-#ifndef HASHTABLE_H
-#define HASHTABLE_H
+/** @file hashtable.h
+ * @brief Hashtable. Standard chained bucket variety.
+ */
+
+#ifndef __HASHTABLE_H__
+#define __HASHTABLE_H__
#include <stdlib.h>
#include <stdio.h>
+#include <string.h>
+#include "mymemory.h"
+#include "common.h"
+/**
+ * @brief HashTable node
+ *
+ * @tparam _Key Type name for the key
+ * @tparam _Val Type name for the values to be stored
+ */
template<typename _Key, typename _Val>
- struct hashlistnode {
- _Key key;
- _Val val;
- struct hashlistnode<_Key,_Val> *next;
- };
-
-template<typename _Key, typename _Val, typename _KeyInt, int _Shift>
- class HashTable {
+struct hashlistnode {
+ _Key key;
+ _Val val;
+};
+
+/**
+ * @brief A simple, custom hash table
+ *
+ * By default it is snapshotting, but you can pass in your own allocation
+ * functions. Note that this table does not support the value 0 (NULL) used as
+ * a key and is designed primarily with pointer-based keys in mind. Other
+ * primitive key types are supported only for non-zero values.
+ *
+ * @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<typename _Key, typename _Val, typename _KeyInt, int _Shift = 0, void * (* _malloc)(size_t) = snapshot_malloc, void * (* _calloc)(size_t, size_t) = snapshot_calloc, void (*_free)(void *) = snapshot_free>
+class HashTable {
public:
- HashTable(unsigned int initialcapacity=1024, double factor=0.5) {
+ /**
+ * @brief Hash table 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> *)_calloc(initialcapacity, sizeof(struct hashlistnode<_Key, _Val>));
loadfactor = factor;
capacity = initialcapacity;
- threshold = initialcapacity*loadfactor;
- mask = (capacity << _Shift)-1;
+ capacitymask = initialcapacity - 1;
+
+ threshold = (unsigned int)(initialcapacity * loadfactor);
size = 0; // Initial number of elements in the hash
}
+ /** @brief Hash table destructor */
~HashTable() {
- for(unsigned int i=0;i<capacity;i++) {
- struct hashlistnode<_Key,_Val> * bin = table[i];
- while(bin!=NULL) {
- struct hashlistnode<_Key,_Val> * next=bin->next;
- free(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);
}
+ /** @brief Reset the table to its initial state. */
void reset() {
- for(int i=0;i<capacity;i++) {
- struct hashlistnode<_Key,_Val> * bin = table[i];
- while(bin!=NULL) {
- struct hashlistnode<_Key,_Val> * next=bin->next;
- free(bin);
- bin=next;
- }
- }
- memset(table, 0, capacity*sizeof(struct hashlistnode<_Key, _Val> *));
- size=0;
+ memset(table, 0, capacity * sizeof(struct hashlistnode<_Key, _Val>));
+ size = 0;
}
-
+
+ /**
+ * @brief Put a key/value pair into the table
+ * @param key The key for the new value; must not be 0 or NULL
+ * @param val The value to store in 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;
+ /* HashTable cannot handle 0 as a key */
+ ASSERT(key);
+
+ if (size > threshold)
+ resize(capacity << 1);
- while(search!=NULL) {
- if (search->key==key) {
- search->val=val;
+ struct hashlistnode<_Key, _Val> *search;
+
+ unsigned int index = ((_KeyInt)key) >> _Shift;
+ do {
+ index &= capacitymask;
+ search = &table[index];
+ if (search->key == key) {
+ search->val = val;
return;
}
- search=search->next;
- }
+ index++;
+ } while (search->key);
- struct hashlistnode<_Key,_Val> *newptr=(struct hashlistnode<_Key,_Val> *)malloc(sizeof(struct hashlistnode<_Key,_Val>));
- newptr->key=key;
- newptr->val=val;
- newptr->next=ptr;
- table[(((_KeyInt)key)&mask)>>_Shift]=newptr;
+ search->key = key;
+ search->val = val;
+ size++;
}
- _Val get(_Key key) {
- struct hashlistnode<_Key,_Val> *search = table[(((_KeyInt)key) & mask)>>_Shift];
-
- while(search!=NULL) {
- if (search->key==key) {
+ /**
+ * @brief Lookup the corresponding value for the given key
+ * @param key The key for finding the value; must not be 0 or NULL
+ * @return The value in the table, if the key is found; otherwise 0
+ */
+ _Val get(_Key key) const {
+ struct hashlistnode<_Key, _Val> *search;
+
+ /* HashTable cannot handle 0 as a key */
+ ASSERT(key);
+
+ unsigned int index = ((_KeyInt)key) >> _Shift;
+ do {
+ index &= capacitymask;
+ search = &table[index];
+ if (search->key == key)
return search->val;
- }
- search=search->next;
- }
+ index++;
+ } while (search->key);
return (_Val)0;
}
- bool contains(_Key key) {
- struct hashlistnode<_Key,_Val> *search = table[(((_KeyInt)key) & mask)>>_Shift];
-
- while(search!=NULL) {
- if (search->key==key) {
+ /**
+ * @brief Check whether the table contains a value for the given key
+ * @param key The key for finding the value; must not be 0 or NULL
+ * @return True, if the key is found; false otherwise
+ */
+ bool contains(_Key key) const {
+ struct hashlistnode<_Key, _Val> *search;
+
+ /* HashTable cannot handle 0 as a key */
+ ASSERT(key);
+
+ unsigned int index = ((_KeyInt)key) >> _Shift;
+ do {
+ index &= capacitymask;
+ search = &table[index];
+ if (search->key == key)
return true;
- }
- search=search->next;
- }
+ index++;
+ } while (search->key);
return false;
}
-
+
+ /**
+ * @brief Resize the table
+ * @param newsize The new size of the table
+ */
void resize(unsigned int newsize) {
- struct hashlistnode<_Key,_Val> ** oldtable = table;
- struct hashlistnode<_Key,_Val> ** newtable;
+ struct hashlistnode<_Key, _Val> *oldtable = table;
+ struct hashlistnode<_Key, _Val> *newtable;
unsigned int oldcapacity = capacity;
-
- if((newtable = (struct hashlistnode<_Key,_Val> **) calloc(newsize, sizeof(struct hashlistnode<_Key,_Val> *))) == NULL) {
- printf("Calloc error %s %d\n", __FILE__, __LINE__);
- exit(-1);
+
+ if ((newtable = (struct hashlistnode<_Key, _Val> *)_calloc(newsize, sizeof(struct hashlistnode<_Key, _Val>))) == NULL) {
+ model_print("calloc error %s %d\n", __FILE__, __LINE__);
+ exit(EXIT_FAILURE);
}
-
- table = newtable; //Update the global hashtable upon resize()
+
+ table = newtable; // Update the global hashtable upon resize()
capacity = newsize;
- threshold = newsize * loadfactor;
- mask = (newsize << _Shift)-1;
-
- for(unsigned int i = 0; i < oldcapacity; i++) {
- struct hashlistnode<_Key, _Val> * bin = oldtable[i];
-
- while(bin!=NULL) {
- _Key key=bin->key;
- struct hashlistnode<_Key, _Val> * next=bin->next;
-
- unsigned int index = (((_KeyInt)key) & mask) >>_Shift;
- struct hashlistnode<_Key, _Val> * tmp=newtable[index];
- bin->next=tmp;
- newtable[index]=bin;
- bin = next;
- }
+ capacitymask = newsize - 1;
+
+ threshold = (unsigned int)(newsize * loadfactor);
+
+ struct hashlistnode<_Key, _Val> *bin = &oldtable[0];
+ struct hashlistnode<_Key, _Val> *lastbin = &oldtable[oldcapacity];
+ for (; bin < lastbin; bin++) {
+ _Key key = bin->key;
+
+ struct hashlistnode<_Key, _Val> *search;
+
+ unsigned int index = ((_KeyInt)key) >> _Shift;
+ do {
+ index &= capacitymask;
+ search = &table[index];
+ index++;
+ } while (search->key);
+
+ search->key = key;
+ search->val = bin->val;
}
-
- 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> *table;
unsigned int capacity;
- _KeyInt mask;
unsigned int size;
+ unsigned int capacitymask;
unsigned int threshold;
double loadfactor;
};
-#endif
+
+#endif /* __HASHTABLE_H__ */
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