channel-discovery.hpp

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
#ifndef NDN_CHANNEL_DISCOVERY_HPP
#define NDN_CHANNEL_DISCOVERY_HPP

#include <map>
#include <ndn-cpp/sync/chrono-sync2013.hpp>

namespace ndntools {

class ChannelDiscovery {
public:
  enum ErrorCode {
    REGISTER_FAILED = 1,
    INTEREST_TIMEOUT = 2
  };

  typedef ndn::func_lib::function<void
    (ChannelDiscovery& channelDiscovery,
     const ndn::ptr_lib::shared_ptr<ndn::Name>& userPrefix)> OnReceivedChannelList;

  typedef ndn::func_lib::function<void
    (ErrorCode errorCode, const std::string& message)> OnError;

  ChannelDiscovery
    (const ndn::Name& applicationDataPrefix,
     const std::string& channelListFilePath,
     const ndn::Name& applicationBroadcastPrefix, ndn::Face& face,
     ndn::KeyChain& keyChain, const ndn::Name& certificateName,
     ndn::Milliseconds syncLifetime,
     const OnReceivedChannelList& onReceivedChannelList, const OnError& onError)
  : impl_(new Impl
      (*this, applicationDataPrefix, channelListFilePath, face, keyChain,
       certificateName, syncLifetime, onReceivedChannelList, onError))
  {
    impl_->initialize(applicationBroadcastPrefix);
  }

  void
  addChannel(const std::string& channel)
  {
    impl_->addChannel(channel);
  }

  void
  removeChannel(const std::string& channel)
  {
    impl_->removeChannel(channel);
  }

  const ndn::Name&
  getApplicationDataPrefix() { return impl_->getApplicationDataPrefix(); }

  ndn::ptr_lib::shared_ptr<std::vector<ndn::Name>>
  getOtherUserPrefixes()
  {
    return impl_->getOtherUserPrefixes();
  }

  ndn::ptr_lib::shared_ptr<std::vector<std::string>>
  getChannelList(const ndn::Name& userPrefix)
  {
    return impl_->getChannelList(userPrefix);
  }

  // TODO: Implement shutdown.

private:
  class Impl : public ndn::ptr_lib::enable_shared_from_this<Impl> {
  public:
    Impl
      (ChannelDiscovery& parent, const ndn::Name& applicationDataPrefix,
       const std::string& channelListFilePath, ndn::Face& face,
       ndn::KeyChain& keyChain, const ndn::Name& certificateName,
       ndn::Milliseconds syncLifetime,
       const OnReceivedChannelList& onReceivedChannelList, const OnError& onError);

    void
    initialize(const ndn::Name& applicationBroadcastPrefix);

    void
    addChannel(const std::string& channel);

    void
    removeChannel(const std::string& channel);

    const ndn::Name&
    getApplicationDataPrefix() { return applicationDataPrefix_; }

    ndn::ptr_lib::shared_ptr<std::vector<ndn::Name>>
    getOtherUserPrefixes();

    ndn::ptr_lib::shared_ptr<std::vector<std::string>>
    getChannelList(const ndn::Name& userPrefix);

    void
    onRegisterApplicationPrefixSuccess
      (const ndn::ptr_lib::shared_ptr<const ndn::Name>& prefix,
       uint64_t registeredPrefixId, const ndn::Name& applicationBroadcastPrefix,
       int previousSequenceNumber);

    void
    onInitialized();

    void
    onReceivedSyncState
      (const std::vector<ndn::ChronoSync2013::SyncState>& syncStates,
       bool isRecovery);

    void
    onData
      (const ndn::ptr_lib::shared_ptr<const ndn::Interest>& interest,
       const ndn::ptr_lib::shared_ptr<ndn::Data>& data);

    void
    onApplicationInterest
      (const ndn::ptr_lib::shared_ptr<const ndn::Name>& prefix,
       const ndn::ptr_lib::shared_ptr<const ndn::Interest>& interest,
       ndn::Face& face, uint64_t interestFilterId,
       const ndn::ptr_lib::shared_ptr<const ndn::InterestFilter>& filter);

    void
    onRegisterFailed(const ndn::ptr_lib::shared_ptr<const ndn::Name>& prefix);

    void
    onTimeout(const ndn::ptr_lib::shared_ptr<const ndn::Interest>& interest);

    void
    publishChannelListData();

    ndn::ptr_lib::shared_ptr<ndn::Data>
    makeChannelListData(int sequenceNo);

    static void
    parseChannelList
      (const ndn::Blob& blob, std::vector<std::string>& channelList);

    static ndn::Blob
    readBase64Blob(const std::string& filePath);

    static void
    writeBase64Blob(const ndn::Blob& blob, const std::string& filePath);

  private:
    ChannelDiscovery& parent_;
    ndn::Name applicationDataPrefix_;
    int sessionNo_;
    std::string channelListFilePath_;
    ndn::Face& face_;
    ndn::KeyChain& keyChain_;
    ndn::Name certificateName_;
    ndn::Milliseconds syncLifetime_;
    OnReceivedChannelList onReceivedChannelList_;
    OnError onError_;
    ndn::ptr_lib::shared_ptr<ndn::ChronoSync2013> sync_;
    std::vector<std::string> myChannelList_;
    // The key is the user's application prefix. The value is the list of channel names.
    std::map<std::string, std::vector<std::string>> otherUserChannelList_;
    ndn::ptr_lib::shared_ptr<ndn::Data> channelListData_;
    bool enabled_;
    bool isInitialized_;
    bool needToPublish_;
  };

  ndn::ptr_lib::shared_ptr<Impl> impl_;
};

}

#endif