shared_ptr<const Data>
InMemoryStorage::find(const Interest& interest)
{
// if the interest contains implicit digest, it is possible to directly locate a packet.
auto it = m_cache.get<byFullName>().find(interest.getName());
// if a packet is located by its full name, it must be the packet to return.
if (it != m_cache.get<byFullName>().end()) {
return ((*it)->getData()).shared_from_this();
}
// if the packet is not discovered by last step, either the packet is not in the storage or
// the interest doesn't contains implicit digest.
it = m_cache.get<byFullName>().lower_bound(interest.getName());
if (it == m_cache.get<byFullName>().end()) {
return nullptr;
}
// to locate the element that has a just smaller name than the interest's
if (it != m_cache.get<byFullName>().begin()) {
it--;
}
InMemoryStorageEntry* ret = selectChild(interest, it);
if (ret == nullptr) {
return nullptr;
}
// let derived class do something with the entry
afterAccess(ret);
return ret->getData().shared_from_this();
}
BOOST_AUTO_TEST_CASE_TEMPLATE(DigestCalculation, T, InMemoryStorages)
{
shared_ptr<Data> data = makeData("/digest/compute");
ndn::ConstBufferPtr digest1 = ndn::crypto::computeSha256Digest(data->wireEncode().wire(),
data->wireEncode().size());
BOOST_CHECK_EQUAL(digest1->size(), 32);
InMemoryStorageEntry* entry = new InMemoryStorageEntry();
entry->setData(*data);
BOOST_CHECK_EQUAL_COLLECTIONS(digest1->begin(), digest1->end(),
entry->getFullName()[-1].value_begin(),
entry->getFullName()[-1].value_end());
}
void
InMemoryStorage::insert(const Data& data, const time::milliseconds& mustBeFreshProcessingWindow)
{
// check if identical Data/Name already exists
auto it = m_cache.get<byFullName>().find(data.getFullName());
if (it != m_cache.get<byFullName>().end())
return;
//if full, double the capacity
bool doesReachLimit = (getLimit() == getCapacity());
if (isFull() && !doesReachLimit) {
// note: This is incorrect if 2*capacity overflows, but memory should run out before that
size_t newCapacity = std::min(2 * getCapacity(), getLimit());
setCapacity(newCapacity);
}
//if full and reach limitation of the capacity, employ replacement policy
if (isFull() && doesReachLimit) {
evictItem();
}
//insert to cache
BOOST_ASSERT(m_freeEntries.size() > 0);
// take entry for the memory pool
InMemoryStorageEntry* entry = m_freeEntries.top();
m_freeEntries.pop();
m_nPackets++;
entry->setData(data);
if (m_scheduler != nullptr && mustBeFreshProcessingWindow > ZERO_WINDOW) {
entry->scheduleMarkStale(*m_scheduler, mustBeFreshProcessingWindow);
}
m_cache.insert(entry);
//let derived class do something with the entry
afterInsert(entry);
}