Fix errcheck warnings. (dgraph-io#856)

backup.go

@@ -166,9 +166,11 @@ func (l *Loader) send() error {
 	if err := l.throttle.Do(); err != nil {
 		return err
 	}
-	l.db.batchSetAsync(l.entries, func(err error) {
+	if err := l.db.batchSetAsync(l.entries, func(err error) {
 		l.throttle.Done(err)
-	})
+	}); err != nil {
+		return err
+	}
 
 	l.entries = make([]*Entry, 0, 1000)
 	return nil

badger/cmd/bank.go

@@ -553,7 +553,7 @@ func runTest(cmd *cobra.Command, args []string) error {
 
 				y.Check(loader.Finish())
 			}
-			db.Subscribe(ctx, updater, accountIDS[0], accountIDS[1:]...)
+			_ = db.Subscribe(ctx, updater, accountIDS[0], accountIDS[1:]...)
 		}()
 	}
 

db.go

@@ -294,7 +294,9 @@ func Open(opt Options) (db *DB, err error) {
 		db.lc.startCompact(db.closers.compactors)
 
 		db.closers.memtable = y.NewCloser(1)
-		go db.flushMemtable(db.closers.memtable) // Need levels controller to be up.
+		go func() {
+			_ = db.flushMemtable(db.closers.memtable) // Need levels controller to be up.
+		}()
 	}
 
 	headKey := y.KeyWithTs(head, math.MaxUint64)
@@ -913,7 +915,7 @@ func (db *DB) handleFlushTask(ft flushTask) error {
 	}
 	// We own a ref on tbl.
 	err = db.lc.addLevel0Table(tbl) // This will incrRef (if we don't error, sure)
-	tbl.DecrRef()                   // Releases our ref.
+	_ = tbl.DecrRef()               // Releases our ref.
 	return err
 }
 
@@ -1231,7 +1233,9 @@ func (db *DB) startCompactions() {
 	if db.closers.memtable != nil {
 		db.flushChan = make(chan flushTask, db.opt.NumMemtables)
 		db.closers.memtable = y.NewCloser(1)
-		go db.flushMemtable(db.closers.memtable)
+		go func() {
+			_ = db.flushMemtable(db.closers.memtable)
+		}()
 	}
 }
 

integration/testgc/main.go

@@ -115,7 +115,9 @@ func main() {
 	}
 	defer db.Close()
 
-	go http.ListenAndServe("localhost:8080", nil)
+	go func() {
+		_ = http.ListenAndServe("localhost:8080", nil)
+	}()
 
 	closer := y.NewCloser(11)
 	go func() {

levels.go

@@ -610,7 +610,7 @@ func (s *levelsController) compactBuildTables(
 		// -- we're the only holders of a ref).
 		for j := 0; j < numBuilds; j++ {
 			if newTables[j] != nil {
-				newTables[j].DecrRef()
+				_ = newTables[j].DecrRef()
 			}
 		}
 		errorReturn := errors.Wrapf(firstErr, "While running compaction for: %+v", cd)

structs.go

@@ -114,13 +114,19 @@ func encodeEntry(e *Entry, buf *bytes.Buffer) (int, error) {
 	hash := crc32.New(y.CastagnoliCrcTable)
 
 	buf.Write(headerEnc[:])
-	hash.Write(headerEnc[:])
+	if _, err := hash.Write(headerEnc[:]); err != nil {
+		return 0, err
+	}
 
 	buf.Write(e.Key)
-	hash.Write(e.Key)
+	if _, err := hash.Write(e.Key); err != nil {
+		return 0, err
+	}
 
 	buf.Write(e.Value)
-	hash.Write(e.Value)
+	if _, err := hash.Write(e.Value); err != nil {
+		return 0, err
+	}
 
 	var crcBuf [crc32.Size]byte
 	binary.BigEndian.PutUint32(crcBuf[:], hash.Sum32())

table/table.go

@@ -87,7 +87,9 @@ func (t *Table) DecrRef() error {
 
 		// It's necessary to delete windows files
 		if t.loadingMode == options.MemoryMap {
-			y.Munmap(t.mmap)
+			if err := y.Munmap(t.mmap); err != nil {
+				return err
+			}
 		}
 		if err := t.fd.Truncate(0); err != nil {
 			// This is very important to let the FS know that the file is deleted.
@@ -191,7 +193,9 @@ func OpenTable(fd *os.File, mode options.FileLoadingMode, cksum []byte) (*Table,
 // Close closes the open table.  (Releases resources back to the OS.)
 func (t *Table) Close() error {
 	if t.loadingMode == options.MemoryMap {
-		y.Munmap(t.mmap)
+		if err := y.Munmap(t.mmap); err != nil {
+			return err
+		}
 	}
 
 	return t.fd.Close()

value.go

@@ -463,7 +463,9 @@ func (vlog *valueLog) rewrite(f *logFile, tr trace.Trace) error {
 	}
 
 	if deleteFileNow {
-		vlog.deleteLogFile(f)
+		if err := vlog.deleteLogFile(f); err != nil {
+			return err
+		}
 	}
 
 	return nil