xref: /haiku/src/add-ons/translators/gif/SFHash.cpp (revision 5e4c29a6b7d6cf23b6ea0d9dd22bd4abf5c89c1a)

////////////////////////////////////////////////////////////////////////////////
//
//	File: SFHash.cpp
//
//	Date: December 1999
//
//	Author: Daniel Switkin
//
//	Copyright 2003 (c) by Daniel Switkin. This file is made publically available
//	under the BSD license, with the stipulations that this complete header must
//	remain at the top of the file indefinitely, and credit must be given to the
//	original author in any about box using this software.
//
////////////////////////////////////////////////////////////////////////////////

// Additional authors:	Stephan Aßmus, <superstippi@gmx.de>
//						John Scipione, <jscipione@gmail.com>


#include "SFHash.h"

#include <stdio.h>
#include <stdlib.h>


SFHash::SFHash(int size) {
	fatalerror = false;
	this->size = size;
	iterate_pos = iterate_depth = 0;
	main_array = (HashItem**)malloc(this->size * sizeof(HashItem*));

	if (main_array == NULL) {
		fatalerror = true;
		return;
	}

	for (int x = 0; x < this->size; x++)
		main_array[x] = NULL;
}


SFHash::~SFHash() {
	for (int x = 0; x < size; x++) {
		HashItem* item = main_array[x];
		while (item != NULL) {
			HashItem* t = item->next;
			delete item;
			item = t;
		}
	}
    free(main_array);
}


void
SFHash::AddItem(HashItem* item) {
	item->next = NULL;
	int pos = item->key % size;

	if (main_array[pos] == NULL)
		main_array[pos] = item;
	else {
		HashItem* temp = main_array[pos];
		while (temp->next != NULL) temp = temp->next;
		temp->next = item;
	}
}


HashItem*
SFHash::GetItem(unsigned int key)
{
	int pos = key % size;
	HashItem* item = main_array[pos];

	while (item != NULL) {
		if (item->key == key) return item;
		item = item->next;
	}

	return NULL;
}


unsigned int
SFHash::CountItems()
{
	unsigned int count = 0;
	for (int x = 0; x < this->size; x++) {
		HashItem* item = main_array[x];
		while (item != NULL) {
			count++;
			item = item->next;
		}
	}

	return count;
}


HashItem*
SFHash::NextItem()
{
	if (iterate_pos >= size) {
		Rewind();
		return NULL;
	}
	HashItem* item;
	while ((item = main_array[iterate_pos]) == NULL)
		iterate_pos++;

	for (int d = 0; d < iterate_depth; d++)
		item = item->next;

	if (item->next != NULL)
		iterate_depth++;
	else {
		iterate_pos++;
		iterate_depth = 0;
	}

	return item;
}


void
SFHash::Rewind() {
	iterate_pos = 0;
	iterate_depth = 0;
}