.com/syndtr/goleveldb/leveldb/opt"
 	"github.com/syndtr/goleveldb/leveldb/storage"
@@ -127,11 +125,16 @@ func (s *session) recover() (err error) {
 		return
 	}
 	defer reader.Close()
-	strict := s.o.GetStrict(opt.StrictManifest)
-	jr := journal.NewReader(reader, dropper{s, m}, strict, true)
 
-	staging := s.stVersion.newStaging()
+	var (
-	rec := &sessionRecord{numLevel: s.o.GetNumLevel()}
+		// Options.
+		numLevel = s.o.GetNumLevel()
+		strict   = s.o.GetStrict(opt.StrictManifest)
+
+		jr      = journal.NewReader(reader, dropper{s, m}, strict, true)
+		rec     = &sessionRecord{}
+		staging = s.stVersion.newStaging()
+	)
 	for {
 		var r io.Reader
 		r, err = jr.Next()
@@ -143,7 +146,7 @@ func (s *session) recover() (err error) {
 			return errors.SetFile(err, m)
 		}
 
-		err = rec.decode(r)
+		err = rec.decode(r, numLevel)
 		if err == nil {
 			// save compact pointers
 			for _, r := range rec.compPtrs {
@@ -206,250 +209,3 @@ func (s *session) commit(r *sessionRecord) (err error) {
 
 	return
 }
-
-// Pick a compaction based on current state; need external synchronization.
-func (s *session) pickCompaction() *compaction {
-	v := s.version()
-
-	var level int
-	var t0 tFiles
-	if v.cScore >= 1 {
-		level = v.cLevel
-		cptr := s.stCompPtrs[level]
-		tables := v.tables[level]
-		for _, t := range tables {
-			if cptr == nil || s.icmp.Compare(t.imax, cptr) > 0 {
-				t0 = append(t0, t)
-				break
-			}
-		}
-		if len(t0) == 0 {
-			t0 = append(t0, tables[0])
-		}
-	} else {
-		if p := atomic.LoadPointer(&v.cSeek); p != nil {
-			ts := (*tSet)(p)
-			level = ts.level
-			t0 = append(t0, ts.table)
-		} else {
-			v.release()
-			return nil
-		}
-	}
-
-	return newCompaction(s, v, level, t0)
-}
-
-// Create compaction from given level and range; need external synchronization.
-func (s *session) getCompactionRange(level int, umin, umax []byte) *compaction {
-	v := s.version()
-
-	t0 := v.tables[level].getOverlaps(nil, s.icmp, umin, umax, level == 0)
-	if len(t0) == 0 {
-		v.release()
-		return nil
-	}
-
-	// Avoid compacting too much in one shot in case the range is large.
-	// But we cannot do this for level-0 since level-0 files can overlap
-	// and we must not pick one file and drop another older file if the
-	// two files overlap.
-	if level > 0 {
-		limit := uint64(v.s.o.GetCompactionSourceLimit(level))
-		total := uint64(0)
-		for i, t := range t0 {
-			total += t.size
-			if total >= limit {
-				s.logf("table@compaction limiting F·%d -> F·%d", len(t0), i+1)
-				t0 = t0[:i+1]
-				break
-			}
-		}
-	}
-
-	return newCompaction(s, v, level, t0)
-}
-
-func newCompaction(s *session, v *version, level int, t0 tFiles) *compaction {
-	c := &compaction{
-		s:             s,
-		v:             v,
-		level:         level,
-		tables:        [2]tFiles{t0, nil},
-		maxGPOverlaps: uint64(s.o.GetCompactionGPOverlaps(level)),
-		tPtrs:         make([]int, s.o.GetNumLevel()),
-	}
-	c.expand()
-	c.save()
-	return c
-}
-
-// compaction represent a compaction state.
-type compaction struct {
-	s *session
-	v *version
-
-	level         int
-	tables        [2]tFiles
-	maxGPOverlaps uint64
-
-	gp                tFiles
-	gpi               int
-	seenKey           bool
-	gpOverlappedBytes uint64
-	imin, imax        iKey
-	tPtrs             []int
-	released          bool
-
-	snapGPI               int
-	snapSeenKey           bool
-	snapGPOverlappedBytes uint64
-	snapTPtrs             []int
-}
-
-func (c *compaction) save() {
-	c.snapGPI = c.gpi
-	c.snapSeenKey = c.seenKey
-	c.snapGPOverlappedBytes = c.gpOverlappedBytes
-	c.snapTPtrs = append(c.snapTPtrs[:0], c.tPtrs...)
-}
-
-func (c *compaction) restore() {
-	c.gpi = c.snapGPI
-	c.seenKey = c.snapSeenKey
-	c.gpOverlappedBytes = c.snapGPOverlappedBytes
-	c.tPtrs = append(c.tPtrs[:0], c.snapTPtrs...)
-}
-
-func (c *compaction) release() {
-	if !c.released {
-		c.released = true
-		c.v.release()
-	}
-}
-
-// Expand compacted tables; need external synchronization.
-func (c *compaction) expand() {
-	limit := uint64(c.s.o.GetCompactionExpandLimit(c.level))
-	vt0, vt1 := c.v.tables[c.level], c.v.tables[c.level+1]
-
-	t0, t1 := c.tables[0], c.tables[1]
-	imin, imax := t0.getRange(c.s.icmp)
-	// We expand t0 here just incase ukey hop across tables.
-	t0 = vt0.getOverlaps(t0, c.s.icmp, imin.ukey(), imax.ukey(), c.level == 0)
-	if len(t0) != len(c.tables[0]) {
-		imin, imax = t0.getRange(c.s.icmp)
-	}
-	t1 = vt1.getOverlaps(t1, c.s.icmp, imin.ukey(), imax.ukey(), false)
-	// Get entire range covered by compaction.
-	amin, amax := append(t0, t1...).getRange(c.s.icmp)
-
-	// See if we can grow the number of inputs in "level" without
-	// changing the number of "level+1" files we pick up.
-	if len(t1) > 0 {
-		exp0 := vt0.getOverlaps(nil, c.s.icmp, amin.ukey(), amax.ukey(), c.level == 0)
-		if len(exp0) > len(t0) && t1.size()+exp0.size() < limit {
-			xmin, xmax := exp0.getRange(c.s.icmp)
-			exp1 := vt1.getOverlaps(nil, c.s.icmp, xmin.ukey(), xmax.ukey(), false)
-			if len(exp1) == len(t1) {
-				c.s.logf("table@compaction expanding L%d+L%d (F·%d S·%s)+(F·%d S·%s) -> (F·%d S·%s)+(F·%d S·%s)",
-					c.level, c.level+1, len(t0), shortenb(int(t0.size())), len(t1), shortenb(int(t1.size())),
-					len(exp0), shortenb(int(exp0.size())), len(exp1), shortenb(int(exp1.size())))
-				imin, imax = xmin, xmax
-				t0, t1 = exp0, exp1
-				amin, amax = append(t0, t1...).getRange(c.s.icmp)
-			}
-		}
-	}
-
-	// Compute the set of grandparent files that overlap this compaction
-	// (parent == level+1; grandparent == level+2)
-	if c.level+2 < c.s.o.GetNumLevel() {
-		c.gp = c.v.tables[c.level+2].getOverlaps(c.gp, c.s.icmp, amin.ukey(), amax.ukey(), false)
-	}
-
-	c.tables[0], c.tables[1] = t0, t1
-	c.imin, c.imax = imin, imax
-}
-
-// Check whether compaction is trivial.
-func (c *compaction) trivial() bool {
-	return len(c.tables[0]) == 1 && len(c.tables[1]) == 0 && c.gp.size() <= c.maxGPOverlaps
-}
-
-func (c *compaction) baseLevelForKey(ukey []byte) bool {
-	for level, tables := range c.v.tables[c.level+2:] {
-		for c.tPtrs[level] < len(tables) {
-			t := tables[c.tPtrs[level]]
-			if c.s.icmp.uCompare(ukey, t.imax.ukey()) <= 0 {
-				// We've advanced far enough.
-				if c.s.icmp.uCompare(ukey, t.imin.ukey()) >= 0 {
-					// Key falls in this file's range, so definitely not base level.
-					return false
-				}
-				break
-			}
-			c.tPtrs[level]++
-		}
-	}
-	return true
-}
-
-func (c *compaction) shouldStopBefore(ikey iKey) bool {
-	for ; c.gpi < len(c.gp); c.gpi++ {
-		gp := c.gp[c.gpi]
-		if c.s.icmp.Compare(ikey, gp.imax) <= 0 {
-			break
-		}
-		if c.seenKey {
-			c.gpOverlappedBytes += gp.size
-		}
-	}
-	c.seenKey = true
-
-	if c.gpOverlappedBytes > c.maxGPOverlaps {
-		// Too much overlap for current output; start new output.
-		c.gpOverlappedBytes = 0
-		return true
-	}
-	return false
-}
-
-// Creates an iterator.
-func (c *compaction) newIterator() iterator.Iterator {
-	// Creates iterator slice.
-	icap := len(c.tables)
-	if c.level == 0 {
-		// Special case for level-0
-		icap = len(c.tables[0]) + 1
-	}
-	its := make([]iterator.Iterator, 0, icap)
-
-	// Options.
-	ro := &opt.ReadOptions{
-		DontFillCache: true,
-		Strict:        opt.StrictOverride,
-	}
-	strict := c.s.o.GetStrict(opt.StrictCompaction)
-	if strict {
-		ro.Strict |= opt.StrictReader
-	}
-
-	for i, tables := range c.tables {
-		if len(tables) == 0 {
-			continue
-		}
-
-		// Level-0 is not sorted and may overlaps each other.
-		if c.level+i == 0 {
-			for _, t := range tables {
-				its = append(its, c.s.tops.newIterator(t, nil, ro))
-			}
-		} else {
-			it := iterator.NewIndexedIterator(tables.newIndexIterator(c.s.tops, c.s.icmp, nil, ro), strict)
-			its = append(its, it)
-		}
-	}
-
-	return iterator.NewMergedIterator(its, c.s.icmp, strict)
-}

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/session_compaction.go

@@ -0,0 +1,287 @@
+// Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com>
+// All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package leveldb
+
+import (
+	"sync/atomic"
+
+	"github.com/syndtr/goleveldb/leveldb/iterator"
+	"github.com/syndtr/goleveldb/leveldb/memdb"
+	"github.com/syndtr/goleveldb/leveldb/opt"
+)
+
+func (s *session) pickMemdbLevel(umin, umax []byte) int {
+	v := s.version()
+	defer v.release()
+	return v.pickMemdbLevel(umin, umax)
+}
+
+func (s *session) flushMemdb(rec *sessionRecord, mdb *memdb.DB, level int) (level_ int, err error) {
+	// Create sorted table.
+	iter := mdb.NewIterator(nil)
+	defer iter.Release()
+	t, n, err := s.tops.createFrom(iter)
+	if err != nil {
+		return level, err
+	}
+
+	// Pick level and add to record.
+	if level < 0 {
+		level = s.pickMemdbLevel(t.imin.ukey(), t.imax.ukey())
+	}
+	rec.addTableFile(level, t)
+
+	s.logf("memdb@flush created L%d@%d N·%d S·%s %q:%q", level, t.file.Num(), n, shortenb(int(t.size)), t.imin, t.imax)
+	return level, nil
+}
+
+// Pick a compaction based on current state; need external synchronization.
+func (s *session) pickCompaction() *compaction {
+	v := s.version()
+
+	var level int
+	var t0 tFiles
+	if v.cScore >= 1 {
+		level = v.cLevel
+		cptr := s.stCompPtrs[level]
+		tables := v.tables[level]
+		for _, t := range tables {
+			if cptr == nil || s.icmp.Compare(t.imax, cptr) > 0 {
+				t0 = append(t0, t)
+				break
+			}
+		}
+		if len(t0) == 0 {
+			t0 = append(t0, tables[0])
+		}
+	} else {
+		if p := atomic.LoadPointer(&v.cSeek); p != nil {
+			ts := (*tSet)(p)
+			level = ts.level
+			t0 = append(t0, ts.table)
+		} else {
+			v.release()
+			return nil
+		}
+	}
+
+	return newCompaction(s, v, level, t0)
+}
+
+// Create compaction from given level and range; need external synchronization.
+func (s *session) getCompactionRange(level int, umin, umax []byte) *compaction {
+	v := s.version()
+
+	t0 := v.tables[level].getOverlaps(nil, s.icmp, umin, umax, level == 0)
+	if len(t0) == 0 {
+		v.release()
+		return nil
+	}
+
+	// Avoid compacting too much in one shot in case the range is large.
+	// But we cannot do this for level-0 since level-0 files can overlap
+	// and we must not pick one file and drop another older file if the
+	// two files overlap.
+	if level > 0 {
+		limit := uint64(v.s.o.GetCompactionSourceLimit(level))
+		total := uint64(0)
+		for i, t := range t0 {
+			total += t.size
+			if total >= limit {
+				s.logf("table@compaction limiting F·%d -> F·%d", len(t0), i+1)
+				t0 = t0[:i+1]
+				break
+			}
+		}
+	}
+
+	return newCompaction(s, v, level, t0)
+}
+
+func newCompaction(s *session, v *version, level int, t0 tFiles) *compaction {
+	c := &compaction{
+		s:             s,
+		v:             v,
+		level:         level,
+		tables:        [2]tFiles{t0, nil},
+		maxGPOverlaps: uint64(s.o.GetCompactionGPOverlaps(level)),
+		tPtrs:         make([]int, s.o.GetNumLevel()),
+	}
+	c.expand()
+	c.save()
+	return c
+}
+
+// compaction represent a compaction state.
+type compaction struct {
+	s *session
+	v *version
+
+	level         int
+	tables        [2]tFiles
+	maxGPOverlaps uint64
+
+	gp                tFiles
+	gpi               int
+	seenKey           bool
+	gpOverlappedBytes uint64
+	imin, imax        iKey
+	tPtrs             []int
+	released          bool
+
+	snapGPI               int
+	snapSeenKey           bool
+	snapGPOverlappedBytes uint64
+	snapTPtrs             []int
+}
+
+func (c *compaction) save() {
+	c.snapGPI = c.gpi
+	c.snapSeenKey = c.seenKey
+	c.snapGPOverlappedBytes = c.gpOverlappedBytes
+	c.snapTPtrs = append(c.snapTPtrs[:0], c.tPtrs...)
+}
+
+func (c *compaction) restore() {
+	c.gpi = c.snapGPI
+	c.seenKey = c.snapSeenKey
+	c.gpOverlappedBytes = c.snapGPOverlappedBytes
+	c.tPtrs = append(c.tPtrs[:0], c.snapTPtrs...)
+}
+
+func (c *compaction) release() {
+	if !c.released {
+		c.released = true
+		c.v.release()
+	}
+}
+
+// Expand compacted tables; need external synchronization.
+func (c *compaction) expand() {
+	limit := uint64(c.s.o.GetCompactionExpandLimit(c.level))
+	vt0, vt1 := c.v.tables[c.level], c.v.tables[c.level+1]
+
+	t0, t1 := c.tables[0], c.tables[1]
+	imin, imax := t0.getRange(c.s.icmp)
+	// We expand t0 here just incase ukey hop across tables.
+	t0 = vt0.getOverlaps(t0, c.s.icmp, imin.ukey(), imax.ukey(), c.level == 0)
+	if len(t0) != len(c.tables[0]) {
+		imin, imax = t0.getRange(c.s.icmp)
+	}
+	t1 = vt1.getOverlaps(t1, c.s.icmp, imin.ukey(), imax.ukey(), false)
+	// Get entire range covered by compaction.
+	amin, amax := append(t0, t1...).getRange(c.s.icmp)
+
+	// See if we can grow the number of inputs in "level" without
+	// changing the number of "level+1" files we pick up.
+	if len(t1) > 0 {
+		exp0 := vt0.getOverlaps(nil, c.s.icmp, amin.ukey(), amax.ukey(), c.level == 0)
+		if len(exp0) > len(t0) && t1.size()+exp0.size() < limit {
+			xmin, xmax := exp0.getRange(c.s.icmp)
+			exp1 := vt1.getOverlaps(nil, c.s.icmp, xmin.ukey(), xmax.ukey(), false)
+			if len(exp1) == len(t1) {
+				c.s.logf("table@compaction expanding L%d+L%d (F·%d S·%s)+(F·%d S·%s) -> (F·%d S·%s)+(F·%d S·%s)",
+					c.level, c.level+1, len(t0), shortenb(int(t0.size())), len(t1), shortenb(int(t1.size())),
+					len(exp0), shortenb(int(exp0.size())), len(exp1), shortenb(int(exp1.size())))
+				imin, imax = xmin, xmax
+				t0, t1 = exp0, exp1
+				amin, amax = append(t0, t1...).getRange(c.s.icmp)
+			}
+		}
+	}
+
+	// Compute the set of grandparent files that overlap this compaction
+	// (parent == level+1; grandparent == level+2)
+	if c.level+2 < c.s.o.GetNumLevel() {
+		c.gp = c.v.tables[c.level+2].getOverlaps(c.gp, c.s.icmp, amin.ukey(), amax.ukey(), false)
+	}
+
+	c.tables[0], c.tables[1] = t0, t1
+	c.imin, c.imax = imin, imax
+}
+
+// Check whether compaction is trivial.
+func (c *compaction) trivial() bool {
+	return len(c.tables[0]) == 1 && len(c.tables[1]) == 0 && c.gp.size() <= c.maxGPOverlaps
+}
+
+func (c *compaction) baseLevelForKey(ukey []byte) bool {
+	for level, tables := range c.v.tables[c.level+2:] {
+		for c.tPtrs[level] < len(tables) {
+			t := tables[c.tPtrs[level]]
+			if c.s.icmp.uCompare(ukey, t.imax.ukey()) <= 0 {
+				// We've advanced far enough.
+				if c.s.icmp.uCompare(ukey, t.imin.ukey()) >= 0 {
+					// Key falls in this file's range, so definitely not base level.
+					return false
+				}
+				break
+			}
+			c.tPtrs[level]++
+		}
+	}
+	return true
+}
+
+func (c *compaction) shouldStopBefore(ikey iKey) bool {
+	for ; c.gpi < len(c.gp); c.gpi++ {
+		gp := c.gp[c.gpi]
+		if c.s.icmp.Compare(ikey, gp.imax) <= 0 {
+			break
+		}
+		if c.seenKey {
+			c.gpOverlappedBytes += gp.size
+		}
+	}
+	c.seenKey = true
+
+	if c.gpOverlappedBytes > c.maxGPOverlaps {
+		// Too much overlap for current output; start new output.
+		c.gpOverlappedBytes = 0
+		return true
+	}
+	return false
+}
+
+// Creates an iterator.
+func (c *compaction) newIterator() iterator.Iterator {
+	// Creates iterator slice.
+	icap := len(c.tables)
+	if c.level == 0 {
+		// Special case for level-0.
+		icap = len(c.tables[0]) + 1
+	}
+	its := make([]iterator.Iterator, 0, icap)
+
+	// Options.
+	ro := &opt.ReadOptions{
+		DontFillCache: true,
+		Strict:        opt.StrictOverride,
+	}
+	strict := c.s.o.GetStrict(opt.StrictCompaction)
+	if strict {
+		ro.Strict |= opt.StrictReader
+	}
+
+	for i, tables := range c.tables {
+		if len(tables) == 0 {
+			continue
+		}
+
+		// Level-0 is not sorted and may overlaps each other.
+		if c.level+i == 0 {
+			for _, t := range tables {
+				its = append(its, c.s.tops.newIterator(t, nil, ro))
+			}
+		} else {
+			it := iterator.NewIndexedIterator(tables.newIndexIterator(c.s.tops, c.s.icmp, nil, ro), strict)
+			its = append(its, it)
+		}
+	}
+
+	return iterator.NewMergedIterator(its, c.s.icmp, strict)
+}

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/session_record.go

@@ -52,8 +52,6 @@ type dtRecord struct {
 }
 
 type sessionRecord struct {
-	numLevel int
-
 	hasRec         int
 	comparer       string
 	journalNum     uint64
@@ -230,7 +228,7 @@ func (p *sessionRecord) readBytes(field string, r byteReader) []byte {
 	return x
 }
 
-func (p *sessionRecord) readLevel(field string, r io.ByteReader) int {
+func (p *sessionRecord) readLevel(field string, r io.ByteReader, numLevel int) int {
 	if p.err != nil {
 		return 0
 	}
@@ -238,14 +236,14 @@ func (p *sessionRecord) readLevel(field string, r io.ByteReader) int {
 	if p.err != nil {
 		return 0
 	}
-	if x >= uint64(p.numLevel) {
+	if x >= uint64(numLevel) {
 		p.err = errors.NewErrCorrupted(nil, &ErrManifestCorrupted{field, "invalid level number"})
 		return 0
 	}
 	return int(x)
 }
 
-func (p *sessionRecord) decode(r io.Reader) error {
+func (p *sessionRecord) decode(r io.Reader, numLevel int) error {
 	br, ok := r.(byteReader)
 	if !ok {
 		br = bufio.NewReader(r)
@@ -286,13 +284,13 @@ func (p *sessionRecord) decode(r io.Reader) error {
 				p.setSeqNum(x)
 			}
 		case recCompPtr:
-			level := p.readLevel("comp-ptr.level", br)
+			level := p.readLevel("comp-ptr.level", br, numLevel)
 			ikey := p.readBytes("comp-ptr.ikey", br)
 			if p.err == nil {
 				p.addCompPtr(level, iKey(ikey))
 			}
 		case recAddTable:
-			level := p.readLevel("add-table.level", br)
+			level := p.readLevel("add-table.level", br, numLevel)
 			num := p.readUvarint("add-table.num", br)
 			size := p.readUvarint("add-table.size", br)
 			imin := p.readBytes("add-table.imin", br)
@@ -301,7 +299,7 @@ func (p *sessionRecord) decode(r io.Reader) error {
 				p.addTable(level, num, size, imin, imax)
 			}
 		case recDelTable:
-			level := p.readLevel("del-table.level", br)
+			level := p.readLevel("del-table.level", br, numLevel)
 			num := p.readUvarint("del-table.num", br)
 			if p.err == nil {
 				p.delTable(level, num)

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/session_record_test.go

@@ -19,8 +19,8 @@ func decodeEncode(v *sessionRecord) (res bool, err error) {
 	if err != nil {
 		return
 	}
-	v2 := &sessionRecord{numLevel: opt.DefaultNumLevel}
+	v2 := &sessionRecord{}
-	err = v.decode(b)
+	err = v.decode(b, opt.DefaultNumLevel)
 	if err != nil {
 		return
 	}
@@ -34,7 +34,7 @@ func decodeEncode(v *sessionRecord) (res bool, err error) {
 
 func TestSessionRecord_EncodeDecode(t *testing.T) {
 	big := uint64(1) << 50
-	v := &sessionRecord{numLevel: opt.DefaultNumLevel}
+	v := &sessionRecord{}
 	i := uint64(0)
 	test := func() {
 		res, err := decodeEncode(v)

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/session_util.go

@@ -182,7 +182,7 @@ func (s *session) newManifest(rec *sessionRecord, v *version) (err error) {
 		defer v.release()
 	}
 	if rec == nil {
-		rec = &sessionRecord{numLevel: s.o.GetNumLevel()}
+		rec = &sessionRecord{}
 	}
 	s.fillRecord(rec, true)
 	v.fillRecord(rec)

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/storage_test.go

@@ -42,6 +42,8 @@ type tsOp uint
 const (
 	tsOpOpen tsOp = iota
 	tsOpCreate
+	tsOpReplace
+	tsOpRemove
 	tsOpRead
 	tsOpReadAt
 	tsOpWrite
@@ -241,6 +243,10 @@ func (tf tsFile) Replace(newfile storage.File) (err error) {
 	if err != nil {
 		return
 	}
+	if tf.shouldErr(tsOpReplace) {
+		err = errors.New("leveldb.testStorage: emulated create error")
+		return
+	}
 	err = tf.File.Replace(newfile.(tsFile).File)
 	if err != nil {
 		ts.t.Errorf("E: cannot replace file, num=%d type=%v: %v", tf.Num(), tf.Type(), err)
@@ -258,6 +264,10 @@ func (tf tsFile) Remove() (err error) {
 	if err != nil {
 		return
 	}
+	if tf.shouldErr(tsOpRemove) {
+		err = errors.New("leveldb.testStorage: emulated create error")
+		return
+	}
 	err = tf.File.Remove()
 	if err != nil {
 		ts.t.Errorf("E: cannot remove file, num=%d type=%v: %v", tf.Num(), tf.Type(), err)

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/table.go

@@ -441,22 +441,26 @@ func newTableOps(s *session) *tOps {
 	var (
 		cacher cache.Cacher
 		bcache *cache.Cache
+		bpool  *util.BufferPool
 	)
 	if s.o.GetOpenFilesCacheCapacity() > 0 {
 		cacher = cache.NewLRU(s.o.GetOpenFilesCacheCapacity())
 	}
-	if !s.o.DisableBlockCache {
+	if !s.o.GetDisableBlockCache() {
 		var bcacher cache.Cacher
 		if s.o.GetBlockCacheCapacity() > 0 {
 			bcacher = cache.NewLRU(s.o.GetBlockCacheCapacity())
 		}
 		bcache = cache.NewCache(bcacher)
 	}
+	if !s.o.GetDisableBufferPool() {
+		bpool = util.NewBufferPool(s.o.GetBlockSize() + 5)
+	}
 	return &tOps{
 		s:      s,
 		cache:  cache.NewCache(cacher),
 		bcache: bcache,
-		bpool:  util.NewBufferPool(s.o.GetBlockSize() + 5),
+		bpool:  bpool,
 	}
 }
 

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/table/reader.go

@@ -14,7 +14,7 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/syndtr/gosnappy/snappy"
+	"github.com/google/go-snappy/snappy"
 
 	"github.com/syndtr/goleveldb/leveldb/cache"
 	"github.com/syndtr/goleveldb/leveldb/comparer"

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/table/writer.go

@@ -12,7 +12,7 @@ import (
 	"fmt"
 	"io"
 
-	"github.com/syndtr/gosnappy/snappy"
+	"github.com/google/go-snappy/snappy"
 
 	"github.com/syndtr/goleveldb/leveldb/comparer"
 	"github.com/syndtr/goleveldb/leveldb/filter"

Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/version.go

@@ -136,9 +136,8 @@ func (v *version) get(ikey iKey, ro *opt.ReadOptions, noValue bool) (value []byt
 		if !tseek {
 			if tset == nil {
 				tset = &tSet{level, t}
-			} else if tset.table.consumeSeek() <= 0 {
+			} else {
 				tseek = true
-				tcomp = atomic.CompareAndSwapPointer(&v.cSeek, nil, unsafe.Pointer(tset))
 			}
 		}
 
@@ -203,6 +202,28 @@ func (v *version) get(ikey iKey, ro *opt.ReadOptions, noValue bool) (value []byt
 		return true
 	})
 
+	if tseek && tset.table.consumeSeek() <= 0 {
+		tcomp = atomic.CompareAndSwapPointer(&v.cSeek, nil, unsafe.Pointer(tset))
+	}
+
+	return
+}
+
+func (v *version) sampleSeek(ikey iKey) (tcomp bool) {
+	var tset *tSet
+
+	v.walkOverlapping(ikey, func(level int, t *tFile) bool {
+		if tset == nil {
+			tset = &tSet{level, t}
+			return true
+		} else {
+			if tset.table.consumeSeek() <= 0 {
+				tcomp = atomic.CompareAndSwapPointer(&v.cSeek, nil, unsafe.Pointer(tset))
+			}
+			return false
+		}
+	}, nil)
+
 	return
 }
 
@@ -279,7 +300,7 @@ func (v *version) offsetOf(ikey iKey) (n uint64, err error) {
 	return
 }
 
-func (v *version) pickLevel(umin, umax []byte) (level int) {
+func (v *version) pickMemdbLevel(umin, umax []byte) (level int) {
 	if !v.tables[0].overlaps(v.s.icmp, umin, umax, true) {
 		var overlaps tFiles
 		maxLevel := v.s.o.GetMaxMemCompationLevel()