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openfoam/src/OpenFOAM/containers/HashTables/HashTable/HashTable.C

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C

/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 1991-2009 OpenCFD Ltd.
\\/ M anipulation |
-------------------------------------------------------------------------------
License
This file is part of OpenFOAM.
OpenFOAM is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OpenFOAM 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 General Public License
for more details.
You should have received a copy of the GNU General Public License
along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
\*---------------------------------------------------------------------------*/
#ifndef HashTable_C
#define HashTable_C
#include "HashTable.H"
#include "List.H"
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
template<class T, class Key, class Hash>
Foam::HashTable<T, Key, Hash>::HashTable(const label size)
:
HashTableCore(),
nElmts_(0),
tableSize_(HashTableCore::canonicalSize(size)),
table_(NULL)
{
if (tableSize_)
{
table_ = new hashedEntry*[tableSize_];
for (label hashIdx = 0; hashIdx < tableSize_; hashIdx++)
{
table_[hashIdx] = 0;
}
}
}
template<class T, class Key, class Hash>
Foam::HashTable<T, Key, Hash>::HashTable(const HashTable<T, Key, Hash>& ht)
:
HashTableCore(),
nElmts_(0),
tableSize_(ht.tableSize_),
table_(NULL)
{
if (tableSize_)
{
table_ = new hashedEntry*[tableSize_];
for (label hashIdx = 0; hashIdx < tableSize_; hashIdx++)
{
table_[hashIdx] = 0;
}
for (const_iterator iter = ht.cbegin(); iter != ht.cend(); ++iter)
{
insert(iter.key(), *iter);
}
}
}
template<class T, class Key, class Hash>
Foam::HashTable<T, Key, Hash>::HashTable
(
const Xfer<HashTable<T, Key, Hash> >& ht
)
:
HashTableCore(),
nElmts_(0),
tableSize_(0),
table_(NULL)
{
transfer(ht());
}
// * * * * * * * * * * * * * * * * Destructor * * * * * * * * * * * * * * * //
template<class T, class Key, class Hash>
Foam::HashTable<T, Key, Hash>::~HashTable()
{
if (table_)
{
clear();
delete[] table_;
}
}
// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
template<class T, class Key, class Hash>
bool Foam::HashTable<T, Key, Hash>::found(const Key& key) const
{
if (nElmts_)
{
const label hashIdx = hashKeyIndex(key);
for (hashedEntry* ep = table_[hashIdx]; ep; ep = ep->next_)
{
if (key == ep->key_)
{
return true;
}
}
}
# ifdef FULLDEBUG
if (debug)
{
Info<< "HashTable<T, Key, Hash>::found(const Key& key) : "
<< "Entry " << key << " not found in hash table\n";
}
# endif
return false;
}
template<class T, class Key, class Hash>
typename Foam::HashTable<T, Key, Hash>::iterator
Foam::HashTable<T, Key, Hash>::find
(
const Key& key
)
{
if (nElmts_)
{
const label hashIdx = hashKeyIndex(key);
for (hashedEntry* ep = table_[hashIdx]; ep; ep = ep->next_)
{
if (key == ep->key_)
{
return iterator(this, ep, hashIdx);
}
}
}
# ifdef FULLDEBUG
if (debug)
{
Info<< "HashTable<T, Key, Hash>::find(const Key& key) : "
<< "Entry " << key << " not found in hash table\n";
}
# endif
return iterator();
}
template<class T, class Key, class Hash>
typename Foam::HashTable<T, Key, Hash>::const_iterator
Foam::HashTable<T, Key, Hash>::find
(
const Key& key
) const
{
if (nElmts_)
{
const label hashIdx = hashKeyIndex(key);
for (hashedEntry* ep = table_[hashIdx]; ep; ep = ep->next_)
{
if (key == ep->key_)
{
return const_iterator(this, ep, hashIdx);
}
}
}
# ifdef FULLDEBUG
if (debug)
{
Info<< "HashTable<T, Key, Hash>::find(const Key& key) const : "
<< "Entry " << key << " not found in hash table\n";
}
# endif
return const_iterator();
}
template<class T, class Key, class Hash>
Foam::List<Key> Foam::HashTable<T, Key, Hash>::toc() const
{
List<Key> keys(nElmts_);
label keyI = 0;
for (const_iterator iter = cbegin(); iter != cend(); ++iter)
{
keys[keyI++] = iter.key();
}
return keys;
}
template<class T, class Key, class Hash>
Foam::List<Key> Foam::HashTable<T, Key, Hash>::sortedToc() const
{
List<Key> sortedLst = this->toc();
sort(sortedLst);
return sortedLst;
}
template<class T, class Key, class Hash>
bool Foam::HashTable<T, Key, Hash>::set
(
const Key& key,
const T& newEntry,
const bool protect
)
{
if (!tableSize_)
{
resize(2);
}
const label hashIdx = hashKeyIndex(key);
hashedEntry* existing = 0;
hashedEntry* prev = 0;
for (hashedEntry* ep = table_[hashIdx]; ep; ep = ep->next_)
{
if (key == ep->key_)
{
existing = ep;
break;
}
prev = ep;
}
// not found, insert it at the head
if (!existing)
{
table_[hashIdx] = new hashedEntry(key, table_[hashIdx], newEntry);
nElmts_++;
if (double(nElmts_)/tableSize_ > 0.8 && tableSize_ < maxTableSize)
{
# ifdef FULLDEBUG
if (debug)
{
Info<< "HashTable<T, Key, Hash>::set"
"(const Key& key, T newEntry) : "
"Doubling table size\n";
}
# endif
resize(2*tableSize_);
}
}
else if (protect)
{
// found - but protected from overwriting
// this corresponds to the STL 'insert' convention
# ifdef FULLDEBUG
if (debug)
{
Info<< "HashTable<T, Key, Hash>::set"
"(const Key& key, T newEntry, true) : "
"Cannot insert " << key << " already in hash table\n";
}
# endif
return false;
}
else
{
// found - overwrite existing entry
// this corresponds to the Perl convention
hashedEntry* ep = new hashedEntry(key, existing->next_, newEntry);
// replace existing element - within list or insert at the head
if (prev)
{
prev->next_ = ep;
}
else
{
table_[hashIdx] = ep;
}
delete existing;
}
return true;
}
template<class T, class Key, class Hash>
bool Foam::HashTable<T, Key, Hash>::iteratorBase::erase()
{
// note: entryPtr_ is NULL for end(), so this catches that too
if (entryPtr_)
{
// Search element before entryPtr_
hashedEntry* prev = 0;
for
(
hashedEntry* ep = hashTable_->table_[hashIndex_];
ep;
ep = ep->next_
)
{
if (ep == entryPtr_)
{
break;
}
prev = ep;
}
if (prev)
{
// has an element before entryPtr - reposition to there
prev->next_ = entryPtr_->next_;
delete entryPtr_;
entryPtr_ = prev;
}
else
{
// entryPtr was first element on SLList
hashTable_->table_[hashIndex_] = entryPtr_->next_;
delete entryPtr_;
// assign any non-NULL pointer value so it doesn't look
// like end()/cend()
entryPtr_ = reinterpret_cast<hashedEntry*>(this);
// Mark with special hashIndex value to signal it has been rewound.
// The next increment will bring it back to the present location.
//
// From the current position 'curPos', we wish to continue at
// prevPos='curPos-1', which we mark as markPos='-curPos-1'.
// The negative lets us notice it is special, the extra '-1'
// is needed to avoid ambiguity for position '0'.
// To retrieve prevPos, we would later use '-(markPos+1) - 1'
hashIndex_ = -hashIndex_ - 1;
}
hashTable_->nElmts_--;
return true;
}
else
{
return false;
}
}
// NOTE:
// We use (const iterator&) here, but manipulate its contents anyhow.
// The parameter should be (iterator&), but then the compiler doesn't find
// it correctly and tries to call as (iterator) instead.
//
template<class T, class Key, class Hash>
bool Foam::HashTable<T, Key, Hash>::erase(const iterator& iter)
{
// adjust iterator after erase
return const_cast<iterator&>(iter).erase();
}
template<class T, class Key, class Hash>
bool Foam::HashTable<T, Key, Hash>::erase(const Key& key)
{
return erase(find(key));
}
template<class T, class Key, class Hash>
Foam::label Foam::HashTable<T, Key, Hash>::erase(const UList<Key>& keys)
{
const label nTotal = nElmts_;
label count = 0;
// Remove listed keys from this table - terminates early if possible
for (label keyI = 0; count < nTotal && keyI < keys.size(); ++keyI)
{
if (erase(keys[keyI]))
{
count++;
}
}
return count;
}
template<class T, class Key, class Hash>
template<class AnyType, class AnyHash>
Foam::label Foam::HashTable<T, Key, Hash>::erase
(
const HashTable<AnyType, Key, AnyHash>& rhs
)
{
label count = 0;
// Remove rhs keys from this table - terminates early if possible
// Could optimize depending on which hash is smaller ...
for (iterator iter = begin(); iter != end(); ++iter)
{
if (rhs.found(iter.key()) && erase(iter))
{
count++;
}
}
return count;
}
template<class T, class Key, class Hash>
void Foam::HashTable<T, Key, Hash>::resize(const label sz)
{
label newSize = HashTableCore::canonicalSize(sz);
if (newSize == tableSize_)
{
# ifdef FULLDEBUG
if (debug)
{
Info<< "HashTable<T, Key, Hash>::resize(const label) : "
<< "new table size == old table size\n";
}
# endif
return;
}
HashTable<T, Key, Hash>* tmpTable = new HashTable<T, Key, Hash>(newSize);
for (const_iterator iter = cbegin(); iter != cend(); ++iter)
{
tmpTable->insert(iter.key(), *iter);
}
label oldSize = tableSize_;
tableSize_ = tmpTable->tableSize_;
tmpTable->tableSize_ = oldSize;
hashedEntry** oldTable = table_;
table_ = tmpTable->table_;
tmpTable->table_ = oldTable;
delete tmpTable;
}
template<class T, class Key, class Hash>
void Foam::HashTable<T, Key, Hash>::clear()
{
if (nElmts_)
{
for (label hashIdx = 0; hashIdx < tableSize_; hashIdx++)
{
if (table_[hashIdx])
{
hashedEntry* ep = table_[hashIdx];
while (hashedEntry* next = ep->next_)
{
delete ep;
ep = next;
}
delete ep;
table_[hashIdx] = 0;
}
}
nElmts_ = 0;
}
}
template<class T, class Key, class Hash>
void Foam::HashTable<T, Key, Hash>::clearStorage()
{
clear();
resize(0);
}
template<class T, class Key, class Hash>
void Foam::HashTable<T, Key, Hash>::shrink()
{
const label newSize = HashTableCore::canonicalSize(nElmts_);
if (newSize < tableSize_)
{
// avoid having the table disappear on us
resize(newSize ? newSize : 2);
}
}
template<class T, class Key, class Hash>
void Foam::HashTable<T, Key, Hash>::transfer(HashTable<T, Key, Hash>& ht)
{
// as per the Destructor
if (table_)
{
clear();
delete[] table_;
}
tableSize_ = ht.tableSize_;
ht.tableSize_ = 0;
table_ = ht.table_;
ht.table_ = NULL;
nElmts_ = ht.nElmts_;
ht.nElmts_ = 0;
}
// * * * * * * * * * * * * * * * Member Operators * * * * * * * * * * * * * //
template<class T, class Key, class Hash>
void Foam::HashTable<T, Key, Hash>::operator=
(
const HashTable<T, Key, Hash>& rhs
)
{
// Check for assignment to self
if (this == &rhs)
{
FatalErrorIn
(
"HashTable<T, Key, Hash>::operator="
"(const HashTable<T, Key, Hash>&)"
) << "attempted assignment to self"
<< abort(FatalError);
}
// could be zero-sized from a previous transfer()
if (!tableSize_)
{
resize(rhs.tableSize_);
}
else
{
clear();
}
for (const_iterator iter = rhs.cbegin(); iter != rhs.cend(); ++iter)
{
insert(iter.key(), *iter);
}
}
template<class T, class Key, class Hash>
bool Foam::HashTable<T, Key, Hash>::operator==
(
const HashTable<T, Key, Hash>& rhs
) const
{
// sizes (number of keys) must match
if (size() != rhs.size())
{
return false;
}
for (const_iterator iter = rhs.cbegin(); iter != rhs.cend(); ++iter)
{
const_iterator fnd = find(iter.key());
if (fnd == cend() || fnd() != iter())
{
return false;
}
}
return true;
}
template<class T, class Key, class Hash>
bool Foam::HashTable<T, Key, Hash>::operator!=
(
const HashTable<T, Key, Hash>& rhs
) const
{
return !(operator==(rhs));
}
// * * * * * * * * * * * * * * * Friend Operators * * * * * * * * * * * * * //
#include "HashTableIO.C"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
#endif
// ************************************************************************* //