src/exclude.hpp

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
/*
 * Copyright (c) 2013, Regents of the University of California
 *                     Alexander Afanasyev
 *
 * BSD license, See the LICENSE file for more information
 *
 * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
 */

#ifndef NDN_EXCLUDE_H
#define NDN_EXCLUDE_H

#include "name-component.hpp"

namespace ndn {

/**
 * @brief Class to represent Exclude component in NDN interests
 */
class Exclude
{
public:
  struct Error : public std::runtime_error { Error(const std::string &what) : std::runtime_error(what) {} };

  
  typedef std::map< name::Component, bool /*any*/, std::greater<name::Component> > exclude_type;

  typedef exclude_type::iterator iterator;
  typedef exclude_type::const_iterator const_iterator;
  typedef exclude_type::reverse_iterator reverse_iterator;
  typedef exclude_type::const_reverse_iterator const_reverse_iterator;

  /**
   * @brief Default constructor an empty exclude
   */
  Exclude ();

  /**
   * @brief Fast encoding or block size estimation
   */
  template<bool T>
  inline size_t
  wireEncode(EncodingImpl<T> &block) const;
  
  /**
   * @brief Encode to a wire format
   */
  inline const Block&
  wireEncode() const;

  /**
   * @brief Decode from the wire format
   */
  inline void 
  wireDecode(const Block &wire);
  
  ///////////////////////////////////////////////////////////////////////////////


  /**
   * @brief Check if name component is excluded
   * @param comp Name component to check against exclude filter
   */
  bool
  isExcluded (const name::Component &comp) const;

  /**
   * @brief Exclude specific name component
   * @param comp component to exclude
   * @returns *this to allow chaining
   */
  Exclude &
  excludeOne (const name::Component &comp);

  /**
   * @brief Exclude components from range [from, to]
   * @param from first element of the range
   * @param to last element of the range
   * @returns *this to allow chaining
   */
  Exclude &
  excludeRange (const name::Component &from, const name::Component &to);

  /**
   * @brief Exclude all components from range [/, to]
   * @param to last element of the range
   * @returns *this to allow chaining
   */
  inline Exclude &
  excludeBefore (const name::Component &to);

  /**
   * @brief Exclude all components from range [from, +Inf]
   * @param to last element of the range
   * @returns *this to allow chaining
   */
  Exclude &
  excludeAfter (const name::Component &from);

  /**
   * @brief Method to directly append exclude element
   * @param name excluded name component
   * @param any  flag indicating if there is a postfix ANY component after the name
   *
   * This method is used during conversion from wire format of exclude filter
   *
   * If there is an error with ranges (e.g., order of components is wrong) an exception is thrown
   */
  inline void
  appendExclude (const name::Component &name, bool any);

  /**
   * @brief Check if exclude filter is empty
   */
  inline bool
  empty () const;

  /**
   * @brief Clear the exclude filter
   */
  inline void
  clear();
  
  /**
   * @brief Get number of exclude terms
   */
  inline size_t
  size () const;

  /**
   * @brief Get begin iterator of the exclude terms
   */
  inline const_iterator
  begin () const;

  /**
   * @brief Get end iterator of the exclude terms
   */
  inline const_iterator
  end () const;

  /**
   * @brief Get begin iterator of the exclude terms
   */
  inline const_reverse_iterator
  rbegin () const;

  /**
   * @brief Get end iterator of the exclude terms
   */
  inline const_reverse_iterator
  rend () const;

  /**
   * @brief Get escaped string representation (e.g., for use in URI) of the exclude filter
   */
  inline std::string
  toUri () const;

private:
  Exclude &
  excludeRange (iterator fromLowerBound, iterator toLowerBound);

private:
  exclude_type m_exclude;

  mutable Block wire_;
};

std::ostream&
operator << (std::ostream &os, const Exclude &name);

inline Exclude &
Exclude::excludeBefore (const name::Component &to)
{
  return excludeRange (name::Component (), to);
}

inline void
Exclude::appendExclude (const name::Component &name, bool any)
{
  m_exclude[name] = any;
}

inline bool
Exclude::empty () const
{
  return m_exclude.empty ();
}

inline void
Exclude::clear ()
{
  m_exclude.clear ();
}


inline size_t
Exclude::size () const
{
  return m_exclude.size ();
}

inline Exclude::const_iterator
Exclude::begin () const
{
  return m_exclude.begin ();
}

inline Exclude::const_iterator
Exclude::end () const
{
  return m_exclude.end ();
}

inline Exclude::const_reverse_iterator
Exclude::rbegin () const
{
  return m_exclude.rbegin ();
}

inline Exclude::const_reverse_iterator
Exclude::rend () const
{
  return m_exclude.rend ();
}

inline std::string
Exclude::toUri () const
{
  std::ostringstream os;
  os << *this;
  return os.str();
}

template<bool T>
inline size_t
Exclude::wireEncode(EncodingImpl<T> &block) const
{
  size_t total_len = 0;

  // Exclude ::= EXCLUDE-TYPE TLV-LENGTH Any? (NameComponent (Any)?)+
  // Any     ::= ANY-TYPE TLV-LENGTH(=0)
  
  for (Exclude::const_iterator i = m_exclude.begin (); i != m_exclude.end (); i++)
    {
      if (i->second)
        {
          total_len += prependBooleanBlock(block, Tlv::Any);
        }
      if (!i->first.empty())
        {
          total_len += i->first.wireEncode(block);
        }
    }

  total_len += block.prependVarNumber(total_len);
  total_len += block.prependVarNumber(Tlv::Exclude);
  return total_len;
}

inline const Block &
Exclude::wireEncode() const
{
  if (wire_.hasWire())
    return wire_;

  EncodingEstimator estimator;
  size_t estimatedSize = wireEncode(estimator);
  
  EncodingBuffer buffer(estimatedSize, 0);
  wireEncode(buffer);

  wire_ = buffer.block();
  return wire_;
}

inline void
Exclude::wireDecode(const Block &wire) 
{
  wire_ = wire;
  wire_.parse();

  // Exclude ::= EXCLUDE-TYPE TLV-LENGTH Any? (NameComponent (Any)?)+
  // Any     ::= ANY-TYPE TLV-LENGTH(=0)
  
  Block::element_const_iterator i = wire_.elements_begin();
  if (i->type() == Tlv::Any)
    {
      appendExclude(name::Component(), true);
      ++i;
    }

  while (i != wire_.elements_end())
    {
      if (i->type() != Tlv::NameComponent)
        throw Error("Incorrect format of Exclude filter");

      name::Component excludedComponent (i->value(), i->value_size());
      ++i;

      if (i != wire_.elements_end())
        {
          if (i->type() == Tlv::Any)
            {
              appendExclude(excludedComponent, true);
              ++i;
            }
          else
            {
              appendExclude(excludedComponent, false);
            }
        }
      else
        {
          appendExclude(excludedComponent, false);
        }
    }
}


} // ndn

#endif // NDN_EXCLUDE_H