fmake.c

// fmake.cpp : This file contains the 'main' function. Program execution begins and ends there.
//
#ifndef _CRT_SECURE_NO_DEPRECATE
#define _CRT_SECURE_NO_DEPRECATE 1
#endif // !_CRT_SECURE_NO_DEPRECATE - fopen and friends 

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <ctime>
#include <cstdint>



#define KBYES (1024)
#define MBYTES (1024 * 1024)
#define MAYBE_UNUSED (void)
#define MAX_RND_BYTES 4096
#define MAX_RND_GEN 4


extern uint8_t** get_randbf(size_t size);

int main(int argc, char** argv)
{
	if (argc < 5) {
		fprintf(stderr, "Use -n <num files> -m <size per file>\r\n");
	}

	size_t i=0, fsize=0, fcount=0, fidx=0, rndidx=0;
	char filename[64];
	static const char FILE_AUX_NAME[][64] = { "small", "medium", "big" };
	
	srand(time(0x00));

	for (i = 1; i < argc; i++) {
		if (!strcmp(argv[i], "-n")) {
			fcount = atoi(argv[i + 1]);
		}
		if (!strcmp(argv[i], "-m")) {
			fsize = atoi(argv[i + 1]);
			fsize *= (MBYTES);		}
	}
	if (fsize < 20 * MBYTES) {
		fidx = 0;
	}
	else if (fsize > 1000 * MBYTES) {
		fidx = 2;
	}
	else {
		fidx = 1;
	}
	uint8_t** buffrnd = get_randbf(MAX_RND_GEN);

	clock_t begin = clock();
	
	for (i = 0; i < fcount; i++) {
		snprintf(filename, sizeof(filename), "%d_%s.file", (int)i, FILE_AUX_NAME[fidx]);
		FILE* fp = fopen(filename, "wb");
		size_t j = 0;
//		unsigned char buffrnd[4][MAX_RND_BYTES] = { 0 };

		for (j = 0; j < 4; j++) {
			for (rndidx=0; rndidx < MAX_RND_BYTES / 8 ; ) {
				buffrnd[j][rndidx++] = (unsigned char)(rand() % 0xff);
				buffrnd[j][rndidx++] = (unsigned char)(rand() % 0xff);
				buffrnd[j][rndidx++] = (unsigned char)(rand() % 0xff);			
				buffrnd[j][rndidx++] = (unsigned char)(rand() % 0xff);
				buffrnd[j][rndidx++] = (unsigned char)(rand() % 0xff);
				buffrnd[j][rndidx++] = (unsigned char)(rand() % 0xff);				
				buffrnd[j][rndidx++] = (unsigned char)(rand() % 0xff);
				buffrnd[j][rndidx++] = (unsigned char)(rand() % 0xff);
			}
		}
		for (j = 0; j < fsize; ) {
			j += fwrite(buffrnd[rndidx++ & MAX_RND_GEN], sizeof(unsigned char), MAX_RND_BYTES, fp);
			j += fwrite(buffrnd[rndidx++ & MAX_RND_GEN], sizeof(unsigned char), MAX_RND_BYTES, fp);
			j += fwrite(buffrnd[rndidx++ & MAX_RND_GEN], sizeof(unsigned char), MAX_RND_BYTES, fp);
			j += fwrite(buffrnd[rndidx++ & MAX_RND_GEN], sizeof(unsigned char), MAX_RND_BYTES, fp);
		}
		fclose(fp);
		fp = 0x00;
	}

	clock_t end = clock();
	double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
	fprintf(stdout, "Time elasped %f\r\n", time_spent);

	for (i = 0; i < MAX_RND_GEN; i++) {
		unsigned char* it = buffrnd[i];
		if (it)
			free(it);
	}
	free(buffrnd);
	
	return 0;
}

uint8_t** get_randbf(size_t size)
{
	uint8_t** buffrnd = 0;
	size_t i;
	buffrnd = (uint8_t**) malloc(sizeof(uint8_t*) * size);
	if (!buffrnd) 
		return 0;

	for (i = 0; i < size; i++) {
		buffrnd[i] = (uint8_t*) malloc(sizeof(uint8_t) * MAX_RND_BYTES);
		if (!buffrnd[i]) {
			size_t j = 0;
			while (buffrnd[j]) {
				free(buffrnd[j]);
				buffrnd[j++] = 0;
			}
			free(buffrnd);
			buffrnd = 0;
			break;
		}
	}
	return buffrnd;
}



// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

// Tips for Getting Started: 
//   1. Use the Solution Explorer window to add/manage files
//   2. Use the Team Explorer window to connect to source control
//   3. Use the Output window to see build output and other messages
//   4. Use the Error List window to view errors
//   5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
//   6. In the future, to open this project again, go to File > Open > Project and select the .sln file

Generates n files of m size for Win32
fmake -n <file count> -m <file size>