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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2013-2018 Regents of the University of California.
*
* This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
*
* ndn-cxx library is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later version.
*
* ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
*
* You should have received copies of the GNU General Public License and GNU Lesser
* General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
* <http://www.gnu.org/licenses/>.
*
* See AUTHORS.md for complete list of ndn-cxx authors and contributors.
*/
#ifndef NDN_INTEREST_HPP
#define NDN_INTEREST_HPP
#include "delegation-list.hpp"
#include "name.hpp"
#include "packet-base.hpp"
#include "selectors.hpp"
#include "util/time.hpp"
namespace ndn {
class Data;
/** @var const unspecified_duration_type DEFAULT_INTEREST_LIFETIME;
* @brief default value for InterestLifetime
*/
const time::milliseconds DEFAULT_INTEREST_LIFETIME = 4_s;
/** @brief Represents an Interest packet.
*/
class Interest : public PacketBase, public std::enable_shared_from_this<Interest>
{
public:
class Error : public tlv::Error
{
public:
explicit
Error(const std::string& what)
: tlv::Error(what)
{
}
};
/** @brief Construct an Interest with given @p name and @p lifetime.
* @throw std::invalid_argument @p lifetime is negative
* @warning In certain contexts that use `Interest::shared_from_this()`, Interest must be created
* using `make_shared`. Otherwise, `shared_from_this()` will trigger undefined behavior.
*/
explicit
Interest(const Name& name = Name(), time::milliseconds lifetime = DEFAULT_INTEREST_LIFETIME);
/** @brief Construct an Interest by decoding from @p wire.
* @warning In certain contexts that use `Interest::shared_from_this()`, Interest must be created
* using `make_shared`. Otherwise, `shared_from_this()` will trigger undefined behavior.
*/
explicit
Interest(const Block& wire);
/** @brief Prepend wire encoding to @p encoder in NDN Packet Format v0.2.
*/
template<encoding::Tag TAG>
size_t
wireEncode(EncodingImpl<TAG>& encoder) const;
/** @brief Encode to a @c Block.
*
* Normally, this function encodes to NDN Packet Format v0.2. However, if this instance has
* cached wire encoding (@c hasWire() is true), the cached encoding is returned and it might
* be in v0.3 format.
*/
const Block&
wireEncode() const;
/** @brief Decode from @p wire in NDN Packet Format v0.2 or v0.3.
*/
void
wireDecode(const Block& wire);
/** @brief Check if this instance has cached wire encoding.
*/
bool
hasWire() const
{
return m_wire.hasWire();
}
/** @brief Return a URI-like string that represents the Interest.
*
* The string starts with `getName().toUri()`.
* If the Interest contains selectors, they are included as a query string.
* Example: "/test/name?ndn.MustBeFresh=1"
*/
std::string
toUri() const;
public: // matching
/** @brief Check if Interest, including selectors, matches the given @p name
* @param name The name to be matched. If this is a Data name, it shall contain the
* implicit digest component
*/
bool
matchesName(const Name& name) const;
/** @brief Check if Interest can be satisfied by @p data.
*
* This method considers Name, MinSuffixComponents, MaxSuffixComponents,
* PublisherPublicKeyLocator, and Exclude.
* This method does not consider ChildSelector and MustBeFresh.
*/
bool
matchesData(const Data& data) const;
/** @brief Check if Interest matches @p other interest
*
* Interest matches @p other if both have the same name, selectors, and link. Other fields
* (e.g., Nonce) may be different.
*
* @todo Implement distinguishing Interests by forwarding hint. The current implementation
* checks only name+selectors (Issue #3162).
*/
bool
matchesInterest(const Interest& other) const;
public: // element access
const Name&
getName() const
{
return m_name;
}
Interest&
setName(const Name& name)
{
m_name = name;
m_wire.reset();
return *this;
}
/** @brief Check whether the CanBePrefix element is present.
*
* This is a getter for the CanBePrefix element as defined in NDN Packet Format v0.3.
* In this implementation, it is mapped to the closest v0.2 semantics:
* MaxSuffixComponents=1 means CanBePrefix is absent.
*/
bool
getCanBePrefix() const
{
return m_selectors.getMaxSuffixComponents() != 1;
}
/** @brief Add or remove CanBePrefix element.
* @param canBePrefix whether CanBePrefix element should be present.
*
* This is a setter for the CanBePrefix element as defined in NDN Packet Format v0.3.
* In this implementation, it is mapped to the closest v0.2 semantics:
* MaxSuffixComponents=1 means CanBePrefix is absent.
*/
Interest&
setCanBePrefix(bool canBePrefix)
{
m_selectors.setMaxSuffixComponents(canBePrefix ? -1 : 1);
m_wire.reset();
return *this;
}
/** @brief Check whether the MustBeFresh element is present.
*
* This is a getter for the MustBeFresh element as defined in NDN Packet Format v0.3.
* In this implementation, it is mapped to the closest v0.2 semantics and appears as
* MustBeFresh element under Selectors.
*/
bool
getMustBeFresh() const
{
return m_selectors.getMustBeFresh();
}
/** @brief Add or remove MustBeFresh element.
* @param mustBeFresh whether MustBeFresh element should be present.
*
* This is a setter for the MustBeFresh element as defined in NDN Packet Format v0.3.
* In this implementation, it is mapped to the closest v0.2 semantics and appears as
* MustBeFresh element under Selectors.
*/
Interest&
setMustBeFresh(bool mustBeFresh)
{
m_selectors.setMustBeFresh(mustBeFresh);
m_wire.reset();
return *this;
}
const DelegationList&
getForwardingHint() const
{
return m_forwardingHint;
}
Interest&
setForwardingHint(const DelegationList& value);
/** @brief Modify ForwardingHint in-place.
* @tparam Modifier a unary function that accepts DelegationList&
*
* This is equivalent to, but more efficient (avoids copying) than:
* @code
* auto fh = interest.getForwardingHint();
* modifier(fh);
* interest.setForwardingHint(fh);
* @endcode
*/
template<typename Modifier>
Interest&
modifyForwardingHint(const Modifier& modifier)
{
modifier(m_forwardingHint);
m_wire.reset();
return *this;
}
/** @brief Check if the Nonce element is present.
*/
bool
hasNonce() const
{
return static_cast<bool>(m_nonce);
}
/** @brief Get nonce value.
*
* If nonce was not present, it is added and assigned a random value.
*/
uint32_t
getNonce() const;
/** @brief Set nonce value.
*/
Interest&
setNonce(uint32_t nonce);
/** @brief Change nonce value.
*
* If the Nonce element is present, the new nonce value will differ from the old value.
* If the Nonce element is not present, this method does nothing.
*/
void
refreshNonce();
time::milliseconds
getInterestLifetime() const
{
return m_interestLifetime;
}
/** @brief Set Interest's lifetime
* @throw std::invalid_argument @p lifetime is negative
*/
Interest&
setInterestLifetime(time::milliseconds lifetime);
public: // Selectors (deprecated)
/** @brief Check if Interest has any selector present.
*/
[[deprecated]]
bool
hasSelectors() const
{
return !m_selectors.empty();
}
[[deprecated]]
const Selectors&
getSelectors() const
{
return m_selectors;
}
[[deprecated]]
Interest&
setSelectors(const Selectors& selectors)
{
m_selectors = selectors;
m_wire.reset();
return *this;
}
[[deprecated]]
int
getMinSuffixComponents() const
{
return m_selectors.getMinSuffixComponents();
}
[[deprecated]]
Interest&
setMinSuffixComponents(int minSuffixComponents)
{
m_selectors.setMinSuffixComponents(minSuffixComponents);
m_wire.reset();
return *this;
}
[[deprecated]]
int
getMaxSuffixComponents() const
{
return m_selectors.getMaxSuffixComponents();
}
[[deprecated]]
Interest&
setMaxSuffixComponents(int maxSuffixComponents)
{
m_selectors.setMaxSuffixComponents(maxSuffixComponents);
m_wire.reset();
return *this;
}
[[deprecated]]
const KeyLocator&
getPublisherPublicKeyLocator() const
{
return m_selectors.getPublisherPublicKeyLocator();
}
[[deprecated]]
Interest&
setPublisherPublicKeyLocator(const KeyLocator& keyLocator)
{
m_selectors.setPublisherPublicKeyLocator(keyLocator);
m_wire.reset();
return *this;
}
[[deprecated]]
const Exclude&
getExclude() const
{
return m_selectors.getExclude();
}
[[deprecated]]
Interest&
setExclude(const Exclude& exclude)
{
m_selectors.setExclude(exclude);
m_wire.reset();
return *this;
}
[[deprecated]]
int
getChildSelector() const
{
return m_selectors.getChildSelector();
}
[[deprecated]]
Interest&
setChildSelector(int childSelector)
{
m_selectors.setChildSelector(childSelector);
m_wire.reset();
return *this;
}
private:
/** @brief Decode @c m_wire as NDN Packet Format v0.2.
* @retval true decoding successful.
* @retval false decoding failed due to structural error.
* @throw tlv::Error decoding error within a sub-element.
*/
bool
decode02();
/** @brief Decode @c m_wire as NDN Packet Format v0.3.
* @throw tlv::Error decoding error.
*/
void
decode03();
private:
Name m_name;
Selectors m_selectors;
mutable optional<uint32_t> m_nonce;
time::milliseconds m_interestLifetime;
DelegationList m_forwardingHint;
mutable Block m_wire;
};
NDN_CXX_DECLARE_WIRE_ENCODE_INSTANTIATIONS(Interest);
std::ostream&
operator<<(std::ostream& os, const Interest& interest);
inline bool
operator==(const Interest& lhs, const Interest& rhs)
{
return lhs.wireEncode() == rhs.wireEncode();
}
inline bool
operator!=(const Interest& lhs, const Interest& rhs)
{
return !(lhs == rhs);
}
} // namespace ndn
#endif // NDN_INTEREST_HPP