Method Call Interception

Listing 1

(a)

#ifndef MCI_H
#define MCI_H

#include <string>
#include "MethodAnalyzer.h"

struct IMciEvents;

class Mci  
{
public:
    Mci(const std::string & filename, int lineNumber, std::string line);
    ~Mci();
    static IMciEvents * & GetSink();
    static void Register(IMciEvents * pSink);
private:
    std::string GetLine(const std::string & filename, int lineNumber);
private:
    std::string     m_filename;
    int             m_lineNumber;   
    MethodInfo      m_methodInfo;
};
#endif // !defined(__MCI_H__)

(b)

#include "Mci.h"
#include "IMciEvents.h"
#include "MethodAnalyzer.h"
#include <fstream>

using std::string;
using std::ifstream;

Mci::Mci(const string & filename, int lineNumber, string line) :
        m_filename(filename),
        m_lineNumber(lineNumber)
{
    if (!GetSink())
        return;
    if (line.empty())
        line = GetLine(filename, lineNumber-2);
    m_methodInfo = MethodAnalyzer::Analyze(line);
    // verify corectness of class name using typeinfo
    GetSink()->OnEnter(m_filename, m_lineNumber, m_methodInfo);
}
Mci::~Mci()
{
    if (!GetSink())
        return;

    GetSink()->OnLeave(m_filename, m_lineNumber, m_methodInfo);
}
IMciEvents * & Mci::GetSink() 
{ 
    static IMciEvents * pSink = 0; 
    return pSink; 
}
void Mci::Register(IMciEvents * pSink) 
{ 
    GetSink() = pSink; 
}
string Mci::GetLine(const string & filename, int lineNumber)
{
    ifstream f;
    f.open(filename.c_str());
    const int BUFF_SIZE = 1024;
    char buff[BUFF_SIZE];
    for (int i = 0; i < lineNumber; i++)
        f.getline(buff, BUFF_SIZE);
    return string(buff);
}