static void
sb__sort_within_major_buckets(
ms_elt_t **by_bucket_cursor, int major_bucket_count,
int* count_by_bucket, SV** dest)
{
int b, i;
for ( b=0 ; b<major_bucket_count ; b++ ) {
if (count_by_bucket[b]) {
if (count_by_bucket[b] > 1) {
ms_elt_t *bvals = by_bucket_cursor[b];
int blen = count_by_bucket[b];
int in_run =0, runstart =0;
U32 prev;
ms_do_mergesort(bvals, blen);
bvals -= blen-1;
/* Fall back to Perl's sort for runs that compared equal by
* both major and minor bucket. */
prev = bvals[0].mse_key;
*dest++ = bvals[0].mse_sv;
for ( i=1 ; i<blen ; i++ ) {
*dest++ = bvals[i].mse_sv;
if (in_run) {
if (bvals[i].mse_key != prev) {
/* End of the run, sort it in dest */
sortsv((dest-1)-(i-runstart), i-runstart, Perl_sv_cmp);
in_run = 0;
prev = bvals[i].mse_key;
}
} else {
if (bvals[i].mse_key == prev) {
/* The start of a new run */
in_run = 1;
runstart = i-1;
} else {
prev = bvals[i].mse_key;
}
}
}
if (in_run) {
/* This bucket ends on a run. */
sortsv(dest-(i-runstart), i-runstart, Perl_sv_cmp);
}
} else {
*dest++ = by_bucket_cursor[b][0].mse_sv;
}
}
}
}
/* Run a query and return a list of ranked results.
* Call this from Perl like `$index->fetch(['water', 'jar'])`. The result
* will be an arrayref, with each entry of it being an arrayref of the form
* [id, rank]. They will be sorted by their rank in descending order, so the
* most relevant document will be at the top. */
SV* fetch(SV* tokens) const
{
AV* av = reinterpret_cast<AV*>(SvRV(tokens));
std::unordered_map<std::string, int> query;
for (int i = 0; i <= av_top_index(av); ++i)
{
std::string token = string_from_sv(*av_fetch(av, i, 0));
++query[token];
}
AV* results = newAV();
for (const auto& id2rank : search(query))
{
AV* entry = newAV();
double length = lengths.find(id2rank.first)->second;
av_push(entry, newSViv(id2rank.first));
av_push(entry, newSVnv(id2rank.second / length));
av_push(results, newRV_noinc(reinterpret_cast<SV*>(entry)));
}
sortsv(AvARRAY(results), av_top_index(results) + 1, sort_ratings);
return newRV_noinc(reinterpret_cast<SV*>(results));
}
