/*--------------------------------------------------------------------*/ /*--- OSet: a fast data structure with no dups. pub_tool_oset.h ---*/ /*--------------------------------------------------------------------*/ /* This file is part of Valgrind, a dynamic binary instrumentation framework. Copyright (C) 2005-2011 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_OSET_H #define __PUB_TOOL_OSET_H // This module implements an ordered set, a data structure with fast // (eg. amortised log(n) or better) insertion, lookup and deletion of // elements. It does not allow duplicates, and will assert if you insert a // duplicate to an OSet. // // It has two interfaces. // // - The "OSetWord_" interface provides an easier-to-use interface for the // case where you just want to store UWord-sized values. The user // provides the allocation and deallocation functions, and possibly a // comparison function. // // - The "OSetGen_" interface provides a totally generic interface, which // allows any kind of structure to be put into the set. The user provides // the allocation and deallocation functions. Also, each element has a // key, which the lookup is done with. The key may be the whole element // (eg. in an OSet of integers, each integer serves both as an element and // a key), or it may be only part of it (eg. if the key is a single field // in a struct). The user can provide a function that compares an element // with a key; this is very flexible, and with the right comparison // function even a (non-overlapping) interval list can be created. But // the cost of calling a function for every comparison can be high during // lookup. If no comparison function is provided, we assume that keys are // (signed or unsigned) words, and that the key is the first word in each // element. This fast comparison is suitable for an OSet containing // structs where the first element is an Addr, for example. // // Each OSet interface also has an iterator, which makes it simple to // traverse all the nodes in order. Note that the iterator maintains state // and so is non-reentrant. // // Note that once you insert an element into an OSet, if you modify any part // of it looked at by your cmp() function, this may cause incorrect // behaviour as the sorted order maintained will be wrong. /*--------------------------------------------------------------------*/ /*--- Types ---*/ /*--------------------------------------------------------------------*/ typedef struct _OSet OSet; // - Cmp: returns -1, 0 or 1 if key is <, == or > elem. // - Alloc: allocates a chunk of memory. // - Free: frees a chunk of memory allocated with Alloc. typedef Word (*OSetCmp_t) ( const void* key, const void* elem ); typedef void* (*OSetAlloc_t) ( HChar* cc, SizeT szB ); typedef void (*OSetFree_t) ( void* p ); /*--------------------------------------------------------------------*/ /*--- Creating and destroying OSets (UWord) ---*/ /*--------------------------------------------------------------------*/ // * Create: allocates and initialises the OSet. Arguments: // - alloc The allocation function used internally for allocating the // OSet and all its nodes. // - cc Cost centre string used by 'alloc'. // - free The deallocation function used internally for freeing nodes // called by VG_(OSetWord_Destroy)(). // // * CreateWithCmp: like Create, but you specify your own comparison // function. // // * Destroy: frees all nodes in the table, plus the memory used by // the table itself. The passed-in function is called on each node first // to allow the destruction of any attached resources; if NULL it is not // called. extern OSet* VG_(OSetWord_Create) ( OSetAlloc_t alloc, HChar* cc, OSetFree_t _free ); extern void VG_(OSetWord_Destroy) ( OSet* os ); /*--------------------------------------------------------------------*/ /*--- Operations on OSets (UWord) ---*/ /*--------------------------------------------------------------------*/ // In everything that follows, the parameter 'key' is always the *address* // of the key, and 'elem' is *address* of the elem, as are the return values // of the functions that return elems. // // * Size: The number of elements in the set. // // * Contains: Determines if the value is in the set. // // * Insert: Inserts a new element into the set. Duplicates are forbidden, // and will cause assertion failures. // // * Remove: Removes the value from the set, if present. Returns a Bool // indicating if the value was removed. // // * ResetIter: Each OSet has an iterator. This resets it to point to the // first element in the OSet. // // * Next: Copies the next value according to the OSet's iterator into &val, // advances the iterator by one, and returns True; the elements are // visited in increasing order of unsigned words (UWord). Or, returns // False if the iterator has reached the set's end. // // You can thus iterate in order through a set like this: // // Word val; // VG_(OSetWord_ResetIter)(oset); // while ( VG_(OSetWord_Next)(oset, &val) ) { // ... do stuff with 'val' ... // } // // Note that iterators are cleared any time an element is inserted or // removed from the OSet, to avoid possible mayhem caused by the iterator // getting out of sync with the OSet's contents. "Cleared" means that // they will return False if VG_(OSetWord_Next)() is called without an // intervening call to VG_(OSetWord_ResetIter)(). extern Word VG_(OSetWord_Size) ( OSet* os ); extern void VG_(OSetWord_Insert) ( OSet* os, UWord val ); extern Bool VG_(OSetWord_Contains) ( OSet* os, UWord val ); extern Bool VG_(OSetWord_Remove) ( OSet* os, UWord val ); extern void VG_(OSetWord_ResetIter) ( OSet* os ); extern Bool VG_(OSetWord_Next) ( OSet* os, /*OUT*/UWord* val ); /*--------------------------------------------------------------------*/ /*--- Creating and destroying OSets and OSet members (Gen) ---*/ /*--------------------------------------------------------------------*/ // * Create: allocates and initialises the OSet. Arguments: // - keyOff The offset of the key within the element. // - cmp The comparison function between keys and elements, or NULL // if the OSet should use fast comparisons. // - alloc The allocation function used for allocating the OSet itself; // it's also called for each invocation of // VG_(OSetGen_AllocNode)(). // - cc Cost centre string used by 'alloc'. // - free The deallocation function used by VG_(OSetGen_FreeNode)() and // VG_(OSetGen_Destroy)(). // // If cmp is NULL, keyOff must be zero. This is checked. // // * Destroy: frees all nodes in the table, plus the memory used by // the table itself. The passed-in function is called on each node first // to allow the destruction of any attached resources; if NULL it is not // called. // // * AllocNode: Allocate and zero memory for a node to go into the OSet. // Uses the alloc function given to VG_(OSetGen_Create)() to allocated a // node which is big enough for both an element and the OSet metadata. // Not all elements in one OSet have to be the same size. // // Note that the element allocated will be at most word-aligned, which may // be less aligned than the element type would normally be. // // * FreeNode: Deallocate a node allocated with OSetGen_AllocNode(). Using // a deallocation function (such as VG_(free)()) directly will likely // lead to assertions in Valgrind's allocator. extern OSet* VG_(OSetGen_Create) ( PtrdiffT keyOff, OSetCmp_t cmp, OSetAlloc_t alloc, HChar* cc, OSetFree_t _free ); extern void VG_(OSetGen_Destroy) ( OSet* os ); extern void* VG_(OSetGen_AllocNode) ( OSet* os, SizeT elemSize ); extern void VG_(OSetGen_FreeNode) ( OSet* os, void* elem ); /*--------------------------------------------------------------------*/ /*--- Operations on OSets (Gen) ---*/ /*--------------------------------------------------------------------*/ // In everything that follows, the parameter 'key' is always the *address* // of the key, and 'elem' is *address* of the elem, as are the return values // of the functions that return elems. // // * Size: The number of elements in the set. // // * Insert: Inserts a new element into the set. Note that 'elem' must // have been allocated using VG_(OSetGen_AllocNode)(), otherwise you will // get assertion failures about "bad magic". Duplicates are forbidden, // and will also cause assertion failures. // // * Contains: Determines if any element in the OSet matches the key. // // * Lookup: Returns a pointer to the element matching the key, if there is // one, otherwise returns NULL. // // * LookupWithCmp: Like Lookup, but you specify the comparison function, // which overrides the OSet's normal one. // // * Remove: Removes the element matching the key, if there is one. Returns // NULL if no element matches the key. // // * ResetIter: Each OSet has an iterator. This resets it to point to the // first element in the OSet. // // * ResetIterAt: Like ResetIter, but instead of resetting the iterator to the // smallest element, it resets the iterator to point to the smallest element // in the set whose key is greater-than-or-equal to the given key. (In many // cases this will be the element whose key equals that of the given key.) // // * Next: Returns a pointer to the element pointed to by the OSet's // iterator, and advances the iterator by one; the elements are visited // in order. Or, returns NULL if the iterator has reached the OSet's end. // // You can thus iterate in order through a set like this: // // VG_(OSetGen_ResetIter)(oset); // while ( (elem = VG_(OSetGen_Next)(oset)) ) { // ... do stuff with 'elem' ... // } // // Note that iterators are cleared any time an element is inserted or // removed from the OSet, to avoid possible mayhem caused by the iterator // getting out of sync with the OSet's contents. "Cleared" means that // they will return NULL if VG_(OSetGen_Next)() is called without an // intervening call to VG_(OSetGen_ResetIter)(). extern Word VG_(OSetGen_Size) ( const OSet* os ); extern void VG_(OSetGen_Insert) ( OSet* os, void* elem ); extern Bool VG_(OSetGen_Contains) ( const OSet* os, const void* key ); extern void* VG_(OSetGen_Lookup) ( const OSet* os, const void* key ); extern void* VG_(OSetGen_LookupWithCmp)( OSet* os, const void* key, OSetCmp_t cmp ); extern void* VG_(OSetGen_Remove) ( OSet* os, const void* key ); extern void VG_(OSetGen_ResetIter) ( OSet* os ); extern void VG_(OSetGen_ResetIterAt) ( OSet* os, const void* key ); extern void* VG_(OSetGen_Next) ( OSet* os ); #endif // __PUB_TOOL_OSET_H /*--------------------------------------------------------------------*/ /*--- end ---*/ /*--------------------------------------------------------------------*/