Need a more eficient way to parse a obj file

bool cObjModel::Parse()
{
	string buffer, keyword;
	Vertex v;
	TextCoord t;
	char c;

	while (m_file.good() && (m_file >> keyword))
	{
		if (keyword == "#" || keyword == "g")		// comment TODO: for now we're also not parsing 'g' operations 
		{				
			ParseComment();		
		}

		else if (keyword == "v")		// vertex data
		{
			m_file >> v.x >> v.y >> v.z;
			AddVertex(v);
		}
		else if(keyword == "vt")	// texture data 
		{
			m_file >> t.x >> t.y >> t.z;
			AddTextCoord(t);
		}
		else if(keyword == "vn")	// vertex normal
		{
			m_file >> v.x >> v.y >> v.z;
			AddNormal(v);
		}
		else if (keyword == "f")	//polygon face
		{
			PolygonFace face;

			int i = 0;
			int vIndex, tIndex, nIndex;
			char c;

			getline(m_file, buffer);
			stringstream line(buffer);

			while(line.good())
			{
				// if doesn't have texture coordinates and normal info
				if (m_textCoordData.size() == 0 && m_normalData.size() == 0)
				{
					line >> vIndex;

					face.m_vertexIndexes.push_back(vIndex - 1);
				}
				else if(m_textCoordData.size() == 0)
				{
					line >> vIndex >> c >> c >> nIndex;

					face.m_vertexIndexes.push_back(vIndex - 1);
					face.m_normalIndexes.push_back(nIndex - 1);
				}
				else if(m_normalData.size() == 0)
				{
					line >> vIndex >> c >> tIndex;

					face.m_vertexIndexes.push_back(vIndex - 1);
					face.m_textCoordsIndexes.push_back(tIndex - 1);
				}
				else
				{

					line >> vIndex >> c >> tIndex >> c >>  nIndex;

					face.m_vertexIndexes.push_back(vIndex - 1);
					face.m_textCoordsIndexes.push_back(tIndex - 1);
					face.m_normalIndexes.push_back(nIndex - 1);
				}

			}

			if (!line.good()) 
			{
				face.m_vertexIndexes.pop_back();
				face.m_textCoordsIndexes.pop_back();
				face.m_textCoordsIndexes.pop_back();
			}
			m_faceData.push_back(face);
		}
		else
			ParseComment();	// skip line
	}

	m_file.close();
	return true;
}