C++ Buffer::committed方法代码示例

            /**
             * Tell the Collector that you are interested in this relation
             * and want it kept until all members have been assembled and
             * it is handed back to you.
             *
             * The relation is copied and stored in a buffer inside the
             * collector.
             */
            void add_relation(const osmium::Relation& relation) {
                const size_t offset = m_relations_buffer.committed();
                m_relations_buffer.add_item(relation);

                RelationMeta relation_meta(offset);

                int n = 0;
                for (auto& member : m_relations_buffer.get<osmium::Relation>(offset).members()) {
                    if (static_cast<TCollector*>(this)->keep_member(relation_meta, member)) {
                        member_meta(member.type()).emplace_back(member.ref(), m_relations.size(), n);
                        relation_meta.increment_need_members();
                    } else {
                        member.ref(0); // set member id to zero to indicate we are not interested
                    }
                    ++n;
                }

                assert(offset == m_relations_buffer.committed());
                if (relation_meta.has_all_members()) {
                    m_relations_buffer.rollback();
                } else {
                    m_relations_buffer.commit();
                    m_relations.push_back(std::move(relation_meta));
//                    std::cerr << "added relation id=" << relation.id() << "\n";
                }
            }

 /**
  * Decide whether to purge removed members and then do it.
  *
  * Currently the purging is done every thousand calls.
  * This could probably be improved upon.
  */
 void possibly_purge_removed_members() {
     ++m_count_complete;
     if (m_count_complete > 10000) { // XXX
         const size_t size_before = m_members_buffer.committed();
         m_members_buffer.purge_removed(this);
         const size_t size_after = m_members_buffer.committed();
         double percent = static_cast<double>(size_before - size_after);
         percent /= size_before;
         percent *= 100;
         std::cerr << "PURGE (size before=" << size_before << " after=" << size_after << " purged=" << (size_before - size_after) << " / " << static_cast<int>(percent) << "%)\n";
         m_count_complete = 0;
     }
 }

                void run() final {
                    osmium::thread::set_thread_name("_osmium_opl_in");

                    line_by_line(*this);

                    if (m_buffer.committed() > 0) {
                        send_to_output_queue(std::move(m_buffer));
                    }
                }

                void maybe_flush() {
                    if (m_buffer.committed() > 800*1024) {
                        osmium::memory::Buffer buffer{1024*1024};
                        using std::swap;
                        swap(m_buffer, buffer);
                        send_to_output_queue(std::move(buffer));

                    }
                }

 void possibly_flush_output_buffer() {
     if (m_output_buffer.committed() > max_buffer_size_for_flush) {
         flush_output_buffer();
     }
 }

    std::string fail_in;

    osmium::io::CompressionFactory::instance().register_compression(osmium::io::file_compression::gzip,
        [&](int, osmium::io::fsync) { return new MockCompressor(fail_in); },
        [](int) { return nullptr; },
        [](const char*, size_t) { return nullptr; }
    );

    osmium::io::Header header;
    header.set("generator", "test_writer_with_mock_compression.cpp");

    osmium::io::Reader reader{with_data_dir("t/io/data.osm")};
    osmium::memory::Buffer buffer = reader.read();
    REQUIRE(buffer);
    REQUIRE(buffer.committed() > 0);
    REQUIRE(buffer.select<osmium::OSMObject>().size() > 0);

    SECTION("fail on construction") {

        fail_in = "constructor";

        REQUIRE_THROWS_AS([&](){
            osmium::io::Writer writer("test-writer-mock-fail-on-construction.osm.gz", header, osmium::io::overwrite::allow);
            writer(std::move(buffer));
            writer.close();
        }(), const std::logic_error&);

    }

    SECTION("fail on write") {

            // XXX
            void operator()(const osmium::memory::Buffer& buffer) {
                osmium::io::detail::reliable_write(m_data_fd, buffer.data(), buffer.committed());

                osmium::apply(buffer.begin(), buffer.end(), *this);
            }

    osmium::memory::Buffer invalid_buffer2;
    osmium::memory::Buffer empty_buffer1{1024};
    osmium::memory::Buffer empty_buffer2{2048};

    REQUIRE_FALSE(invalid_buffer1);
    REQUIRE_FALSE(invalid_buffer2);
    REQUIRE(empty_buffer1);
    REQUIRE(empty_buffer2);

    REQUIRE(invalid_buffer1 == invalid_buffer2);
    REQUIRE(invalid_buffer1 != empty_buffer1);
    REQUIRE(empty_buffer1   != empty_buffer2);

    REQUIRE(invalid_buffer1.capacity()  == 0);
    REQUIRE(invalid_buffer1.written()   == 0);
    REQUIRE(invalid_buffer1.committed() == 0);
    REQUIRE(invalid_buffer1.clear() == 0);

    REQUIRE(empty_buffer1.capacity()  == 1024);
    REQUIRE(empty_buffer1.written()   ==    0);
    REQUIRE(empty_buffer1.committed() ==    0);
    REQUIRE(empty_buffer1.is_aligned());
    REQUIRE(empty_buffer1.clear() == 0);

    REQUIRE(empty_buffer2.capacity()  == 2048);
    REQUIRE(empty_buffer2.written()   ==    0);
    REQUIRE(empty_buffer2.committed() ==    0);
    REQUIRE(empty_buffer2.is_aligned());
    REQUIRE(empty_buffer2.clear() == 0);
}