From: bdemsky <bdemsky>
Date: Wed, 3 Sep 2008 02:32:59 +0000 (+0000)
Subject: new hash table
X-Git-Tag: buildscript^6~61
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d2bf7562ea7422bde720d2ebd994225d7c998327;p=IRC.git
new hash table
---
diff --git a/Robust/src/Runtime/chash.c b/Robust/src/Runtime/chash.c
new file mode 100644
index 00000000..0f6fa5c0
--- /dev/null
+++ b/Robust/src/Runtime/chash.c
@@ -0,0 +1,202 @@
+#include "clookup.h"
+#define INLINE inline __attribute__((always_inline))
+
+chashtable_t *chashCreate(unsigned int size, float loadfactor) {
+ chashtable_t *ctable;
+ chashlistnode_t *nodes;
+ int i;
+
+ if((ctable = calloc(1, sizeof(chashtable_t))) == NULL) {
+ printf("Calloc error %s %d\n", __FILE__, __LINE__);
+ return NULL;
+ }
+
+ // Allocate space for the hash table
+ if((nodes = calloc(size, sizeof(chashlistnode_t))) == NULL) {
+ printf("Calloc error %s %d\n", __FILE__, __LINE__);
+ free(ctable);
+ return NULL;
+ }
+
+ ctable->table = nodes;
+ ctable->size = size;
+ ctable->mask = (size << 1)-1;
+ ctable->numelements = 0; // Initial number of elements in the hash
+ ctable->loadfactor = loadfactor;
+
+ return ctable;
+}
+
+//Finds the right bin in the hash table
+static INLINE unsigned int chashFunction(chashtable_t *table, unsigned int key) {
+ return ( key & (table->mask))>>1; //throw away low order bit
+}
+
+//Store objects and their pointers into hash
+unsigned int chashInsert(chashtable_t *table, unsigned int key, void *val) {
+ unsigned int newsize;
+ int index;
+ chashlistnode_t *ptr, *node;
+
+ if(table->numelements > (table->loadfactor * table->size)) {
+ //Resize
+ newsize = table->size << 1;
+ chashResize(table,newsize);
+ }
+
+ ptr = table->table;
+ table->numelements++;
+ index = chashFunction(table, key);
+#ifdef DEBUG
+ printf("chashInsert(): DEBUG -> index = %d, key = %d, val = %x\n", index, key, val);
+#endif
+ if(ptr[index].next == NULL && ptr[index].key == 0) { // Insert at the first position in the hashtable
+ ptr[index].key = key;
+ ptr[index].val = val;
+ } else { // Insert in the beginning of linked list
+ if ((node = calloc(1, sizeof(chashlistnode_t))) == NULL) {
+ printf("Calloc error %s, %d\n", __FILE__, __LINE__);
+ return 1;
+ }
+ node->key = key;
+ node->val = val;
+ node->next = ptr[index].next;
+ ptr[index].next = node;
+ }
+ return 0;
+}
+
+// Search for an address for a given oid
+INLINE void * chashSearch(chashtable_t *table, unsigned int key) {
+ //REMOVE HASH FUNCTION CALL TO MAKE SURE IT IS INLINED HERE
+ chashlistnode_t *node = &table->table[(key & table->mask)>>1];
+
+ while(node != NULL) {
+ if(node->key == key) {
+ return node->val;
+ }
+ node = node->next;
+ }
+ return NULL;
+}
+
+unsigned int chashRemove(chashtable_t *table, unsigned int key) {
+ int index;
+ chashlistnode_t *curr, *prev;
+ chashlistnode_t *ptr, *node;
+
+ ptr = table->table;
+ index = chashFunction(table,key);
+ curr = &ptr[index];
+
+ for (; curr != NULL; curr = curr->next) {
+ if (curr->key == key) { // Find a match in the hash table
+ table->numelements--; // Decrement the number of elements in the global hashtable
+ if ((curr == &ptr[index]) && (curr->next == NULL)) { // Delete the first item inside the hashtable with no linked list of chashlistnode_t
+ curr->key = 0;
+ curr->val = NULL;
+ } else if ((curr == &ptr[index]) && (curr->next != NULL)) { //Delete the first item with a linked list of chashlistnode_t connected
+ curr->key = curr->next->key;
+ curr->val = curr->next->val;
+ node = curr->next;
+ curr->next = curr->next->next;
+ free(node);
+ } else { // Regular delete from linked listed
+ prev->next = curr->next;
+ free(curr);
+ }
+ return 0;
+ }
+ prev = curr;
+ }
+ return 1;
+}
+
+unsigned int chashResize(chashtable_t *table, unsigned int newsize) {
+ chashlistnode_t *node, *ptr, *curr, *next; // curr and next keep track of the current and the next chashlistnodes in a linked list
+ unsigned int oldsize;
+ int isfirst; // Keeps track of the first element in the chashlistnode_t for each bin in hashtable
+ int i,index;
+ chashlistnode_t *newnode;
+
+ ptr = table->table;
+ oldsize = table->size;
+
+ if((node = calloc(newsize, sizeof(chashlistnode_t))) == NULL) {
+ printf("Calloc error %s %d\n", __FILE__, __LINE__);
+ return 1;
+ }
+
+ table->table = node; //Update the global hashtable upon resize()
+ table->size = newsize;
+ table->mask = (newsize << 1)-1;
+ table->numelements = 0;
+
+ for(i = 0; i < oldsize; i++) { //Outer loop for each bin in hash table
+ curr = &ptr[i];
+ isfirst = 1;
+ while (curr != NULL) { //Inner loop to go through linked lists
+ if (curr->key == 0) { //Exit inner loop if there the first element for a given bin/index is NULL
+ break; //key = val =0 for element if not present within the hash table
+ }
+ next = curr->next;
+
+ index = chashFunction(table, curr->key);
+#ifdef DEBUG
+ printf("DEBUG(resize) -> index = %d, key = %d, val = %x\n", index, curr->key, curr->val);
+#endif
+ // Insert into the new table
+ if(table->table[index].next == NULL && table->table[index].key == 0) {
+ table->table[index].key = curr->key;
+ table->table[index].val = curr->val;
+ table->numelements++;
+ } else {
+ if((newnode = calloc(1, sizeof(chashlistnode_t))) == NULL) {
+ printf("Calloc error %s, %d\n", __FILE__, __LINE__);
+ return 1;
+ }
+ newnode->key = curr->key;
+ newnode->val = curr->val;
+ newnode->next = table->table[index].next;
+ table->table[index].next = newnode;
+ table->numelements++;
+ }
+
+ //free the linked list of chashlistnode_t if not the first element in the hash table
+ if (isfirst != 1) {
+ free(curr);
+ }
+
+ isfirst = 0;
+ curr = next;
+ }
+ }
+
+ free(ptr); //Free the memory of the old hash table
+ return 0;
+}
+
+//Delete the entire hash table
+void chashDelete(chashtable_t *ctable) {
+ int i, isFirst;
+ chashlistnode_t *ptr, *curr, *next;
+ ptr = ctable->table;
+
+ for(i=0 ; i<ctable->size ; i++) {
+ curr = &ptr[i];
+ isFirst = 1 ;
+ while(curr != NULL) {
+ next = curr->next;
+ if(isFirst != 1) {
+ free(curr);
+ }
+ isFirst = 0;
+ curr = next;
+ }
+ }
+
+ free(ptr);
+ ptr = NULL;
+ free(ctable);
+ ctable = NULL;
+}
diff --git a/Robust/src/Runtime/chash.h b/Robust/src/Runtime/chash.h
new file mode 100644
index 00000000..a07a4225
--- /dev/null
+++ b/Robust/src/Runtime/chash.h
@@ -0,0 +1,35 @@
+#ifndef _CHASH_H_
+#define _CHASH_H_
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#define CLOADFACTOR 0.25
+#define CHASH_SIZE 1024
+
+typedef struct chashlistnode {
+ unsigned int key;
+ void *val; //this can be cast to another type or used to point to a larger structure
+ struct chashlistnode *next;
+} chashlistnode_t;
+
+typedef struct chashtable {
+ chashlistnode_t *table; // points to beginning of hash table
+ unsigned int size;
+ unsigned int mask;
+ unsigned int numelements;
+ float loadfactor;
+} chashtable_t;
+
+/* Prototypes for hash*/
+chashtable_t *chashCreate(unsigned int size, float loadfactor);
+static unsigned int chashFunction(chashtable_t *table, unsigned int key);
+unsigned int chashInsert(chashtable_t *table, unsigned int key, void *val);
+void *chashSearch(chashtable_t *table, unsigned int key); //returns val, NULL if not found
+unsigned int chashRemove(chashtable_t *table, unsigned int key); //returns -1 if not found
+unsigned int chashResize(chashtable_t *table, unsigned int newsize);
+void chashDelete(chashtable_t *table);
+/* end hash */
+
+#endif
+