Use unsafe.SliceData()

Author: jdemeyer

kafka/event.go

@@ -224,7 +224,7 @@ out:
 			// or to the global Producer.Events channel, or none.
 			rkmessages := make([]*C.rd_kafka_message_t, int(C.rd_kafka_event_message_count(rkev)))
 
-			cnt := int(C.rd_kafka_event_message_array(rkev, (**C.rd_kafka_message_t)(unsafe.Pointer(&rkmessages[0])), C.size_t(len(rkmessages))))
+			cnt := int(C.rd_kafka_event_message_array(rkev, unsafe.SliceData(rkmessages), C.size_t(len(rkmessages))))
 
 			for _, rkmessage := range rkmessages[:cnt] {
 				msg := h.newMessageFromC(rkmessage)

kafka/handle.go

@@ -309,14 +309,9 @@ func (h *handle) setOAuthBearerToken(oauthBearerToken OAuthBearerToken) error {
 		extensionSize++
 	}
 
-	var cExtensionsToUse **C.char
-	if extensionSize > 0 {
-		cExtensionsToUse = (**C.char)(unsafe.Pointer(&cExtensions[0]))
-	}
-
 	cErr := C.rd_kafka_oauthbearer_set_token(h.rk, cTokenValue,
-		C.int64_t(oauthBearerToken.Expiration.UnixNano()/(1000*1000)), cPrincipal,
-		cExtensionsToUse, C.size_t(extensionSize), cErrstr, cErrstrSize)
+		C.int64_t(oauthBearerToken.Expiration.UnixMilli()), cPrincipal,
+		unsafe.SliceData(cExtensions), C.size_t(extensionSize), cErrstr, cErrstrSize)
 	if cErr == C.RD_KAFKA_RESP_ERR_NO_ERROR {
 		return nil
 	}

kafka/producer.go

@@ -70,13 +70,11 @@ void free_tmphdrs (tmphdr_t *tmphdrs, size_t tmphdrsCnt) {
 rd_kafka_resp_err_t do_produce (rd_kafka_t *rk,
           rd_kafka_topic_t *rkt, int32_t partition,
           int msgflags,
-          int valIsNull, void *val, size_t val_len,
-          int keyIsNull, void *key, size_t key_len,
+          void *valp, size_t val_len,
+          void *keyp, size_t key_len,
           int64_t timestamp,
           tmphdr_t *tmphdrs, size_t tmphdrsCnt,
           uintptr_t cgoid) {
-  void *valp = valIsNull ? NULL : val;
-  void *keyp = keyIsNull ? NULL : key;
 #ifdef RD_KAFKA_V_TIMESTAMP
 rd_kafka_resp_err_t err;
 #ifdef RD_KAFKA_V_HEADERS
@@ -179,55 +177,6 @@ func (p *Producer) produce(msg *Message, msgFlags int, deliveryChan chan Event)
 
 	crkt := p.handle.getRkt(*msg.TopicPartition.Topic)
 
-	// Three problems:
-	//  1) There's a difference between an empty Value or Key (length 0, proper pointer) and
-	//     a null Value or Key (length 0, null pointer).
-	//  2) we need to be able to send a null Value or Key, but the unsafe.Pointer(&slice[0])
-	//     dereference can't be performed on a nil slice.
-	//  3) cgo's pointer checking requires the unsafe.Pointer(slice..) call to be made
-	//     in the call to the C function.
-	//
-	// Solution:
-	//  Keep track of whether the Value or Key were nil (1), but let the valp and keyp pointers
-	//  point to a 1-byte slice (but the length to send is still 0) so that the dereference (2)
-	//  works.
-	//  Then perform the unsafe.Pointer() on the valp and keyp pointers (which now either point
-	//  to the original msg.Value and msg.Key or to the 1-byte slices) in the call to C (3).
-	//
-	var valp []byte
-	var keyp []byte
-	oneByte := []byte{0}
-	var valIsNull C.int
-	var keyIsNull C.int
-	var valLen int
-	var keyLen int
-
-	if msg.Value == nil {
-		valIsNull = 1
-		valLen = 0
-		valp = oneByte
-	} else {
-		valLen = len(msg.Value)
-		if valLen > 0 {
-			valp = msg.Value
-		} else {
-			valp = oneByte
-		}
-	}
-
-	if msg.Key == nil {
-		keyIsNull = 1
-		keyLen = 0
-		keyp = oneByte
-	} else {
-		keyLen = len(msg.Key)
-		if keyLen > 0 {
-			keyp = msg.Key
-		} else {
-			keyp = oneByte
-		}
-	}
-
 	var cgoid int
 
 	// Per-message state that needs to be retained through the C code:
@@ -242,7 +191,7 @@ func (p *Producer) produce(msg *Message, msgFlags int, deliveryChan chan Event)
 
 	var timestamp int64
 	if !msg.Timestamp.IsZero() {
-		timestamp = msg.Timestamp.UnixNano() / 1000000
+		timestamp = msg.Timestamp.UnixMilli()
 	}
 
 	// Convert headers to C-friendly tmphdrs
@@ -270,20 +219,15 @@ func (p *Producer) produce(msg *Message, msgFlags int, deliveryChan chan Event)
 				tmphdrs[n].size = C.ssize_t(-1)
 			}
 		}
-	} else {
-		// no headers, need a dummy tmphdrs of size 1 to avoid index
-		// out of bounds panic in do_produce() call below.
-		// tmphdrsCnt will be 0.
-		tmphdrs = []C.tmphdr_t{{nil, nil, 0}}
 	}
 
 	cErr := C.do_produce(p.handle.rk, crkt,
 		C.int32_t(msg.TopicPartition.Partition),
 		C.int(msgFlags)|C.RD_KAFKA_MSG_F_COPY,
-		valIsNull, unsafe.Pointer(&valp[0]), C.size_t(valLen),
-		keyIsNull, unsafe.Pointer(&keyp[0]), C.size_t(keyLen),
+		unsafe.Pointer(unsafe.SliceData(msg.Value)), C.size_t(len(msg.Value)),
+		unsafe.Pointer(unsafe.SliceData(msg.Key)), C.size_t(len(msg.Key)),
 		C.int64_t(timestamp),
-		(*C.tmphdr_t)(unsafe.Pointer(&tmphdrs[0])), C.size_t(tmphdrsCnt),
+		(*C.tmphdr_t)(unsafe.SliceData(tmphdrs)), C.size_t(tmphdrsCnt),
 		(C.uintptr_t)(cgoid))
 	if cErr != C.RD_KAFKA_RESP_ERR_NO_ERROR {
 		if cgoid != 0 {
@@ -326,7 +270,7 @@ func (p *Producer) produceBatch(topic string, msgs []*Message, msgFlags int) err
 		p.handle.messageToC(m, &cmsgs[i])
 	}
 	r := C.rd_kafka_produce_batch(crkt, C.RD_KAFKA_PARTITION_UA, C.int(msgFlags)|C.RD_KAFKA_MSG_F_FREE,
-		(*C.rd_kafka_message_t)(&cmsgs[0]), C.int(len(msgs)))
+		unsafe.SliceData(cmsgs), C.int(len(cmsgs)))
 	if r == -1 {
 		return newError(C.rd_kafka_last_error())
 	}