add more linters, fix errors found by them.

.pre-commit-config.yaml

@@ -22,7 +22,7 @@
     hooks:
     -   id: clang-formater
 -   repo: https://github.com/PaddlePaddle/pre-commit-golang
-    sha: fb3ba0e9e38a516543925e96cef76740b61321ab
+    sha: 16398aeccf263adaf53b2495eed0406347d76281
     hooks:
       -   id: go-fmt
           types: [go]

go/master/c/client.go

@@ -23,7 +23,6 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-var nullPtr = unsafe.Pointer(uintptr(0))
 var mu sync.Mutex
 var handleMap = make(map[C.paddle_master_client]*master.Client)
 var curHandle C.paddle_master_client
@@ -114,13 +113,13 @@ func paddle_next_record(client C.paddle_master_client, record **C.uchar) C.int {
 	if err != nil {
 		// Error
 		// TODO: return the type of error?
-		*record = (*C.uchar)(nullPtr)
+		*record = (*C.uchar)(nil)
 		return -1
 	}
 
 	if len(r) == 0 {
 		// Empty record
-		*record = (*C.uchar)(nullPtr)
+		*record = (*C.uchar)(nil)
 		return 0
 	}
 

go/master/etcd_client.go

@@ -30,7 +30,7 @@ type EtcdClient struct {
 // NewEtcdClient creates a new EtcdClient.
 func NewEtcdClient(endpoints []string, addr string, lockPath, addrPath, statePath string, ttlSec int) (*EtcdClient, error) {
 	log.Debugf("Connecting to etcd at %v", endpoints)
-	// TODO(helin): gracefully shutdown etcd store. Becuase etcd
+	// TODO(helin): gracefully shutdown etcd store. Because etcd
 	// store holds a etcd lock, even though the lock will expire
 	// when the lease timeout, we need to implement graceful
 	// shutdown to release the lock.
@@ -60,7 +60,7 @@ func NewEtcdClient(endpoints []string, addr string, lockPath, addrPath, statePat
 	}
 	log.Debugf("Successfully acquired lock at %s.", lockPath)
 
-	put := clientv3.OpPut(addrPath, string(addr))
+	put := clientv3.OpPut(addrPath, addr)
 	resp, err := cli.Txn(context.Background()).If(lock.IsOwner()).Then(put).Commit()
 	if err != nil {
 		return nil, err

go/master/inmem_store.go

@@ -4,7 +4,7 @@ import "sync"
 
 // InMemStore is an in memory implementation of Store interface.
 //
-// It does not tolerate the fault that casues the program to crash.
+// It does not tolerate the fault that causes the program to crash.
 type InMemStore struct {
 	mu  sync.Mutex
 	buf []byte

go/master/service.go

@@ -160,7 +160,7 @@ func (s *Service) recover() (bool, error) {
 
 // snapshot *must* be called with s.mu being held.
 func (s *Service) snapshot() error {
-	// TOOD(helin): etcd request has a size limit, so the snapshot
+	// TODO(helin): etcd request has a size limit, so the snapshot
 	// size is limited by the max request size. We should either
 	// divide the snapshot into smaller chunks and save under
 	// different keys, or configure the request size to be big
@@ -289,7 +289,6 @@ func (s *Service) processFailedTask(t taskEntry, epoch int) {
 
 	log.Warningf("Task %v failed %d times, discard.", t.Task, t.NumFailure)
 	s.taskQueues.Todo = append(s.taskQueues.Todo, t)
-	return
 }
 
 func (s *Service) checkTimeoutFunc(taskID int, epoch int) func() {

go/pserver/client/c/cclient.go

@@ -34,7 +34,6 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-var nullPtr = unsafe.Pointer(uintptr(0))
 var mu sync.Mutex
 var handleMap = make(map[C.paddle_pserver_client]*client.Client)
 var curHandle C.paddle_pserver_client
@@ -63,7 +62,7 @@ func remove(client C.paddle_pserver_client) *client.Client {
 }
 
 func cArrayToSlice(p unsafe.Pointer, len int) []byte {
-	if p == nullPtr {
+	if p == nil {
 		return nil
 	}
 
@@ -137,7 +136,7 @@ func paddle_init_param(client C.paddle_pserver_client, param C.paddle_parameter,
 
 	if err != nil {
 		if err.Error() == pserver.AlreadyInitialized {
-			log.Warningf("parameter %s already initialized, treat paddle_init_param as sucessful.", name)
+			log.Warningf("parameter %s already initialized, treat paddle_init_param as successful.", name)
 			return C.PSERVER_OK
 		}
 		log.Errorln(err)
@@ -153,7 +152,7 @@ func paddle_finish_init_params(client C.paddle_pserver_client) C.int {
 	err := c.FinishInitParams()
 	if err != nil {
 		if err.Error() == pserver.AlreadyInitialized {
-			log.Warningln("parameters already initialized, treat paddle_finish_init_params as sucessful.")
+			log.Warningln("parameters already initialized, treat paddle_finish_init_params as successful.")
 			return C.PSERVER_OK
 		}
 
@@ -223,12 +222,12 @@ func paddle_get_params(client C.paddle_pserver_client, dst **C.paddle_parameter,
 		p := ps[i]
 		param := *(**C.paddle_parameter)(unsafe.Pointer((uintptr(unsafe.Pointer(dst)) + uintptr(i)*unsafe.Sizeof(*dst))))
 
-		if unsafe.Pointer(param) == nullPtr {
+		if unsafe.Pointer(param) == nil {
 			log.Errorln("must pre-allocate parameter.")
 			return C.PSERVER_ERROR
 		}
 
-		if unsafe.Pointer(param.content) != nullPtr {
+		if unsafe.Pointer(param.content) != nil {
 			if int(param.content_len) != len(p.Content) {
 				log.Errorf("the pre-allocated content len does not match parameter content len. Pre-allocated len: %d, returned len: %d", param.content_len, len(p.Content))
 				return C.PSERVER_ERROR

go/pserver/etcd_client.go

@@ -177,10 +177,10 @@ func (e *EtcdClient) registerPserverEtcd(ctx context.Context, port int) (int, er
 				break
 			}
 		}
-		if registered == true {
+		if registered {
 			return nil
 		}
-		return errors.New("not registerd, may due to already have enough pservers")
+		return errors.New("not registered, may due to already have enough pservers")
 	}, concurrency.WithAbortContext(ctx), concurrency.WithIsolation(concurrency.RepeatableReads))
 
 	if err != nil {
@@ -211,8 +211,5 @@ func (e *EtcdClient) PutKey(key string, value []byte, timeout time.Duration) err
 	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 	_, err := e.etcdClient.Put(ctx, key, string(value))
 	cancel()
-	if err != nil {
 	return err
-	}
-	return nil
 }

go/pserver/optimizer.go

@@ -14,8 +14,6 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-var nullPtr = unsafe.Pointer(uintptr(0))
-
 type optimizer struct {
 	opt         *C.struct_paddle_optimizer
 	elementType ElementType
@@ -23,7 +21,7 @@ type optimizer struct {
 }
 
 func cArrayToSlice(p unsafe.Pointer, len int) []byte {
-	if p == nullPtr {
+	if p == nil {
 		return nil
 	}
 
@@ -92,8 +90,8 @@ func (o *optimizer) UpdateParameter(g Gradient) error {
 }
 
 func (o *optimizer) Cleanup() {
-	if unsafe.Pointer(o.opt) != nullPtr {
+	if unsafe.Pointer(o.opt) != nil {
 		C.paddle_release_optimizer(o.opt)
-		o.opt = (*C.struct_paddle_optimizer)(nullPtr)
+		o.opt = (*C.struct_paddle_optimizer)(nil)
 	}
 }

go/pserver/service.go

@@ -211,7 +211,7 @@ func (s *Service) GetParam(name string, parameter *Parameter) error {
 	// learning optimization methods are stochastic in
 	// nature. This race condition is allowed deliberately
 	// to save the program from making a copy of the
-	// paramter content.
+	// parameter content.
 	parameter.Name = name
 	parameter.ElementType = opt.elementType
 	parameter.Content = opt.GetWeights()