void Device::DropCaches() {
// give advice to disable caching
int ret = posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED);
if(ret)
ReportWarning();
// empty caches
QFile caches("/proc/sys/vm/drop_caches");
caches.open(QIODevice::WriteOnly);
if(caches.isOpen()) {
caches.putChar('3');
caches.close();
} else {
ReportWarning();
}
}
std::string cache_manager::stat_json() const {
rapidjson::Document doc;
doc.SetObject();
auto &allocator = doc.GetAllocator();
rapidjson::Value total_cache(rapidjson::kObjectType);
rapidjson::Value size_stats(rapidjson::kObjectType);
get_total_caches_size_stats_json(size_stats, allocator);
total_cache.AddMember("size_stats", size_stats, allocator);
doc.AddMember("total_cache", total_cache, allocator);
rapidjson::Value caches(rapidjson::kObjectType);
get_caches_size_stats_json(caches, allocator);
doc.AddMember("caches", caches, allocator);
rapidjson::StringBuffer buffer;
rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
doc.Accept(writer);
return buffer.GetString();
}