Method GetEventDataWithCount

PresentData/TraceConsumer.cpp:207–266

}

uint32_t EventMetadata::GetEventDataWithCount(EVENT_RECORD* eventRecord, EventDataDesc* desc, uint32_t descCount)
{
    // Look up stored metadata.  If not found, look up metadata using TDH and
    // cache it for future events.
    EventMetadataKey key;
    key.guid_ = eventRecord->EventHeader.ProviderId;
    key.desc_ = eventRecord->EventHeader.EventDescriptor;
    auto ii = metadata_.find(key);
    if (ii == metadata_.end()) {
        ULONG bufferSize = 0;
        auto status = TdhGetEventInformation(eventRecord, 0, nullptr, nullptr, &bufferSize);
        if (status == ERROR_INSUFFICIENT_BUFFER) {
            ii = metadata_.emplace(key, std::vector<uint8_t>(bufferSize, 0)).first;

            status = TdhGetEventInformation(eventRecord, 0, nullptr, (TRACE_EVENT_INFO*) ii->second.data(), &bufferSize);
            assert(status == ERROR_SUCCESS);
        } else {
            // No schema registered with system, nor ETL-embedded metadata.
            ii = metadata_.emplace(key, std::vector<uint8_t>(sizeof(TRACE_EVENT_INFO), 0)).first;
            assert(false);
        }
}

    auto tei = (TRACE_EVENT_INFO*) ii->second.data();

    // Lookup properties in metadata
    uint32_t foundCount = 0;

#if 0 /* Helper to see all property names while debugging */
    std::vector<wchar_t const*> props(tei->TopLevelPropertyCount, nullptr);
    for (uint32_t i = 0; i < tei->TopLevelPropertyCount; ++i) {
        props[i] = TEI_PROPERTY_NAME(tei, &tei->EventPropertyInfoArray[i]);
    }
#endif

    for (uint32_t i = 0, offset = 0; i < tei->TopLevelPropertyCount; ++i) {
        auto info = GetPropertyInfo(*tei, *eventRecord, i, offset);

        auto propName = TEI_PROPERTY_NAME(tei, &tei->EventPropertyInfoArray[i]);
        if (propName != nullptr) {
            for (uint32_t j = 0; j < descCount; ++j) {
                if (desc[j].status_ == PROP_STATUS_NOT_FOUND && wcscmp(propName, desc[j].name_) == 0) {
                    desc[j].data_   = (void*) ((uintptr_t) eventRecord->UserData + offset);
                    desc[j].size_   = info.size_;
                    desc[j].count_  = info.count_;
                    desc[j].status_ = info.status_ | PROP_STATUS_FOUND;

                    foundCount += 1;
                    if (foundCount == descCount) {
                        return foundCount;
                    }
                }
            }
        }

        offset += info.size_ * info.count_;
    }