image_container.c

#include <rtgui/image_container.h>

#ifdef RTGUI_IMAGE_CONTAINER
typedef unsigned int (*rtgui_hash_func_t) (const void* key);
typedef struct _rtgui_hash_table  rtgui_hash_table_t;
typedef rt_bool_t (*rtgui_equal_func_t) (const void* a, const void* b);
typedef void (*rtgui_user_func_t) (const void* value, const void* data);

/*
 *Hash tables
 */
rtgui_hash_table_t* hash_table_create(rtgui_hash_func_t hash_func, rtgui_equal_func_t key_equal_func);
void hash_table_destroy (rtgui_hash_table_t* hash_table);

void* hash_table_find (rtgui_hash_table_t* hash_table, void* key);
void hash_table_insert (rtgui_hash_table_t* hash_table, void* key, void* value);
rt_bool_t hash_table_remove (rtgui_hash_table_t* hash_table, void* key);

void hash_table_foreach(rtgui_hash_table_t* hash_table, rtgui_user_func_t user_func, void* data);
unsigned int hash_table_get_size (rtgui_hash_table_t* hash_table);

/* Hash Functions
 */
unsigned int direct_hash (void* v);

#define HASH_TABLE_MIN_SIZE 11
#define HASH_TABLE_MAX_SIZE 6247

typedef struct _gui_hash_node rtgui_hash_node_t;
struct _gui_hash_node
{
	void* key;
	void* value;
	rtgui_hash_node_t *next;
};

struct _rtgui_hash_table
{
	rt_uint16_t size;
	rt_uint16_t nnodes;

	rtgui_hash_node_t **nodes;
	rtgui_hash_func_t hash_func;
	rtgui_equal_func_t key_equal_func;
};

static const unsigned int primes[] =
{
	11,
	19,
	37,
	73,
	109,
	163,
	251,
	367,
	557,
	823,
	1237,
	1861,
	2777,
	4177,
	6247,
/*
	9371,
	14057,
	21089,
	31627,
	47431,
	71143,
	106721,
	160073,
	240101,
	360163,
	540217,
	810343,
	1215497,
	1823231,
	2734867,
	4102283,
	6153409,
	9230113,
	13845163,
*/
};

static const unsigned int nprimes = sizeof (primes) / sizeof (primes[0]);

static void hash_table_resize (rtgui_hash_table_t *hash_table);
static rtgui_hash_node_t** hash_table_find_node (rtgui_hash_table_t *hash_table, void* key);
static rtgui_hash_node_t* hash_node_create (void* key, void* value);
static void hash_node_destroy (rtgui_hash_node_t *hash_node);
static void hash_nodes_destroy (rtgui_hash_node_t *hash_node);
static unsigned int primes_closest (unsigned int num);
static void hash_table_needresize(rtgui_hash_table_t *hash_table);

rt_inline unsigned int primes_closest (unsigned int num)
{
	int i;

	for (i = 0; i < nprimes; i++)
		if (primes[i] > num)
			return primes[i];

	return primes[nprimes - 1];
}

/* directly hash */
unsigned int direct_hash (void* v)
{
	return (unsigned int)v;
}

rtgui_hash_table_t* hash_table_create(rtgui_hash_func_t hash_func, rtgui_equal_func_t key_equal_func)
{
	rtgui_hash_table_t *hash_table;

	hash_table = (rtgui_hash_table_t*) rt_malloc (sizeof(rtgui_hash_table_t));
	if (hash_table != RT_NULL)
	{
		hash_table->size               = HASH_TABLE_MIN_SIZE;
		hash_table->nnodes             = 0;
		hash_table->hash_func          = hash_func ? hash_func : direct_hash;
		hash_table->key_equal_func     = key_equal_func;
		hash_table->nodes              = (rtgui_hash_node_t **)rt_malloc ( sizeof(rtgui_hash_node_t*) * hash_table->size);
		if (hash_table->nodes == RT_NULL)
		{
			/* no memory yet */
			rt_free(hash_table);
			return RT_NULL;
		}

		rt_memset(hash_table->nodes, 0, sizeof(rtgui_hash_node_t*) * hash_table->size);
	}

	return hash_table;
}

void hash_table_destroy (rtgui_hash_table_t *hash_table)
{
	unsigned int i;

	RT_ASSERT(hash_table != RT_NULL);

	for (i = 0; i < hash_table->size; i++)
		hash_nodes_destroy (hash_table->nodes[i]);

	rt_free (hash_table->nodes);
	rt_free (hash_table);
}

static rtgui_hash_node_t** hash_table_find_node (rtgui_hash_table_t *hash_table, void* key)
{
	rtgui_hash_node_t **node;

	node = &hash_table->nodes [(* hash_table->hash_func) (key) % hash_table->size];

	if (hash_table->key_equal_func)
		while (*node && !(*hash_table->key_equal_func) ((*node)->key, key))
			node = &(*node)->next;
	else
		while (*node && (*node)->key != key)
			node = &(*node)->next;

	return node;
}

void* hash_table_find (rtgui_hash_table_t* hash_table, void* key)
{
	rtgui_hash_node_t *node;

	RT_ASSERT(hash_table != RT_NULL);
	RT_ASSERT(key != RT_NULL);

	node = *hash_table_find_node (hash_table, key);

	if (node) return node->value;
	else return RT_NULL;
}

void hash_table_insert (rtgui_hash_table_t *hash_table, void* key, void* value)
{
	rtgui_hash_node_t **node;

	if (hash_table == RT_NULL)return;

	node = hash_table_find_node (hash_table, key);
	if (*node)
	{
		(*node)->value = value;
	}
	else
	{
		*node = hash_node_create (key, value);
		hash_table->nnodes++;
		hash_table_needresize (hash_table);
	}
}

rt_bool_t hash_table_remove (rtgui_hash_table_t *hash_table, void*  key)
{
	rtgui_hash_node_t **node, *dest;

	if (hash_table == RT_NULL) return RT_FALSE;

	node = hash_table_find_node (hash_table, key);
	if (*node)
	{
		dest = *node;
		(*node) = dest->next;
		hash_node_destroy (dest);
		hash_table->nnodes--;

		hash_table_needresize (hash_table);

		return RT_TRUE;
	}

	return RT_FALSE;
}

void hash_table_foreach(rtgui_hash_table_t *hash_table, rtgui_user_func_t user_func, void* data)
{
	rtgui_hash_node_t *node;
	int i;

	RT_ASSERT(hash_table != RT_NULL);
	RT_ASSERT(user_func != RT_NULL);

	for (i = 0; i < hash_table->size; i++)
		for (node = hash_table->nodes[i]; node; node = node->next)
			(* user_func) (node->value, data);
}

unsigned int hash_table_get_size (rtgui_hash_table_t *hash_table)
{
	if ( hash_table ==NULL ) return 0;

	return hash_table->nnodes;
}

static void hash_table_needresize(rtgui_hash_table_t *hash_table)
{
	if ((hash_table->size >= 3*hash_table->nnodes && hash_table->size > HASH_TABLE_MIN_SIZE) ||
	        (3 * hash_table->size <= hash_table->nnodes && hash_table->size < HASH_TABLE_MAX_SIZE))
		hash_table_resize (hash_table);
}

static void hash_table_resize (rtgui_hash_table_t *hash_table)
{
	rtgui_hash_node_t **new_nodes;
	rtgui_hash_node_t *node;
	rtgui_hash_node_t *next;
	unsigned int hash_val;
	int new_size;
	int i;

	i = primes_closest(hash_table->nnodes);
	new_size = i > HASH_TABLE_MAX_SIZE ? HASH_TABLE_MAX_SIZE : i < HASH_TABLE_MIN_SIZE ? HASH_TABLE_MIN_SIZE : i ;

	new_nodes = (rtgui_hash_node_t **)rt_malloc ( sizeof(rtgui_hash_node_t*) * new_size);
	if (new_nodes == RT_NULL) return; /* no memory yet */
	rt_memset(new_nodes, 0, sizeof(rtgui_hash_node_t*) * new_size);

	for (i = 0; i < hash_table->size; i++)
	{
		for (node = hash_table->nodes[i]; node; node = next)
		{
			next = node->next;

			hash_val = (* hash_table->hash_func) (node->key) % new_size;

			node->next = new_nodes[hash_val];
			new_nodes[hash_val] = node;
		}
	}

	rt_free (hash_table->nodes);
	hash_table->nodes = new_nodes;
	hash_table->size = new_size;
}

static rtgui_hash_node_t* hash_node_create (void* key, void* value)
{
	rtgui_hash_node_t *hash_node;

	hash_node = (rtgui_hash_node_t*) rt_malloc ( sizeof(rtgui_hash_node_t) );
	if (hash_node != RT_NULL)
	{
		/* set value and key */
		hash_node->key = key;
		hash_node->value = value;;

		hash_node->next = RT_NULL;
	}

	return hash_node;
}

static void hash_node_destroy (rtgui_hash_node_t *hash_node)
{
	rt_free(hash_node);
}

static void hash_nodes_destroy (rtgui_hash_node_t *hash_node)
{
	if (hash_node)
	{
		rtgui_hash_node_t *node = hash_node;
		rtgui_hash_node_t *temp;

		while (node->next)
		{
			node->key = NULL;
			node->value = NULL;

			temp = node;
			node = node->next;
			rt_free(temp);
		}

		node->key = NULL;
		node->value = NULL;
		rt_free(node);
	}
}

unsigned int string_hash_func(const void* self)
{
	const char *p;
	int h=0, g;

	for(p = self; *p != '\0'; p += 1)
	{
		h = ( h << 4 ) + *p;
		if ( ( g = h & 0xf0000000 ) )
		{
			h = h ^ (g >> 24);
			h = h ^ g;
		}
	}

	return h ;
}
rt_bool_t string_equal_func(const void* a, const void* b)
{
	const char *str1, *str2;

	str1 = (const char*)a;
	str2 = (const char*)b;

	if (strcmp(str1, str2) == 0) return RT_TRUE;
	return RT_FALSE;
}

static rtgui_hash_table_t* image_hash_table;
static rt_bool_t load_image = RT_FALSE;
void rtgui_system_image_container_init(rt_bool_t load)
{
	/* create image hash table */
	image_hash_table = hash_table_create(string_hash_func, string_equal_func);
	RT_ASSERT(image_hash_table != RT_NULL);

	/* set load type */
	load_image = load;
}

rtgui_image_item_t* rtgui_image_container_get(const char* filename)
{
	struct rtgui_image_item* item;
	
	item = hash_table_find(image_hash_table, filename);
	if (item == RT_NULL)
	{
		item = (struct rtgui_image_item*) rt_malloc (sizeof(struct rtgui_image_item));
		if (item == RT_NULL) return RT_NULL;

		/* create a image object */
		item->image = rtgui_image_create(filename, load_image);
		if (item->image == RT_NULL)
		{
			rt_free(item);
			return RT_NULL; /* create image failed */
		}

		item->refcount = 1;
		item->filename = rt_strdup(filename);
		hash_table_insert(image_hash_table, item->filename, item);
	}
	else
	{
		item->refcount ++; /* increase refcount */
	}

	return item;
}

rtgui_image_item_t* rtgui_image_container_get_memref(const char* type, const rt_uint8_t* memory, rt_uint32_t length)
{
	char filename[32];
	struct rtgui_image_item* item;

	/* create filename for image identification */
	rt_snprintf(filename, sizeof(filename), "0x%08x_%s", memory, type);

	/* search in container */
	item = hash_table_find(image_hash_table, filename);
	if (item == RT_NULL)
	{
		item = (struct rtgui_image_item*) rt_malloc (sizeof(struct rtgui_image_item));
		if (item == RT_NULL) return RT_NULL;

		/* create image object */
		item->image = rtgui_image_create_from_mem(type, memory, length, load_image);
		if (item->image == RT_NULL)
		{
			rt_free(item);
			return RT_NULL; /* create image failed */
		}

		item->refcount = 1;
		item->filename = rt_strdup(filename);
		hash_table_insert(image_hash_table, item->filename, item);
	}
	else item->refcount ++;

	return item;
}

void rtgui_image_container_put(rtgui_image_item_t* item)
{
	item->refcount --;
	if (item->refcount == 0)
	{
		/* remove item from container */
		hash_table_remove(image_hash_table, item->filename);

		/* destroy image and image item */
		rt_free(item->filename);
		rtgui_image_destroy(item->image);
		rt_free(item);
	}
}

#endif