文章开头放一下IBM的google protocol buffer的介绍链接。http://www.ibm.com/developerworks/cn/linux/l-cn-gpb/
对于这种技术不断更新的东西,我只能这么理解:因为技术在更新,版本在变化,之前很详尽的技术博文可能在之后的版本中遇到无法预知的问题,所以我们在使用时要注意甄别。废话不多说,进入正文部分。
安装什么的都是小问题了,还是贴一下步骤吧。
tar -xzf protobuf-2.5.0.tar.gz cd protobuf-2.5.0 ./configure --prefix=$INSTALL_DIR make make check make install
很简单的标准*nix的安装方法。随后将安装目录的bin目录下的protoc创建一个软连接到/usr/bin目录下即可。
随后可以进行简单的例子测试了。我这里有一个测试例子:
file:base.taskinfo.proto
package base; message funcinfo { required string funchandle = 1;//处理函数列表 optional string funcinit = 2; //初始化函数 optional string funcclean = 3; //清理函数 } message taskinfo { required int32 taskid = 1; //任务id required int32 pidcount = 2; //进程数目 required string filepath = 3; //输入文件路径 required string filename = 4; //文件名 required string temppath = 5; //临时文件路径 required string scriptpath = 6; //脚本路径 required funcinfo func = 7; //函数信息 required string redisconn = 8; //redis链接ip及port }
然后用它来生成c++类型的相对应的文件:protoc --cpp_out=./ base.taskinfo.proto
就生成了两个标准c++的头文件和源文件:base.taskinfo.pb.cc base.taskinfo.pb.h
然后就可以写简单的例子进行测试了,这里写了一个叫write.cpp的简单例子:(以下****部分涉及个人隐私,避免被人肉)
#include "base.taskinfo.pb.h" #include <iostream> #include <fstream> using namespace std; int main() { base::funcinfo func; func.set_funchandle("GetKeyVal"); base::taskinfo msg1; msg1.set_taskid(1); msg1.set_pidcount(3); msg1.set_filepath("/data/home/****/data/basetest/indir"); msg1.set_filename("CH_PW_WAY"); msg1.set_temppath("/data/home/****/data/basetest/tmpdir"); msg1.set_scriptpath("/data/home/****/data/basetest/perl/CH_PW_WAY.pl"); msg1.set_allocated_func(&func); msg1.set_redisconn("10.200.25.155:7379"); fstream output("./log", ios::out | ios::trunc | ios::binary); if (!msg1.SerializeToOstream(&output)) { cerr<<"Failed to write msg."<< endl; return -1; } return 0; }
然后就可以写个Makefile去编译这1个cpp,1个cc和1和h文件(protoc生成的.cc文件)
#makefile by **** #2015年1月4日09:07:28 cc = g++ cpp = -fPIC -Wall -g inc += -I./ inc += -I/soft/protobuf-2.5.0/include libs += -L/soft/protobuf-2.5.0/lib -lprotobuf -lpthread objs=$(patsubst %.cc,%.o, $(wildcard *.cc)) objs+=$(patsubst %.cpp,%.o, $(wildcard *.cpp)) %.o:%.cc $(cc) $(cpp) $(inc) -o [email protected] -c $< @echo "[email protected]" %.o:%.cpp $(cc) $(cpp) $(inc) -o [email protected] -c $< @echo "[email protected]" module=./writer all:$(module) $(module):$(objs) $(cc) $(cpp) $(inc) -o $(module) $^ $(libs) @echo "[email protected]" clean: @rm -f $(objs) $(module) @echo "clean done."
编译没问题,然后很快乐的就生成了可执行文件
随后就是 执行,让他生成log文件就行了,执行的时候出现了无法找到lib的错误,好吧,把刚才的安装目录下的lib目录添加到环境变量$LD_LIBRARY_PATH中去,再执行就出现了:
*** glibc detected *** ./writer: munmap_chunk(): invalid pointer: 0x00007fff8521b9b0 ***
======= Backtrace: =========
/lib64/libc.so.6(+0x75358)[0x7fa138d93358]
./writer[0x4046f1]
./writer[0x403732]
./writer[0x4044ae]
./writer[0x409010]
/lib64/libc.so.6(__libc_start_main+0xe6)[0x7fa138d3cc36]
./writer[0x403099]
======= Memory map: ========
..以下省略数千个字符。总之就是core掉了。试试gdb工具,调试结果如下所示:
Missing separate debuginfo for /lib64/ld-linux-x86-64.so.2 Try: zypper install -C "debuginfo(build-id)=c81de241a528795f8dbfde0f0e0e236f9a6554e6" Core was generated by `./writer‘. Program terminated with signal 6, Aborted. #0 0x00007fad42931b55 in raise () from /lib64/libc.so.6 (gdb) bt #0 0x00007fad42931b55 in raise () from /lib64/libc.so.6 #1 0x00007fad42933131 in abort () from /lib64/libc.so.6 #2 0x00007fad4296ec2f in __libc_message () from /lib64/libc.so.6 #3 0x00007fad42974358 in malloc_printerr () from /lib64/libc.so.6 #4 0x00000000004046e1 in base::funcinfo::~funcinfo (this=0x7fff3026a2c0, __in_chrg=<optimized out>) at base.taskinfo.pb.cc:167 #5 0x0000000000403722 in base::taskinfo::SharedDtor (this=0x7fff3026a270) at base.taskinfo.pb.cc:537 #6 0x000000000040449e in base::taskinfo::~taskinfo (this=0x7fff3026a270, __in_chrg=<optimized out>) at base.taskinfo.pb.cc:517 #7 0x0000000000409000 in main () at writer.cpp:25
应该是析构函数出错了,看一下到底protoc给我们生成了什么东西吧。这段代码摘自base.taskinfo.pb.cc
void taskinfo::SharedDtor() { if (filepath_ != &::google::protobuf::internal::kEmptyString) { delete filepath_; } if (filename_ != &::google::protobuf::internal::kEmptyString) { delete filename_; } if (temppath_ != &::google::protobuf::internal::kEmptyString) { delete temppath_; } if (scriptpath_ != &::google::protobuf::internal::kEmptyString) { delete scriptpath_; } if (redisconn_ != &::google::protobuf::internal::kEmptyString) { delete redisconn_; } if (this != default_instance_) { delete func_; } }
我擦。(请原谅我的粗鲁),居然是delete func_,我顿时就不能淡定了。我申请的是栈内存,你给我来个delete,不core才怪了~好吧,请原谅我没有看你这个生成的1061行的源代码。
改一下上面的write.cpp的代码:
#include "base.taskinfo.pb.h" #include <iostream> #include <fstream> using namespace std; int main() { base::funcinfo *func = new base::funcinfo(); func->set_funchandle("GetKeyVal"); base::taskinfo *msg1 = new base::taskinfo(); msg1->set_taskid(1); msg1->set_pidcount(3); msg1->set_filepath("/data/home/****/data/basetest/indir"); msg1->set_filename("CH_PW_WAY"); msg1->set_temppath("/data/home/****/data/basetest/tmpdir"); msg1->set_scriptpath("/data/home/****/data/basetest/perl/CH_PW_WAY.pl"); msg1->set_allocated_func(func); msg1->set_redisconn("10.200.25.155:7379"); fstream output("./log", ios::out | ios::trunc | ios::binary); if (!msg1->SerializeToOstream(&output)) { cerr<<"Failed to write msg."<< endl; return -1; } return 0; }
好 编译运行没问题了,都解决了。生成了一个log文件,这文件没办法看了。内容按照他自己的格式写的,有一些乱码和一些能看得懂的,自己写进去的东西。