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:
  class Error : public std::runtime_error
  {
  public:
    explicit
    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 Create from wire encoding
   */
  explicit
  Exclude(const Block& wire)
  {
    wireDecode(wire);
  }

  /**
   * @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 m_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 totalLength = 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)
        {
          totalLength += prependBooleanBlock(block, Tlv::Any);
        }
      if (!i->first.empty())
        {
          totalLength += i->first.wireEncode(block);
        }
    }

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

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

  EncodingEstimator estimator;
  size_t estimatedSize = wireEncode(estimator);

  EncodingBuffer buffer(estimatedSize, 0);
  wireEncode(buffer);

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

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

  // Exclude ::= EXCLUDE-TYPE TLV-LENGTH Any? (NameComponent (Any)?)+
  // Any     ::= ANY-TYPE TLV-LENGTH(=0)

  Block::element_const_iterator i = m_wire.elements_begin();
  if (i->type() == Tlv::Any)
    {
      appendExclude(name::Component(), true);
      ++i;
    }

  while (i != m_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 != m_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