#include "pstringfactory.h"

PstringFactory *  PstringFactory::ourFactory = 0;

PstringFactory::PstringFactory()
{
    // nothing to do here
}

void PstringFactory::reportStorage()
// post: report on all storage used    
{
    long storage=0;
    IT it;

    for(it=myStorage.begin(); it != myStorage.end(); it++)
    {
	storage += sizeof(*it) + string(*it).length()*sizeof(char);
    }
    cout << "total entries = " << myStorage.size() << endl;
    cout << "total storage = " << storage << endl;
}

PstringFactory * PstringFactory::getInstance()
// create one factory for entire program
// post: return pointer to a factory    
{
    if (ourFactory == 0)
    {
	ourFactory = new PstringFactory();
    }
    return ourFactory;
}

Pstring PstringFactory::getString(const string& s)
// post: return Pstring equivalent to s
//       internally stores s once in a Pstring and looks
//       s up to see if it's there already    
{
    IT it;
    Pstring lookup(&s);              // need this to search for s
    it = myStorage.find(lookup);     // already seen?
    if (it == myStorage.end())       // no, store and return 
    {
	Pstring ps = Pstring(new string(s));
	myStorage.insert(ps);
	return ps;
    }
    else                             // already seen string, return 
    {
	return *it;
    }
}