/*
 The contents of this file are subject to the Mozilla Public
 License Version 1.1 (the "License"); you may not use this file
 except in compliance with the License. You may obtain a copy of
 the License at http://www.mozilla.org/MPL/

 Software distributed under the License is distributed on an "AS
 IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 implied. See the License for the specific language governing
 rights and limitations under the License.

 The Original Code is expat.

 The Initial Developer of the Original Code is James Clark.
 Portions created by James Clark are
 Copyright (C) 1998 James Clark. All
 Rights Reserved.

 Contributor(s): 
*/

#include <stdlib.h>
#include <string.h>

#include "xmldef.h"
#include "hashtable.h"

#ifdef XML_UNICODE
#define keycmp wcscmp
#else
#define keycmp strcmp
#endif

#define INIT_SIZE 64

static
unsigned long hash(KEY s)
{
  unsigned long h = 0;
  while (*s)
    h = (h << 5) + h + (unsigned char)*s++;
  return h;
}

NAMED *lookup(HASH_TABLE *table, KEY name, size_t createSize)
{
  size_t i;
  if (table->size == 0) {
    if (!createSize)
      return 0;
    table->v = calloc(INIT_SIZE, sizeof(NAMED *));
    if (!table->v)
      return 0;
    table->size = INIT_SIZE;
    table->usedLim = INIT_SIZE / 2;
    i = hash(name) & (table->size - 1);
  }
  else {
    unsigned long h = hash(name);
    for (i = h & (table->size - 1);
         table->v[i];
         i == 0 ? i = table->size - 1 : --i) {
      if (keycmp(name, table->v[i]->name) == 0)
	return table->v[i];
    }
    if (!createSize)
      return 0;
    if (table->used == table->usedLim) {
      /* check for overflow */
      size_t newSize = table->size * 2;
      NAMED **newV = calloc(newSize, sizeof(NAMED *));
      if (!newV)
	return 0;
      for (i = 0; i < table->size; i++)
	if (table->v[i]) {
	  size_t j;
	  for (j = hash(table->v[i]->name) & (newSize - 1);
	       newV[j];
	       j == 0 ? j = newSize - 1 : --j)
	    ;
	  newV[j] = table->v[i];
	}
      free(table->v);
      table->v = newV;
      table->size = newSize;
      table->usedLim = newSize/2;
      for (i = h & (table->size - 1);
	   table->v[i];
	   i == 0 ? i = table->size - 1 : --i)
	;
    }
  }
  table->v[i] = calloc(1, createSize);
  if (!table->v[i])
    return 0;
  table->v[i]->name = name;
  (table->used)++;
  return table->v[i];
}

void hashTableDestroy(HASH_TABLE *table)
{
  size_t i;
  for (i = 0; i < table->size; i++) {
    NAMED *p = table->v[i];
    if (p)
      free(p);
  }
  free(table->v);
}

void hashTableInit(HASH_TABLE *p)
{
  p->size = 0;
  p->usedLim = 0;
  p->used = 0;
  p->v = 0;
}

void hashTableIterInit(HASH_TABLE_ITER *iter, const HASH_TABLE *table)
{
  iter->p = table->v;
  iter->end = iter->p + table->size;
}

NAMED *hashTableIterNext(HASH_TABLE_ITER *iter)
{
  while (iter->p != iter->end) {
    NAMED *tem = *(iter->p)++;
    if (tem)
      return tem;
  }
  return 0;
}