ccan/ccan/jbitset/_info

#include <stdio.h>
#include <string.h>
#include "config.h"

/**
 * jbitset - variable-length bitset (based on libJudy)
 *
 * This provides a convenient wrapper for using Judy bitsets; using
 * integers or pointers as an index, Judy arrays provide an efficient
 * bit array or bit map of variable size.
 *
 * jbitset.h simply contains wrappers for a size_t-indexed bitset, and
 * jbitset_type.h contain a wrapper macro for pointer bitsets.
 *
 * Example:
 * // Simple analysis of one-byte mallocs.
 * #include <stdlib.h>
 * #include <stdio.h>
 * #include <err.h>
 * #include <ccan/jbitset/jbitset_type.h>
 * 
 * // Define jbit_char_<op> and jbitset_char, for char * bitset.
 * JBIT_DEFINE_TYPE(char, char);
 * 
 * int main(int argc, char *argv[])
 * {
 * 	unsigned int i, runs, reuse;
 * 	size_t mindist = -1;
 * 	struct jbitset_char *set = jbit_char_new();
 * 	char *p, *prev;
 * 
 * 	runs = (argc == 1 ? 1000 : atoi(argv[1]));
 * 	if (!runs)
 * 		errx(1, "Invalid number of allocations '%s'", argv[1]);
 * 
 * 	for (i = 0; i < runs; i++)
 * 		if (!jbit_char_set(set, malloc(1)))
 * 			errx(1, "same pointer allocated twice!");
 * 
 * 	// Calculate minimum distance
 * 	prev = jbit_char_first(set)+1;
 * 	for (p = jbit_char_first(set); p; prev = p, p = jbit_char_next(set,p))
 * 		if (p - prev < mindist)
 * 			mindist = p - prev;
 * 
 * 	// Free them all, see how many we reallocate.
 * 	for (p = jbit_char_first(set); p; p = jbit_char_next(set, p))
 * 		free(p);
 * 	for (reuse = 0, i = 0; i < runs; i++)
 * 		reuse += jbit_char_test(set, malloc(1));
 * 
 * 	printf("Allocation density (bytes): %zu\n"
 * 	       "Minimum inter-pointer distance: %zu\n"
 * 	       "Reuse rate: %.0f%%\n",
 * 	       (jbit_char_last(set) - jbit_char_first(set)) / runs,
 * 	       mindist,
 * 	       100.0 * reuse / runs);
 * 	return 0;
 * }
 *
 * License: LGPL (2 or any later version)
 * Author: Rusty Russell <rusty@rustcorp.com.au>
 */
int main(int argc, char *argv[])
{
	if (argc != 2)
		return 1;

	if (strcmp(argv[1], "depends") == 0) {
		printf("ccan/build_assert\n");
		printf("ccan/compiler\n");
		printf("Judy\n");
		return 0;
	}

	if (strcmp(argv[1], "libs") == 0) {
		printf("Judy\n");
		return 0;
	}

	return 1;
}