PeerStreamer

/*

 *  Copyright (c) 2010 Csaba Kiraly

 *  Copyright (c) 2010 Luca Abeni

 *

 *  This is free software; see gpl-3.0.txt

 */

#include <string.h>

#include <stdlib.h>

#include <stdint.h>

#include <net_helper.h>

#include "nodeid_set.h"

#define MIN(A,B) (((A) < (B)) ? (A) : (B))

// The usual shuffle

void shuffle(void *base, size_t nmemb, size_t size) {

  int i;

  unsigned char t[size];

  unsigned char* b = base;

  for (i = nmemb - 1; i > 0; i--) {

    int newpos = (rand()/(RAND_MAX + 1.0)) * (i + 1);

    memcpy(t, b + size * newpos, size);

    memmove(b + size * newpos, b + size * i, size);

    memcpy(b + size * i, t, size);

  }

}

void nidset_shuffle(const struct nodeID **base, size_t nmemb) {

  shuffle(base, nmemb, sizeof(struct nodeID *));

}

int nidset_filter(const struct nodeID **dst, size_t *dst_size, const struct nodeID **src, size_t src_size, bool(*f)(const struct nodeID *)) {

  size_t i;

  size_t max_size = *dst_size;

  *dst_size = 0;

  for (i = 0; i < src_size; i++) {

    if (f(src[i])) {

      if (*dst_size < max_size) {

        dst[(*dst_size)++] = src[i];

      } else {

        return -1;

      }

    }

  }

  return 0;

}

// B \ A

int nidset_complement(const struct nodeID **dst, size_t *dst_size, const struct nodeID **bs, size_t bs_size, const struct nodeID **as, size_t as_size) {

  size_t i, j;

  size_t max_size = *dst_size;

  *dst_size = 0;

  for (i = 0; i < bs_size; i++) {

    for (j = 0; j < as_size; j++) {

      if (nodeid_equal(bs[i], as[j])) {

        break;

      }

    }

    if (j >= as_size) {

      if (*dst_size < max_size) {

        dst[(*dst_size)++] = bs[i];

      } else {

        return -1;

      }

    }

  }

  return 0;

}

bool nidset_find(size_t *i, const struct nodeID **ids, size_t ids_size, const struct nodeID *id) {

  for (*i = 0; *i < ids_size; (*i)++) {

    if (nodeid_equal(ids[*i],id)) {

      return true;

    }

  }

  return false;

}

int nidset_add(const struct nodeID **dst, size_t *dst_size, const struct nodeID **as, size_t as_size, const struct nodeID **bs, size_t bs_size) {

  int r;

  size_t i;

  size_t max_size = *dst_size;

  i = MIN(as_size, max_size);

  memcpy(dst, as, i * sizeof(struct nodeID*));

  *dst_size = i;

  if (i < as_size) return -1;

  max_size -= *dst_size;

  r = nidset_complement(dst + *dst_size, &max_size, bs, bs_size, as, as_size);

  *dst_size += max_size;

  return r;

}

int nidset_add_i(const struct nodeID **dst, size_t *dst_size, size_t max_size, const struct nodeID **as, size_t as_size) {

  int r;

  max_size -= *dst_size;

  r = nidset_complement(dst + *dst_size, &max_size, as, as_size, dst, *dst_size);

  *dst_size += max_size;

  return r;

}