name-prefix-list: compare names only in operator==

NamePrefixList type is now a sorted container. The sort() method is
deleted.

The remove() method is renamed to erase(), in accordance with ndn-cxx
code style recommendations.

refs #4094

Change-Id: I2d3f2fa768a8dd9a51108f6f4064243b21fd6df8
diff --git a/src/lsa/name-lsa.cpp b/src/lsa/name-lsa.cpp
index 90f946f..50e4cb7 100644
--- a/src/lsa/name-lsa.cpp
+++ b/src/lsa/name-lsa.cpp
@@ -138,9 +138,6 @@
   auto nlsa = std::static_pointer_cast<NameLsa>(lsa);
   bool updated = false;
 
-  m_npl.sort();
-  nlsa->getNpl().sort();
-
   // Obtain the set difference of the current and the incoming
   // name prefix sets, and add those.
   std::list<ndn::Name> newNames = nlsa->getNpl().getNames();
@@ -153,8 +150,6 @@
     updated = true;
   }
 
-  m_npl.sort();
-
   // Also remove any names that are no longer being advertised.
   std::list<ndn::Name> namesToRemove;
   std::set_difference(oldNames.begin(), oldNames.end(), newNames.begin(), newNames.end(),
diff --git a/src/lsa/name-lsa.hpp b/src/lsa/name-lsa.hpp
index 1705abc..5e4cfa6 100644
--- a/src/lsa/name-lsa.hpp
+++ b/src/lsa/name-lsa.hpp
@@ -78,7 +78,7 @@
   removeName(const ndn::Name& name)
   {
     m_wire.reset();
-    m_npl.remove(name);
+    m_npl.erase(name);
   }
 
   bool
diff --git a/src/name-prefix-list.cpp b/src/name-prefix-list.cpp
index c858c96..5af7062 100644
--- a/src/name-prefix-list.cpp
+++ b/src/name-prefix-list.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  The University of Memphis,
+ * Copyright (c) 2014-2023,  The University of Memphis,
  *                           Regents of the University of California,
  *                           Arizona Board of Regents.
  *
@@ -28,85 +28,39 @@
 
 NamePrefixList::NamePrefixList(ndn::span<const ndn::Name> names)
 {
-  std::transform(names.begin(), names.end(), std::back_inserter(m_names),
-                 [] (const auto& name) { return NamePair{name, {""}}; });
-}
-
-std::vector<NamePrefixList::NamePair>::iterator
-NamePrefixList::get(const ndn::Name& name)
-{
-  return std::find_if(m_names.begin(), m_names.end(),
-                      [&] (const NamePrefixList::NamePair& pair) {
-                        return name == std::get<NamePrefixList::NamePairIndex::NAME>(pair);
-                      });
-}
-
-std::vector<std::string>::iterator
-NamePrefixList::getSource(const std::string& source, std::vector<NamePair>::iterator& entry)
-{
-  return std::find_if(std::get<NamePairIndex::SOURCES>(*entry).begin(),
-                      std::get<NamePairIndex::SOURCES>(*entry).end(),
-                      [&] (const std::string& containerSource) {
-                        return source == containerSource;
-                      });
+  for (const auto& name : names) {
+    insert(name);
+  }
 }
 
 bool
 NamePrefixList::insert(const ndn::Name& name, const std::string& source)
 {
-  auto pairItr = get(name);
-  if (pairItr == m_names.end()) {
-    std::vector<std::string> sources{source};
-    m_names.emplace_back(name, sources);
-    return true;
-  }
-  else {
-    auto& sources = std::get<NamePrefixList::NamePairIndex::SOURCES>(*pairItr);
-    auto sourceItr = getSource(source, pairItr);
-    if (sourceItr == sources.end()) {
-      sources.push_back(source);
-      return true;
-    }
-  }
-  return false;
+  auto& sources = m_namesSources[name];
+  return sources.insert(source).second;
 }
 
 bool
-NamePrefixList::remove(const ndn::Name& name, const std::string& source)
+NamePrefixList::erase(const ndn::Name& name, const std::string& source)
 {
-  auto pairItr = get(name);
-  if (pairItr != m_names.end()) {
-    auto& sources = std::get<NamePrefixList::NamePairIndex::SOURCES>(*pairItr);
-    auto sourceItr = getSource(source, pairItr);
-    if (sourceItr != sources.end()) {
-      sources.erase(sourceItr);
-      if (sources.empty()) {
-        m_names.erase(pairItr);
-      }
-      return true;
-    }
+  auto it = m_namesSources.find(name);
+  if (it == m_namesSources.end()) {
+    return false;
   }
-  return false;
-}
 
-bool
-NamePrefixList::operator==(const NamePrefixList& other) const
-{
-  return m_names == other.m_names;
-}
-
-void
-NamePrefixList::sort()
-{
-  std::sort(m_names.begin(), m_names.end());
+  bool isRemoved = it->second.erase(source);
+  if (it->second.empty()) {
+    m_namesSources.erase(it);
+  }
+  return isRemoved;
 }
 
 std::list<ndn::Name>
 NamePrefixList::getNames() const
 {
   std::list<ndn::Name> names;
-  for (const auto& namePair : m_names) {
-    names.push_back(std::get<NamePrefixList::NamePairIndex::NAME>(namePair));
+  for (const auto& [name, sources] : m_namesSources) {
+    names.push_back(name);
   }
   return names;
 }
@@ -120,16 +74,16 @@
 const std::vector<std::string>
 NamePrefixList::getSources(const ndn::Name& name) const
 {
-  auto it = std::find_if(m_names.begin(), m_names.end(),
-                         [&] (const NamePrefixList::NamePair& pair) {
-                           return name == std::get<NamePrefixList::NamePairIndex::NAME>(pair);
-                         });
-  if (it != m_names.end()) {
-    return std::get<NamePrefixList::NamePairIndex::SOURCES>(*it);
-  }
-  else {
+  auto it = m_namesSources.find(name);
+  if (it == m_namesSources.end()) {
     return {};
   }
+
+  std::vector<std::string> result;
+  for (const auto& source : it->second) {
+    result.push_back(source);
+  }
+  return result;
 }
 
 std::ostream&
diff --git a/src/name-prefix-list.hpp b/src/name-prefix-list.hpp
index 46eb0d0..68e6b81 100644
--- a/src/name-prefix-list.hpp
+++ b/src/name-prefix-list.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  The University of Memphis,
+ * Copyright (c) 2014-2023,  The University of Memphis,
  *                           Regents of the University of California,
  *                           Arizona Board of Regents.
  *
@@ -24,17 +24,20 @@
 
 #include "test-access-control.hpp"
 
+#include <ndn-cxx/name.hpp>
+
+#include <boost/operators.hpp>
+
 #include <initializer_list>
 #include <list>
+#include <map>
+#include <set>
 #include <string>
-#include <tuple>
 #include <vector>
 
-#include <ndn-cxx/name.hpp>
-
 namespace nlsr {
 
-class NamePrefixList
+class NamePrefixList : private boost::equality_comparable<NamePrefixList>
 {
 public:
   using NamePair = std::tuple<ndn::Name, std::vector<std::string>>;
@@ -56,8 +59,12 @@
   }
 
   NamePrefixList(std::initializer_list<NamePair> namesAndSources)
-    : m_names(namesAndSources)
   {
+    for (const auto& np : namesAndSources) {
+      for (const auto& source : std::get<NamePrefixList::NamePairIndex::SOURCES>(np)) {
+        insert(std::get<NamePrefixList::NamePairIndex::NAME>(np), source);
+      }
+    }
   }
 #endif
 
@@ -73,23 +80,17 @@
       \retval false If the name failed to be removed.
    */
   bool
-  remove(const ndn::Name& name, const std::string& source = "");
-
-  void
-  sort();
+  erase(const ndn::Name& name, const std::string& source = "");
 
   size_t
   size() const
   {
-    return m_names.size();
+    return m_namesSources.size();
   }
 
   std::list<ndn::Name>
   getNames() const;
 
-  bool
-  operator==(const NamePrefixList& other) const;
-
   /*! Returns how many unique sources this name has.
 
     \retval 0 if the name is not in the list, else the number of sources.
@@ -108,24 +109,22 @@
   void
   clear()
   {
-    m_names.clear();
+    m_namesSources.clear();
+  }
+
+private: // non-member operators
+  // NOTE: the following "hidden friend" operators are available via
+  //       argument-dependent lookup only and must be defined inline.
+  // boost::equality_comparable provides != operators.
+
+  friend bool
+  operator==(const NamePrefixList& lhs, const NamePrefixList& rhs)
+  {
+    return lhs.getNames() == rhs.getNames();
   }
 
 private:
-  /*! Obtain an iterator to the entry matching name.
-
-    \note We could do this quite easily inline with a lambda, but this
-    is slightly more efficient.
-   */
-  std::vector<NamePair>::iterator
-  get(const ndn::Name& name);
-
-  /*! Obtain an iterator to a specific source in an entry
-   */
-  std::vector<std::string>::iterator
-  getSource(const std::string& source, std::vector<NamePair>::iterator& entry);
-
-  std::vector<NamePair> m_names;
+  std::map<ndn::Name, std::set<std::string>> m_namesSources;
 };
 
 std::ostream&
diff --git a/src/update/manager-base.cpp b/src/update/manager-base.cpp
index 238a88f..3e0b612 100644
--- a/src/update/manager-base.cpp
+++ b/src/update/manager-base.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  The University of Memphis,
+ * Copyright (c) 2014-2023,  The University of Memphis,
  *                           Regents of the University of California,
  *                           Arizona Board of Regents.
  *
@@ -102,7 +102,7 @@
     static_cast<const ndn::nfd::ControlParameters&>(parameters);
 
   // Only build a Name LSA if the added name is new
-  if (m_namePrefixList.remove(castParams.getName())) {
+  if (m_namePrefixList.erase(castParams.getName())) {
     NLSR_LOG_INFO("Withdrawing/Removing name: " << castParams.getName() << "\n");
     m_lsdb.buildAndInstallOwnNameLsa();
     if (castParams.hasFlags() && castParams.getFlags() == PREFIX_FLAG) {