| /********** |
| This 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. (See <http://www.gnu.org/copyleft/lesser.html>.) |
| |
| This 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 a copy of the GNU Lesser General Public License |
| along with this library; if not, write to the Free Software Foundation, Inc., |
| 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| **********/ |
| // Copyright (c) 1996-2020 Live Networks, Inc. All rights reserved. |
| // Generic Hash Table |
| // C++ header |
| |
| #ifndef _HASH_TABLE_HH |
| #define _HASH_TABLE_HH |
| |
| #ifndef _BOOLEAN_HH |
| #include "Boolean.hh" |
| #endif |
| |
| class HashTable { |
| public: |
| virtual ~HashTable(); |
| |
| // The following must be implemented by a particular |
| // implementation (subclass): |
| static HashTable* create(int keyType); |
| |
| virtual void* Add(char const* key, void* value) = 0; |
| // Returns the old value if different, otherwise 0 |
| virtual Boolean Remove(char const* key) = 0; |
| virtual void* Lookup(char const* key) const = 0; |
| // Returns 0 if not found |
| virtual unsigned numEntries() const = 0; |
| Boolean IsEmpty() const { return numEntries() == 0; } |
| |
| // Used to iterate through the members of the table: |
| class Iterator { |
| public: |
| // The following must be implemented by a particular |
| // implementation (subclass): |
| static Iterator* create(HashTable const& hashTable); |
| |
| virtual ~Iterator(); |
| |
| virtual void* next(char const*& key) = 0; // returns 0 if none |
| |
| protected: |
| Iterator(); // abstract base class |
| }; |
| |
| // A shortcut that can be used to successively remove each of |
| // the entries in the table (e.g., so that their values can be |
| // deleted, if they happen to be pointers to allocated memory). |
| void* RemoveNext(); |
| |
| // Returns the first entry in the table. |
| // (This is useful for deleting each entry in the table, if the entry's destructor also removes itself from the table.) |
| void* getFirst(); |
| |
| protected: |
| HashTable(); // abstract base class |
| }; |
| |
| // Warning: The following are deliberately the same as in |
| // Tcl's hash table implementation |
| int const STRING_HASH_KEYS = 0; |
| int const ONE_WORD_HASH_KEYS = 1; |
| |
| #endif |