NS-3 based Named Data Networking (NDN) simulator
ndnSIM 2.3: NDN, CCN, CCNx, content centric networks
API Documentation
cache-policy.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2013-2017 Regents of the University of California.
4  *
5  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
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7  * ndn-cxx library is free software: you can redistribute it and/or modify it under the
8  * terms of the GNU Lesser General Public License as published by the Free Software
9  * Foundation, either version 3 of the License, or (at your option) any later version.
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13  * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
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16  * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
17  * <http://www.gnu.org/licenses/>.
18  *
19  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
20  *
21  * @author Eric Newberry <enewberry@email.arizona.edu>
22  */
23 
24 #include "cache-policy.hpp"
25 #include "../encoding/block-helpers.hpp"
26 
27 namespace ndn {
28 namespace lp {
29 
30 std::ostream&
31 operator<<(std::ostream& os, CachePolicyType policy)
32 {
33  switch (policy) {
35  os << "NoCache";
36  break;
37  default:
38  os << "None";
39  break;
40  }
41 
42  return os;
43 }
44 
46  : m_policy(CachePolicyType::NONE)
47 {
48 }
49 
51 {
52  wireDecode(block);
53 }
54 
55 template<encoding::Tag TAG>
56 size_t
57 CachePolicy::wireEncode(EncodingImpl<TAG>& encoder) const
58 {
59  if (m_policy == CachePolicyType::NONE) {
60  BOOST_THROW_EXCEPTION(Error("CachePolicyType must be set"));
61  }
62 
63  size_t length = 0;
64  length += prependNonNegativeIntegerBlock(encoder, tlv::CachePolicyType, static_cast<uint32_t>(m_policy));
65  length += encoder.prependVarNumber(length);
66  length += encoder.prependVarNumber(tlv::CachePolicy);
67  return length;
68 }
69 
71 
72 const Block&
74 {
75  if (m_policy == CachePolicyType::NONE) {
76  BOOST_THROW_EXCEPTION(Error("CachePolicyType must be set"));
77  }
78 
79  if (m_wire.hasWire()) {
80  return m_wire;
81  }
82 
83  EncodingEstimator estimator;
84  size_t estimatedSize = wireEncode(estimator);
85 
86  EncodingBuffer buffer(estimatedSize, 0);
87  wireEncode(buffer);
88 
89  m_wire = buffer.block();
90 
91  return m_wire;
92 }
93 
94 void
96 {
97  if (wire.type() != tlv::CachePolicy) {
98  BOOST_THROW_EXCEPTION(Error("expecting CachePolicy block"));
99  }
100 
101  m_wire = wire;
102  m_wire.parse();
103 
105  if (it != m_wire.elements_end() && it->type() == tlv::CachePolicyType) {
106  m_policy = static_cast<CachePolicyType>(readNonNegativeInteger(*it));
107  if (this->getPolicy() == CachePolicyType::NONE) {
108  BOOST_THROW_EXCEPTION(Error("unknown CachePolicyType"));
109  }
110  }
111  else {
112  BOOST_THROW_EXCEPTION(Error("expecting CachePolicyType block"));
113  }
114 }
115 
118 {
119  switch (m_policy) {
121  return m_policy;
122  default:
123  return CachePolicyType::NONE;
124  }
125 }
126 
129 {
130  m_policy = policy;
131  m_wire.reset();
132  return *this;
133 }
134 
135 } // namespace lp
136 } // namespace ndn
void wireDecode(const Block &wire)
get CachePolicyType from wire format
represents a CachePolicy header field
Copyright (c) 2011-2015 Regents of the University of California.
NDN_CXX_DEFINE_WIRE_ENCODE_INSTANTIATIONS(CachePolicy)
size_t prependNonNegativeIntegerBlock(EncodingImpl< TAG > &encoder, uint32_t type, uint64_t value)
Prepend a TLV element containing a non-negative integer.
CachePolicyType getPolicy() const
CachePolicy & setPolicy(CachePolicyType policy)
set policy type code
element_container::const_iterator element_const_iterator
Definition: block.hpp:47
Represents a TLV element of NDN packet format.
Definition: block.hpp:42
uint64_t readNonNegativeInteger(const Block &block)
Read a non-negative integer from a TLV element.
CachePolicyType
indicates the cache policy applied to a Data packet
void reset()
Reset wire buffer of the element.
Definition: block.cpp:256
void parse() const
Parse TLV-VALUE into sub elements.
Definition: block.cpp:334
uint32_t type() const
Get TLV-TYPE.
Definition: block.hpp:235
std::ostream & operator<<(std::ostream &os, CachePolicyType policy)
const Block & wireEncode() const
encode CachePolicy into wire format
bool hasWire() const
Check if the Block has fully encoded wire.
Definition: block.cpp:250
element_const_iterator elements_end() const
Equivalent to elements().end()
Definition: block.hpp:363
element_const_iterator elements_begin() const
Equivalent to elements().begin()
Definition: block.hpp:355
EncodingImpl< EncoderTag > EncodingBuffer
EncodingImpl< EstimatorTag > EncodingEstimator