CODEWITHSUNDEEP
c++stl
Vikram Ranabhatt
Vikram Ranabhatt

Reputation: 7630

maximum size of std::vector

I am using vector in my code 

    std::vector<CEventLogInfo >

    class CEventLogInfo 
    { 
      // date and time
  unsigned short    m_sMonth;
  unsigned short    m_sDay;
  unsigned int  m_nYear;
  unsigned short    m_sHour;
  unsigned short    m_sMin;
  unsigned short    m_sSec;

  unsigned long m_nGatewayMacID;
  unsigned char m_byCommandType;
  unsigned char m_byStatus;
  unsigned char m_byEventName;
  unsigned char m_byDirection;
  unsigned short    m_nPacketLen;
  char*         m_pPacket;
     // ..some method 
 }
 CEventLogInfo::CEventLogInfo(const CEventLogInfo& refMessage)
 {      
m_sMonth        = refMessage.m_sMonth;
m_sDay          = refMessage.m_sDay;
m_nYear         = refMessage.m_nYear;
m_sHour         = refMessage.m_sHour;
m_sMin          = refMessage.m_sMin;
m_sSec          = refMessage.m_sSec;

m_nGatewayMacID = refMessage.m_nGatewayMacID;
m_byCommandType = refMessage.m_byCommandType;
m_byStatus      = refMessage.m_byStatus;
m_byDirection   = refMessage.m_byDirection;
m_byEventName   = refMessage.m_byEventName;
m_nPacketLen    = refMessage.m_nPacketLen;  
if ( m_nPacketLen!=0)
{
    m_pPacket       = new char[m_nPacketLen];
    memcpy(m_pPacket,refMessage.m_pPacket,m_nPacketLen);

}
else
    m_pPacket = NULL;

  }    


 void CEventLoggerBody::SetEventInfoList(EventInfoList& ListEventLog)
 {
EventInfoList::iterator itrEventLogInfo;
for ( itrEventLogInfo = ListEventLog.begin(); itrEventLogInfo != ListEventLog.end();itrEventLogInfo++)
{
    CEventLogInfo* pEventLogInfo = new CEventLogInfo(*itrEventLogInfo);


    m_ListEventLog.push_back(*pEventLogInfo);
}
 }
  1. here m_nPacketLen is variable but won't go beyond 22 bytes.
  2. this vector is working fine for 2000 record(44*2000)88000 bytes but when it goes beyond this it is crashing.I tested it for 5000 records it is crashing in the copy constructor when SetEventInfoList is called.

So the question is

  1. what is the maximum capacity of a vector that it can hold information in it.
  2. If vector doesn't support this much bytes then what STL container I should use for this.

Note:third party library is not allowed in my project,please suggest on pure c++ solution for this.

Upvotes: 1

Views: 4488

Answers (4)

NPE
NPE

Reputation: 500903

Your problem isn't the size of the vector (while there are practical limits, you're nowhere near them). It is most likely due to some bug in your code that gets exposed when you create more objects.

I would recommend examining the stack trace at the point of the crash, and perhaps adding it to your question. Another good strategy is to reduce your code to the absolute minimum that's needed to reproduce the problem and -- if that doesn't help you figure out the problem -- post the resulting code here.

Upvotes: 8

piotrek
piotrek

Reputation: 1363

Mayby try to use object pool patern http://sourcemaking.com/design_patterns/object_pool ?

Upvotes: 1

johnsyweb
johnsyweb

Reputation: 141988

Your std::vector contains a small number (5000) of pointers. This is very unlikely to be pushing any boundaries.

  1. There is no limit imposed by the container itself.
  2. n/a.

Sorry. Your bug is in another castle (I suspect in the one labelled m_pPacket).

Upvotes: 1

Xeo
Xeo

Reputation: 131897

Your elements in the vector will always be 4 / 8 bytes each, depending if you're on a 32bit or 64bit system because you're storing pointers. 2k records will lead to 8kb / 16kb memory used, so 5k will lead to 16kb / 32kb That shouldn't be a problem whatsoever (embedded systems not counted). There is most likely a bug somewhere in your code.

Upvotes: 7

Related Questions