chores(linter): enable rest of the linters

.golangci.yml

@@ -5,17 +5,21 @@ run:
 linters-settings:
   lll:
     line-length: 120
+  staticcheck:
+    checks:
+      - all
+      - '-SA1019' # it is okay to use math/rand at times
 
 linters:
   disable-all: true
   enable:
-  #  - errcheck
-  #  - ineffassign
-  #  - gas
+    - errcheck
+    - ineffassign
+    # - gas
     - gofmt
-  #  - gosimple
-  #  - govet
-  #  - lll
-  #  - unused
-  #  - staticcheck
+    - gosimple
+    - govet
+    - lll
+    - unused
+    - staticcheck
     - goimports

backup.go

@@ -79,8 +79,7 @@ func (stream *Stream) Backup(w io.Writer, since uint64) (uint64, error) {
 			var valCopy []byte
 			if !item.IsDeletedOrExpired() {
 				// No need to copy value, if item is deleted or expired.
-				var err error
-				err = item.Value(func(val []byte) error {
+				err := item.Value(func(val []byte) error {
 					valCopy = a.Copy(val)
 					return nil
 				})

badger/cmd/flatten.go

@@ -67,7 +67,7 @@ func flatten(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-	if fo.compressionType < 0 || fo.compressionType > 2 {
+	if fo.compressionType > 2 {
 		return errors.Errorf(
 			"compression value must be one of 0 (disabled), 1 (Snappy), or 2 (ZSTD)")
 	}

badger/cmd/rotate_test.go

@@ -108,9 +108,9 @@ func TestRotatePlainTextToEncrypted(t *testing.T) {
 	db, err := badger.Open(opts)
 	require.NoError(t, err)
 
-	db.Update(func(txn *badger.Txn) error {
+	require.NoError(t, db.Update(func(txn *badger.Txn) error {
 		return txn.Set([]byte("foo"), []byte("bar"))
-	})
+	}))
 
 	require.NoError(t, db.Close())
 
@@ -140,7 +140,7 @@ func TestRotatePlainTextToEncrypted(t *testing.T) {
 	db, err = badger.Open(opts)
 	require.NoError(t, err)
 
-	db.View(func(txn *badger.Txn) error {
+	require.NoError(t, db.View(func(txn *badger.Txn) error {
 		iopt := badger.DefaultIteratorOptions
 		it := txn.NewIterator(iopt)
 		defer it.Close()
@@ -150,6 +150,6 @@ func TestRotatePlainTextToEncrypted(t *testing.T) {
 		}
 		require.Equal(t, 1, count)
 		return nil
-	})
+	}))
 	require.NoError(t, db.Close())
 }

badger/cmd/stream.go

@@ -85,7 +85,7 @@ func stream(cmd *cobra.Command, args []string) error {
 		WithEncryptionKey(encKey)
 
 	// Options for output DB.
-	if so.compressionType < 0 || so.compressionType > 2 {
+	if so.compressionType > 2 {
 		return errors.Errorf(
 			"compression value must be one of 0 (disabled), 1 (Snappy), or 2 (ZSTD)")
 	}
@@ -126,6 +126,7 @@ func stream(cmd *cobra.Command, args []string) error {
 		f, err := os.OpenFile(so.outFile, os.O_RDWR|os.O_CREATE, 0666)
 		y.Check(err)
 		_, err = stream.Backup(f, 0)
+		y.Check(err)
 	}
 	fmt.Println("Done.")
 	return err

badger/cmd/write_bench.go

@@ -314,7 +314,7 @@ func writeBench(cmd *cobra.Command, args []string) error {
 	}
 
 	c.SignalAndWait()
-	fmt.Printf(db.LevelsToString())
+	fmt.Println(db.LevelsToString())
 	return err
 }
 
@@ -401,7 +401,7 @@ func reportStats(c *z.Closer, db *badger.DB) {
 				humanize.IBytes(uint64(z.NumAllocBytes())))
 
 			if count%10 == 0 {
-				fmt.Printf(db.LevelsToString())
+				fmt.Println(db.LevelsToString())
 			}
 		}
 	}

db.go

@@ -49,10 +49,6 @@ var (
 	bannedNsKey  = []byte("!badger!banned") // For storing the banned namespaces.
 )
 
-const (
-	maxNumSplits = 128
-)
-
 type closers struct {
 	updateSize  *z.Closer
 	compactors  *z.Closer
@@ -1872,7 +1868,10 @@ func (db *DB) Subscribe(ctx context.Context, cb func(kv *KVList) error, matches
 	}
 
 	c := z.NewCloser(1)
-	s := db.pub.newSubscriber(c, matches)
+	s, err := db.pub.newSubscriber(c, matches)
+	if err != nil {
+		return y.Wrapf(err, "while creating a new subscriber")
+	}
 	slurp := func(batch *pb.KVList) error {
 		for {
 			select {
@@ -1926,11 +1925,6 @@ func (db *DB) Subscribe(ctx context.Context, cb func(kv *KVList) error, matches
 	}
 }
 
-// shouldEncrypt returns bool, which tells whether to encrypt or not.
-func (db *DB) shouldEncrypt() bool {
-	return len(db.opt.EncryptionKey) > 0
-}
-
 func (db *DB) syncDir(dir string) error {
 	if db.opt.InMemory {
 		return nil
@@ -1971,7 +1965,7 @@ func (db *DB) StreamDB(outOptions Options) error {
 	defer outDB.Close()
 	writer := outDB.NewStreamWriter()
 	if err := writer.Prepare(); err != nil {
-		y.Wrapf(err, "cannot create stream writer in out DB at %s", outDir)
+		return y.Wrapf(err, "cannot create stream writer in out DB at %s", outDir)
 	}
 
 	// Stream contents of DB to the output DB.

db2_test.go

@@ -883,7 +883,7 @@ func TestMaxVersion(t *testing.T) {
 		rand.Read(k)
 		// Create multiple version of the same key.
 		for i := 1; i <= N; i++ {
-			wb.SetEntryAt(&Entry{Key: k}, uint64(i))
+			require.NoError(t, wb.SetEntryAt(&Entry{Key: k}, uint64(i)))
 		}
 		require.NoError(t, wb.Flush())
 
@@ -906,7 +906,7 @@ func TestMaxVersion(t *testing.T) {
 
 		// This will create commits from 1 to N.
 		for i := 1; i <= N; i++ {
-			wb.SetEntryAt(&Entry{Key: []byte(fmt.Sprintf("%d", i))}, uint64(i))
+			require.NoError(t, wb.SetEntryAt(&Entry{Key: []byte(fmt.Sprintf("%d", i))}, uint64(i)))
 		}
 		require.NoError(t, wb.Flush())
 
@@ -1001,12 +1001,12 @@ func TestKeyCount(t *testing.T) {
 
 		write := func(kvs *pb.KVList) error {
 			buf := z.NewBuffer(1<<20, "test")
-			defer buf.Release()
+			defer func() { require.NoError(t, buf.Release()) }()
 
 			for _, kv := range kvs.Kv {
 				KVToBuffer(kv, buf)
 			}
-			writer.Write(buf)
+			require.NoError(t, writer.Write(buf))
 			return nil
 		}
 

db_test.go

@@ -610,7 +610,7 @@ func TestGetMore(t *testing.T) {
 			}
 			require.NoError(t, txn.Commit())
 		}
-		db.validate()
+		require.NoError(t, db.validate())
 		for i := 0; i < n; i++ {
 			if (i % 10000) == 0 {
 				// Display some progress. Right now, it's not very fast with no caching.
@@ -643,7 +643,7 @@ func TestExistsMore(t *testing.T) {
 			}
 			require.NoError(t, txn.Commit())
 		}
-		db.validate()
+		require.NoError(t, db.validate())
 
 		for i := 0; i < n; i++ {
 			if (i % 1000) == 0 {
@@ -673,7 +673,7 @@ func TestExistsMore(t *testing.T) {
 			}
 			require.NoError(t, txn.Commit())
 		}
-		db.validate()
+		require.NoError(t, db.validate())
 		for i := 0; i < n; i++ {
 			if (i % 10000) == 0 {
 				// Display some progress. Right now, it's not very fast with no caching.
@@ -1231,7 +1231,7 @@ func TestDiscardVersionsBelow(t *testing.T) {
 		opts.PrefetchValues = false
 
 		// Verify that there are 4 versions, and record 3rd version (2nd from top in iteration)
-		db.View(func(txn *Txn) error {
+		require.NoError(t, db.View(func(txn *Txn) error {
 			it := txn.NewIterator(opts)
 			defer it.Close()
 			var count int
@@ -1245,7 +1245,7 @@ func TestDiscardVersionsBelow(t *testing.T) {
 			}
 			require.Equal(t, 4, count)
 			return nil
-		})
+		}))
 
 		// Set new version and discard older ones.
 		err := db.Update(func(txn *Txn) error {
@@ -1255,7 +1255,7 @@ func TestDiscardVersionsBelow(t *testing.T) {
 
 		// Verify that there are only 2 versions left, and versions
 		// below ts have been deleted.
-		db.View(func(txn *Txn) error {
+		require.NoError(t, db.View(func(txn *Txn) error {
 			it := txn.NewIterator(opts)
 			defer it.Close()
 			var count int
@@ -1269,7 +1269,7 @@ func TestDiscardVersionsBelow(t *testing.T) {
 			}
 			require.Equal(t, 1, count)
 			return nil
-		})
+		}))
 	})
 }
 
@@ -1478,7 +1478,7 @@ func TestGetSetDeadlock(t *testing.T) {
 	timeout, done := time.After(10*time.Second), make(chan bool)
 
 	go func() {
-		db.Update(func(txn *Txn) error {
+		require.NoError(t, db.Update(func(txn *Txn) error {
 			item, err := txn.Get(key)
 			require.NoError(t, err)
 			err = item.Value(nil) // This take a RLock on file
@@ -1488,7 +1488,7 @@ func TestGetSetDeadlock(t *testing.T) {
 			require.NoError(t, txn.SetEntry(NewEntry(key, val)))
 			require.NoError(t, txn.SetEntry(NewEntry([]byte("key2"), val)))
 			return nil
-		})
+		}))
 		done <- true
 	}()
 
@@ -1818,9 +1818,9 @@ func TestMinReadTs(t *testing.T) {
 		db.orc.readMark.Done(uint64(20)) // Because we called readTs.
 
 		for i := 0; i < 10; i++ {
-			db.View(func(txn *Txn) error {
+			require.NoError(t, db.View(func(txn *Txn) error {
 				return nil
-			})
+			}))
 		}
 		time.Sleep(time.Millisecond)
 		require.Equal(t, uint64(20), db.orc.readMark.DoneUntil())
@@ -2089,7 +2089,7 @@ func TestVerifyChecksum(t *testing.T) {
 			st := 0
 
 			buf := z.NewBuffer(10<<20, "test")
-			defer buf.Release()
+			defer func() { require.NoError(t, buf.Release()) }()
 			for i := 0; i < 1000; i++ {
 				key := make([]byte, 8)
 				binary.BigEndian.PutUint64(key, uint64(i))
@@ -2153,12 +2153,12 @@ func TestWriteInemory(t *testing.T) {
 			item, err := txn.Get([]byte(fmt.Sprintf("key%d", j)))
 			require.NoError(t, err)
 			expected := []byte(fmt.Sprintf("val%d", j))
-			item.Value(func(val []byte) error {
+			require.NoError(t, item.Value(func(val []byte) error {
 				require.Equal(t, expected, val,
 					"Invalid value for key %q. expected: %q, actual: %q",
 					item.Key(), expected, val)
 				return nil
-			})
+			}))
 		}
 		return nil
 	})
@@ -2242,7 +2242,7 @@ func TestOpenDBReadOnly(t *testing.T) {
 	var count int
 	read := func() {
 		count = 0
-		db.View(func(txn *Txn) error {
+		require.NoError(t, db.View(func(txn *Txn) error {
 			it := txn.NewIterator(DefaultIteratorOptions)
 			defer it.Close()
 			for it.Rewind(); it.Valid(); it.Next() {
@@ -2254,7 +2254,7 @@ func TestOpenDBReadOnly(t *testing.T) {
 				count++
 			}
 			return nil
-		})
+		}))
 	}
 	read()
 	require.Equal(t, 10, count)

iterator_test.go

@@ -147,7 +147,7 @@ func TestIterateSinceTs(t *testing.T) {
 		iopt := DefaultIteratorOptions
 		iopt.SinceTs = sinceTs
 
-		db.View(func(txn *Txn) error {
+		require.NoError(t, db.View(func(txn *Txn) error {
 			it := txn.NewIterator(iopt)
 			defer it.Close()
 
@@ -156,7 +156,7 @@ func TestIterateSinceTs(t *testing.T) {
 				require.GreaterOrEqual(t, i.Version(), sinceTs)
 			}
 			return nil
-		})
+		}))
 
 	})
 }

levels.go

@@ -998,20 +998,14 @@ func containsPrefix(table *table.Table, prefix []byte) bool {
 		// In table iterator's Seek, we assume that key has version in last 8 bytes. We set
 		// version=0 (ts=math.MaxUint64), so that we don't skip the key prefixed with prefix.
 		ti.Seek(y.KeyWithTs(prefix, math.MaxUint64))
-		if bytes.HasPrefix(ti.Key(), prefix) {
-			return true
-		}
-		return false
+		return bytes.HasPrefix(ti.Key(), prefix)
 	}
 
 	if bytes.Compare(prefix, smallValue) > 0 &&
 		bytes.Compare(prefix, largeValue) < 0 {
 		// There may be a case when table contains [0x0000,...., 0xffff]. If we are searching for
 		// k=0x0011, we should not directly infer that k is present. It may not be present.
-		if !isPresent() {
-			return false
-		}
-		return true
+		return isPresent()
 	}
 
 	return false
@@ -1426,8 +1420,8 @@ func (s *levelsController) runCompactDef(id, l int, cd compactDef) (err error) {
 		cd.splits = append(cd.splits, keyRange{})
 	}
 
-	// Table should never be moved directly between levels, always be rewritten to allow discarding
-	// invalid versions.
+	// Table should never be moved directly between levels,
+	// always be rewritten to allow discarding invalid versions.
 
 	newTables, decr, err := s.compactBuildTables(l, cd)
 	if err != nil {