markscottwright / faker

Faker for C++

Introduction

This is a C++ implementation of a large subset of the Perl::Fake module. Strings were stolen from that module, and the implementation is modeled on it.

Building

It is a header-only implementation, so you should be able to just #include it in your project.

Extending

New faker types can be created via sub-classing fakerbase. then creating an appropriately named function on faker or usafaker (I broke them into two in case I every want to create locale-aware fake demographic data) that returns a fakerp to your new class.

You may find that a combination of faker::series, faker::oneof, faker::digit, faker::template and faker::str a sufficient for your needs without creating a fakerbase-derived class.

Rationale

Perl and python both have nice, feature-laden libraries for generating fake demographic data. I first tried using the python module faker - but I wanted a million or so rows of data and faker was slow. It took around 20 minutes to generate those million rows. Mod::Fake was a little better, but still slow enough that generating large amounts of data was painful.

My C++ faker is around 30 times faster than python's faker - fast enough that 1,000,000 rows only takes a few minutes on my dual core i7 laptop.

To compare, here are two functionally equivalent CSV data generators (source below)::

$ time python mkdata.py 10000 > t
real    0m53.317s
user    0m47.890s
sys     0m5.358s

$ time ./mkdata.exe 10000 > t
real    0m2.192s
user    0m2.156s
sys     0m0.046s

Here's mkdata.py::

import sys

n = 1
base = 0

if len(sys.argv) > 1:
    n = int(sys.argv[1])
if len(sys.argv) > 2:
    base = int(sys.argv[2])
    
fake = Factory.create()
for i in range(n):
    print "|".join([
        str(i+base),
        fake.user_name(),
        fake.email(),
        fake.name(),
        fake.ssn(),
        fake.phone_number(),
        fake.date(),
        fake.street_address(),
        fake.city(),
        fake.state_abbr(),
        fake.zipcode()])
    if i % 100 == 0:
        sys.stderr.write(str(i))
        sys.stderr.write("\r")

And mkdata.cpp::

#include <iostream>
#include "faker.h"

int main(int argc, char* argv[])
{
    using namespace std;
    faker::usafaker f;

    int n=1;
    int base=0;

    if (argc > 1)
        n = atoi(argv[1]);
    if (argc > 2)
        base = atoi(argv[2]);
    
    for (int i=0; i < n; ++i) {
        cout << i+base
            << "|" << f.username()
            << "|" << f.email()
            << "|" << f.name()
            << "|" << f.ssn()
            << "|" << f.phone_number()
            << "|" << f.date()
            << "|" << f.street_address()
            << "|" << f.city()
            << "|" << f.state_abbr()
            << "|" << f.zipcode()
            << endl;
        if (i % 100 == 0)
            cerr << i << "\r";
    }

    return 0;
}