PeerStreamer

/*

 *  Copyright (c) 2010 Luca Abeni

 *  Copyright (c) 2010 Csaba Kiraly

 *

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

 */

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <stdint.h>

#include "chunklock.h"

#include "net_helper.h"

static struct timeval toutdiff = {0, 300000};

struct lock {

  int chunkid;

  struct nodeID *peer;

  struct timeval timestamp;

};

struct lock *locks;

static size_t lsize, lcount=0;

#define LSIZE_INCREMENT 10

void locks_init()

{

  if (!locks) {

    lsize = LSIZE_INCREMENT;

    locks = malloc(sizeof(struct lock) * lsize);

    lcount = 0;

  }

  if (lcount == lsize) {

    lsize += LSIZE_INCREMENT;

    locks = realloc(locks , sizeof(struct lock) * lsize);

  }

  if (!locks) {

    fprintf(stderr, "Error allocating memory for locks!\n");

    exit(EXIT_FAILURE);

  }

}

int chunk_lock_timed_out(struct lock *l)

{

  struct timeval tnow,tout;

  gettimeofday(&tnow, NULL);

  timeradd(&l->timestamp, &toutdiff, &tout);

  return timercmp(&tnow, &tout, >);

}

void chunk_lock_remove(struct lock *l){

  nodeID_free(l->peer);

  memmove(l, l+1, sizeof(struct lock) * (locks+lcount-l-1));

  lcount--;

}

void chunk_locks_cleanup(){

  int i;

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

    if (chunk_lock_timed_out(locks+i)) {

      chunk_lock_remove(locks+i);

    }

  }

}

void chunk_lock(int chunkid,struct peer *from){

  locks_init();

  locks[lcount].chunkid = chunkid;

  locks[lcount].peer = nodeid_dup(from->id);

  gettimeofday(&locks[lcount].timestamp,NULL);

  lcount++;

}

void chunk_unlock(int chunkid){

  int i;

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

    if (locks[i].chunkid == chunkid) {

      chunk_lock_remove(locks+i);

      break;

    }

  }

}

int chunk_islocked(int chunkid){

  int i;

  chunk_locks_cleanup();

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

    if (locks[i].chunkid == chunkid) {

      return 1;

    }

  }

  return 0;

}