Bug #1298: Interest with implicit digest component cannot be satisfied - ndn-cxx - NDN project issue tracking system

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Bug #1298

closed

Interest with implicit digest component cannot be satisfied

Added by Junxiao Shi about 10 years ago. Updated almost 10 years ago.

Status:

Closed

Priority:

Normal

Assignee:

Alex Afanasyev

Category:

Base

Target version:

v0.2

Start date:

Due date:

% Done:

100%

Estimated time:

2.00 h

Description

Steps to reproduce:

Send an Interest with implicit digest as its last NameComponent
Producer answers with a Data that can match this Interest

Expected: OnData callback is invoked

Actual: OnData callback is not invoked

Relevant snippets:

Face::onReceiveElement {
  getEntryIndexForExpressedInterest(data->getName()); // implicit digest is not computed
}

Face::getEntryIndexForExpressedInterest {
  getInterest()->matchesName(name) // Interest may contain implicit digest and be one component longer than Data Name
}

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Updated by Junxiao Shi almost 10 years ago

I propose fixing this bug with the following pseudocode:

bool canSatisfy(const Interest& interest, const Data& data)
{
  Name fullName(data.getName());
  fullName.append(data.computeDigest());

  if (!interest.getName().isPrefixOf(fullName))
    return false;

  size_t nSuffixComponents = fullName.size() - interest.getName().size();
  if (interest->hasMinSuffixComponents() &&
      nSuffixComponents < interest->getMinSuffixComponents())
    return false;
  if (interest->hasMaxSuffixComponents() &&
      nSuffixComponents > interest->getMaxSuffixComponents())
    return false;

  if (interest->hasExclude()) {
    if (fullName.size() == interest->getName().size())
      return false;
    Name::Component nextComponent = fullName.at(interest.getName().size());
    if (interest->getExclude()->isExcluded(nextComponent))
      return false;
  }

  if (interest->hasPublisherPublicKeyLocator() &&
      (!data->hasKeyLocator() ||
       data->getKeyLocator() != interest->getPublisherPublicKeyLocator()))
    return false;

  return true;
}

To reduce the overhead of Data::computeDigest, its result will be cached in Data class.

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