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      1 
      2 /*--------------------------------------------------------------------*/
      3 /*--- OSet: a fast data structure with no dups.    pub_tool_oset.h ---*/
      4 /*--------------------------------------------------------------------*/
      5 
      6 /*
      7    This file is part of Valgrind, a dynamic binary instrumentation
      8    framework.
      9 
     10    Copyright (C) 2005-2010 Nicholas Nethercote
     11       njn (at) valgrind.org
     12 
     13    This program is free software; you can redistribute it and/or
     14    modify it under the terms of the GNU General Public License as
     15    published by the Free Software Foundation; either version 2 of the
     16    License, or (at your option) any later version.
     17 
     18    This program is distributed in the hope that it will be useful, but
     19    WITHOUT ANY WARRANTY; without even the implied warranty of
     20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     21    General Public License for more details.
     22 
     23    You should have received a copy of the GNU General Public License
     24    along with this program; if not, write to the Free Software
     25    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
     26    02111-1307, USA.
     27 
     28    The GNU General Public License is contained in the file COPYING.
     29 */
     30 
     31 #ifndef __PUB_TOOL_OSET_H
     32 #define __PUB_TOOL_OSET_H
     33 
     34 // This module implements an ordered set, a data structure with fast
     35 // (eg. amortised log(n) or better) insertion, lookup and deletion of
     36 // elements.  It does not allow duplicates, and will assert if you insert a
     37 // duplicate to an OSet.
     38 //
     39 // It has two interfaces.
     40 //
     41 // - The "OSetWord_" interface provides an easier-to-use interface for the
     42 //   case where you just want to store UWord-sized values.  The user
     43 //   provides the allocation and deallocation functions, and possibly a
     44 //   comparison function.
     45 //
     46 // - The "OSetGen_" interface provides a totally generic interface, which
     47 //   allows any kind of structure to be put into the set.  The user provides
     48 //   the allocation and deallocation functions.  Also, each element has a
     49 //   key, which the lookup is done with.  The key may be the whole element
     50 //   (eg. in an OSet of integers, each integer serves both as an element and
     51 //   a key), or it may be only part of it (eg. if the key is a single field
     52 //   in a struct).  The user can provide a function that compares an element
     53 //   with a key;  this is very flexible, and with the right comparison
     54 //   function even a (non-overlapping) interval list can be created.  But
     55 //   the cost of calling a function for every comparison can be high during
     56 //   lookup.  If no comparison function is provided, we assume that keys are
     57 //   (signed or unsigned) words, and that the key is the first word in each
     58 //   element.  This fast comparison is suitable for an OSet containing
     59 //   structs where the first element is an Addr, for example.
     60 //
     61 // Each OSet interface also has an iterator, which makes it simple to
     62 // traverse all the nodes in order.  Note that the iterator maintains state
     63 // and so is non-reentrant.
     64 //
     65 // Note that once you insert an element into an OSet, if you modify any part
     66 // of it looked at by your cmp() function, this may cause incorrect
     67 // behaviour as the sorted order maintained will be wrong.
     68 
     69 /*--------------------------------------------------------------------*/
     70 /*--- Types                                                        ---*/
     71 /*--------------------------------------------------------------------*/
     72 
     73 typedef struct _OSet     OSet;
     74 
     75 // - Cmp:   returns -1, 0 or 1 if key is <, == or > elem.
     76 // - Alloc: allocates a chunk of memory.
     77 // - Free:  frees a chunk of memory allocated with Alloc.
     78 
     79 typedef Word  (*OSetCmp_t)         ( const void* key, const void* elem );
     80 typedef void* (*OSetAlloc_t)       ( HChar* cc, SizeT szB );
     81 typedef void  (*OSetFree_t)        ( void* p );
     82 
     83 /*--------------------------------------------------------------------*/
     84 /*--- Creating and destroying OSets (UWord)                        ---*/
     85 /*--------------------------------------------------------------------*/
     86 
     87 // * Create: allocates and initialises the OSet.  Arguments:
     88 //   - alloc     The allocation function used internally for allocating the
     89 //               OSet and all its nodes.
     90 //   - cc        Cost centre string used by 'alloc'.
     91 //   - free      The deallocation function used internally for freeing nodes
     92 //               called by VG_(OSetWord_Destroy)().
     93 //
     94 // * CreateWithCmp: like Create, but you specify your own comparison
     95 //   function.
     96 //
     97 // * Destroy: frees all nodes in the table, plus the memory used by
     98 //   the table itself.  The passed-in function is called on each node first
     99 //   to allow the destruction of any attached resources;  if NULL it is not
    100 //   called.
    101 
    102 extern OSet* VG_(OSetWord_Create)       ( OSetAlloc_t alloc, HChar* cc,
    103                                           OSetFree_t _free );
    104 extern void  VG_(OSetWord_Destroy)      ( OSet* os );
    105 
    106 /*--------------------------------------------------------------------*/
    107 /*--- Operations on OSets (UWord)                                  ---*/
    108 /*--------------------------------------------------------------------*/
    109 
    110 // In everything that follows, the parameter 'key' is always the *address*
    111 // of the key, and 'elem' is *address* of the elem, as are the return values
    112 // of the functions that return elems.
    113 //
    114 // * Size: The number of elements in the set.
    115 //
    116 // * Contains: Determines if the value is in the set.
    117 //
    118 // * Insert: Inserts a new element into the set.  Duplicates are forbidden,
    119 //   and will cause assertion failures.
    120 //
    121 // * Remove: Removes the value from the set, if present.  Returns a Bool
    122 //   indicating if the value was removed.
    123 //
    124 // * ResetIter: Each OSet has an iterator.  This resets it to point to the
    125 //   first element in the OSet.
    126 //
    127 // * Next: Copies the next value according to the OSet's iterator into &val,
    128 //   advances the iterator by one, and returns True;  the elements are
    129 //   visited in increasing order of unsigned words (UWord).  Or, returns
    130 //   False if the iterator has reached the set's end.
    131 //
    132 //   You can thus iterate in order through a set like this:
    133 //
    134 //     Word val;
    135 //     VG_(OSetWord_ResetIter)(oset);
    136 //     while ( VG_(OSetWord_Next)(oset, &val) ) {
    137 //        ... do stuff with 'val' ...
    138 //     }
    139 //
    140 //   Note that iterators are cleared any time an element is inserted or
    141 //   removed from the OSet, to avoid possible mayhem caused by the iterator
    142 //   getting out of sync with the OSet's contents.  "Cleared" means that
    143 //   they will return False if VG_(OSetWord_Next)() is called without an
    144 //   intervening call to VG_(OSetWord_ResetIter)().
    145 
    146 extern Word  VG_(OSetWord_Size)         ( OSet* os );
    147 extern void  VG_(OSetWord_Insert)       ( OSet* os, UWord val );
    148 extern Bool  VG_(OSetWord_Contains)     ( OSet* os, UWord val );
    149 extern Bool  VG_(OSetWord_Remove)       ( OSet* os, UWord val );
    150 extern void  VG_(OSetWord_ResetIter)    ( OSet* os );
    151 extern Bool  VG_(OSetWord_Next)         ( OSet* os, /*OUT*/UWord* val );
    152 
    153 
    154 /*--------------------------------------------------------------------*/
    155 /*--- Creating and destroying OSets and OSet members (Gen)         ---*/
    156 /*--------------------------------------------------------------------*/
    157 
    158 // * Create: allocates and initialises the OSet.  Arguments:
    159 //   - keyOff    The offset of the key within the element.
    160 //   - cmp       The comparison function between keys and elements, or NULL
    161 //               if the OSet should use fast comparisons.
    162 //   - alloc     The allocation function used for allocating the OSet itself;
    163 //               it's also called for each invocation of
    164 //               VG_(OSetGen_AllocNode)().
    165 //   - cc        Cost centre string used by 'alloc'.
    166 //   - free      The deallocation function used by VG_(OSetGen_FreeNode)() and
    167 //               VG_(OSetGen_Destroy)().
    168 //
    169 //   If cmp is NULL, keyOff must be zero.  This is checked.
    170 //
    171 // * Destroy: frees all nodes in the table, plus the memory used by
    172 //   the table itself.  The passed-in function is called on each node first
    173 //   to allow the destruction of any attached resources;  if NULL it is not
    174 //   called.
    175 //
    176 // * AllocNode: Allocate and zero memory for a node to go into the OSet.
    177 //   Uses the alloc function given to VG_(OSetGen_Create)() to allocated a
    178 //   node which is big enough for both an element and the OSet metadata.
    179 //   Not all elements in one OSet have to be the same size.
    180 //
    181 //   Note that the element allocated will be at most word-aligned, which may
    182 //   be less aligned than the element type would normally be.
    183 //
    184 // * FreeNode: Deallocate a node allocated with OSetGen_AllocNode().  Using
    185 //   a deallocation function (such as VG_(free)()) directly will likely
    186 //   lead to assertions in Valgrind's allocator.
    187 
    188 extern OSet* VG_(OSetGen_Create)    ( PtrdiffT keyOff, OSetCmp_t cmp,
    189                                       OSetAlloc_t alloc, HChar* cc,
    190                                       OSetFree_t _free );
    191 extern void  VG_(OSetGen_Destroy)   ( OSet* os );
    192 extern void* VG_(OSetGen_AllocNode) ( OSet* os, SizeT elemSize );
    193 extern void  VG_(OSetGen_FreeNode)  ( OSet* os, void* elem );
    194 
    195 /*--------------------------------------------------------------------*/
    196 /*--- Operations on OSets (Gen)                                    ---*/
    197 /*--------------------------------------------------------------------*/
    198 
    199 // In everything that follows, the parameter 'key' is always the *address*
    200 // of the key, and 'elem' is *address* of the elem, as are the return values
    201 // of the functions that return elems.
    202 //
    203 // * Size: The number of elements in the set.
    204 //
    205 // * Insert: Inserts a new element into the set.  Note that 'elem' must
    206 //   have been allocated using VG_(OSetGen_AllocNode)(), otherwise you will
    207 //   get assertion failures about "bad magic".  Duplicates are forbidden,
    208 //   and will also cause assertion failures.
    209 //
    210 // * Contains: Determines if any element in the OSet matches the key.
    211 //
    212 // * Lookup: Returns a pointer to the element matching the key, if there is
    213 //   one, otherwise returns NULL.
    214 //
    215 // * LookupWithCmp: Like Lookup, but you specify the comparison function,
    216 //   which overrides the OSet's normal one.
    217 //
    218 // * Remove: Removes the element matching the key, if there is one.  Returns
    219 //   NULL if no element matches the key.
    220 //
    221 // * ResetIter: Each OSet has an iterator.  This resets it to point to the
    222 //   first element in the OSet.
    223 //
    224 // * ResetIterAt: Like ResetIter, but instead of resetting the iterator to the
    225 //   smallest element, it resets the iterator to point to the smallest element
    226 //   in the set whose key is greater-than-or-equal to the given key.  (In many
    227 //   cases this will be the element whose key equals that of the given key.)
    228 //
    229 // * Next: Returns a pointer to the element pointed to by the OSet's
    230 //   iterator, and advances the iterator by one;  the elements are visited
    231 //   in order.  Or, returns NULL if the iterator has reached the OSet's end.
    232 //
    233 //   You can thus iterate in order through a set like this:
    234 //
    235 //     VG_(OSetGen_ResetIter)(oset);
    236 //     while ( (elem = VG_(OSetGen_Next)(oset)) ) {
    237 //        ... do stuff with 'elem' ...
    238 //     }
    239 //
    240 //   Note that iterators are cleared any time an element is inserted or
    241 //   removed from the OSet, to avoid possible mayhem caused by the iterator
    242 //   getting out of sync with the OSet's contents.  "Cleared" means that
    243 //   they will return NULL if VG_(OSetGen_Next)() is called without an
    244 //   intervening call to VG_(OSetGen_ResetIter)().
    245 
    246 extern Word  VG_(OSetGen_Size)         ( const OSet* os );
    247 extern void  VG_(OSetGen_Insert)       ( OSet* os, void* elem );
    248 extern Bool  VG_(OSetGen_Contains)     ( const OSet* os, const void* key );
    249 extern void* VG_(OSetGen_Lookup)       ( const OSet* os, const void* key );
    250 extern void* VG_(OSetGen_LookupWithCmp)( OSet* os,
    251                                          const void* key, OSetCmp_t cmp );
    252 extern void* VG_(OSetGen_Remove)       ( OSet* os, const void* key );
    253 extern void  VG_(OSetGen_ResetIter)    ( OSet* os );
    254 extern void  VG_(OSetGen_ResetIterAt)  ( OSet* os, const void* key );
    255 extern void* VG_(OSetGen_Next)         ( OSet* os );
    256 
    257 
    258 #endif   // __PUB_TOOL_OSET_H
    259 
    260 /*--------------------------------------------------------------------*/
    261 /*--- end                                                          ---*/
    262 /*--------------------------------------------------------------------*/
    263