Creation of OpenFOAM-dev repository 15/04/2008

applications/utilities/parallelProcessing/decompositionMethods/metis-5.0pre2/GKlib/trunk/htable.c

@@ -0,0 +1,247 @@
+/*
+ * Copyright 2004, Regents of the University of Minnesota
+ *
+ * This file contains routines for manipulating a direct-access hash table
+ *
+ * Started 3/22/04
+ * George
+ *
+ */
+
+#include <GKlib.h>
+
+/******************************************************************************
+* This function creates the hash-table
+*******************************************************************************/
+gk_HTable_t *HTable_Create(int nelements)
+{
+  gk_HTable_t *htable;
+
+  htable            = gk_malloc(sizeof(gk_HTable_t), "HTable_Create: htable");
+  htable->harray    = gk_ikvmalloc(nelements, "HTable_Create: harray");
+  htable->nelements = nelements;
+
+  HTable_Reset(htable);
+
+  return htable;
+}
+
+
+/******************************************************************************
+* This function resets the data-structures associated with the hash-table
+*******************************************************************************/
+void HTable_Reset(gk_HTable_t *htable)
+{
+  int i;
+
+  for (i=0; i<htable->nelements; i++)
+    htable->harray[i].key = HTABLE_EMPTY;
+  htable->htsize = 0;
+
+}
+
+/******************************************************************************
+* This function resizes the hash-table
+*******************************************************************************/
+void HTable_Resize(gk_HTable_t *htable, int nelements)
+{
+  int i, old_nelements;
+  gk_ikv_t *old_harray;
+
+  old_nelements = htable->nelements;
+  old_harray = htable->harray;
+
+  /* prepare larger hash */
+  htable->nelements = nelements;
+  htable->htsize = 0;
+  htable->harray = gk_ikvmalloc(nelements, "HTable_Resize: harray");
+  for (i=0; i<nelements; i++)
+    htable->harray[i].key = HTABLE_EMPTY;
+
+  /* reassign the values */
+  for (i=0; i<old_nelements; i++)
+    if (old_harray[i].key != HTABLE_EMPTY)
+       HTable_Insert(htable, old_harray[i].key, old_harray[i].val);
+
+  /* remove old harray */
+  gk_free((void *)&old_harray, LTERM);
+}
+
+
+/******************************************************************************
+* This function inserts a key-value pair in the array
+*******************************************************************************/
+void HTable_Insert(gk_HTable_t *htable, int key, int val)
+{
+  int i, first;
+
+  if (htable->htsize > htable->nelements/2)
+    HTable_Resize(htable, 2*htable->nelements);
+
+  first = HTable_HFunction(htable->nelements, key);
+
+  for (i=first; i<htable->nelements; i++) {
+    if (htable->harray[i].key == HTABLE_EMPTY || htable->harray[i].key == HTABLE_DELETED) {
+      htable->harray[i].key = key;
+      htable->harray[i].val = val;
+      htable->htsize++;
+      return;
+    }
+  }
+
+  for (i=0; i<first; i++) {
+    if (htable->harray[i].key == HTABLE_EMPTY || htable->harray[i].key == HTABLE_DELETED) {
+      htable->harray[i].key = key;
+      htable->harray[i].val = val;
+      htable->htsize++;
+      return;
+    }
+  }
+
+}
+
+
+/******************************************************************************
+* This function deletes key from the htable
+*******************************************************************************/
+void HTable_Delete(gk_HTable_t *htable, int key)
+{
+  int i, first;
+
+  first = HTable_HFunction(htable->nelements, key);
+
+  for (i=first; i<htable->nelements; i++) {
+    if (htable->harray[i].key == key) {
+      htable->harray[i].key = HTABLE_DELETED;
+      htable->htsize--;
+      return;
+    }
+  }
+
+  for (i=0; i<first; i++) {
+    if (htable->harray[i].key == key) {
+      htable->harray[i].key = HTABLE_DELETED;
+      htable->htsize--;
+      return;
+    }
+  }
+
+}
+
+
+/******************************************************************************
+* This function returns the data associated with the key in the hastable
+*******************************************************************************/
+int HTable_Search(gk_HTable_t *htable, int key)
+{
+  int i, first;
+
+  first = HTable_HFunction(htable->nelements, key);
+
+  for (i=first; i<htable->nelements; i++) {
+    if (htable->harray[i].key == key) 
+      return htable->harray[i].val;
+    else if (htable->harray[i].key == HTABLE_EMPTY)
+      return -1;
+  }
+
+  for (i=0; i<first; i++) {
+    if (htable->harray[i].key == key) 
+      return htable->harray[i].val;
+    else if (htable->harray[i].key == HTABLE_EMPTY)
+      return -1;
+  }
+
+  return -1;
+}
+
+
+/******************************************************************************
+* This function returns the next key/val
+*******************************************************************************/
+int HTable_GetNext(gk_HTable_t *htable, int key, int *r_val, int type)
+{
+  int i;
+  static int first, last;
+
+  if (type == HTABLE_FIRST)
+    first = last = HTable_HFunction(htable->nelements, key);
+
+  if (first > last) {
+    for (i=first; i<htable->nelements; i++) {
+      if (htable->harray[i].key == key) {
+        *r_val = htable->harray[i].val;
+        first = i+1;
+        return 1;
+      }
+      else if (htable->harray[i].key == HTABLE_EMPTY)
+        return -1;
+    }
+    first = 0;
+  }
+
+  for (i=first; i<last; i++) {
+    if (htable->harray[i].key == key) {
+      *r_val = htable->harray[i].val;
+      first = i+1;
+      return 1;
+    }
+    else if (htable->harray[i].key == HTABLE_EMPTY)
+      return -1;
+  }
+
+  return -1;
+}
+
+
+/******************************************************************************
+* This function returns the data associated with the key in the hastable
+*******************************************************************************/
+int HTable_SearchAndDelete(gk_HTable_t *htable, int key)
+{
+  int i, first;
+
+  first = HTable_HFunction(htable->nelements, key);
+
+  for (i=first; i<htable->nelements; i++) {
+    if (htable->harray[i].key == key) {
+      htable->harray[i].key = HTABLE_DELETED;
+      htable->htsize--;
+      return htable->harray[i].val;
+    }
+    else if (htable->harray[i].key == HTABLE_EMPTY)
+      gk_errexit(SIGERR, "HTable_SearchAndDelete: Failed to find the key!\n");
+  }
+
+  for (i=0; i<first; i++) {
+    if (htable->harray[i].key == key) {
+      htable->harray[i].key = HTABLE_DELETED;
+      htable->htsize--;
+      return htable->harray[i].val;
+    }
+    else if (htable->harray[i].key == HTABLE_EMPTY)
+      gk_errexit(SIGERR, "HTable_SearchAndDelete: Failed to find the key!\n");
+  }
+
+  return -1;
+
+}
+
+
+
+/******************************************************************************
+* This function destroys the data structures associated with the hash-table
+*******************************************************************************/
+void HTable_Destroy(gk_HTable_t *htable)
+{
+  gk_free((void *)&htable->harray, &htable, LTERM);
+}
+
+
+/******************************************************************************
+* This is the hash-function. Based on multiplication
+*******************************************************************************/
+int HTable_HFunction(int nelements, int key)
+{
+  return (int)(key%nelements);
+}