link.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2013-2023 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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8  * terms of the GNU Lesser General Public License as published by the Free Software
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21 
22 #include "ndn-cxx/link.hpp"
23 
24 #include <algorithm>
25 
26 namespace ndn {
27 
28 Link::Link() = default;
29 
30 Link::Link(const Block& wire)
31 {
32  this->wireDecode(wire);
33 }
34 
35 Link::Link(const Name& name, std::initializer_list<Name> delegations)
36  : Data(name)
37  , m_delegations(delegations)
38 {
39  encodeContent();
40 }
41 
42 void
43 Link::encodeContent()
44 {
46  setContent(makeNestedBlock(tlv::Content, m_delegations.begin(), m_delegations.end()));
47 }
48 
49 void
50 Link::wireDecode(const Block& wire)
51 {
52  Data::wireDecode(wire);
53 
55  NDN_THROW(Error("Expecting ContentType Link, got " + to_string(getContentType())));
56  }
57 
58  // LinkContent = CONTENT-TYPE TLV-LENGTH 1*Name
59 
60  m_delegations.clear();
61  auto content = getContent();
62  content.parse();
63  for (const auto& del : content.elements()) {
64  if (del.type() == tlv::Name) {
65  m_delegations.emplace_back(del);
66  }
67  else if (tlv::isCriticalType(del.type())) {
68  NDN_THROW(Error("Unexpected TLV-TYPE " + to_string(del.type()) + " while decoding LinkContent"));
69  }
70  }
71 }
72 
73 void
74 Link::setDelegationList(std::vector<Name> delegations)
75 {
76  m_delegations = std::move(delegations);
77  encodeContent();
78 }
79 
80 bool
82 {
83  if (std::find(m_delegations.begin(), m_delegations.end(), name) != m_delegations.end()) {
84  return false;
85  }
86 
87  m_delegations.push_back(name);
88  encodeContent();
89  return true;
90 }
91 
92 bool
94 {
95  auto last = std::remove(m_delegations.begin(), m_delegations.end(), name);
96  if (last == m_delegations.end()) {
97  return false;
98  }
99 
100  m_delegations.erase(last, m_delegations.end());
101  encodeContent();
102  return true;
103 }
104 
105 } // namespace ndn
Represents a TLV element of the NDN packet format.
Definition: block.hpp:45
Represents a Data packet.
Definition: data.hpp:39
void wireDecode(const Block &wire)
Decode from wire.
Definition: data.cpp:118
Data & setContent(const Block &block)
Set Content from a Block.
Definition: data.cpp:239
uint32_t getContentType() const noexcept
Return the value of ContentType.
Definition: data.hpp:312
const Block & getContent() const noexcept
Get the Content element.
Definition: data.hpp:188
Data & setContentType(uint32_t type)
Set the ContentType.
Definition: data.cpp:337
Represents an absolute name.
Definition: name.hpp:45
#define NDN_THROW(e)
Definition: exception.hpp:56
Block makeNestedBlock(uint32_t type, const U &value)
Create a TLV block containing a nested TLV element.
std::string to_string(const errinfo_stacktrace &x)
Definition: exception.cpp:30
@ Name
Definition: tlv.hpp:71
@ Content
Definition: tlv.hpp:93
constexpr bool isCriticalType(uint32_t type) noexcept
Determine whether a TLV-TYPE is "critical" for evolvability purpose.
Definition: tlv.hpp:162
@ ContentType_Link
another name that identifies the actual data content
Definition: tlv.hpp:146
Definition: data.cpp:25