1MEMCACHED_RESULT_CAS(3) libmemcached-awesome MEMCACHED_RESULT_CAS(3)
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6 memcached_result_cas - Working with result sets
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9 #include <libmemcached/memcached.h>
10 Compile and link with -lmemcachedutil -lmemcached
11 typedef struct memcached_result_st memcached_result_st
13 memcached_result_st *memcached_result_create(memcached_st *ptr,
15 memcached_result_st *result)
16 Parameters
18 • ptr -- pointer to initialized memcached_st struct
20 • result -- pointer to an memcached_result_st instance to
22 initialize or nullptr to allocate a new instance
23 Returns
25 pointer to initialized memcached_result_st instance
26 void memcached_result_free(memcached_result_st *result)
28 Parameters
30 result -- pointer to initialized memcached_result_st
31 struct
32 const char *memcached_result_key_value(memcached_result_st *result)
34 Parameters
36 result -- pointer to initialized memcached_result_st
37 struct
38 Returns
40 the key value associated with the current result object
41 size_t memcached_result_key_length(const memcached_result_st *result)
43 Parameters
45 result -- pointer to initialized memcached_result_st
46 struct
47 Returns
49 the key length associated with the current result object
50 const char *memcached_result_value(memcached_result_st *result)
52 Parameters
54 result -- pointer to initialized memcached_result_st
55 struct
56 Returns
58 the result value associated with the current result ob‐
59 ject
60 char *memcached_result_take_value(memcached_result_st *result)
62 Parameters
64 result -- pointer to initialized memcached_result_st
65 struct
66 Returns
68 the result value associated with the current result ob‐
69 ject
70 size_t memcached_result_length(const memcached_result_st *result)
72 Parameters
74 result -- pointer to initialized memcached_result_st
75 struct
76 Returns
78 the result length associated with the current result ob‐
79 ject
80 uint32_t memcached_result_flags(const memcached_result_st *result)
82 Parameters
84 result -- pointer to initialized memcached_result_st
85 struct
86 Returns
88 the flags associated with the current result object
89 uint64_t memcached_result_cas(const memcached_result_st *result)
91 Parameters
93 result -- pointer to initialized memcached_result_st
94 struct
95 Returns
97 the cas associated with the current result object
98 memcached_return_t memcached_result_set_value(memcached_result_st *re‐
100 sult, const char *value, size_t length)
101 Parameters
103 • result -- pointer to initialized memcached_result_st
105 struct
106 • value -- byte array to set the value of the current re‐
108 sult object to
109 • length -- the length of value wothout any terminating
111 zero
112 Returns
114 memcached_return_t indicating success
115 void memcached_result_set_flags(memcached_result_st *result, uint32_t
117 flags)
118 Parameters
120 • result -- pointer to initialized memcached_result_st
122 struct
123 • flags -- a new value for the flags field
125 void memcached_result_set_expiration(memcached_result_st *result,
127 time_t expiration)
128 Parameters
130 • result -- pointer to initialized memcached_result_st
132 struct
133 • expiration -- a new value for the expiration field
135
137 libmemcached can optionally return a memcached_result_st which acts as
138 a result object. The result objects have added benefits over the char‐
139 acter pointer return values, in that they are forward compatible with
140 new return items that future memcached servers may implement (the best
141 current example of this is the CAS return item). The structures can
142 also be reused, which will save on calls to malloc(3). It is suggested
143 that you use result objects over char * return functions.
144 The structure of memcached_result_st has been encapsulated, you should
146 not write code directly accessing members of the structure.
147 memcached_result_create() will either allocate memory for a
149 memcached_result_st or will initialize a structure passed to it.
150 memcached_result_free() will deallocate any memory attached to the
152 structure. If the structure was also allocated, it will deallocate it.
153 memcached_result_key_value() returns the key value associated with the
155 current result object.
156 memcached_result_key_length() returns the key length associated with
158 the current result object.
159 memcached_result_value() returns the result value associated with the
161 current result object.
162 memcached_result_take_value() returns and hands over the result value
164 associated with the current result object. You must call free(3) to re‐
165 lease this value, unless you have made use of a custom allocator. Use
166 of a custom allocator requires that you create your own custom free()
167 to release it.
168 memcached_result_length() returns the result length associated with the
170 current result object.
171 memcached_result_flags() returns the flags associated with the current
173 result object.
174 memcached_result_cas() returns the cas associated with the current re‐
176 sult object. This value will only be available if the server tests it.
177 memcached_result_set_value() takes a byte array and a size and sets the
179 result to this value. This function is used for trigger responses.
180 memcached_result_set_flags() takes a result structure and stores a new
182 value for the flags field.
183 memcached_result_set_expiration() takes a result structure and stores a
185 new value for the expiration field (this is only used by read through
186 triggers).
187
189 Varies, see particular functions. All structures must have
190 memcached_result_free() called on them for cleanup purposes. Failure to
191 do this will result in leaked memory.
192
194 memcached(1) libmemcached(3) memcached_strerror(3) memcached_memory_al‐
195 locators(3)
1961.1 Sep 20, 2021 MEMCACHED_RESULT_CAS(3)