| |
| /*--------------------------------------------------------------------*/ |
| /*--- A hash table implementation. pub_tool_hashtable.h ---*/ |
| /*--------------------------------------------------------------------*/ |
| |
| /* |
| This file is part of Valgrind, a dynamic binary instrumentation |
| framework. |
| |
| Copyright (C) 2005-2007 Nicholas Nethercote |
| njn@valgrind.org |
| |
| This program 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 2 of the |
| License, or (at your option) any later version. |
| |
| This program 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 this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307, USA. |
| |
| The GNU General Public License is contained in the file COPYING. |
| */ |
| |
| #ifndef __PUB_TOOL_HASHTABLE_H |
| #define __PUB_TOOL_HASHTABLE_H |
| |
| /* Generic type for a separately-chained hash table. Via a kind of dodgy |
| C-as-C++ style inheritance, tools can extend the VgHashNode type, so long |
| as the first two fields match the sizes of these two fields. Requires |
| a bit of casting by the tool. */ |
| |
| // Problems with this data structure: |
| // - Separate chaining gives bad cache behaviour. Hash tables with linear |
| // probing give better cache behaviour. |
| |
| typedef |
| struct _VgHashNode { |
| struct _VgHashNode * next; |
| UWord key; |
| } |
| VgHashNode; |
| |
| typedef struct _VgHashTable * VgHashTable; |
| |
| /* Make a new table. Allocates the memory with VG_(calloc)(), so can |
| be freed with VG_(free)(). The table starts small but will |
| periodically be expanded. This is transparent to the users of this |
| module. */ |
| extern VgHashTable VG_(HT_construct) ( HChar* name ); |
| |
| /* Count the number of nodes in a table. */ |
| extern Int VG_(HT_count_nodes) ( VgHashTable table ); |
| |
| /* Add a node to the table. */ |
| extern void VG_(HT_add_node) ( VgHashTable t, void* node ); |
| |
| /* Looks up a VgHashNode in the table. Returns NULL if not found. */ |
| extern void* VG_(HT_lookup) ( VgHashTable table, UWord key ); |
| |
| /* Removes a VgHashNode from the table. Returns NULL if not found. */ |
| extern void* VG_(HT_remove) ( VgHashTable table, UWord key ); |
| |
| /* Allocates a suitably-sized array, copies all the hashtable elements |
| into it, then returns both the array and the size of it. This is |
| used by the memory-leak detector. The array must be freed with |
| VG_(free). */ |
| extern VgHashNode** VG_(HT_to_array) ( VgHashTable t, /*OUT*/ UInt* n_elems ); |
| |
| /* Reset the table's iterator to point to the first element. */ |
| extern void VG_(HT_ResetIter) ( VgHashTable table ); |
| |
| /* Return the element pointed to by the iterator and move on to the |
| next one. Returns NULL if the last one has been passed, or if |
| HT_ResetIter() has not been called previously. Asserts if the |
| table has been modified (HT_add_node, HT_remove) since |
| HT_ResetIter. This guarantees that callers cannot screw up by |
| modifying the table whilst iterating over it (and is necessary to |
| make the implementation safe; specifically we must guarantee that |
| the table will not get resized whilst iteration is happening. |
| Since resizing only happens as a result of calling HT_add_node, |
| disallowing HT_add_node during iteration should give the required |
| assurance. */ |
| extern void* VG_(HT_Next) ( VgHashTable table ); |
| |
| /* Destroy a table. */ |
| extern void VG_(HT_destruct) ( VgHashTable t ); |
| |
| |
| #endif // __PUB_TOOL_HASHTABLE_H |
| |
| /*--------------------------------------------------------------------*/ |
| /*--- end ---*/ |
| /*--------------------------------------------------------------------*/ |