[c++,bson]bson::BSONObj 与 std::vector 互相转化代码示例

编程的时候，需要使用到将 bson::BSONObj 对象 与 std::vector 进行相互转换，所以写了一个代码进行测试。

在将 bson::BSONObj ---> std::vector 的时候只需要借助于 bson::BSONObjBuilder
作为中间转化媒介即可。
在将 bson::BSONObj ---> std::vector 的时候，需要借助于bson::BSONObjIterator 即可。

对于复杂的结构体类型，
如:
vectore
struct node
{
  int i ;
  char c ;
} ;
暂时还没找到解决方法

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编程环境: linux
编译工具: g++ , autotools {autoscan , aclocal , autoconf , autoheader , make}
autotools 的使用方法参见文档  [c++,bson]bson 的安装与使用

示例代码如下:

1. build.sh

#!/bin/sh
autoscan
aclocal
autoconf
autoheader
automake --add-missing
./configure CXXFLAGS= CFLAGS=
make

2. configure.in

#                                               -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.

AC_INIT(Bson_Vector_test)

AC_USE_SYSTEM_EXTENSIONS

AM_INIT_AUTOMAKE(Bson_Vector_test, 1.0)

AC_CONFIG_SRCDIR([bson_vector_test.cpp])

AC_CONFIG_HEADERS([config.h])

# Checks for programs.
AC_PROG_CXX

AC_PROG_CC

# Checks for libraries.

# Checks for header files.

# Checks for typedefs, structures, and compiler characteristics.

# Checks for library functions.

AC_OUTPUT(Makefile)

3. Makefile.am

AUTOMAKE_OPTIONS=foreign
bin_PROGRAMS=Bson_Vector_test
BSON_SRC_PATH=/unixC/Bson/bson/src
BOOST_LIB_PATH=/unixC/Boost/boost_1_58_0

#what source files  Bson_Vector_test needs ?
Bson_Vector_test_SOURCES=\
bson_vector_test.cpp \
$(BSON_SRC_PATH)/bsonobj.cpp $(BSON_SRC_PATH)/util/json.cpp \
$(BSON_SRC_PATH)/oid.cpp $(BSON_SRC_PATH)/lib/base64.cpp \
$(BSON_SRC_PATH)/lib/md5.cpp $(BSON_SRC_PATH)/lib/nonce.cpp


Bson_Vector_test_CXXFLAGS=\
-I$(BOOST_LIB_PATH) -I$(BSON_SRC_PATH) -D_FILE_OFFSET_BITS=64 \
-ggdb -Wall -O0


Bson_Vector_test_LDADD=\
-lpthread -lm -lboost_system -lboost_thread \
-lboost_thread -lboost_program_options -lrt

Bson_Vector_test_LDFLAGS=\
-fPIC -rdynamic -L$(BOOST_LIB_PATH)/stage/lib -pthread

4. bson_vector_test.cpp

// test how to push and extract vector object
// into and from a BSONObj

// first test a int type vector
// second test char type vector
// then test a struct node type vector

//


#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>

#include <bson.h>

using namespace std ;
using namespace bson ;

int main ( int argc , char ** argv )
{
  vector <int> list1, list2 ; // list2 stored content extract from obj1
  BSONObjBuilder builder ;
  BSONObj obj1 ; // push in obj1

  // insert contents into list
  for ( int i = 0 ; i < 30 ; i++ )
      list1.push_back (i) ;

   builder.append ("Integer_List", list1) ;

   obj1 = builder.obj () ;

   cout << "here is the bson obj content "<< endl ;
   cout << obj1.toString () << endl ;

   // extract from obj1

   BSONObjIterator iter (obj1["Integer_List"].embeddedObjectUserCheck()) ;

   while ( iter.more() )
      list2.push_back (iter.next().number()) ;

   for ( int i = 0 ; i < list2.size () ; i++ )
      cout << list2[i] << endl ;


  cout <<"-----------test bson vector------------------------"<< endl ;
  vector<char> charList1, charList2 ;
  BSONObj cObj1 ;
  BSONObjBuilder cBuilder ;

  for ( int i = 0 ; i < 100 ; i++ )
  {
    char c = 0x01 ;
    charList1.push_back(c) ;
  }

  for ( int i = 0 ; i < charList1.size() ; i++ )
     cout << charList1[i] << endl ;
 cBuilder.append ("bit_field",charList1) ;

 cObj1 = cBuilder.obj () ;

 cout << "here is cObj1 " << cObj1.toString () << endl ;

 // extract info from BSONObj stroed it  into charList2

 BSONObjIterator cIter (cObj1["bit_field"].embeddedObjectUserCheck()) ;

 while (cIter.more () )
 {
    charList2.push_back ((char)cIter.next().number()) ;
 }

 cout << "output contents in charList2 " << endl ;

 for ( int i = 0 ; i < charList2.size () ; i++ )
   cout << charList2[i] << endl ;


   return 0 ;
}

end