int main(int argc, char ** argv) {
if (argc<2) {
fprintf(stderr, "usage: wcc [path] [memory budget in GB]\n");
exit(-1);
}
std::string path = argv[1];
long memory_bytes = (argc>=3)?atol(argv[2])*1024l*1024l*1024l:8l*1024l*1024l*1024l;
Graph graph(path,atoi(argv[3]));
graph.set_memory_bytes(memory_bytes);
Bitmap * active_in = graph.alloc_bitmap();
Bitmap * active_out = graph.alloc_bitmap();
BigVector<VertexId> label(graph.path+"/label", graph.vertices);
graph.set_vertex_data_bytes( graph.vertices * sizeof(VertexId) );
active_out->fill();
VertexId active_vertices = graph.stream_vertices<VertexId>([&](VertexId i){
label[i] = i;
return 1;
});
double start_time = get_time();
int iteration = 0;
while (active_vertices!=0) {
iteration++;
printf("%7d: %d\n", iteration, active_vertices);
std::swap(active_in, active_out);
active_out->clear();
graph.hint(label);
active_vertices = graph.stream_edges<VertexId>([&](Edge & e){
if (label[e.source]<label[e.target]) {
if (write_min(&label[e.target], label[e.source])) {
active_out->set_bit(e.target);
return 1;
}
}
return 0;
}, active_in);
}
double end_time = get_time();
BigVector<VertexId> label_stat(graph.path+"/label_stat", graph.vertices);
label_stat.fill(0);
graph.stream_vertices<VertexId>([&](VertexId i){
write_add(&label_stat[label[i]], 1);
return 1;
});
VertexId components = graph.stream_vertices<VertexId>([&](VertexId i){
return label_stat[i]!=0;
});
printf("%d components found in %.2f seconds\n", components, end_time - start_time);
return 0;
}
static int merge_cont(int degree) {
/* Get the minimum of the top element of each buffer
Write it into ioBufs[degree], which is the buffer of output file
Refill with the next element of this buffer block
Until all the buffer block is empty. */
int ret = 0;
topElem = (GIT_T *)malloc(sizeof(GIT_T) * (degree + 1));
if (topElem == NULL) {
printf("Malloc memory for topElem failed.\n");
return -1;
}
memset(topElem, 0, sizeof(GIT_T) * (degree + 1));
// Initiate topElem[i] with the first record of each input file.
int i;
for (i = 0; i < degree ; i++) {
get_next_word(i);
}
int min = 0;
// If all files are done, min = -1.
while (min >= 0) {
// Get the order of buffer with minimum word_id
min = sort_curr(degree);
// Copy minimum to output buffer
ret = write_min(min, degree);
if (ret != 0) {
return -1;
}
// Update record of that buffer
get_next_word(min);
}
free(topElem);
return 0;
}