PeerStreamer

/*

 *  Copyright (c) 2010 Csaba Kiraly

 *  Copyright (c) 2010 Luca Abeni

 *

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

 */

#include <stdint.h>

#include <stdio.h>

#include <sys/time.h>

#include <time.h>

#include <stdlib.h>

#include <math.h>

#include <net_helper.h>

#include <peerset.h>

#include <peer.h>

#include <grapes_msg_types.h>

#include <topmanager.h>

#include <tman.h>

#include "compatibility/timer.h"

#include "topology.h"

#include "streaming.h"

#include "dbg.h"

#include "measures.h"

#include "streamer.h"

double desired_rtt = 0.2;

double alpha_target = 0.5;

int NEIGHBORHOOD_TARGET_SIZE = 20;

double NEIGHBORHOOD_ROTATE_RATIO = 1.0;

#define TMAN_MAX_IDLE 10

#define TMAN_LOG_EVERY 1000

static struct peerset *pset;

static struct timeval tout_bmap = {10, 0};

static int counter = 0;

static int simpleRanker (const void *tin, const void *p1in, const void *p2in);

static tmanRankingFunction rankFunct = simpleRanker;

struct metadata {

  uint16_t cb_size;

  uint16_t cps;

  float recv_delay;

};

static struct metadata my_metadata;

static int cnt = 0;

static struct nodeID *me = NULL;

static unsigned char mTypes[] = {MSG_TYPE_TOPOLOGY,MSG_TYPE_TMAN};

static struct nodeID ** neighbors;

static void update_metadata(void) {

        my_metadata.cb_size = am_i_source() ? 0 : get_cb_size();

        my_metadata.recv_delay = get_receive_delay();

        my_metadata.cps = get_chunks_per_sec();

}

static int simpleRanker (const void *tin, const void *p1in, const void *p2in) {

        double t,p1,p2;

        t = *((const double *)tin);

        p1 = *((const double *)p1in);

        p2 = *((const double *)p2in);

        if (isnan(t) || (isnan(p1) && isnan(p2))) return 0;

        else if (isnan(p1)) return 2;

        else if (isnan(p2)) return 1;

        else return (fabs(t-p1) == fabs(t-p2))?0:(fabs(t-p1) < fabs(t-p2))?1:2;

}

int topologyInit(struct nodeID *myID, const char *config)

{

        int i;

        for (i=0;i<2;i++)

                bind_msg_type(mTypes[i]);

        update_metadata();

        me = myID;

        return (topInit(myID, &my_metadata, sizeof(my_metadata), config) && tmanInit(myID,&my_metadata, sizeof(my_metadata),rankFunct,0));

}

void topologyShutdown(void)

{

}

int topoAddNeighbour(struct nodeID *neighbour, void *metadata, int metadata_size)

{

        // TODO: check this!! Just to use this function to bootstrap ncast...

        struct metadata m = {0};        //TODO: check what metadata option should mean

        if (counter < TMAN_MAX_IDLE)

                return topAddNeighbour(neighbour,&m,sizeof(m));

        else return tmanAddNeighbour(neighbour,&m,sizeof(m));

}

static int topoParseData(const uint8_t *buff, int len)

{

        int res = -1,ncs = 0,msize;

        const struct nodeID **n; const void *m;

        if (!buff || buff[0] == MSG_TYPE_TOPOLOGY) {

                res = topParseData(buff,len);

//                if (counter <= TMAN_MAX_IDLE)

//                        counter++;

        }

        if (counter >= TMAN_MAX_IDLE && (!buff || buff[0] == MSG_TYPE_TMAN))

        {

                n = topGetNeighbourhood(&ncs);

                if (ncs) {

                m = topGetMetadata(&msize);

                res = tmanParseData(buff,len,n,ncs,m,msize);

                }

        }

  return res;

}

static const struct nodeID **topoGetNeighbourhood(int *n)

{

        int i; double d;

        if (counter > TMAN_MAX_IDLE) {

                uint8_t *mdata; int msize;

                *n = tmanGetNeighbourhoodSize();

                if (neighbors) free(neighbors);

                neighbors = calloc(*n,sizeof(struct nodeID *));

                tmanGetMetadata(&msize);

                mdata = calloc(*n,msize);

                tmanGivePeers(*n,neighbors,(void *)mdata);

                if (cnt % TMAN_LOG_EVERY == 0) {

                        fprintf(stderr,"abouttopublish,%s,%s,,Tman_chunk_delay,%f\n",node_addr(me),node_addr(me),my_metadata.recv_delay);

                        for (i=0;i<(*n) && i<NEIGHBORHOOD_TARGET_SIZE;i++) {

                                d = *((double *)(mdata+i*msize));

                                fprintf(stderr,"abouttopublish,%s,",node_addr(me));

                                fprintf(stderr,"%s,,Tman_chunk_delay,%f\n",node_addr(neighbors[i]),d);

                        }

                        fprintf(stderr,"abouttopublish,%s,%s,,Tman_neighborhood_size,%d\n\n",node_addr(me),node_addr(me),*n);

                }

                free(mdata);

                return (const struct nodeID **)neighbors;

        }

        else

                return topGetNeighbourhood(n);

}

static void topoAddToBL (struct nodeID *id)

{

        if (counter >= TMAN_MAX_IDLE)

                tmanAddToBlackList(id);

//        else

                topAddToBlackList(id);

}

void add_peer(const struct nodeID *id, const struct metadata *m)

{

      dprintf("Adding %s to neighbourhood! cb_size:%d\n", node_addr(id), m?m->cb_size:-1);

      peerset_add_peer(pset, id);

      if (m) peerset_get_peer(pset, id)->cb_size = m->cb_size;

      /* add measures here */

      add_measures(id);

      send_bmap(id);

}

void remove_peer(struct nodeID *id)

{

      dprintf("Removing %s from neighbourhood!\n", node_addr(id));

      /* add measures here */

      delete_measures(id);

      peerset_remove_peer(pset, id);

}

//get the rtt. Currenly only MONL version is supported

static double get_rtt_of(struct nodeID* n){

#ifdef MONL

  double rtt = get_rtt(n);

#else

  return NAN;

#endif

}

//returns: 1:yes 0:no -1:unknown

int is_desired(struct nodeID* n) {

  double rtt = get_rtt_of(n);

  return isnan(rtt) ? -1 : ((rtt <= desired_rtt) ? 1 : 0);

}

// currently it just makes the peerset grow

void update_peers(struct nodeID *from, const uint8_t *buff, int len)

{

  int n_ids, metasize, i;

  static const struct nodeID **ids;

  static const struct metadata *metas;

  struct peer *peers;

  struct timeval tnow, told;

//  dprintf("Update peers: topo_msg:%d, ",len);

//  if (from) {

//    dprintf("from:%s, ",node_addr(from));

//    if (peerset_check(pset, from) < 0) {

//      topAddNeighbour(from, NULL, 0);        //@TODO: this is agressive

//      if (!NEIGHBORHOOD_TARGET_SIZE || peerset_size(pset) < NEIGHBORHOOD_TARGET_SIZE) {

//        add_peer(from);

//      }

//    }

//  }

  if (cnt++ % 100 == 0) {

        update_metadata();

    if (counter > TMAN_MAX_IDLE) {

        tmanChangeMetadata(&my_metadata,sizeof(my_metadata));

    }

  }

  topoParseData(buff, len);

  if (!buff) {

    reg_neigh_size(peerset_size(pset));

    return;

  }

  fprintf(stderr,"Topo modify start\n");

  peers = peerset_get_peers(pset);

  for (i = 0; i < peerset_size(pset); i++) {

    fprintf(stderr," %s - RTT: %f\n", node_addr(peers[i].id) , get_rtt_of(peers[i].id));

  }

  ids = topoGetNeighbourhood(&n_ids);        //TODO handle both tman and topo

  metas = topGetMetadata(&metasize);        //TODO: check metasize

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

    if(peerset_check(pset, ids[i]) < 0) {

      if (!NEIGHBORHOOD_TARGET_SIZE || peerset_size(pset) < NEIGHBORHOOD_TARGET_SIZE) {

        add_peer(ids[i],&metas[i]);

      } else {  //rotate neighbourhood

        if (rand()/((double)RAND_MAX + 1) < NEIGHBORHOOD_ROTATE_RATIO) {

          add_peer(ids[i],&metas[i]);

        }

      }

    }

  }

  if timerisset(&tout_bmap) {

    gettimeofday(&tnow, NULL);

    timersub(&tnow, &tout_bmap, &told);

    peers = peerset_get_peers(pset);

    for (i = 0; i < peerset_size(pset); i++) {

      if ( (!timerisset(&peers[i].bmap_timestamp) && timercmp(&peers[i].creation_timestamp, &told, <) ) ||

           ( timerisset(&peers[i].bmap_timestamp) && timercmp(&peers[i].bmap_timestamp, &told, <)     )   ) {

        //if (peerset_size(pset) > 1) {        // avoid dropping our last link to the world

        topoAddToBL(peers[i].id);

        remove_peer(peers[i--].id);

        //}

      }

    }

  }

  n_ids = peerset_size(pset);

  fprintf(stderr,"Topo remove start (peers:%d)\n", n_ids);

  while (NEIGHBORHOOD_TARGET_SIZE && peerset_size(pset) > NEIGHBORHOOD_TARGET_SIZE) { //reduce back neighbourhood to target size

    int n, desired, desired_not, desired_unknown;

    struct peer *ds[n_ids], *dns[n_ids], *dus[n_ids];

    double alpha;

    peers = peerset_get_peers(pset);

    n = peerset_size(pset);

    desired = desired_not = desired_unknown = 0;

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

      switch (is_desired(peers[i].id)) {

        case 1:

          ds[desired++] = &peers[i];

          break;

        case 0:

          dns[desired_not++] = &peers[i];

          break;

        case -1:

          dus[desired_unknown++] = &peers[i];

          break;

        default:

          fprintf(stderr,"error with desiredness!\n");

          exit(1);

      }

    }

    alpha = (double) desired / n;

    fprintf(stderr," peers:%d desired:%d unknown:%d notdesired:%d alpha: %f (target:%f)\n",n, desired, desired_unknown, desired_not, alpha, alpha_target);

    if (alpha > alpha_target && desired > 0) {

      remove_peer(ds[rand() % desired]->id);

    } else if (alpha < alpha_target && desired_not > 0) {

      remove_peer(dns[rand() % desired_not]->id);

    } else if (desired_unknown > 0) {

      remove_peer(dus[rand() % desired_unknown]->id);

    } else {

      remove_peer(peers[rand() % n].id);

    }

  }

  fprintf(stderr,"Topo remove end\n");

  reg_neigh_size(peerset_size(pset));

}

struct peer *nodeid_to_peer(const struct nodeID* id, int reg)

{

  struct peer *p = peerset_get_peer(pset, id);

  if (!p) {

    //fprintf(stderr,"warning: received message from unknown peer: %s!%s\n",node_addr(id), reg ? " Adding it to pset." : "");

    if (reg) {

      add_peer(id,NULL);

      p = peerset_get_peer(pset,id);

    }

  }

  return p;

}

int peers_init(void)

{

  fprintf(stderr,"peers_init\n");

  pset = peerset_init(0);

  return pset ? 1 : 0;

}

struct peerset *get_peers(void)

{

  return pset;

}