X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=hashtable.h;h=a337df41ea03f7856595ab1d9aa15579dce51f51;hp=f372f9e7b96f0efb7f08d6574d768a6cc7cdf2db;hb=81ea453e58cbb85fddff3aa8919dfbc59c3140eb;hpb=f7e1577b22ac26c12dc57a43de2761aa9249227c diff --git a/hashtable.h b/hashtable.h index f372f9e7..a337df41 100644 --- a/hashtable.h +++ b/hashtable.h @@ -1,64 +1,141 @@ +/** @file hashtable.h + * @brief Hashtable. Standard chained bucket variety. + */ + #ifndef HASHTABLE_H #define HASHTABLE_H #include #include +#include "mymemory.h" + +/** + * Hashtable linked node class, for chained storage of hash table conflicts. By + * default it is snapshotting, but you can pass in your own allocation + * functions. + * + * @tparam _Key Type name for the key + * @tparam _Val Type name for the values to be stored + * @tparam _malloc Provide your own 'malloc' for the table, or default to + * snapshotting. + * @tparam _calloc Provide your own 'calloc' for the table, or default to + * snapshotting. + * @tparam _free Provide your own 'free' for the table, or default to + * snapshotting. + */ +template +struct hashlistnode { + _Key key; + _Val val; + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *next; + + void * operator new(size_t size) { + return _malloc(size); + } + + void operator delete(void *p, size_t size) { + _free(p); + } + + void * operator new[](size_t size) { + return _malloc(size); + } -template - struct hashlistnode { - _Key key; - _Val val; - struct hashlistnode<_Key,_Val> *next; - }; + void operator delete[](void *p, size_t size) { + _free(p); + } +}; -template +/** + * Hashtable class. By default it is snapshotting, but you can pass in your own + * allocation functions. + * + * @tparam _Key Type name for the key + * @tparam _Val Type name for the values to be stored + * @tparam _KeyInt Integer type that is at least as large as _Key. Used for key + * manipulation and storage. + * @tparam _Shift Logical shift to apply to all keys. Default 0. + * @tparam _malloc Provide your own 'malloc' for the table, or default to + * snapshotting. + * @tparam _calloc Provide your own 'calloc' for the table, or default to + * snapshotting. + * @tparam _free Provide your own 'free' for the table, or default to + * snapshotting. + */ +template class HashTable { public: + /** + * Constructor + * @param initialcapacity Sets the initial capacity of the hash table. + * Default size 1024. + * @param factor Sets the percentage full before the hashtable is + * resized. Default ratio 0.5. + */ HashTable(unsigned int initialcapacity=1024, double factor=0.5) { // Allocate space for the hash table - table = (struct hashlistnode<_Key,_Val> **) calloc(initialcapacity, sizeof(struct hashlistnode<_Key,_Val> *)); + table = (struct hashlistnode<_Key,_Val, _malloc, _calloc,_free> **) _calloc(initialcapacity, sizeof(struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *)); loadfactor = factor; capacity = initialcapacity; - threshold = initialcapacity*loadfactor; + threshold = (unsigned int) (initialcapacity*loadfactor); mask = (capacity << _Shift)-1; size = 0; // Initial number of elements in the hash } + /** Destructor */ ~HashTable() { for(unsigned int i=0;i * bin = table[i]; + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> * bin = table[i]; while(bin!=NULL) { - struct hashlistnode<_Key,_Val> * next=bin->next; - free(bin); + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> * next=bin->next; + delete bin; bin=next; } } - free(table); + _free(table); + } + + /** Override: new operator */ + void * operator new(size_t size) { + return _malloc(size); + } + + /** Override: delete operator */ + void operator delete(void *p, size_t size) { + _free(p); } + /** Override: new[] operator */ + void * operator new[](size_t size) { + return _malloc(size); + } + + /** Override: delete[] operator */ + void operator delete[](void *p, size_t size) { + _free(p); + } + + /** Reset the table to its initial state. */ void reset() { - for(int i=0;i * bin = table[i]; + for(unsigned int i=0;i * bin = table[i]; while(bin!=NULL) { - struct hashlistnode<_Key,_Val> * next=bin->next; - free(bin); + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> * next=bin->next; + delete bin; bin=next; } } - memset(table, 0, capacity*sizeof(struct hashlistnode<_Key, _Val> *)); + memset(table, 0, capacity*sizeof(struct hashlistnode<_Key, _Val, _malloc, _calloc, _free> *)); size=0; } - + + /** Put a key value pair into the table. */ void put(_Key key, _Val val) { - if(size > threshold) { - //Resize - unsigned int newsize = capacity << 1; - resize(newsize); - } - - struct hashlistnode<_Key,_Val> *ptr = table[(((_KeyInt)key) & mask)>>_Shift]; - size++; - struct hashlistnode<_Key,_Val> *search = ptr; + if (size > threshold) + resize(capacity << 1); + + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *ptr = table[(((_KeyInt)key) & mask)>>_Shift]; + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *search = ptr; while(search!=NULL) { if (search->key==key) { @@ -68,16 +145,50 @@ template search=search->next; } - struct hashlistnode<_Key,_Val> *newptr=(struct hashlistnode<_Key,_Val> *)malloc(sizeof(struct hashlistnode<_Key,_Val>)); + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *newptr=(struct hashlistnode<_Key,_Val,_malloc,_calloc,_free> *)new struct hashlistnode<_Key,_Val, _malloc, _calloc, _free>; newptr->key=key; newptr->val=val; newptr->next=ptr; table[(((_KeyInt)key)&mask)>>_Shift]=newptr; + size++; + } + + /** + * @brief Get a valid pointer to a value corresponding to a given key + * + * Ensure that key is present in the hash table, then return a pointer + * to its value bin. This may require either creating a new bin for + * this key (with a default-constructed value) or simply locating and + * returning a pointer to an existing value. + * @param key The key to check + * @return A pointer to the value in the table + */ + _Val * get_safe_ptr(_Key key) { + if (size > threshold) + resize(capacity << 1); + + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *ptr = table[(((_KeyInt)key) & mask)>>_Shift]; + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *search = ptr; + + while(search!=NULL) { + if (search->key==key) { + return &search->val; + } + search=search->next; + } + + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *newptr=(struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *)new struct hashlistnode<_Key,_Val, _malloc, _calloc, _free>; + newptr->key=key; + newptr->next=ptr; + table[(((_KeyInt)key)&mask)>>_Shift]=newptr; + size++; + return &newptr->val; } + /** Lookup the corresponding value for the given key. */ _Val get(_Key key) { - struct hashlistnode<_Key,_Val> *search = table[(((_KeyInt)key) & mask)>>_Shift]; - + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *search = table[(((_KeyInt)key) & mask)>>_Shift]; + while(search!=NULL) { if (search->key==key) { return search->val; @@ -87,9 +198,23 @@ template return (_Val)0; } + /** Lookup the corresponding value for the given key. */ + _Val * getptr(_Key key) { + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *search = table[(((_KeyInt)key) & mask)>>_Shift]; + + while(search!=NULL) { + if (search->key==key) { + return & search->val; + } + search=search->next; + } + return (_Val *) NULL; + } + + /** Check whether the table contains a value for the given key. */ bool contains(_Key key) { - struct hashlistnode<_Key,_Val> *search = table[(((_KeyInt)key) & mask)>>_Shift]; - + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *search = table[(((_KeyInt)key) & mask)>>_Shift]; + while(search!=NULL) { if (search->key==key) { return true; @@ -98,42 +223,43 @@ template } return false; } - + + /** Resize the table. */ void resize(unsigned int newsize) { - struct hashlistnode<_Key,_Val> ** oldtable = table; - struct hashlistnode<_Key,_Val> ** newtable; + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> ** oldtable = table; + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> ** newtable; unsigned int oldcapacity = capacity; - - if((newtable = (struct hashlistnode<_Key,_Val> **) calloc(newsize, sizeof(struct hashlistnode<_Key,_Val> *))) == NULL) { + + if((newtable = (struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> **) _calloc(newsize, sizeof(struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> *))) == NULL) { printf("Calloc error %s %d\n", __FILE__, __LINE__); exit(-1); } - + table = newtable; //Update the global hashtable upon resize() capacity = newsize; - threshold = newsize * loadfactor; + threshold = (unsigned int) (newsize * loadfactor); mask = (newsize << _Shift)-1; - + for(unsigned int i = 0; i < oldcapacity; i++) { - struct hashlistnode<_Key, _Val> * bin = oldtable[i]; - + struct hashlistnode<_Key, _Val, _malloc, _calloc, _free> * bin = oldtable[i]; + while(bin!=NULL) { _Key key=bin->key; - struct hashlistnode<_Key, _Val> * next=bin->next; - + struct hashlistnode<_Key, _Val, _malloc, _calloc, _free> * next=bin->next; + unsigned int index = (((_KeyInt)key) & mask) >>_Shift; - struct hashlistnode<_Key, _Val> * tmp=newtable[index]; + struct hashlistnode<_Key, _Val, _malloc, _calloc, _free> * tmp=newtable[index]; bin->next=tmp; newtable[index]=bin; bin = next; } } - - free(oldtable); //Free the memory of the old hash table + + _free(oldtable); //Free the memory of the old hash table } - + private: - struct hashlistnode<_Key,_Val> **table; + struct hashlistnode<_Key,_Val, _malloc, _calloc, _free> **table; unsigned int capacity; _KeyInt mask; unsigned int size;