Started implementing namespace association.

src/coins.cpp

@@ -14,6 +14,7 @@ bool CCoinsView::GetNamespace(const valtype &nameSpace, CKevaData &data) const {
 bool CCoinsView::GetName(const valtype &nameSpace, const valtype &key, CKevaData &data) const { return false; }
 bool CCoinsView::GetNamesForHeight(unsigned nHeight, std::set<valtype>& names) const { return false; }
 CKevaIterator* CCoinsView::IterateKeys(const valtype& nameSpace) const { assert (false); }
+CKevaIterator* CCoinsView::IterateAssociatedNamespaces(const valtype& nameSpace) const { assert (false); }
 bool CCoinsView::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock, const CKevaCache &names) { return false; }
 CCoinsViewCursor *CCoinsView::Cursor() const { return nullptr; }
 bool CCoinsView::ValidateKevaDB() const {
@@ -43,6 +44,7 @@ bool CCoinsViewBacked::GetNamesForHeight(unsigned nHeight, std::set<valtype>& na
     return base->GetNamesForHeight(nHeight, names);
 }
 CKevaIterator* CCoinsViewBacked::IterateKeys(const valtype& nameSpace) const { return base->IterateKeys(nameSpace); }
+CKevaIterator* CCoinsViewBacked::IterateAssociatedNamespaces(const valtype& nameSpace) const { return base->IterateAssociatedNamespaces(nameSpace); }
 void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; }
 bool CCoinsViewBacked::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock, const CKevaCache &names) {
     return base->BatchWrite(mapCoins, hashBlock, names);
@@ -198,6 +200,10 @@ CKevaIterator* CCoinsViewCache::IterateKeys(const valtype& nameSpace) const {
     return cacheNames.iterateKeys(base->IterateKeys(nameSpace));
 }
 
+CKevaIterator* CCoinsViewCache::IterateAssociatedNamespaces(const valtype& nameSpace) const {
+    return cacheNames.IterateAssociatedNamespaces(base->IterateAssociatedNamespaces(nameSpace));
+}
+
 /* undo is set if the change is due to disconnecting blocks / going back in
    time.  The ordinary case (!undo) means that we update the name normally,
    going forward in time.  This is important for keeping track of the
@@ -210,6 +216,18 @@ void CCoinsViewCache::SetName(const valtype &nameSpace, const valtype &key, cons
         cacheNames.setNamespace(nameSpace, namespaceData);
     }
     cacheNames.set(nameSpace, key, data);
+
+    // Handle namespace association.
+    valtype associdateNamespace;
+    if (!cacheNames.getAssociateNamespaces(data.getValue(), associdateNamespace)) {
+        return;
+    }
+
+    CKevaData dummyData;
+    if (!GetNamespace(associdateNamespace, dummyData)) {
+        return;
+    }
+    cacheNames.associateNamespaces(nameSpace, associdateNamespace);
 }
 
 void CCoinsViewCache::DeleteName(const valtype &nameSpace, const valtype &key) {
@@ -218,6 +236,18 @@ void CCoinsViewCache::DeleteName(const valtype &nameSpace, const valtype &key) {
         assert(false);
     }
     cacheNames.remove(nameSpace, key);
+
+    // Handle namespace association.
+    valtype associdateNamespace;
+    if (!cacheNames.getAssociateNamespaces(oldData.getValue(), associdateNamespace)) {
+        return;
+    }
+
+    CKevaData dummyData;
+    if (!GetNamespace(associdateNamespace, dummyData)) {
+        return;
+    }
+    cacheNames.disassociateNamespaces(nameSpace, associdateNamespace);
 }
 
 bool CCoinsViewCache::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlockIn, const CKevaCache &names) {

src/coins.h

@@ -176,6 +176,9 @@ public:
     // Get a key iterator.
     virtual CKevaIterator* IterateKeys(const valtype& nameSpace) const;
 
+    // Get the associated namespace iterator.
+    virtual CKevaIterator* IterateAssociatedNamespaces(const valtype& nameSpace) const;
+
     //! Do a bulk modification (multiple Coin changes + BestBlock change).
     //! The passed mapCoins can be modified.
     virtual bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock, const CKevaCache &names);
@@ -210,6 +213,7 @@ public:
     bool GetName(const valtype& nameSpace, const valtype& key, CKevaData& data) const override;
     bool GetNamesForHeight(unsigned nHeight, std::set<valtype>& names) const override;
     CKevaIterator* IterateKeys(const valtype& nameSpace) const override;
+    virtual CKevaIterator* IterateAssociatedNamespaces(const valtype& nameSpace) const override;
     void SetBackend(CCoinsView &viewIn);
     bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock, const CKevaCache &names) override;
     CCoinsViewCursor *Cursor() const override;
@@ -252,6 +256,7 @@ public:
     bool GetName(const valtype &nameSpace, const valtype &key, CKevaData& data) const override;
     bool GetNamesForHeight(unsigned nHeight, std::set<valtype>& names) const override;
     CKevaIterator* IterateKeys(const valtype& nameSpace) const override;
+    CKevaIterator* IterateAssociatedNamespaces(const valtype& nameSpace) const override;
     bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock, const CKevaCache &names) override;
     CCoinsViewCursor* Cursor() const override {
         throw std::logic_error("CCoinsViewCache cursor iteration not supported.");

src/keva/common.cpp

@@ -7,7 +7,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <keva/common.h>
-
+#include <base58.h>
 #include <script/keva.h>
 
 
@@ -55,6 +55,9 @@ private:
   /** Base iterator to combine with the cache.  */
   CKevaIterator* base;
 
+  /** Whether or not it is for namespace association.  */
+  bool isAssociation;
+
   /** Whether or not the base iterator has more entries.  */
   bool baseHasMore;
 
@@ -79,7 +82,7 @@ public:
    * @param c The cache object to use.
    * @param b The base iterator.
    */
-  CCacheKeyIterator(const CKevaCache& c, CKevaIterator* b);
+  CCacheKeyIterator(const CKevaCache& c, CKevaIterator* b, bool association=false);
 
   /* Destruct, this deletes also the base iterator.  */
   ~CCacheKeyIterator();
@@ -90,8 +93,8 @@ public:
 
 };
 
-CCacheKeyIterator::CCacheKeyIterator(const CKevaCache& c, CKevaIterator* b)
+CCacheKeyIterator::CCacheKeyIterator(const CKevaCache& c, CKevaIterator* b, bool association)
-  : CKevaIterator(b->getNamespace()), cache(c), base(b)
+  : CKevaIterator(b->getNamespace()), cache(c), base(b), isAssociation(association)
 {
   /* Add a seek-to-start to ensure that everything is consistent.  This call
      may be superfluous if we seek to another position afterwards anyway,
@@ -116,7 +119,8 @@ CCacheKeyIterator::advanceBaseIterator()
 void
 CCacheKeyIterator::seek(const valtype& start)
 {
-  cacheIter = cache.entries.lower_bound(std::make_tuple(nameSpace, start));
+  auto &entries = isAssociation ? cache.associations : cache.entries;
+  cacheIter = entries.lower_bound(std::make_tuple(nameSpace, start));
   base->seek(start);
 
   baseHasMore = true;
@@ -127,15 +131,15 @@ bool CCacheKeyIterator::next(valtype& key, CKevaData& data)
 {
   /* Exit early if no more data is available in either the cache
      nor the base iterator.  */
-
+  auto &entries = isAssociation ? cache.associations : cache.entries;
   bool endOfCacheNamespace = false;
-  if (cacheIter != cache.entries.end()) {
+  if (cacheIter != entries.end()) {
     valtype curNameSpace = std::get<0>(cacheIter->first);
     if (curNameSpace != nameSpace) {
       endOfCacheNamespace = true;
     }
   }
-  bool noMoreCache = (cacheIter == cache.entries.end()) || endOfCacheNamespace;
+  bool noMoreCache = (cacheIter == entries.end()) || endOfCacheNamespace;
   if (!baseHasMore && noMoreCache) {
     return false;
   }
@@ -144,7 +148,7 @@ bool CCacheKeyIterator::next(valtype& key, CKevaData& data)
   bool useBase = false;
   if (!baseHasMore) {
     useBase = false;
-  } else if (cacheIter == cache.entries.end()) {
+  } else if (cacheIter == entries.end()) {
     useBase = true;
   } else {
     if (baseKey == std::get<1>(cacheIter->first)) {
@@ -182,6 +186,8 @@ bool CCacheKeyIterator::next(valtype& key, CKevaData& data)
 /* ************************************************************************** */
 /* CKevaCache.  */
 
+const std::string CKevaCache::associatePrefix = "_A_";
+
 bool
 CKevaCache::get(const valtype& nameSpace, const valtype& key, CKevaData& data) const
 {
@@ -233,12 +239,55 @@ CKevaCache::remove(const valtype& nameSpace, const valtype& key)
   deleted.insert(name);
 }
 
+/* If the value is an associated namespace (_A_N...), return the namespace */
+bool
+CKevaCache::getAssociateNamespaces(const valtype& value, valtype& nameSpace)
+{
+  std::string valueStr = ValtypeToString(value);
+  if (valueStr.rfind(associatePrefix, 0) != 0) {
+    return false;
+  }
+  valueStr.erase(0, associatePrefix.length());
+  if (!DecodeKevaNamespace(valueStr, Params(), nameSpace)) {
+    return false;
+  }
+  return true;
+}
+
+void
+CKevaCache::associateNamespaces(const valtype& nameSpace, const valtype& nameSpaceOther)
+{
+  auto name = std::make_tuple(nameSpaceOther, nameSpace);
+  const NamespaceMap::iterator ei = associations.find(name);
+  CKevaData data;
+  if (ei != entries.end())
+    ei->second = data;
+  else
+    associations.insert(std::make_pair(name, data));
+}
+
+void
+CKevaCache::disassociateNamespaces(const valtype& nameSpace, const valtype& nameSpaceOther)
+{
+  auto name = std::make_tuple(nameSpaceOther, nameSpace);
+  const NamespaceMap::iterator ei = entries.find(name);
+  if (ei != entries.end()) {
+    associations.erase(ei);
+  }
+}
+
 CKevaIterator*
 CKevaCache::iterateKeys(CKevaIterator* base) const
 {
   return new CCacheKeyIterator(*this, base);
 }
 
+CKevaIterator*
+CKevaCache::IterateAssociatedNamespaces(CKevaIterator* base) const
+{
+  return new CCacheKeyIterator(*this, base, true);
+}
+
 void
 CKevaCache::updateNamesForHeight (unsigned nHeight,
                                   std::set<valtype>& names) const
@@ -253,6 +302,10 @@ void CKevaCache::apply(const CKevaCache& cache)
     set(std::get<0>(i->first), std::get<1>(i->first), i->second);
   }
 
+  for (NamespaceMap::const_iterator i = associations.begin(); i != associations.end(); ++i) {
+    set(std::get<0>(i->first), std::get<1>(i->first), i->second);
+  }
+
   for (std::set<NamespaceKeyType>::const_iterator i = cache.deleted.begin(); i != cache.deleted.end(); ++i) {
     remove(std::get<0>(*i), std::get<1>(*i));
   }

src/keva/common.h

@@ -2,7 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-// Copyright (c) 2018
+// Copyright (c) 2018-2020 The Kevacoin Core Developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -298,6 +298,8 @@ class CKevaCache
 
 private:
 
+  const static std::string associatePrefix;
+
   /**
    * Special comparator class for names that compares by length first.
    * This is used to sort the cache entry map in the same way as the
@@ -336,6 +338,8 @@ public:
 
   typedef std::tuple<valtype, valtype> NamespaceKeyType;
 
+  typedef std::map<std::tuple<valtype, valtype>, CKevaData, KeyComparator> NamespaceMap;
+
 private:
 
   /** New or updated names.  */
@@ -344,15 +348,19 @@ private:
   /** Deleted names.  */
   std::set<NamespaceKeyType> deleted;
 
+  /** Namespace association.  */
+  NamespaceMap associations;
+
   friend class CCacheKeyIterator;
 
 public:
 
   inline void
-  clear ()
+  clear()
   {
-    entries.clear ();
+    entries.clear();
-    deleted.clear ();
+    deleted.clear();
+    associations.clear();
   }
 
   /**
@@ -362,9 +370,9 @@ public:
    * @return True iff no changes are cached.
    */
   inline bool
-  empty () const
+  empty() const
   {
-    if (entries.empty() && deleted.empty()) {
+    if (entries.empty() && deleted.empty() && associations.empty()) {
       return true;
     }
 
@@ -394,11 +402,23 @@ public:
   /* Delete a name.  If it is in the "entries" set also, remove it there.  */
   void remove(const valtype& nameSpace, const valtype& key);
 
+  /* If the value is an associated namespace (_A_N...), return the namespace */
+  bool getAssociateNamespaces(const valtype& value, valtype& nameSpace);
+
+  /* Associate nameSpace with nameSpaceOther */
+  void associateNamespaces(const valtype& nameSpace, const valtype& nameSpaceOther);
+
+  /* Disassociate nameSpace with nameSpaceOther */
+  void disassociateNamespaces(const valtype& nameSpace, const valtype& nameSpaceOther);
+
   /* Return a name iterator that combines a "base" iterator with the changes
      made to it according to the cache.  The base iterator is taken
      ownership of.  */
   CKevaIterator* iterateKeys(CKevaIterator* base) const;
 
+  // Get the associated namespace iterator.
+  CKevaIterator* IterateAssociatedNamespaces(CKevaIterator* base) const;
+
   /* Query the cached changes to the expire index.  In particular,
      for a given height and a given set of names that were indexed to
      this update height, apply possible changes to the set that

src/rpc/rpckeva_nonwallet.cpp

@@ -2,7 +2,7 @@
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-// Copyright (c) 2018 the Kevacoin Core Developers
+// Copyright (c) 2018-2020 the Kevacoin Core Developers
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 

src/txdb.cpp

@@ -26,6 +26,7 @@ static const char DB_TXINDEX = 't';
 static const char DB_BLOCK_INDEX = 'b';
 
 static const char DB_NAME = 'n';
+static const char DB_NS_ASSOC = 'a';
 
 static const char DB_BEST_BLOCK = 'B';
 static const char DB_HEAD_BLOCKS = 'H';
@@ -92,6 +93,9 @@ private:
     /* The backing LevelDB iterator.  */
     CDBIterator* iter;
 
+    /* This iterator is for namespace association search. */
+    bool isAssociation;
+
 public:
 
     ~CDbKeyIterator();
@@ -100,7 +104,7 @@ public:
      * Construct a new name iterator for the database.
      * @param db The database to create the iterator for.
      */
-    CDbKeyIterator(const CDBWrapper& db, const valtype& nameSpace);
+    CDbKeyIterator(const CDBWrapper& db, const valtype& nameSpace, bool association=false);
 
     /* Implement iterator methods.  */
     void seek(const valtype& start);
@@ -112,22 +116,24 @@ CDbKeyIterator::~CDbKeyIterator() {
     delete iter;
 }
 
-CDbKeyIterator::CDbKeyIterator(const CDBWrapper& db, const valtype& ns)
+CDbKeyIterator::CDbKeyIterator(const CDBWrapper& db, const valtype& ns, bool association)
-    : CKevaIterator(ns), iter(const_cast<CDBWrapper*>(&db)->NewIterator())
+    : CKevaIterator(ns), iter(const_cast<CDBWrapper*>(&db)->NewIterator()), isAssociation(association)
 {
     seek(valtype());
 }
 
 void CDbKeyIterator::seek(const valtype& start) {
-    iter->Seek(std::make_pair(DB_NAME, std::make_pair(nameSpace, start)));
+    auto &prefix = isAssociation ? DB_NS_ASSOC : DB_NAME;
+    iter->Seek(std::make_pair(prefix, std::make_pair(nameSpace, start)));
 }
 
 bool CDbKeyIterator::next(valtype& key, CKevaData& data) {
     if (!iter->Valid())
         return false;
 
+    auto &prefix = isAssociation ? DB_NS_ASSOC : DB_NAME;
     std::pair<char, std::pair<valtype, valtype>> curKey;
-    if (!iter->GetKey(curKey) || curKey.first != DB_NAME)
+    if (!iter->GetKey(curKey) || curKey.first != prefix)
         return false;
 
     valtype curNameSpace = std::get<0>(curKey.second);
@@ -148,6 +154,10 @@ CKevaIterator* CCoinsViewDB::IterateKeys(const valtype& nameSpace) const {
     return new CDbKeyIterator(db, nameSpace);
 }
 
+CKevaIterator* CCoinsViewDB::IterateAssociatedNamespaces(const valtype& nameSpace) const {
+    return new CDbKeyIterator(db, nameSpace, true);
+}
+
 bool CCoinsViewDB::GetNamespace(const valtype &nameSpace, CKevaData &data) const {
     return db.Read(std::make_pair(DB_NAME, std::make_pair(nameSpace, CKevaScript::KEVA_DISPLAY_NAME_KEY)), data);
 }
@@ -324,6 +334,11 @@ void CKevaCache::writeBatch (CDBBatch& batch) const
     batch.Write(std::make_pair(DB_NAME, name), i->second);
   }
 
+  for (NamespaceMap::const_iterator i = associations.begin(); i != associations.end(); ++i) {
+    std::pair<valtype, valtype> name = std::make_pair(std::get<0>(i->first), std::get<1>(i->first));
+    batch.Write(std::make_pair(DB_NS_ASSOC, name), i->second);
+  }
+
   for (std::set<NamespaceKeyType>::const_iterator i = deleted.begin(); i != deleted.end(); ++i) {
     std::pair<valtype, valtype> name = std::make_pair(std::get<0>(*i), std::get<1>(*i));
     batch.Erase(std::make_pair(DB_NAME, name));

src/txdb.h

@@ -80,6 +80,7 @@ public:
     bool GetName(const valtype &nameSpace, const valtype &key, CKevaData &data) const override;
     bool GetNamesForHeight(unsigned nHeight, std::set<valtype>& names) const override;
     CKevaIterator* IterateKeys(const valtype& nameSpace) const override;
+    CKevaIterator* IterateAssociatedNamespaces(const valtype& nameSpace) const override;
     bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock, const CKevaCache &names) override;
     CCoinsViewCursor *Cursor() const override;