src/ccnx-tunnel.cpp

#include "ccnx-tunnel.h"
#include "ccnx-pco.h"

namespace Ccnx
{

CcnxTunnel::CcnxTunnel()
                          : CcnxWrapper()
                          , m_localPrefix("/")
{
  refreshLocalPrefix();
}

CcnxTunnel::~CcnxTunnel() 
{
}

void
CcnxTunnel::refreshLocalPrefix() 
{
  string newPrefix = getLocalPrefix();
  if (!newPrefix.empty() && m_localPrefix != newPrefix)
  {
    CcnxWrapper::clearInterestFilter(m_localPrefix);
    CcnxWrapper::setInterestFilter(newPrefix, bind(&CcnxTunnel::handleTunneledInterest, this, _1));
    m_localPrefix = newPrefix;
  }
}

int
CcnxTunnel::sendInterest (const std::string &interest, const DataCallback &dataCallback, int retry, const TimeoutCallback &timeoutCallback)
{
  string tunneledInterest = queryRoutableName(interest);
  ClosurePass *cp = new TunnelClosurePass(retry, dataCallback, timeoutCallback, this, interest);
  CcnxWrapper::sendInterest(tunneledInterest, cp);
}

void 
CcnxTunnel::handleTunneledData(const string &name, const Bytes &tunneledData, const DataCallback &originalDataCallback)
{
  ParsedContentObject pco(tunneledData);
  originalDataCallback(pco.name(), pco.content());
}

int
CcnxTunnel::publishData(const string &name, const char *buf, size_t len, int freshness)
{
  Bytes content = createContentObject(name, buf, len, freshness);
  storeContentObject(name, content);
  
  string tunneledName = m_localPrefix + name;
  Bytes tunneledCo = createContentObject(tunneledName, (const char*)&content[0], content.size(), freshness);

  return putToCcnd(tunneledCo);
}

void
CcnxTunnel::handleTunneledInterest(const string &tunneledInterest)
{
  // The interest must have m_localPrefix as a prefix (component-wise), otherwise ccnd would not deliver it to us
  string interest = (m_localPrefix == "/") 
                    ? tunneledInterest
                    : tunneledInterest.substr(m_localPrefix.size());

  ReadLock(m_ritLock); 
  
  // This is linear scan, but should be acceptable under the assumption that the caller wouldn't be listening to a lot prefixes (as of now, most app listen to one or two prefixes)
  for (RitIter it = m_rit.begin(); it != m_rit.end(); it++)
  {
    // evoke callback for any prefix that is the prefix of the interest
    if (isPrefix(it->first, interest))
    {
      (it->second)(interest);
    }
  }
}

bool
CcnxTunnel::isPrefix(const string &prefix, const string &name)
{
  // prefix is literally prefix of name 
  if (name.find(prefix) == 0)
  {
    // name and prefix are exactly the same, or the next character in name
    // is '/'; in both case, prefix is the ccnx prefix of name (component-wise)
    if (name.size() == prefix.size() || name.at(prefix.size()) == '/')
    {
      return true;
    }
  }
  return false;
}

int 
CcnxTunnel::setInterestFilter(const string &prefix, const InterestCallback &interestCallback)
{
  WriteLock(m_ritLock);
  // make sure copy constructor for boost::function works properly
  m_rit.insert(make_pair(prefix, interestCallback));
  return 0;
}

void 
CcnxTunnel::clearInterestFilter(const string &prefix)
{
  WriteLock(m_ritLock);
  // remove all
  m_rit.erase(prefix);
}

TunnelClosurePass::TunnelClosurePass(int retry, const CcnxWrapper::DataCallback &dataCallback, const CcnxWrapper::TimeoutCallback &timeoutCallback, CcnxTunnel *tunnel, const string &originalInterest)
                  : ClosurePass(retry, dataCallback, timeoutCallback)
                  , m_tunnel(tunnel)
                  , m_originalInterest(originalInterest)
{
}

void 
TunnelClosurePass::runDataCallback(const string &name, const Bytes &content)
{
  if (m_tunnel != NULL)
  {
    m_tunnel->handleTunneledData(name, content, (*m_dataCallback));
  }
}

CcnxWrapper::TimeoutCallbackReturnValue
TunnelClosurePass::runTimeoutCallback(const string &interest)
{
  return ClosurePass::runTimeoutCallback(m_originalInterest);
}

} // Ccnx