u_handle_table.h

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 *
 * Copyright 2008 VMware, Inc.
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/**
 * @file
 * Generic handle table.
 *  
 * @author José Fonseca <[email protected]>
 */

#ifndef U_HANDLE_TABLE_H_
#define U_HANDLE_TABLE_H_


#ifdef __cplusplus
extern "C" {
#endif

   
/**
 * Abstract data type to map integer handles to objects.
 * 
 * Also referred as "pointer array".
 */
struct handle_table;


struct handle_table *
handle_table_create(void);


/**
 * Set an optional destructor callback.
 * 
 * If set, it will be called during handle_table_remove and 
 * handle_table_destroy calls.
 */
void
handle_table_set_destroy(struct handle_table *ht,
                         void (*destroy)(void *object));


/**
 * Add a new object.
 * 
 * Returns a zero handle on failure (out of memory).
 */
unsigned
handle_table_add(struct handle_table *ht, 
                 void *object);

/**
 * Returns zero on failure (out of memory).
 */
unsigned
handle_table_set(struct handle_table *ht, 
                 unsigned handle,
                 void *object);

/**
 * Fetch an existing object.
 * 
 * Returns NULL for an invalid handle.
 */
void *
handle_table_get(struct handle_table *ht, 
                 unsigned handle);


void
handle_table_remove(struct handle_table *ht, 
                    unsigned handle);


void
handle_table_destroy(struct handle_table *ht);


unsigned
handle_table_get_first_handle(struct handle_table *ht);


unsigned
handle_table_get_next_handle(struct handle_table *ht,
                             unsigned handle);


#ifdef __cplusplus
}
#endif

#endif /* U_HANDLE_TABLE_H_ */