lustre/include/class_hash.h

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  */
   4
   5 #ifndef __CLASS_HASH_H
   6 #define __CLASS_HASH_H
   7
   8 #include <lustre_lib.h>
   9
  10 /* #define LUSTRE_HASH_DEBUG 1 */
  11
  12 /* define the hash bucket*/
  13 struct lustre_hash_bucket {
  14         struct hlist_head lhb_head;
  15         spinlock_t lhb_lock;
  16 #ifdef LUSTRE_HASH_DEBUG
  17         /* the number of hash item per bucket,
  18          * it will help us to analyse the hash distribute
  19          */
  20         int lhb_item_count;
  21 #endif
  22 };
  23
  24 struct lustre_hash_operations;
  25
  26 struct lustre_class_hash_body {
  27         char hashname[128];
  28         spinlock_t lchb_lock; /* body lock */
  29         struct lustre_hash_bucket *lchb_hash_tables;
  30         __u32 lchb_hash_max_size; /* define the hash tables size */
  31         /* define the hash operations */
  32         struct lustre_hash_operations *lchb_hash_operations;
  33 };
  34
  35 /* hash operations method define */
  36 struct lustre_hash_operations {
  37         __u32 (*lustre_hashfn) (struct lustre_class_hash_body *hash_body,
  38                                 void *key);
  39         int   (*lustre_hash_key_compare) (void *key,
  40                                           struct hlist_node *compared_hnode);
  41         /* add refcount */
  42         void* (*lustre_hash_object_refcount_get) (struct hlist_node *hash_item);
  43         /* dec refcount */
  44         void  (*lustre_hash_object_refcount_put) (struct hlist_node *hash_item);
  45 };
  46
  47 static inline struct hlist_node *
  48 lustre_hash_getitem_in_bucket_nolock(struct lustre_class_hash_body *hash_body,
  49                                      int hashent, void *key)
  50 {
  51         struct lustre_hash_bucket *bucket;
  52         struct hlist_node  *hash_item_node;
  53         struct lustre_hash_operations *hop = hash_body->lchb_hash_operations;
  54         int find = 0;
  55         ENTRY;
  56
  57         bucket = &hash_body->lchb_hash_tables[hashent];
  58         hlist_for_each(hash_item_node, &(bucket->lhb_head)) {
  59                 find = hop->lustre_hash_key_compare(key, hash_item_node);
  60                 if (find == 1)
  61                         break;
  62         }
  63         RETURN(find == 1 ? hash_item_node : NULL);
  64 }
  65
  66 static inline int
  67 lustre_hash_delitem_nolock(struct lustre_class_hash_body *hash_body,
  68                            int hashent, struct hlist_node * hash_item)
  69 {
  70         struct lustre_hash_operations *hop = hash_body->lchb_hash_operations;
  71
  72         hlist_del_init(hash_item);
  73
  74         hop->lustre_hash_object_refcount_put(hash_item);
  75
  76 #ifdef LUSTRE_HASH_DEBUG
  77         hash_body->lchb_hash_tables[hashent].lhb_item_count--;
  78         CDEBUG(D_INFO, "hashname[%s] bucket[%d] has [%d] hashitem\n",
  79                         hash_body->hashname, hashent,
  80                         hash_body->lchb_hash_tables[hashent].lhb_item_count);
  81 #endif
  82
  83         RETURN(0);
  84 }
  85
  86 typedef void (*hash_item_iterate_cb) (void *obj, void *data);
  87
  88 int lustre_hash_init(struct lustre_class_hash_body **hash_body,
  89                      char *hashname, __u32 hashsize,
  90                      struct lustre_hash_operations *hash_operations);
  91 void lustre_hash_exit(struct lustre_class_hash_body **hash_body);
  92 int lustre_hash_additem_unique(struct lustre_class_hash_body *hash_body,
  93                                void *key, struct hlist_node *actual_hnode);
  94 void *lustre_hash_findadd_unique(struct lustre_class_hash_body *hash_body,
  95                                  void *key, struct hlist_node *actual_hnode);
  96 int lustre_hash_additem(struct lustre_class_hash_body *hash_body, void *key,
  97                         struct hlist_node *actual_hnode);
  98 int lustre_hash_delitem_by_key(struct lustre_class_hash_body *hash_body,
  99                                void *key);
 100 int lustre_hash_delitem(struct lustre_class_hash_body *hash_body, void *key,
 101                         struct hlist_node *hash_item);
 102 void lustre_hash_bucket_iterate(struct lustre_class_hash_body *hash_body,
 103                                 void *key, hash_item_iterate_cb,
 104                                 void *data);
 105 void lustre_hash_iterate_all(struct lustre_class_hash_body *hash_body,
 106                              hash_item_iterate_cb, void *data);
 107
 108 void * lustre_hash_get_object_by_key(struct lustre_class_hash_body *hash_body,
 109                                       void *key);
 110
 111 __u32 djb2_hashfn(struct lustre_class_hash_body *hash_body, void* key,
 112                   size_t size);
 113
 114 /* ( uuid <-> export ) hash operations define */
 115 __u32 uuid_hashfn(struct lustre_class_hash_body *hash_body,  void * key);
 116 int uuid_hash_key_compare(void *key, struct hlist_node * compared_hnode);
 117 void * uuid_export_refcount_get(struct hlist_node * actual_hnode);
 118 void uuid_export_refcount_put(struct hlist_node * actual_hnode);
 119
 120 /* ( nid <-> export ) hash operations define */
 121 __u32 nid_hashfn(struct lustre_class_hash_body *hash_body,  void * key);
 122 int nid_hash_key_compare(void *key, struct hlist_node * compared_hnode);
 123 void * nid_export_refcount_get(struct hlist_node * actual_hnode);
 124 void nid_export_refcount_put(struct hlist_node * actual_hnode);
 125
 126 /* ( net_peer <-> connection ) hash operations define */
 127 __u32 conn_hashfn(struct lustre_class_hash_body *hash_body,  void * key);
 128 int conn_hash_key_compare(void *key, struct hlist_node * compared_hnode);
 129 void * conn_refcount_get(struct hlist_node * actual_hnode);
 130 void conn_refcount_put(struct hlist_node * actual_hnode);
 131
 132 /* ( nid <-> nidstats ) hash operations define. uses nid_hashfn */
 133 int nidstats_hash_key_compare(void *key, struct hlist_node * compared_hnode);
 134 void* nidstats_refcount_get(struct hlist_node * actual_hnode);
 135 void nidstats_refcount_put(struct hlist_node * actual_hnode);
 136 extern struct lustre_hash_operations nid_stat_hash_operations;
 137
 138 #endif /* __CLASS_HASH_H */