src/ccnx-wrapper.cpp

#include "ccnx-wrapper.h"
extern "C" {
#include <ccn/fetch.h>
}
#include <poll.h>
#include <boost/throw_exception.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/random.hpp>
#include <sstream>

typedef boost::error_info<struct tag_errmsg, std::string> errmsg_info_str;
typedef boost::error_info<struct tag_errmsg, int> errmsg_info_int;

using namespace std;
using namespace boost;

namespace Ccnx {

CcnxWrapper::CcnxWrapper()
  : m_handle (0)
  , m_running (true)
  , m_connected (false)
{
  connectCcnd();
  m_thread = thread (&CcnxWrapper::ccnLoop, this);
}

void
CcnxWrapper::connectCcnd()
{
  //if (m_handle != 0) {
    //ccn_disconnect (m_handle);
    //ccn_destroy (&m_handle);
  //}

  m_handle = ccn_create ();
  UniqueRecLock(m_mutex);
  if (ccn_connect(m_handle, NULL) < 0)
  {
    BOOST_THROW_EXCEPTION (CcnxOperationException() << errmsg_info_str("connection to ccnd failed"));
  }
  m_connected = true;

  //if (!m_registeredInterests.empty())
  //{
   // for (map<Name, InterestCallback>::const_iterator it = m_registeredInterests.begin(); it != m_registeredInterests.end(); ++it)
    //{
      // clearInterestFilter(it->first);
     // setInterestFilter(it->first, it->second);
    //}
  //}
}

CcnxWrapper::~CcnxWrapper()
{
  {
    UniqueRecLock(m_mutex);
    m_running = false;
  }

  m_thread.join ();
  ccn_disconnect (m_handle);
  //ccn_destroy (&m_handle);
}

void
CcnxWrapper::ccnLoop ()
{
  static boost::mt19937 randomGenerator (static_cast<unsigned int> (std::time (0)));
  static boost::variate_generator<boost::mt19937&, boost::uniform_int<> > rangeUniformRandom (randomGenerator, uniform_int<> (0,1000));

  while (m_running)
    {
      try
        {
          int res = 0;
          {
            UniqueRecLock(m_mutex);
            res = ccn_run (m_handle, 0);
          }

          if (!m_running) break;

          if (res < 0)
            BOOST_THROW_EXCEPTION (CcnxOperationException()
                                 << errmsg_info_str("ccn_run returned error"));


          pollfd pfds[1];
          {
            UniqueRecLock(m_mutex);

            pfds[0].fd = ccn_get_connection_fd (m_handle);
            pfds[0].events = POLLIN;
            if (ccn_output_is_pending (m_handle))
              pfds[0].events |= POLLOUT;
          }

          int ret = poll (pfds, 1, 1);
          if (ret < 0)
            {
              BOOST_THROW_EXCEPTION (CcnxOperationException() << errmsg_info_str("ccnd socket failed (probably ccnd got stopped)"));
            }
        }
        catch (CcnxOperationException &e)
        {
          // do not try reconnect for now
          throw e;
          /*
          m_connected = false;
          // probably ccnd has been stopped
          // try reconnect with sleep
          int interval = 1;
          int maxInterval = 32;
          while (m_running)
          {
            try
            {
              this_thread::sleep (boost::get_system_time () + TIME_SECONDS(interval) + TIME_MILLISECONDS (rangeUniformRandom ()));

              connectCcnd();
              _LOG_DEBUG("reconnect to ccnd succeeded");
              break;
            }
            catch (CcnxOperationException &e)
            {
              this_thread::sleep (boost::get_system_time () + TIME_SECONDS(interval) + TIME_MILLISECONDS (rangeUniformRandom ()));

              // do exponential backup for reconnect interval
              if (interval < maxInterval)
              {
                interval *= 2;
              }
            }
          }
          */
        }
        catch (const std::exception &exc)
          {
            // catch anything thrown within try block that derives from std::exception
            std::cerr << exc.what();
          }
        catch (...)
          {
            cout << "UNKNOWN EXCEPTION !!!" << endl;
          }
     }
}

Bytes
CcnxWrapper::createContentObject(const Name  &name, const void *buf, size_t len, int freshness)
{
  CcnxCharbufPtr ptr = name.toCcnxCharbuf();
  ccn_charbuf *pname = ptr->getBuf();
  ccn_charbuf *content = ccn_charbuf_create();

  struct ccn_signing_params sp = CCN_SIGNING_PARAMS_INIT;
  sp.freshness = freshness;

  if (ccn_sign_content(m_handle, content, pname, &sp, buf, len) != 0)
  {
    BOOST_THROW_EXCEPTION(CcnxOperationException() << errmsg_info_str("sign content failed"));
  }

  Bytes bytes;
  readRaw(bytes, content->buf, content->length);

  ccn_charbuf_destroy (&content);

  return bytes;
}

int
CcnxWrapper::putToCcnd (const Bytes &contentObject)
{
  UniqueRecLock(m_mutex);
  if (!m_running || !m_connected)
    return -1;


  if (ccn_put(m_handle, head(contentObject), contentObject.size()) < 0)
  {
    // BOOST_THROW_EXCEPTION(CcnxOperationException() << errmsg_info_str("ccnput failed"));
  }

  return 0;
}

int
CcnxWrapper::publishData (const Name &name, const unsigned char *buf, size_t len, int freshness)
{
  Bytes co = createContentObject(name, buf, len, freshness);
  return putToCcnd(co);
}

int
CcnxWrapper::publishData (const Name &name, const Bytes &content, int freshness)
{
  return publishData(name, head(content), content.size(), freshness);
}


static ccn_upcall_res
incomingInterest(ccn_closure *selfp,
                 ccn_upcall_kind kind,
                 ccn_upcall_info *info)
{
  CcnxWrapper::InterestCallback *f = static_cast<CcnxWrapper::InterestCallback*> (selfp->data);

  switch (kind)
    {
    case CCN_UPCALL_FINAL: // effective in unit tests
      delete f;
      delete selfp;
      return CCN_UPCALL_RESULT_OK;

    case CCN_UPCALL_INTEREST:
      break;

    default:
      return CCN_UPCALL_RESULT_OK;
    }

  Name interest(info->interest_ccnb, info->interest_comps);

  (*f) (interest);
  return CCN_UPCALL_RESULT_OK;
}

static ccn_upcall_res
incomingData(ccn_closure *selfp,
             ccn_upcall_kind kind,
             ccn_upcall_info *info)
{
  Closure *cp = static_cast<Closure *> (selfp->data);

  switch (kind)
    {
    case CCN_UPCALL_FINAL:  // effecitve in unit tests
      delete cp;
      cp = NULL;
      delete selfp;
      return CCN_UPCALL_RESULT_OK;

    case CCN_UPCALL_CONTENT:
      break;

    case CCN_UPCALL_INTEREST_TIMED_OUT: {
      if (cp != NULL && cp->getRetry() > 0) {
        cp->decRetry();
        return CCN_UPCALL_RESULT_REEXPRESS;
      }

      Name interest(info->interest_ccnb, info->interest_comps);
      Closure::TimeoutCallbackReturnValue rv = cp->runTimeoutCallback(interest);
      switch(rv)
      {
        case Closure::RESULT_OK : return CCN_UPCALL_RESULT_OK;
        case Closure::RESULT_REEXPRESS : return CCN_UPCALL_RESULT_REEXPRESS;
        default : break;
      }
      return CCN_UPCALL_RESULT_OK;
    }

    default:
      return CCN_UPCALL_RESULT_OK;
    }

  const unsigned char *pcontent;
  size_t len;
  if (ccn_content_get_value(info->content_ccnb, info->pco->offset[CCN_PCO_E], info->pco, &pcontent, &len) < 0)
  {
    // BOOST_THROW_EXCEPTION(CcnxOperationException() << errmsg_info_str("decode ContentObject failed"));
  }

  Name name(info->content_ccnb, info->content_comps);

  Bytes content;
  // copy content and do processing on the copy
  // otherwise the pointed memory may have been changed during the processing
  readRaw(content, pcontent, len);

  cp->runDataCallback(name, content);

  return CCN_UPCALL_RESULT_OK;
}

int CcnxWrapper::sendInterest (const Name &interest, const Closure *closure, const Selectors &selectors)
{
  UniqueRecLock(m_mutex);
  if (!m_running || !m_connected)
    return -1;

  CcnxCharbufPtr namePtr = interest.toCcnxCharbuf();
  ccn_charbuf *pname = namePtr->getBuf();
  ccn_closure *dataClosure = new ccn_closure;

  Closure *myClosure = closure->dup();
  dataClosure->data = (void *)myClosure;

  dataClosure->p = &incomingData;

  CcnxCharbufPtr selectorsPtr = selectors.toCcnxCharbuf();
  ccn_charbuf *templ = NULL;
  if (selectorsPtr != CcnxCharbuf::Null)
  {
    templ = selectorsPtr->getBuf();
  }

  if (ccn_express_interest (m_handle, pname, dataClosure, templ) < 0)
  {
  }

  return 0;
}

int CcnxWrapper::setInterestFilter (const Name &prefix, const InterestCallback &interestCallback)
{
  UniqueRecLock(m_mutex);
  if (!m_running || !m_connected)
    return -1;

  CcnxCharbufPtr ptr = prefix.toCcnxCharbuf();
  ccn_charbuf *pname = ptr->getBuf();
  ccn_closure *interestClosure = new ccn_closure;

  interestClosure->data = new InterestCallback (interestCallback); // should be removed when closure is removed
  interestClosure->p = &incomingInterest;
  int ret = ccn_set_interest_filter (m_handle, pname, interestClosure);
  if (ret < 0)
  {
  }

  m_registeredInterests.insert(pair<Name, InterestCallback>(prefix, interestCallback));

  return ret;
}

void
CcnxWrapper::clearInterestFilter (const Name &prefix)
{
  UniqueRecLock(m_mutex);
  if (!m_running || !m_connected)
    return;

  CcnxCharbufPtr ptr = prefix.toCcnxCharbuf();
  ccn_charbuf *pname = ptr->getBuf();

  int ret = ccn_set_interest_filter (m_handle, pname, 0);
  if (ret < 0)
  {
  }

  m_registeredInterests.erase(prefix);
}

Name
CcnxWrapper::getLocalPrefix ()
{
  struct ccn * tmp_handle = ccn_create ();
  int res = ccn_connect (tmp_handle, NULL);
  if (res < 0)
    {
      return Name();
    }

  string retval = "";

  struct ccn_charbuf *templ = ccn_charbuf_create();
  ccn_charbuf_append_tt(templ, CCN_DTAG_Interest, CCN_DTAG);
  ccn_charbuf_append_tt(templ, CCN_DTAG_Name, CCN_DTAG);
  ccn_charbuf_append_closer(templ); /* </Name> */
  // XXX - use pubid if possible
  ccn_charbuf_append_tt(templ, CCN_DTAG_MaxSuffixComponents, CCN_DTAG);
  ccnb_append_number(templ, 1);
  ccn_charbuf_append_closer(templ); /* </MaxSuffixComponents> */
  ccnb_tagged_putf(templ, CCN_DTAG_Scope, "%d", 2);
  ccn_charbuf_append_closer(templ); /* </Interest> */

  struct ccn_charbuf *name = ccn_charbuf_create ();
  res = ccn_name_from_uri (name, "/local/ndn/prefix");
  if (res < 0) {
  }
  else
    {
      struct ccn_fetch *fetch = ccn_fetch_new (tmp_handle);

      struct ccn_fetch_stream *stream = ccn_fetch_open (fetch, name, "/local/ndn/prefix",
                                                        NULL, 4, CCN_V_HIGHEST, 0);
      if (stream == NULL) {
      }
      else
        {
          ostringstream os;

          int counter = 0;
          char buf[256];
          while (true) {
            res = ccn_fetch_read (stream, buf, sizeof(buf));

            if (res == 0) {
              break;
            }

            if (res > 0) {
              os << string(buf, res);
            } else if (res == CCN_FETCH_READ_NONE) {
              if (counter < 2)
                {
                  ccn_run(tmp_handle, 1000);
                  counter ++;
                }
              else
                {
                  break;
                }
            } else if (res == CCN_FETCH_READ_END) {
              break;
            } else if (res == CCN_FETCH_READ_TIMEOUT) {
              break;
            } else {
              break;
            }
          }
          retval = os.str ();
          stream = ccn_fetch_close(stream);
        }
      fetch = ccn_fetch_destroy(fetch);
    }

  ccn_charbuf_destroy (&name);

  ccn_disconnect (tmp_handle);
  ccn_destroy (&tmp_handle);

  return Name(retval);
}

}