cherry-picks: bring fixes from master to release branch

README.md

@@ -58,8 +58,6 @@ $ go get github.com/dgraph-io/badger/v3
 ```
 This will retrieve the library.
 
-##### Note: Badger does not directly use CGO but it relies on https://github.com/DataDog/zstd for compression and it requires gcc/cgo. If you wish to use badger without gcc/cgo, you can run `CGO_ENABLED=0 go get github.com/dgraph-io/badger/v3` which will download badger without the support for ZSTD compression algorithm.
-
 #### Installing Badger Command Line Tool
 
 Download and extract the latest Badger DB release from https://github.com/dgraph-io/badger/releases and then run the following commands.

db.go

@@ -172,11 +172,6 @@ func checkAndSetOptions(opt *Options) error {
 		return ErrValueLogSize
 	}
 
-	// Return error if badger is built without cgo and compression is set to ZSTD.
-	if opt.Compression == options.ZSTD && !y.CgoEnabled {
-		return y.ErrZstdCgo
-	}
-
 	if opt.ReadOnly {
 		// Do not perform compaction in read only mode.
 		opt.CompactL0OnClose = false

go.mod

@@ -5,15 +5,15 @@ go 1.12
 // replace github.com/dgraph-io/ristretto => /home/amanbansal/go/src/github.com/dgraph-io/ristretto
 
 require (
-	github.com/DataDog/zstd v1.4.1
 	github.com/cespare/xxhash v1.1.0
-	github.com/dgraph-io/ristretto v0.0.4-0.20210309073149-3836124cdc5a
+	github.com/dgraph-io/ristretto v0.1.0
 	github.com/dustin/go-humanize v1.0.0
 	github.com/gogo/protobuf v1.3.2
 	github.com/golang/protobuf v1.3.1
-	github.com/golang/snappy v0.0.1
+	github.com/golang/snappy v0.0.3
 	github.com/google/flatbuffers v1.12.0
 	github.com/google/go-cmp v0.5.4 // indirect
+	github.com/klauspost/compress v1.12.3
 	github.com/kr/pretty v0.1.0 // indirect
 	github.com/pkg/errors v0.9.1
 	github.com/spaolacci/murmur3 v1.1.0 // indirect

go.sum

@@ -1,12 +1,12 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
-github.com/DataDog/zstd v1.4.1 h1:3oxKN3wbHibqx897utPC2LTQU4J+IHWWJO+glkAkpFM=
-github.com/DataDog/zstd v1.4.1/go.mod h1:1jcaCB/ufaK+sKp1NBhlGmpz41jOoPQ35bpF36t7BBo=
 github.com/OneOfOne/xxhash v1.2.2 h1:KMrpdQIwFcEqXDklaen+P1axHaj9BSKzvpUUfnHldSE=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
 github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
+github.com/cespare/xxhash/v2 v2.1.1 h1:6MnRN8NT7+YBpUIWxHtefFZOKTAPgGjpQSxqLNn0+qY=
+github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
 github.com/coreos/go-etcd v2.0.0+incompatible/go.mod h1:Jez6KQU2B/sWsbdaef3ED8NzMklzPG4d5KIOhIy30Tk=
@@ -15,8 +15,8 @@ github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwc
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/dgraph-io/ristretto v0.0.4-0.20210309073149-3836124cdc5a h1:1cMMkx3iegOzbAxVl1ZZQRHk+gaCf33Y5/4I3l0NNSg=
-github.com/dgraph-io/ristretto v0.0.4-0.20210309073149-3836124cdc5a/go.mod h1:MIonLggsKgZLUSt414ExgwNtlOL5MuEoAJP514mwGe8=
+github.com/dgraph-io/ristretto v0.1.0 h1:Jv3CGQHp9OjuMBSne1485aDpUkTKEcUqF+jm/LuerPI=
+github.com/dgraph-io/ristretto v0.1.0/go.mod h1:fux0lOrBhrVCJd3lcTHsIJhq1T2rokOu6v9Vcb3Q9ug=
 github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2 h1:tdlZCpZ/P9DhczCTSixgIKmwPv6+wP5DGjqLYw5SUiA=
 github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2/go.mod h1:SqUrOPUnsFjfmXRMNPybcSiG0BgUW2AuFH8PAnS2iTw=
 github.com/dustin/go-humanize v1.0.0 h1:VSnTsYCnlFHaM2/igO1h6X3HA71jcobQuxemgkq4zYo=
@@ -32,11 +32,10 @@ github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfb
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1 h1:YF8+flBXS5eO826T4nzqPrxfhQThhXl0YzfuUPu4SBg=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
-github.com/golang/snappy v0.0.1 h1:Qgr9rKW7uDUkrbSmQeiDsGa8SjGyCOGtuasMWwvp2P4=
-github.com/golang/snappy v0.0.1/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
+github.com/golang/snappy v0.0.3 h1:fHPg5GQYlCeLIPB9BZqMVR5nR9A+IM5zcgeTdjMYmLA=
+github.com/golang/snappy v0.0.3/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/google/flatbuffers v1.12.0 h1:/PtAHvnBY4Kqnx/xCQ3OIV9uYcSFGScBsWI3Oogeh6w=
 github.com/google/flatbuffers v1.12.0/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
-github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.5.4 h1:L8R9j+yAqZuZjsqh/z+F1NCffTKKLShY6zXTItVIZ8M=
 github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
@@ -45,6 +44,8 @@ github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NH
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/klauspost/compress v1.12.3 h1:G5AfA94pHPysR56qqrkO2pxEexdDzrpFJ6yt/VqWxVU=
+github.com/klauspost/compress v1.12.3/go.mod h1:8dP1Hq4DHOhN9w426knH3Rhby4rFm6D8eO+e+Dq5Gzg=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
@@ -111,7 +112,6 @@ golang.org/x/sys v0.0.0-20181205085412-a5c9d58dba9a/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190502145724-3ef323f4f1fd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f h1:+Nyd8tzPX9R7BWHguqsrbFdRx3WQ/1ib8I44HXV5yTA=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c h1:VwygUrnw9jn88c4u8GD3rZQbqrP/tgas88tPUbBxQrk=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

iterator.go

@@ -638,7 +638,7 @@ func (it *Iterator) parseItem() bool {
 	// Skip any versions which are beyond the readTs.
 	version := y.ParseTs(key)
 	// Ignore everything that is above the readTs and below or at the sinceTs.
-	if version > it.readTs || version <= it.opt.SinceTs {
+	if version > it.readTs || (it.opt.SinceTs > 0 && version <= it.opt.SinceTs) {
 		mi.Next()
 		return false
 	}

iterator_test.go

@@ -160,6 +160,24 @@ func TestIterateSinceTs(t *testing.T) {
 	})
 }
 
+func TestIterateSinceTsWithPendingWrites(t *testing.T) {
+	// The pending entries still have version=0. Even IteratorOptions.SinceTs is 0, the entries
+	// should be visible.
+	runBadgerTest(t, nil, func(t *testing.T, db *DB) {
+		txn := db.NewTransaction(true)
+		defer txn.Discard()
+		require.NoError(t, txn.Set([]byte("key1"), []byte("value1")))
+		require.NoError(t, txn.Set([]byte("key2"), []byte("value2")))
+		itr := txn.NewIterator(DefaultIteratorOptions)
+		defer itr.Close()
+		count := 0
+		for itr.Rewind(); itr.Valid(); itr.Next() {
+			count++
+		}
+		require.Equal(t, 2, count)
+	})
+}
+
 func TestIteratePrefix(t *testing.T) {
 	if !*manual {
 		t.Skip("Skipping test meant to be run manually.")

levels.go

@@ -829,34 +829,29 @@ func (s *levelsController) subcompact(it y.Iterator, kr keyRange, cd compactDef,
 			continue
 		}
 		numBuilds++
-		fileID := s.reserveFileID()
 		if err := inflightBuilders.Do(); err != nil {
 			// Can't return from here, until I decrRef all the tables that I built so far.
 			break
 		}
-		go func(builder *table.Builder) {
+		go func(builder *table.Builder, fileID uint64) {
 			var err error
 			defer inflightBuilders.Done(err)
 			defer builder.Close()
 
-			build := func(fileID uint64) (*table.Table, error) {
-				fname := table.NewFilename(fileID, s.kv.opt.Dir)
-				return table.CreateTable(fname, builder)
-			}
-
 			var tbl *table.Table
 			if s.kv.opt.InMemory {
 				tbl, err = table.OpenInMemoryTable(builder.Finish(), fileID, &bopts)
 			} else {
-				tbl, err = build(fileID)
+				fname := table.NewFilename(fileID, s.kv.opt.Dir)
+				tbl, err = table.CreateTable(fname, builder)
 			}
 
 			// If we couldn't build the table, return fast.
 			if err != nil {
 				return
 			}
 			res <- tbl
-		}(builder)
+		}(builder, s.reserveFileID())
 	}
 	s.kv.vlog.updateDiscardStats(discardStats)
 	s.kv.opt.Debugf("Discard stats: %v", discardStats)

options.go

@@ -159,6 +159,7 @@ func DefaultOptions(path string) Options {
 		// compression is ratio supposed to increase with increasing compression level but since the
 		// input for compression algorithm is small (4 KB), we don't get significant benefit at
 		// level 3.
+		// NOTE: The benchmarks are with DataDog ZSTD that requires CGO. Hence, no longer valid.
 		// no_compression-16              10	 502848865 ns/op	 165.46 MB/s	-
 		// zstd_compression/level_1-16     7	 739037966 ns/op	 112.58 MB/s	2.93
 		// zstd_compression/level_3-16     7	 756950250 ns/op	 109.91 MB/s	2.72
@@ -712,6 +713,7 @@ func (opt Options) WithInMemory(b bool) Options {
 // algorithm is small (4 KB), we don't get significant benefit at level 3. It is advised to write
 // your own benchmarks before choosing a compression algorithm or level.
 //
+// NOTE: The benchmarks are with DataDog ZSTD that requires CGO. Hence, no longer valid.
 // no_compression-16              10	 502848865 ns/op	 165.46 MB/s	-
 // zstd_compression/level_1-16     7	 739037966 ns/op	 112.58 MB/s	2.93
 // zstd_compression/level_3-16     7	 756950250 ns/op	 109.91 MB/s	2.72

txn.go

@@ -160,12 +160,12 @@ func (o *oracle) hasConflict(txn *Txn) bool {
 	return false
 }
 
-func (o *oracle) newCommitTs(txn *Txn) uint64 {
+func (o *oracle) newCommitTs(txn *Txn) (uint64, bool) {
 	o.Lock()
 	defer o.Unlock()
 
 	if o.hasConflict(txn) {
-		return 0
+		return 0, true
 	}
 
 	var ts uint64
@@ -194,7 +194,7 @@ func (o *oracle) newCommitTs(txn *Txn) uint64 {
 		})
 	}
 
-	return ts
+	return ts, false
 }
 
 func (o *oracle) doneRead(txn *Txn) {
@@ -537,10 +537,8 @@ func (txn *Txn) commitAndSend() (func() error, error) {
 	orc.writeChLock.Lock()
 	defer orc.writeChLock.Unlock()
 
-	commitTs := orc.newCommitTs(txn)
-	// The commitTs can be zero if the transaction is running in managed mode.
-	// Individual entries might have their own timestamps.
-	if commitTs == 0 && !txn.db.opt.managedTxns {
+	commitTs, conflict := orc.newCommitTs(txn)
+	if conflict {
 		return nil, ErrConflict
 	}
 

txn_test.go

@@ -817,6 +817,15 @@ func TestManagedDB(t *testing.T) {
 			}
 		}
 		txn.Discard()
+
+		// Write data to same key, causing a conflict
+		txn = db.NewTransactionAt(10, true)
+		txnb := db.NewTransactionAt(10, true)
+		txnb.Get(key(0))
+		require.NoError(t, txn.SetEntry(NewEntry(key(0), val(0))))
+		require.NoError(t, txnb.SetEntry(NewEntry(key(0), val(1))))
+		require.NoError(t, txn.CommitAt(11, nil))
+		require.Equal(t, ErrConflict, txnb.CommitAt(11, nil))
 	}
 	t.Run("disk mode", func(t *testing.T) {
 		db, err := Open(opt)

y/y.go

@@ -40,11 +40,6 @@ var (
 	// and encountering the end of slice.
 	ErrEOF = errors.New("ErrEOF: End of file")
 
-	// ErrZstdCgo indicates that badger was built without cgo but ZSTD
-	// compression algorithm is being used for compression. ZSTD cannot work
-	// without CGO.
-	ErrZstdCgo = errors.New("ErrZstdCgo: zstd compression requires building badger with cgo enabled")
-
 	// ErrCommitAfterFinish indicates that write batch commit was called after
 	// finish
 	ErrCommitAfterFinish = errors.New("Batch commit not permitted after finish")

y/zstd_cgo.go → y/zstd.go

@@ -1,5 +1,3 @@
-// +build cgo
-
 /*
  * Copyright 2019 Dgraph Labs, Inc. and Contributors
  *
@@ -19,23 +17,48 @@
 package y
 
 import (
-	"github.com/DataDog/zstd"
+	"sync"
+
+	"github.com/klauspost/compress/zstd"
 )
 
-// CgoEnabled is used to check if CGO is enabled while building badger.
-const CgoEnabled = true
+var (
+	decoder *zstd.Decoder
+	encoder *zstd.Encoder
+
+	encOnce, decOnce sync.Once
+)
 
 // ZSTDDecompress decompresses a block using ZSTD algorithm.
 func ZSTDDecompress(dst, src []byte) ([]byte, error) {
-	return zstd.Decompress(dst, src)
+	decOnce.Do(func() {
+		var err error
+		decoder, err = zstd.NewReader(nil)
+		Check(err)
+	})
+	return decoder.DecodeAll(src, dst[:0])
 }
 
 // ZSTDCompress compresses a block using ZSTD algorithm.
 func ZSTDCompress(dst, src []byte, compressionLevel int) ([]byte, error) {
-	return zstd.CompressLevel(dst, src, compressionLevel)
+	encOnce.Do(func() {
+		var err error
+		level := zstd.EncoderLevelFromZstd(compressionLevel)
+		encoder, err = zstd.NewWriter(nil, zstd.WithEncoderLevel(level))
+		Check(err)
+	})
+	return encoder.EncodeAll(src, dst[:0]), nil
 }
 
 // ZSTDCompressBound returns the worst case size needed for a destination buffer.
+// Klauspost ZSTD library does not provide any API for Compression Bound. This
+// calculation is based on the DataDog ZSTD library.
+// See https://pkg.go.dev/github.com/DataDog/zstd#CompressBound
 func ZSTDCompressBound(srcSize int) int {
-	return zstd.CompressBound(srcSize)
+	lowLimit := 128 << 10 // 128 kB
+	var margin int
+	if srcSize < lowLimit {
+		margin = (lowLimit - srcSize) >> 11
+	}
+	return srcSize + (srcSize >> 8) + margin
 }