/**
* Grab pivot's adjacency list into memory.
*/
int grab_adj(graphchi_vertex<uint32_t, uint32_t> &v) {
if(is_pivot(v.id())) {
int ncount = v.num_edges();
// Count how many neighbors have larger id than v
v.sort_edges_indirect();
int actcount = 0;
vid_t lastvid = 0;
for(int i=0; i<ncount; i++) {
if (v.edge(i)->vertexid > v.id() && v.edge(i)->vertexid != lastvid)
actcount++; // Need to store only ids larger than me
lastvid = v.edge(i)->vertex_id();
}
// Allocate the in-memory adjacency list, using the
// knowledge of the number of edges.
dense_adj dadj = dense_adj(actcount, (vid_t*) calloc(sizeof(vid_t), actcount));
actcount = 0;
lastvid = 0;
for(int i=0; i<ncount; i++) {
if (v.edge(i)->vertexid > v.id() && v.edge(i)->vertexid != lastvid) { // Need to store only ids larger than me
dadj.adjlist[actcount++] = v.edge(i)->vertex_id();
}
lastvid = v.edge(i)->vertex_id();
}
assert(dadj.count == actcount);
adjs[v.id() - pivot_st] = dadj;
assert(v.id() - pivot_st < adjs.size());
__sync_add_and_fetch(&grabbed_edges, actcount);
return actcount;
}
return 0;
}
/**
* Vertex update function.
*/
void update(graphchi_vertex<VertexDataType, EdgeDataType> &v, graphchi_context &gcontext) {
if (gcontext.iteration % 2 == 0) {
adjcontainer->grab_adj(v);
} else {
uint32_t oldcount = v.get_data();
uint32_t newcounts = 0;
v.sort_edges_indirect();
vid_t lastvid = 0;
/**
* Iterate through the edges, and if an edge is from a
* pivot vertex, compute intersection of the relevant
* adjacency lists.
*/
for(int i=0; i<v.num_edges(); i++) {
graphchi_edge<uint32_t> * e = v.edge(i);
if (e->vertexid > v.id() && e->vertexid >= adjcontainer->pivot_st) {
assert(!is_deleted_edge_value(e->get_data()));
if (e->vertexid != lastvid) { // Handles reciprocal edges (a->b, b<-a)
if (adjcontainer->is_pivot(e->vertexid)) {
uint32_t pivot_triangle_count = adjcontainer->intersection_size(v, e->vertexid, i);
newcounts += pivot_triangle_count;
/* Write the number of triangles into edge between this vertex and pivot */
if (pivot_triangle_count == 0 && e->get_data() == 0) {
/* ... or remove the edge, if the count is zero. */
v.remove_edge(i);
} else {
e->set_data(e->get_data() + pivot_triangle_count);
}
} else {
break;
}
}
lastvid = e->vertexid;
}
assert(newcounts >= 0);
}
if (newcounts > 0) {
v.set_data(oldcount + newcounts);
}
}
/* Collect triangle counts matched by vertices with id lower than
his one, and delete */
if (gcontext.iteration % 2 == 0) {
int newcounts = 0;
for(int i=0; i < v.num_edges(); i++) {
graphchi_edge<uint32_t> * e = v.edge(i);
if (e->vertexid < v.id()) {
newcounts += e->get_data();
e->set_data(0);
// This edge can be now deleted. Is there some other situations we can delete?
if (v.id() < adjcontainer->pivot_st && e->vertexid < adjcontainer->pivot_st) {
v.remove_edge(i);
}
}
}
v.set_data(v.get_data() + newcounts);
}
}
