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cache-policy.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2013-2025 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
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19  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
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21  * @author Eric Newberry <enewberry@email.arizona.edu>
22  */
23 
26 
27 namespace ndn::lp {
28 
29 std::ostream&
30 operator<<(std::ostream& os, CachePolicyType policy)
31 {
32  switch (policy) {
34  return os << "NoCache";
35  default:
36  return os << "None";
37  }
38 }
39 
41 {
42  wireDecode(block);
43 }
44 
45 template<encoding::Tag TAG>
46 size_t
48 {
49  if (m_policy == CachePolicyType::NONE) {
50  NDN_THROW(Error("CachePolicyType must be set"));
51  }
52 
53  size_t length = 0;
54  length += prependNonNegativeIntegerBlock(encoder, tlv::CachePolicyType, static_cast<uint64_t>(m_policy));
55  length += encoder.prependVarNumber(length);
56  length += encoder.prependVarNumber(tlv::CachePolicy);
57  return length;
58 }
59 
61 
62 const Block&
64 {
65  if (m_policy == CachePolicyType::NONE) {
66  NDN_THROW(Error("CachePolicyType must be set"));
67  }
68 
69  if (m_wire.hasWire()) {
70  return m_wire;
71  }
72 
73  EncodingEstimator estimator;
74  size_t estimatedSize = wireEncode(estimator);
75 
76  EncodingBuffer buffer(estimatedSize, 0);
77  wireEncode(buffer);
78 
79  m_wire = buffer.block();
80  return m_wire;
81 }
82 
83 void
85 {
86  if (wire.type() != tlv::CachePolicy) {
87  NDN_THROW(Error("CachePolicy", wire.type()));
88  }
89  m_wire = wire;
90  m_wire.parse();
91 
92  m_policy = CachePolicyType::NONE;
93 
94  auto it = m_wire.elements_begin();
95  if (it != m_wire.elements_end() && it->type() == tlv::CachePolicyType) {
96  m_policy = readNonNegativeIntegerAs<CachePolicyType>(*it);
98  NDN_THROW(Error("Unknown CachePolicyType " + std::to_string(to_underlying(m_policy))));
99  }
100  }
101  else {
102  NDN_THROW(Error("CachePolicyType is missing or out of order"));
103  }
104 }
105 
108 {
109  switch (m_policy) {
111  return m_policy;
112  default:
113  return CachePolicyType::NONE;
114  }
115 }
116 
119 {
120  m_policy = policy;
121  m_wire.reset();
122  return *this;
123 }
124 
125 } // namespace ndn::lp
Represents a TLV element of the NDN packet format.
Definition: block.hpp:45
element_const_iterator elements_begin() const noexcept
Equivalent to elements().begin().
Definition: block.hpp:433
element_const_iterator elements_end() const noexcept
Equivalent to elements().end().
Definition: block.hpp:442
bool hasWire() const noexcept
Check if the Block contains a fully encoded wire representation.
Definition: block.hpp:205
uint32_t type() const noexcept
Return the TLV-TYPE of the Block.
Definition: block.hpp:275
void reset() noexcept
Reset the Block to a default-constructed state.
Definition: block.cpp:293
void parse() const
Parse TLV-VALUE into sub-elements.
Definition: block.cpp:326
Represents a CachePolicy header field.
CachePolicyType getPolicy() const
Get policy type code.
void wireDecode(const Block &wire)
Get CachePolicyType from wire format.
const Block & wireEncode() const
Encode CachePolicy into wire format.
CachePolicy & setPolicy(CachePolicyType policy)
Set policy type code.
#define NDN_CXX_DEFINE_WIRE_ENCODE_INSTANTIATIONS(ClassName)
#define NDN_THROW(e)
Definition: exception.hpp:56
EncodingImpl< EstimatorTag > EncodingEstimator
size_t prependNonNegativeIntegerBlock(EncodingImpl< TAG > &encoder, uint32_t type, uint64_t value)
Prepend a TLV element containing a non-negative integer.
EncodingImpl< EncoderTag > EncodingBuffer
std::string to_string(const errinfo_stacktrace &x)
Definition: exception.cpp:30
@ CachePolicy
Definition: tlv.hpp:47
@ CachePolicyType
Definition: tlv.hpp:48
Contains classes and functions related to NDNLPv2.
CachePolicyType
Indicates the cache policy applied to a Data packet.
std::ostream & operator<<(std::ostream &os, CachePolicyType policy)
constexpr std::underlying_type_t< T > to_underlying(T val) noexcept
Definition: backports.hpp:44