mono/utils/mono-value-hash.h

   1 /*
   2  * mono-value-hash.h: A hash table which only stores values in the hash nodes.
   3  *
   4  * Author:
   5  *   Mark Probst (mark.probst@gmail.com)
   6  *   Zoltan Varga (vargaz@gmail.com)
   7  *
   8  * (C) 2008 Novell, Inc.
   9  *
  10  */
  11 #ifndef __MONO_UTILS_MONO_VALUE_HASH__
  12 #define __MONO_UTILS_MONO_VALUE_HASH__
  13
  14 #include <glib.h>
  15 #include "mono-compiler.h"
  16
  17 G_BEGIN_DECLS
  18
  19 /*
  20  * This is a hash table with the following features/restrictions:
  21  * - Keys are not stored in the table, instead a function must be supplied which
  22  *   computes them from the value.
  23  * - Values are assumed to be normal pointers, i.e. their lowest 2-3 bits should be
  24  *   zero.
  25  * - NULL values are not allowed.
  26  * - It uses internal probing instead of chaining.
  27  * - The above restrictions mean that this hash table will be somewhat slower than
  28  *   hash tables which store the key (or even the key hash) in the hash nodes. But
  29  *   it also means that each hash node has a size of one machine word, instead of
  30  * 4 in GHashTable.
  31  * - Removal of entries is not supported, as it is not needed by the runtime right
  32  *   now.
  33  */
  34
  35 typedef struct _MonoValueHashTable MonoValueHashTable;
  36
  37 typedef gpointer (*MonoValueHashKeyExtractFunc) (gpointer value);
  38
  39 MonoValueHashTable* mono_value_hash_table_new (GHashFunc hash_func,
  40                                                                                            GEqualFunc key_equal_func,
  41                                                                                            MonoValueHashKeyExtractFunc key_extract);
  42
  43 void
  44 mono_value_hash_table_destroy (MonoValueHashTable *table);
  45
  46 gpointer
  47 mono_value_hash_table_lookup (MonoValueHashTable *table, gconstpointer key);
  48
  49 /* The key pointer is actually only passed here to check a debugging
  50    assertion and to make the API look more familiar. */
  51 void
  52 mono_value_hash_table_insert (MonoValueHashTable *table,
  53                                  gpointer key, gpointer value);
  54
  55 G_END_DECLS
  56
  57 #endif