add PackageWrapper for MySQL Binlog

BUILD

@@ -55,6 +55,7 @@ cc_library(
 		'src/protocol/DnsMessage.cc',
 		'src/protocol/DnsUtil.cc',
 		'src/protocol/SSLWrapper.cc',
+		'src/protocol/PackageWrapper.cc',
 		'src/protocol/dns_parser.c',
 		'src/server/WFServer.cc',
 		'src/kernel/CommRequest.cc',

CMakeLists_Headers.txt

@@ -50,6 +50,7 @@ set(INCLUDE_HEADERS
 	src/protocol/mysql_parser.h
 	src/protocol/mysql_types.h
 	src/protocol/mysql_byteorder.h
+	src/protocol/PackageWrapper.h
 	src/protocol/SSLWrapper.h
 	src/protocol/dns_parser.h
 	src/protocol/DnsMessage.h

src/include/workflow/PackageWrapper.h

@@ -0,0 +1 @@
+../../protocol/PackageWrapper.h

src/protocol/CMakeLists.txt

@@ -2,10 +2,11 @@ cmake_minimum_required(VERSION 3.6)
 project(protocol)
 
 set(SRC
+	PackageWrapper.cc
+	SSLWrapper.cc
 	dns_parser.c
 	DnsMessage.cc
 	DnsUtil.cc
-	SSLWrapper.cc
 	http_parser.c
 	HttpMessage.cc
 	HttpUtil.cc

src/protocol/PackageWrapper.cc

@@ -0,0 +1,66 @@
+/*
+  Copyright (c) 2022 Sogou, Inc.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+  Author: Xie Han (xiehan@sogou-inc.com)
+*/
+
+#include <errno.h>
+#include "PackageWrapper.h"
+
+namespace protocol
+{
+
+int PackageWrapper::encode(struct iovec vectors[], int max)
+{
+	int cnt = 0;
+	int ret;
+
+	while (max >= 8)
+	{
+		ret = this->ProtocolWrapper::encode(vectors, max);
+		if ((unsigned int)ret > (unsigned int)max)
+		{
+			if (ret < 0)
+				return ret;
+
+			break;
+		}
+
+		cnt += ret;
+		this->msg = this->next(this->msg);
+		if (!this->msg)
+			return cnt;
+
+		vectors += ret;
+		max -= ret;
+	}
+
+	errno = EOVERFLOW;
+	return -1;
+}
+
+int PackageWrapper::append(const void *buf, size_t *size)
+{
+	int ret = this->ProtocolWrapper::append(buf, size);
+
+	if (ret <= 0)
+		return ret;
+
+	this->msg = this->next(this->msg);
+	return !this->msg;
+}
+
+}
+

src/protocol/PackageWrapper.h

@@ -0,0 +1,48 @@
+/*
+  Copyright (c) 2022 Sogou, Inc.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+  Author: Xie Han (xiehan@sogou-inc.com)
+*/
+
+#ifndef _PACKAGEWRAPPER_H_
+#define _PACKAGEWRAPPER_H_
+
+#include "ProtocolMessage.h"
+
+namespace protocol
+{
+
+class PackageWrapper : public ProtocolWrapper
+{
+private:
+	virtual ProtocolMessage *next(ProtocolMessage *msg)
+	{
+		return NULL;
+	}
+
+protected:
+	virtual int encode(struct iovec vectors[], int max);
+	virtual int append(const void *buf, size_t *size);
+
+public:
+	PackageWrapper(ProtocolMessage *msg) : ProtocolWrapper(msg)
+	{
+	}
+};
+
+}
+
+#endif
+