HashTbl changes

- iterators store pointers instead of references to the HashTbl.
  This lets us use the default bitwise copy/assignment

- add empty constructor for iterators. It returns the equivalent to end().
  This lets us do this:
      HashTbl<label>::iterator iter;
      // some time later
      iter = find(Value);

- erase(const HashTbl<AnyType, Key, AnyHash>&) is now more generous.
  Only the Key type matters, not the hashing function.

applications/test/HashTable/hashTableTest.C

@@ -40,6 +40,7 @@ using namespace Foam;
 int main()
 {
     HASHTABLE_CLASS<double> table1(13);
+    HASHTABLE_CLASS<double>::iterator iter;
 
     table1.insert("aaa", 1.0);
     table1.insert("aba", 2.0);
@@ -52,8 +53,12 @@ int main()
     table1.insert("adx", 9.0);
     table1.insert("aec", 10.0);
 
+    // erase by key
     table1.erase("aaw");
-    table1.erase("abs");
+
+    // erase by iterator
+    iter = table1.find("abs");
+    table1.erase(iter);
 
     Info<< "\ntable1 toc: " << table1.toc() << endl;
     Info<< "\ntable1 sortedToc: " << table1.sortedToc() << endl;

src/OpenFOAM/containers/HashTables/HashTbl/HashTbl.C

@@ -66,8 +66,8 @@ Foam::HashTbl<T, Key, Hash>::HashTbl(const label size)
     nElmts_(0),
     tableSize_(canonicalSize(size)),
     table_(NULL),
-    endIter_(*this, NULL, 0),
-    endConstIter_(*this, NULL, 0)
+    endIter_(),
+    endConstIter_()
 {
     if (tableSize_)
     {
@@ -88,8 +88,8 @@ Foam::HashTbl<T, Key, Hash>::HashTbl(const HashTbl<T, Key, Hash>& ht)
     nElmts_(0),
     tableSize_(ht.tableSize_),
     table_(NULL),
-    endIter_(*this, NULL, 0),
-    endConstIter_(*this, NULL, 0)
+    endIter_(),
+    endConstIter_()
 {
     if (tableSize_)
     {
@@ -117,8 +117,8 @@ Foam::HashTbl<T, Key, Hash>::HashTbl
     nElmts_(0),
     tableSize_(0),
     table_(NULL),
-    endIter_(*this, NULL, 0),
-    endConstIter_(*this, NULL, 0)
+    endIter_(),
+    endConstIter_()
 {
     transfer(ht());
 }
@@ -182,7 +182,7 @@ Foam::HashTbl<T, Key, Hash>::find
         {
             if (key == ep->key_)
             {
-                return iterator(*this, ep, hashIdx);
+                return iterator(this, ep, hashIdx);
             }
         }
     }
@@ -214,7 +214,7 @@ Foam::HashTbl<T, Key, Hash>::find
         {
             if (key == ep->key_)
             {
-                return const_iterator(*this, ep, hashIdx);
+                return const_iterator(this, ep, hashIdx);
             }
         }
     }
@@ -344,7 +344,8 @@ bool Foam::HashTbl<T, Key, Hash>::set
 template<class T, class Key, class Hash>
 bool Foam::HashTbl<T, Key, Hash>::erase(const iterator& cit)
 {
-    if (cit.elmtPtr_)    // note: endIter_ also has 0 elmtPtr_
+    // note: endIter_ has NULL elmtPtr_, so this also catches that
+    if (cit.elmtPtr_)
     {
         // Search element before elmtPtr_
         hashedEntry* prev = 0;
@@ -377,9 +378,8 @@ bool Foam::HashTbl<T, Key, Hash>::erase(const iterator& cit)
             // assign an non-NULL value so it doesn't look like end()/cend()
             iter.elmtPtr_ = reinterpret_cast<hashedEntry*>(this);
 
-            // mark with special hashIndex value
-            // to signal that it has been rewound
-            // the next increment will bring it bach to the present location
+            // mark with special hashIndex value to signal it has been rewound
+            // the next increment will bring it back to the present location
             iter.hashIndex_ = -iter.hashIndex_ - 1;
         }
 
@@ -400,7 +400,7 @@ bool Foam::HashTbl<T, Key, Hash>::erase(const iterator& cit)
 #       ifdef FULLDEBUG
         if (debug)
         {
-            Info<< "HashTbl<T, Key, Hash>::erase(iterator&) : "
+            Info<< "HashTbl<T, Key, Hash>::erase(const iterator&) : "
                 << "cannot remove hashedEntry from hash table\n";
         }
 #       endif
@@ -448,10 +448,10 @@ Foam::label Foam::HashTbl<T, Key, Hash>::erase(const UList<Key>& keys)
 
 
 template<class T, class Key, class Hash>
-template<class AnyType>
+template<class AnyType, class AnyHash>
 Foam::label Foam::HashTbl<T, Key, Hash>::erase
 (
-    const HashTbl<AnyType, Key, Hash>& rhs
+    const HashTbl<AnyType, Key, AnyHash>& rhs
 )
 {
     label count = 0;

src/OpenFOAM/containers/HashTables/HashTbl/HashTbl.H

@@ -119,7 +119,7 @@ class HashTbl
         //- The current number of elements in table
         label nElmts_;
 
-        //- Number of primary entries allocated in table (not necessarily used)
+        //- Number of primary entries allocated in table
         label tableSize_;
 
         //- The table of primary entries
@@ -140,17 +140,18 @@ class HashTbl
 
 public:
 
+    // Forward declaration of STL iterators
+        class iterator;
+        class const_iterator;
+
         //- Declare friendship with the HashPtrTable class
         template<class T2, class Key2, class Hash2>
         friend class HashPtrTable;
 
-
-    // Forward declaration of STL iterators
-
-        class iterator;
+        //- Declare friendship with the iterator
         friend class iterator;
 
-        class const_iterator;
+        //- Declare friendship with the const_iterator
         friend class const_iterator;
 
 
@@ -181,7 +182,7 @@ public:
             //- The size of the underlying table
             inline label capacity() const;
 
-            //- Return number of elements in table.
+            //- Return number of elements in table
             inline label size() const;
 
             //- Return true if the hash table is empty
@@ -215,10 +216,11 @@ public:
             //- Assign a new hashedEntry, overwriting existing entries
             inline bool set(const Key&, const T& newElmt);
 
-            //- Erase an hashedEntry specified by given iterator
+            //- Erase a hashedEntry specified by given iterator
+            //  This invalidates the iterator until the operator++
             bool erase(const iterator&);
 
-            //- Erase an hashedEntry specified by given key if in table
+            //- Erase a hashedEntry specified by the given key
             bool erase(const Key&);
 
             //- Remove entries given by the listed keys from this HashTbl
@@ -227,10 +229,10 @@ public:
 
             //- Remove entries given by the given keys from this HashTbl
             //  Return the number of elements removed.
-            //  The parameter HashTbl needs the same type of keys, but
-            //  but the type of values held is arbitrary.
-            template<class AnyType>
-            label erase(const HashTbl<AnyType, Key, Hash>&);
+            //  The parameter HashTbl needs the same type of key, but the
+            //  type of values held and the hashing function is arbitrary.
+            template<class AnyType, class AnyHash>
+            label erase(const HashTbl<AnyType, Key, AnyHash>&);
 
             //- Resize the hash table for efficiency
             void resize(const label newSize);
@@ -255,13 +257,13 @@ public:
 
     // Member Operators
 
-        //- Find and return an hashedEntry
+        //- Find and return a hashedEntry
         inline T& operator[](const Key&);
 
-        //- Find and return an hashedEntry
+        //- Find and return a hashedEntry
         inline const T& operator[](const Key&) const;
 
-        //- Find and return an hashedEntry, create it null if not present.
+        //- Find and return a hashedEntry, create it null if not present
         inline T& operator()(const Key&);
 
         //- Assignment
@@ -295,7 +297,7 @@ public:
         typedef label size_type;
 
 
-    // STL iterator
+    // Iterators and helpers
 
         //- An STL-conforming iterator
         class iterator
@@ -305,8 +307,9 @@ public:
 
             // Private data
 
-                //- Reference to the HashTbl this is an iterator for
-                HashTbl<T, Key, Hash>& hashTable_;
+                //- Pointer to the HashTbl for which this is an iterator
+                //  This also lets us use the default bitwise copy/assignment
+                HashTbl<T, Key, Hash>* hashTable_;
 
                 //- Current element
                 hashedEntry* elmtPtr_;
@@ -318,34 +321,43 @@ public:
 
             // Constructors
 
+                //- Construct null (end iterator)
+                inline iterator();
+
                 //- Construct from hash table, element and hash index
                 inline iterator
                 (
-                    HashTbl<T, Key, Hash>& curHashTbl,
+                    HashTbl<T, Key, Hash>* curHashTbl,
                     hashedEntry* elmt,
-                    label hashIndex
+                    const label hashIndex
                 );
 
+
             // Member operators
 
-                inline void operator=(const iterator&);
+                // Access
 
+                //- Return the Key corresponding to the iterator
+                inline const Key& key() const;
+
+                //- Compare hashedEntry element pointers
                 inline bool operator==(const iterator&) const;
                 inline bool operator!=(const iterator&) const;
 
+                //- Compare hashedEntry element pointers
                 inline bool operator==(const const_iterator&) const;
                 inline bool operator!=(const const_iterator&) const;
 
+                //- Return referenced hash value
                 inline T& operator*();
                 inline T& operator()();
 
+                //- Return referenced hash value
                 inline const T& operator*() const;
                 inline const T& operator()() const;
 
                 inline iterator& operator++();
                 inline iterator operator++(int);
-
-                inline const Key& key() const;
         };
 
 
@@ -365,8 +377,9 @@ public:
 
             // Private data
 
-                //- Reference to the HashTbl this is an iterator for
-                const HashTbl<T, Key, Hash>& hashTable_;
+                //- Pointer to the HashTbl for which this is an iterator
+                //  This also lets us use the default bitwise copy/assignment
+                const HashTbl<T, Key, Hash>* hashTable_;
 
                 //- Current element
                 const hashedEntry* elmtPtr_;
@@ -374,17 +387,19 @@ public:
                 //- Current hash index
                 label hashIndex_;
 
-
         public:
 
             // Constructors
 
+                //- Construct null (end iterator)
+                inline const_iterator();
+
                 //- Construct from hash table, element and hash index
                 inline const_iterator
                 (
-                    const HashTbl<T, Key, Hash>& curHashTbl,
+                    const HashTbl<T, Key, Hash>* curHashTbl,
                     const hashedEntry* elmt,
-                    label hashIndex
+                    const label hashIndex
                 );
 
                 //- Construct from the non-const iterator
@@ -393,21 +408,26 @@ public:
 
             // Member operators
 
-                inline void operator=(const const_iterator&);
+                // Access
 
+                //- Return the Key corresponding to the iterator
+                inline const Key& key() const;
+
+                //- Compare hashedEntry element pointers
                 inline bool operator==(const const_iterator&) const;
                 inline bool operator!=(const const_iterator&) const;
 
+                //- Compare hashedEntry element pointers
                 inline bool operator==(const iterator&) const;
                 inline bool operator!=(const iterator&) const;
 
+                //- Return referenced hash value
                 inline const T& operator*() const;
                 inline const T& operator()() const;
 
                 inline const_iterator& operator++();
                 inline const_iterator operator++(int);
 
-                inline const Key& key() const;
         };
 
 

src/OpenFOAM/containers/HashTables/HashTbl/HashTblI.H

@@ -164,9 +164,9 @@ inline T& Foam::HashTbl<T, Key, Hash>::operator()(const Key& key)
 template<class T, class Key, class Hash>
 inline Foam::HashTbl<T, Key, Hash>::iterator::iterator
 (
-    HashTbl<T, Key, Hash>& hashTbl,
+    HashTbl<T, Key, Hash>* hashTbl,
     hashedEntry* elmt,
-    label hashIndex
+    const label hashIndex
 )
 :
     hashTable_(hashTbl),
@@ -176,14 +176,12 @@ inline Foam::HashTbl<T, Key, Hash>::iterator::iterator
 
 
 template<class T, class Key, class Hash>
-inline void Foam::HashTbl<T, Key, Hash>::iterator::operator=
-(
-    const iterator& iter
-)
-{
-    elmtPtr_ = iter.elmtPtr_;
-    hashIndex_ = iter.hashIndex_;
-}
+inline Foam::HashTbl<T, Key, Hash>::iterator::iterator()
+:
+    hashTable_(0),
+    elmtPtr_(0),
+    hashIndex_(0)
+{}
 
 
 template<class T, class Key, class Hash>
@@ -278,12 +276,12 @@ Foam::HashTbl<T, Key, Hash>::iterator::operator++()
     // Step to the next table entry
     while
     (
-        ++hashIndex_ < hashTable_.tableSize_
-     && !(elmtPtr_ = hashTable_.table_[hashIndex_])
+        ++hashIndex_ < hashTable_->tableSize_
+     && !(elmtPtr_ = hashTable_->table_[hashIndex_])
     )
     {}
 
-    if (hashIndex_ >= hashTable_.tableSize_)
+    if (hashIndex_ >= hashTable_->tableSize_)
     {
         // make an end iterator
         elmtPtr_ = 0;
@@ -318,19 +316,19 @@ template<class T, class Key, class Hash>
 inline typename Foam::HashTbl<T, Key, Hash>::iterator
 Foam::HashTbl<T, Key, Hash>::begin()
 {
-    label i = 0;
+    label hashIdx = 0;
 
     if (nElmts_)
     {
-        while (table_ && !table_[i] && ++i < tableSize_)
+        while (table_ && !table_[hashIdx] && ++hashIdx < tableSize_)
         {}
     }
     else
     {
-        i = tableSize_;
+        hashIdx = tableSize_;
     }
 
-    if (i == tableSize_)
+    if (hashIdx >= tableSize_)
     {
 #       ifdef FULLDEBUG
         if (debug)
@@ -343,7 +341,7 @@ Foam::HashTbl<T, Key, Hash>::begin()
     }
     else
     {
-        return iterator(*this, table_[i], i);
+        return iterator(this, table_[hashIdx], hashIdx);
     }
 }
 
@@ -358,12 +356,21 @@ Foam::HashTbl<T, Key, Hash>::end()
 
 // * * * * * * * * * * * * * * * STL const_iterator * * * * * * * * * * * * * //
 
+template<class T, class Key, class Hash>
+inline Foam::HashTbl<T, Key, Hash>::const_iterator::const_iterator()
+:
+    hashTable_(0),
+    elmtPtr_(0),
+    hashIndex_(0)
+{}
+
+
 template<class T, class Key, class Hash>
 inline Foam::HashTbl<T, Key, Hash>::const_iterator::const_iterator
 (
-    const HashTbl<T, Key, Hash>& hashTbl,
+    const HashTbl<T, Key, Hash>* hashTbl,
     const hashedEntry* elmt,
-    label hashIndex
+    const label hashIndex
 )
 :
     hashTable_(hashTbl),
@@ -384,17 +391,6 @@ inline Foam::HashTbl<T, Key, Hash>::const_iterator::const_iterator
 {}
 
 
-template<class T, class Key, class Hash>
-inline void Foam::HashTbl<T, Key, Hash>::const_iterator::operator=
-(
-    const const_iterator& iter
-)
-{
-    elmtPtr_ = iter.elmtPtr_;
-    hashIndex_ = iter.hashIndex_;
-}
-
-
 template<class T, class Key, class Hash>
 inline bool Foam::HashTbl<T, Key, Hash>::const_iterator::operator==
 (
@@ -458,14 +454,14 @@ Foam::HashTbl<T, Key, Hash>::const_iterator::operator++()
     if
     (
         !(elmtPtr_ = elmtPtr_->next_)
-     && ++hashIndex_ < hashTable_.tableSize_
-     && !(elmtPtr_ = hashTable_.table_[hashIndex_])
+     && ++hashIndex_ < hashTable_->tableSize_
+     && !(elmtPtr_ = hashTable_->table_[hashIndex_])
     )
     {
         while
         (
-            ++hashIndex_ < hashTable_.tableSize_
-         && !(elmtPtr_ = hashTable_.table_[hashIndex_])
+            ++hashIndex_ < hashTable_->tableSize_
+         && !(elmtPtr_ = hashTable_->table_[hashIndex_])
         )
         {}
     }
@@ -499,19 +495,19 @@ template<class T, class Key, class Hash>
 inline typename Foam::HashTbl<T, Key, Hash>::const_iterator
 Foam::HashTbl<T, Key, Hash>::cbegin() const
 {
-    label i = 0;
+    label hashIdx = 0;
 
     if (nElmts_)
     {
-        while (table_ && !table_[i] && ++i < tableSize_)
+        while (table_ && !table_[hashIdx] && ++hashIdx < tableSize_)
         {}
     }
     else
     {
-        i = tableSize_;
+        hashIdx = tableSize_;
     }
 
-    if (i == tableSize_)
+    if (hashIdx >= tableSize_)
     {
 #       ifdef FULLDEBUG
         if (debug)
@@ -524,7 +520,7 @@ Foam::HashTbl<T, Key, Hash>::cbegin() const
     }
     else
     {
-        return const_iterator(*this, table_[i], i);
+        return const_iterator(this, table_[hashIdx], hashIdx);
     }
 }
 

src/OpenFOAM/containers/HashTables/HashTbl/HashTblIO.C

@@ -37,8 +37,8 @@ Foam::HashTbl<T, Key, Hash>::HashTbl(Istream& is, const label size)
     nElmts_(0),
     tableSize_(canonicalSize(size)),
     table_(new hashedEntry*[tableSize_]),
-    endIter_(*this, NULL, 0),
-    endConstIter_(*this, NULL, 0)
+    endIter_(),
+    endConstIter_()
 {
     for (label hashIdx = 0; hashIdx < tableSize_; hashIdx++)
     {