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 the hash bucket*/
  11 struct lustre_hash_bucket {
  12         struct hlist_head lhb_head;
  13         spinlock_t lhb_lock;
  14 #ifdef LUSTRE_HASH_DEBUG
  15         /* the number of hash item per bucket,
  16          * it will help us to analyse the hash distribute
  17          */
  18         int lhb_item_count;
  19 #endif
  20 };
  21
  22 struct lustre_hash_operations;
  23
  24 struct lustre_class_hash_body {
  25         char hashname[128];
  26         spinlock_t lchb_lock; /* body lock */
  27         struct lustre_hash_bucket *lchb_hash_tables;
  28         __u32 lchb_hash_max_size; /* define the hash tables size */
  29         /* define the hash operations */
  30         struct lustre_hash_operations *lchb_hash_operations;
  31 };
  32
  33 /* hash operations method define */
  34 struct lustre_hash_operations {
  35         __u32 (*lustre_hashfn) (struct lustre_class_hash_body *hash_body,
  36                                 void *key);
  37         int   (*lustre_hash_key_compare) (void *key,
  38                                           struct hlist_node *compared_hnode);
  39         /* add refcount */
  40         void* (*lustre_hash_object_refcount_get) (struct hlist_node *hash_item);
  41         /* dec refcount */
  42         void  (*lustre_hash_object_refcount_put) (struct hlist_node *hash_item);
  43 };
  44
  45 static inline struct hlist_node *
  46 lustre_hash_getitem_in_bucket_nolock(struct lustre_class_hash_body *hash_body,
  47                                      int hashent, void *key)
  48 {
  49         struct lustre_hash_bucket *bucket;
  50         struct hlist_node  *hash_item_node;
  51         struct lustre_hash_operations *hop = hash_body->lchb_hash_operations;
  52         int find = 0;
  53         ENTRY;
  54
  55         bucket = &hash_body->lchb_hash_tables[hashent];
  56         hlist_for_each(hash_item_node, &(bucket->lhb_head)) {
  57                 find = hop->lustre_hash_key_compare(key, hash_item_node);
  58                 if (find == 1)
  59                         break;
  60         }
  61         RETURN(find == 1 ? hash_item_node : NULL);
  62 }
  63
  64 static inline int
  65 lustre_hash_delitem_nolock(struct lustre_class_hash_body *hash_body,
  66                            int hashent, struct hlist_node * hash_item)
  67 {
  68         struct lustre_hash_operations *hop = hash_body->lchb_hash_operations;
  69
  70         hlist_del_init(hash_item);
  71
  72         hop->lustre_hash_object_refcount_put(hash_item);
  73
  74 #ifdef LUSTRE_HASH_DEBUG
  75         hash_body->lchb_hash_tables[hashent].lhb_item_count--;
  76         CDEBUG(D_INFO, "hashname[%s] bucket[%d] has [%d] hashitem\n",
  77                         hash_body->hashname, hashent,
  78                         hash_body->lchb_hash_tables[hashent].lhb_item_count);
  79 #endif
  80
  81         RETURN(0);
  82 }
  83
  84 int lustre_hash_init(struct lustre_class_hash_body **hash_body,
  85                      char *hashname, __u32 hashsize,
  86                      struct lustre_hash_operations *hash_operations);
  87 void lustre_hash_exit(struct lustre_class_hash_body **hash_body);
  88 int lustre_hash_additem_unique(struct lustre_class_hash_body *hash_body,
  89                                void *key, struct hlist_node *actual_hnode);
  90 int lustre_hash_additem(struct lustre_class_hash_body *hash_body, void *key,
  91                         struct hlist_node *actual_hnode);
  92 int lustre_hash_delitem_by_key(struct lustre_class_hash_body *hash_body,
  93                                void *key);
  94 int lustre_hash_delitem(struct lustre_class_hash_body *hash_body, void *key,
  95                         struct hlist_node *hash_item);
  96 void * lustre_hash_get_object_by_key(struct lustre_class_hash_body *hash_body,
  97                                       void *key);
  98
  99 /* ( uuid <-> export ) hash operations define */
 100 __u32 uuid_hashfn(struct lustre_class_hash_body *hash_body,  void * key);
 101 int uuid_hash_key_compare(void *key, struct hlist_node * compared_hnode);
 102 void * uuid_export_refcount_get(struct hlist_node * actual_hnode);
 103 void uuid_export_refcount_put(struct hlist_node * actual_hnode);
 104
 105 /* ( nid <-> export ) hash operations define */
 106 __u32 nid_hashfn(struct lustre_class_hash_body *hash_body,  void * key);
 107 int nid_hash_key_compare(void *key, struct hlist_node * compared_hnode);
 108 void * nid_export_refcount_get(struct hlist_node * actual_hnode);
 109 void nid_export_refcount_put(struct hlist_node * actual_hnode);
 110
 111 /* ( net_peer <-> connection ) hash operations define */
 112 __u32 conn_hashfn(struct lustre_class_hash_body *hash_body,  void * key);
 113 int conn_hash_key_compare(void *key, struct hlist_node * compared_hnode);
 114 void * conn_refcount_get(struct hlist_node * actual_hnode);
 115 void conn_refcount_put(struct hlist_node * actual_hnode);
 116
 117 #endif /* __CLASS_HASH_H */