link: add Link abstraction
Change-Id: I1e4bafe8559ef87135de6cb6f209fc94dfa231a3
Refs: #2587
diff --git a/src/link.cpp b/src/link.cpp
new file mode 100644
index 0000000..07ac0d9
--- /dev/null
+++ b/src/link.cpp
@@ -0,0 +1,199 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2015 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.
+ */
+
+#include "link.hpp"
+#include "interest.hpp"
+#include "encoding/block-helpers.hpp"
+#include "util/crypto.hpp"
+#include "security/key-chain.hpp"
+#include "util/concepts.hpp"
+
+#include <algorithm>
+
+#include <boost/range/adaptors.hpp>
+
+namespace ndn {
+
+BOOST_CONCEPT_ASSERT((boost::EqualityComparable<Link>));
+BOOST_CONCEPT_ASSERT((WireEncodable<Link>));
+BOOST_CONCEPT_ASSERT((WireDecodable<Link>));
+static_assert(std::is_base_of<Data::Error, Link::Error>::value,
+ "Link::Error should inherit from Data::Error");
+
+Link::Link(const Block& block)
+{
+ wireDecode(block);
+}
+
+Link::Link(const Name& name)
+ : Data(name)
+{
+}
+
+Link::Link(const Name& name, std::initializer_list<std::pair<uint32_t, Name>> links)
+ : Data(name)
+{
+ m_delegations.insert(links);
+ encodeContent();
+}
+
+void
+Link::addDelegation(uint32_t preference, const Name& name)
+{
+ this->removeDelegationNoEncode(name);
+ m_delegations.insert({preference, name});
+ encodeContent();
+}
+
+bool
+Link::removeDelegation(const Name& name)
+{
+ bool hasRemovedDelegation = this->removeDelegationNoEncode(name);
+ if (hasRemovedDelegation) {
+ encodeContent();
+ }
+ return hasRemovedDelegation;
+}
+
+const Link::DelegationSet&
+Link::getDelegations() const
+{
+ return m_delegations;
+}
+
+template<encoding::Tag TAG>
+size_t
+Link::encodeContent(EncodingImpl<TAG>& encoder) const
+{
+ // LinkContent ::= CONTENT-TYPE TLV-LENGTH
+ // Delegation+
+
+ // Delegation ::= LINK-DELEGATION-TYPE TLV-LENGTH
+ // Preference
+ // Name
+
+ // Preference ::= LINK-PREFERENCE-TYPE TLV-LENGTH
+ // nonNegativeInteger
+
+ size_t totalLength = 0;
+ for (const auto& delegation : m_delegations | boost::adaptors::reversed) {
+ size_t delegationLength = 0;
+ delegationLength += std::get<1>(delegation).wireEncode(encoder);
+ delegationLength += prependNonNegativeIntegerBlock(encoder, tlv::LinkPreference,
+ std::get<0>(delegation));
+ delegationLength += encoder.prependVarNumber(delegationLength);
+ delegationLength += encoder.prependVarNumber(tlv::LinkDelegation);
+ totalLength += delegationLength;
+ }
+ totalLength += encoder.prependVarNumber(totalLength);
+ totalLength += encoder.prependVarNumber(tlv::Content);
+ return totalLength;
+}
+
+template size_t
+Link::encodeContent<encoding::EncoderTag>(EncodingImpl<encoding::EncoderTag>&) const;
+
+template size_t
+Link::encodeContent<encoding::EstimatorTag>(EncodingImpl<encoding::EstimatorTag>&) const;
+
+void
+Link::encodeContent()
+{
+ onChanged();
+
+ EncodingEstimator estimator;
+ size_t estimatedSize = encodeContent(estimator);
+
+ EncodingBuffer buffer(estimatedSize, 0);
+ encodeContent(buffer);
+
+ setContentType(tlv::ContentType_Link);
+ setContent(buffer.block());
+}
+
+void
+Link::decodeContent()
+{
+ // LinkContent ::= CONTENT-TYPE TLV-LENGTH
+ // Delegation+
+
+ // Delegation ::= LINK-DELEGATION-TYPE TLV-LENGTH
+ // Preference
+ // Name
+
+ // Preference ::= LINK-PREFERENCE-TYPE TLV-LENGTH
+ // nonNegativeInteger
+
+ if (getContentType() != tlv::ContentType_Link)
+ {
+ throw Error("Expected Content Type Link");
+ }
+
+ const Block& content = getContent();
+ content.parse();
+
+ for (auto& delegation : content.elements()) {
+ delegation.parse();
+ Block::element_const_iterator val = delegation.elements_begin();
+ if (val == delegation.elements_end()) {
+ throw Error("Unexpected Link Encoding");
+ }
+ uint32_t preference;
+ try {
+ preference = static_cast<uint32_t>(readNonNegativeInteger(*val));
+ }
+ catch (tlv::Error&) {
+ throw Error("Missing preference field in Link Encoding");
+ }
+ ++val;
+ if (val == delegation.elements_end()) {
+ throw Error("Missing name field in Link Encoding");
+ }
+ Name name(*val);
+ m_delegations.insert({preference, name});
+ }
+}
+
+void
+Link::wireDecode(const Block& wire)
+{
+ Data::wireDecode(wire);
+ decodeContent();
+}
+
+bool
+Link::removeDelegationNoEncode(const Name& name)
+{
+ bool hasRemoved = false;
+ auto i = m_delegations.begin();
+ while (i != m_delegations.end()) {
+ if (i->second == name) {
+ hasRemoved = true;
+ i = m_delegations.erase(i);
+ }
+ else {
+ ++i;
+ }
+ }
+ return hasRemoved;
+}
+
+} // namespace ndn