Function ListSpans

src/brpc/span.cpp:983–1020

}

void ListSpans(int64_t starting_realtime, size_t max_scan,
               std::deque<BriefSpan>* out, SpanFilter* filter) {
    out->clear();
    butil::intrusive_ptr<SpanDB> db;
    if (GetSpanDB(&db) != 0) {
        return;
    }
    leveldb::Iterator* it = db->time_db->NewIterator(leveldb::ReadOptions());
    uint32_t time_data[2];
    ToBigEndian(starting_realtime, time_data);
    leveldb::Slice key((char*)time_data, sizeof(time_data));
    it->Seek(key);
    if (!it->Valid()) {
        it->SeekToLast();
    }
    BriefSpan brief;
    size_t nscan = 0;
    for (; nscan < max_scan && it->Valid(); it->Prev()) {
        const int64_t key_tm = ToLittleEndian((const uint32_t*)it->key().data());
        // May have some bigger time at the beginning, because leveldb returns
        // keys >= starting_realtime.
        if (key_tm > starting_realtime) {
            continue;
        }
        brief.Clear();
        if (brief.ParseFromArray(it->value().data(), it->value().size())) {
            if (NULL == filter || filter->Keep(brief)) {
                out->push_back(brief);
            }
            // We increase the count no matter filter passed or not to avoid
            // scaning too many entries.
            ++nscan;
        } else {
            LOG(ERROR) << "Fail to parse from value";
        }
    }
    delete it;
}

void DescribeSpanDB(std::ostream& os) {
    butil::intrusive_ptr<SpanDB> db;