diff options
Diffstat (limited to 'libihash/ihash.h')
| -rw-r--r-- | libihash/ihash.h | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/libihash/ihash.h b/libihash/ihash.h index fdfc3673..28fefe80 100644 --- a/libihash/ihash.h +++ b/libihash/ihash.h @@ -1,5 +1,5 @@ /* ihash.h - Integer keyed hash table interface. - Copyright (C) 1995, 2003, 2004 Free Software Foundation, Inc. + Copyright (C) 1995, 2003, 2004, 2014, 2015 Free Software Foundation, Inc. Written by Miles Bader <miles@gnu.org>. Revised by Marcus Brinkmann <marcus@gnu.org>. @@ -57,6 +57,20 @@ typedef uintptr_t hurd_ihash_key_t; typedef hurd_ihash_value_t *hurd_ihash_locp_t; +/* We support non-integer keys using the generalized key interface. + + To use it, supply a pair of functions matching the following + specification, and use pointers to the key instead of the key + itself in all calls to libihash. */ + +/* The type of a function computing a hash for the given key. */ +typedef hurd_ihash_key_t (*hurd_ihash_fct_hash_t) (const void *); + +/* The type of a function comparing two given keys. Return true if + both keys are equal. */ +typedef int (*hurd_ihash_fct_cmp_t) (const void *, const void *); + + /* The type of the cleanup function, which is called for every value removed from the hash table. */ typedef void (*hurd_ihash_cleanup_t) (hurd_ihash_value_t value, void *arg); @@ -95,6 +109,10 @@ struct hurd_ihash second argument. This does not happen if CLEANUP is NULL. */ hurd_ihash_cleanup_t cleanup; void *cleanup_data; + + /* User-supplied functions for the generalized key interface. */ + hurd_ihash_fct_hash_t fct_hash; + hurd_ihash_fct_cmp_t fct_cmp; }; typedef struct hurd_ihash *hurd_ihash_t; @@ -118,6 +136,16 @@ typedef struct hurd_ihash *hurd_ihash_t; .max_load = HURD_IHASH_MAX_LOAD_DEFAULT, \ .locp_offset = (locp_offs)} +#define HURD_IHASH_INITIALIZER_GKI(locp_offs, f_clean, f_clean_data, \ + f_hash, f_compare) \ + { .nr_items = 0, .size = 0, \ + .cleanup = (f_clean), \ + .cleanup_data = (f_clean_data), \ + .max_load = HURD_IHASH_MAX_LOAD_DEFAULT, \ + .locp_offset = (locp_offs), \ + .fct_hash = (f_hash), \ + .fct_cmp = (f_compare)} \ + /* Initialize the hash table at address HT. If LOCP_OFFSET is not HURD_IHASH_NO_LOCP, then this is an offset (in bytes) from the address of a hash value where a location pointer can be found. The @@ -152,6 +180,12 @@ void hurd_ihash_free (hurd_ihash_t ht); void hurd_ihash_set_cleanup (hurd_ihash_t ht, hurd_ihash_cleanup_t cleanup, void *cleanup_data); +/* Use the generalized key interface. Must be called before any item + is inserted into the table. */ +void hurd_ihash_set_gki (hurd_ihash_t ht, + hurd_ihash_fct_hash_t fct_hash, + hurd_ihash_fct_cmp_t fct_cmp); + /* Set the maximum load factor in binary percent to MAX_LOAD, which should be between 64 and 128. The default is HURD_IHASH_MAX_LOAD_DEFAULT. New elements are only added to the |