PeerStreamer

/*

 *  Copyright (c) 2010 Luca Abeni

 *  Copyright (c) 2010 Csaba Kiraly

 *

 *  This is free software; see lgpl-2.1.txt

 */

#include <stdlib.h>

#include <stdint.h>

#include <string.h>

#include <limits.h>

#include "peerset_private.h"

#include "peer.h"

#include "peerset.h"

#include "chunkidset.h"

#include "net_helper.h"

#include "config.h"

#define DEFAULT_SIZE_INCREMENT 32

struct nodeID;

struct peerset *peerset_init(const char *config)

{

  struct peerset *p;

  struct tag *cfg_tags;

  int res;

  p = malloc(sizeof(struct peerset));

  if (p == NULL) {

    return NULL;

  }

  p->n_elements = 0;

  cfg_tags = config_parse(config);

  if (!cfg_tags) {

    free(p);

    return NULL;

  }

  res = config_value_int(cfg_tags, "size", &p->size);

  if (!res) {

    p->size = 0;

  }

  free(cfg_tags);

  if (p->size) {

    p->elements = malloc(p->size * sizeof(struct peer));

  } else {

    p->elements = NULL;

  }

  return p;

}

static int peerset_check_insert_pos(const struct peerset *h, const struct nodeID *id);

int peerset_add_peer(struct peerset *h, struct nodeID *id)

{

  struct peer *e;

  int pos;

  pos = peerset_check_insert_pos(h, id);

  if (pos < 0){

    return 0;

  }

  if (h->n_elements == h->size) {

    int *res;

    res = realloc(h->elements, (h->size + DEFAULT_SIZE_INCREMENT) * sizeof(struct peer));

    if (res == NULL) {

      return -1;

    }

    h->size += DEFAULT_SIZE_INCREMENT;

    h->elements = (struct peer*) res;

  }

  memmove(&h->elements[pos + 1], &h->elements[pos] , ((h->n_elements++) - pos) * sizeof(struct peer));

  e = &(h->elements[pos]);

  e->id = nodeid_dup(id);

  gettimeofday(&e->creation_timestamp,NULL);

  e->bmap = chunkID_set_init("type=bitmap");

  timerclear(&e->bmap_timestamp);

  e->cb_size = INT_MAX;

  return h->n_elements;

}

void peerset_add_peers(struct peerset *h, struct nodeID **ids, int n)

{

  int i;

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

    peerset_add_peer(h, ids[i]);

  }

}

int peerset_size(const struct peerset *h)

{

  return h->n_elements;

}

struct peer* peerset_get_peers(const struct peerset *h)

{

  return h->elements;

}

struct peer *peerset_get_peer(const struct peerset *h, const struct nodeID *id)

{

  int i = peerset_check(h,id);

  return (i<0) ? NULL : &(h->elements[i]);

}

int peerset_remove_peer(struct peerset *h, const struct nodeID *id){

  int i = peerset_check(h,id);

  if (i >= 0) {

    struct peer *e = h->elements + i;

    nodeid_free(e->id);

    chunkID_set_free(e->bmap);

    memmove(e, e + 1, ((h->n_elements--) - (i+1)) * sizeof(struct peer));

    return i;

  }

  return -1;

}

static int nodeid_peer_cmp(const void *id, const void *peer)

{

  return nodeid_cmp( (const struct nodeID *) id, ((const struct peer *) peer)->id);

}

int peerset_check(const struct peerset *h, const struct nodeID *id)

{

  struct peer *p;

  p = bsearch(id, h->elements, (size_t) h->n_elements, sizeof(h->elements[0]), nodeid_peer_cmp);

  return p ? p - h->elements : -1;

}

static int peerset_check_insert_pos(const struct peerset *h, const struct nodeID *id)

{

  int a, b, c, r;

  if (! h->n_elements) {

    return 0;

  }

  a = 0;

  b = c = h->n_elements - 1;

  while ((r = nodeid_peer_cmp(id, &h->elements[b])) != 0) {

    if (r > 0) {

      if (b == c) {

        return b + 1;

      } else {

        a = b + 1;

      }

    } else {

      if (b == a) {

        return b;

      } else {

        c = b;

      }

    }

    b = (a + c) / 2;

  }

  return -1;

}

void peerset_clear(struct peerset *h, int size)

{

  int i;

  for (i = 0; i < h->n_elements; i++) {

    struct peer *e = h->elements + i;

    nodeid_free(e->id);

    chunkID_set_free(e->bmap);

  }

  h->n_elements = 0;

  h->size = size;

  h->elements = realloc(h->elements, size * sizeof(struct peer));

  if (h->elements == NULL) {

    h->size = 0;

  }

}