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      1 /**************************************************************************
      2  *
      3  * Copyright 2008 VMware, Inc.
      4  * All Rights Reserved.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a
      7  * copy of this software and associated documentation files (the
      8  * "Software"), to deal in the Software without restriction, including
      9  * without limitation the rights to use, copy, modify, merge, publish,
     10  * distribute, sub license, and/or sell copies of the Software, and to
     11  * permit persons to whom the Software is furnished to do so, subject to
     12  * the following conditions:
     13  *
     14  * The above copyright notice and this permission notice (including the
     15  * next paragraph) shall be included in all copies or substantial portions
     16  * of the Software.
     17  *
     18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
     21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
     22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
     23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
     24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     25  *
     26  **************************************************************************/
     27 
     28 /**
     29  * @file
     30  * Generic handle table.
     31  *
     32  * @author Jos Fonseca <jfonseca (at) vmware.com>
     33  */
     34 
     35 #ifndef U_HANDLE_TABLE_H_
     36 #define U_HANDLE_TABLE_H_
     37 
     38 
     39 #ifdef __cplusplus
     40 extern "C" {
     41 #endif
     42 
     43 
     44 /**
     45  * Abstract data type to map integer handles to objects.
     46  *
     47  * Also referred as "pointer array".
     48  */
     49 struct handle_table;
     50 
     51 
     52 struct handle_table *
     53 handle_table_create(void);
     54 
     55 
     56 /**
     57  * Set an optional destructor callback.
     58  *
     59  * If set, it will be called during handle_table_remove and
     60  * handle_table_destroy calls.
     61  */
     62 void
     63 handle_table_set_destroy(struct handle_table *ht,
     64                          void (*destroy)(void *object));
     65 
     66 
     67 /**
     68  * Add a new object.
     69  *
     70  * Returns a zero handle on failure (out of memory).
     71  */
     72 unsigned
     73 handle_table_add(struct handle_table *ht,
     74                  void *object);
     75 
     76 /**
     77  * Returns zero on failure (out of memory).
     78  */
     79 unsigned
     80 handle_table_set(struct handle_table *ht,
     81                  unsigned handle,
     82                  void *object);
     83 
     84 /**
     85  * Fetch an existing object.
     86  *
     87  * Returns NULL for an invalid handle.
     88  */
     89 void *
     90 handle_table_get(struct handle_table *ht,
     91                  unsigned handle);
     92 
     93 
     94 void
     95 handle_table_remove(struct handle_table *ht,
     96                     unsigned handle);
     97 
     98 
     99 void
    100 handle_table_destroy(struct handle_table *ht);
    101 
    102 
    103 unsigned
    104 handle_table_get_first_handle(struct handle_table *ht);
    105 
    106 
    107 unsigned
    108 handle_table_get_next_handle(struct handle_table *ht,
    109                              unsigned handle);
    110 
    111 
    112 #ifdef __cplusplus
    113 }
    114 #endif
    115 
    116 #endif /* U_HANDLE_TABLE_H_ */
    117