Cleanup dead files in libmemcached.
[m6w6/libmemcached] / libmemcached / hash.c
1 #include "common.h"
2
3
4 uint32_t memcached_generate_hash_value(const char *key, size_t key_length, memcached_hash_t hash_algorithm)
5 {
6 return libhashkit_digest(key, key_length, (hashkit_hash_algorithm_t)hash_algorithm);
7 }
8
9 uint32_t generate_hash(memcached_st *ptr, const char *key, size_t key_length)
10 {
11 uint32_t hash= 1; /* Just here to remove compile warning */
12
13
14 WATCHPOINT_ASSERT(memcached_server_count(ptr));
15
16 if (memcached_server_count(ptr) == 1)
17 return 0;
18
19 hash= hashkit_digest(&ptr->hashkit, key, key_length);
20 WATCHPOINT_ASSERT(hash);
21
22 return hash;
23 }
24
25 static uint32_t dispatch_host(memcached_st *ptr, uint32_t hash)
26 {
27 switch (ptr->distribution)
28 {
29 case MEMCACHED_DISTRIBUTION_CONSISTENT:
30 case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA:
31 case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY:
32 {
33 uint32_t num= ptr->continuum_points_counter;
34 WATCHPOINT_ASSERT(ptr->continuum);
35
36 hash= hash;
37 memcached_continuum_item_st *begin, *end, *left, *right, *middle;
38 begin= left= ptr->continuum;
39 end= right= ptr->continuum + num;
40
41 while (left < right)
42 {
43 middle= left + (right - left) / 2;
44 if (middle->value < hash)
45 left= middle + 1;
46 else
47 right= middle;
48 }
49 if (right == end)
50 right= begin;
51 return right->index;
52 }
53 case MEMCACHED_DISTRIBUTION_MODULA:
54 return hash % memcached_server_count(ptr);
55 case MEMCACHED_DISTRIBUTION_RANDOM:
56 return (uint32_t) random() % memcached_server_count(ptr);
57 case MEMCACHED_DISTRIBUTION_CONSISTENT_MAX:
58 default:
59 WATCHPOINT_ASSERT(0); /* We have added a distribution without extending the logic */
60 return hash % memcached_server_count(ptr);
61 }
62 /* NOTREACHED */
63 }
64
65 /*
66 One day make this public, and have it return the actual memcached_server_st
67 to the calling application.
68 */
69 uint32_t memcached_generate_hash(memcached_st *ptr, const char *key, size_t key_length)
70 {
71 uint32_t hash= 1; /* Just here to remove compile warning */
72
73 WATCHPOINT_ASSERT(memcached_server_count(ptr));
74
75 if (memcached_server_count(ptr) == 1)
76 return 0;
77
78 if (ptr->flags.hash_with_prefix_key)
79 {
80 size_t temp_length= ptr->prefix_key_length + key_length;
81 char temp[temp_length];
82
83 if (temp_length > MEMCACHED_MAX_KEY -1)
84 return 0;
85
86 strncpy(temp, ptr->prefix_key, ptr->prefix_key_length);
87 strncpy(temp + ptr->prefix_key_length, key, key_length);
88 hash= generate_hash(ptr, temp, temp_length);
89 }
90 else
91 {
92 hash= generate_hash(ptr, key, key_length);
93 }
94
95 WATCHPOINT_ASSERT(hash);
96
97 if (memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_AUTO_EJECT_HOSTS) && ptr->next_distribution_rebuild)
98 {
99 struct timeval now;
100
101 if (gettimeofday(&now, NULL) == 0 &&
102 now.tv_sec > ptr->next_distribution_rebuild)
103 {
104 run_distribution(ptr);
105 }
106 }
107
108 return dispatch_host(ptr, hash);
109 }