2 * Copyright (C) 2006-2009 Brian Aker
5 * Use and distribution licensed under the BSD license. See
6 * the COPYING file in the parent directory for full text.
8 * Summary: Get functions for libmemcached
15 What happens if no servers exist?
17 char *memcached_get(memcached_st
*ptr
, const char *key
,
21 memcached_return_t
*error
)
23 return memcached_get_by_key(ptr
, NULL
, 0, key
, key_length
, value_length
,
27 static memcached_return_t
memcached_mget_by_key_real(memcached_st
*ptr
,
28 const char *master_key
,
29 size_t master_key_length
,
30 const char * const *keys
,
31 const size_t *key_length
,
32 size_t number_of_keys
,
35 char *memcached_get_by_key(memcached_st
*ptr
,
36 const char *master_key
,
37 size_t master_key_length
,
38 const char *key
, size_t key_length
,
41 memcached_return_t
*error
)
46 memcached_return_t dummy_error
;
48 unlikely (ptr
->flags
.use_udp
)
50 *error
= MEMCACHED_NOT_SUPPORTED
;
55 *error
= memcached_mget_by_key_real(ptr
, master_key
, master_key_length
,
56 (const char * const *)&key
,
57 &key_length
, 1, false);
59 value
= memcached_fetch(ptr
, NULL
, NULL
,
60 value_length
, flags
, error
);
61 /* This is for historical reasons */
62 if (*error
== MEMCACHED_END
)
63 *error
= MEMCACHED_NOTFOUND
;
67 if (ptr
->get_key_failure
&& *error
== MEMCACHED_NOTFOUND
)
69 memcached_return_t rc
;
71 memcached_result_reset(&ptr
->result
);
72 rc
= ptr
->get_key_failure(ptr
, key
, key_length
, &ptr
->result
);
74 /* On all failure drop to returning NULL */
75 if (rc
== MEMCACHED_SUCCESS
|| rc
== MEMCACHED_BUFFERED
)
77 if (rc
== MEMCACHED_BUFFERED
)
79 uint64_t latch
; /* We use latch to track the state of the original socket */
80 latch
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
);
82 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 1);
84 rc
= memcached_set(ptr
, key
, key_length
,
85 (memcached_result_value(&ptr
->result
)),
86 (memcached_result_length(&ptr
->result
)),
88 (memcached_result_flags(&ptr
->result
)));
90 if (rc
== MEMCACHED_BUFFERED
&& latch
== 0)
91 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 0);
95 rc
= memcached_set(ptr
, key
, key_length
,
96 (memcached_result_value(&ptr
->result
)),
97 (memcached_result_length(&ptr
->result
)),
99 (memcached_result_flags(&ptr
->result
)));
102 if (rc
== MEMCACHED_SUCCESS
|| rc
== MEMCACHED_BUFFERED
)
105 *value_length
= memcached_result_length(&ptr
->result
);
106 *flags
= memcached_result_flags(&ptr
->result
);
107 return memcached_string_c_copy(&ptr
->result
.value
);
115 (void)memcached_fetch(ptr
, NULL
, NULL
,
116 &dummy_length
, &dummy_flags
,
118 WATCHPOINT_ASSERT(dummy_length
== 0);
123 memcached_return_t
memcached_mget(memcached_st
*ptr
,
124 const char * const *keys
,
125 const size_t *key_length
,
126 size_t number_of_keys
)
128 return memcached_mget_by_key(ptr
, NULL
, 0, keys
, key_length
, number_of_keys
);
131 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
132 uint32_t master_server_key
,
133 bool is_master_key_set
,
134 const char * const *keys
,
135 const size_t *key_length
,
136 size_t number_of_keys
,
139 static memcached_return_t
memcached_mget_by_key_real(memcached_st
*ptr
,
140 const char *master_key
,
141 size_t master_key_length
,
142 const char * const *keys
,
143 const size_t *key_length
,
144 size_t number_of_keys
,
147 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
148 const char *get_command
= "get ";
149 uint8_t get_command_length
= 4;
150 unsigned int master_server_key
= (unsigned int)-1; /* 0 is a valid server id! */
151 bool is_master_key_set
= false;
153 unlikely (ptr
->flags
.use_udp
)
154 return MEMCACHED_NOT_SUPPORTED
;
156 LIBMEMCACHED_MEMCACHED_MGET_START();
158 if (number_of_keys
== 0)
159 return MEMCACHED_NOTFOUND
;
161 if (memcached_server_count(ptr
) == 0)
162 return MEMCACHED_NO_SERVERS
;
164 if (ptr
->flags
.verify_key
&& (memcached_key_test(keys
, key_length
, number_of_keys
) == MEMCACHED_BAD_KEY_PROVIDED
))
165 return MEMCACHED_BAD_KEY_PROVIDED
;
167 if (master_key
&& master_key_length
)
169 if (ptr
->flags
.verify_key
&& (memcached_key_test((const char * const *)&master_key
, &master_key_length
, 1) == MEMCACHED_BAD_KEY_PROVIDED
))
170 return MEMCACHED_BAD_KEY_PROVIDED
;
171 master_server_key
= memcached_generate_hash_with_redistribution(ptr
, master_key
, master_key_length
);
172 is_master_key_set
= true;
176 Here is where we pay for the non-block API. We need to remove any data sitting
177 in the queue before we start our get.
179 It might be optimum to bounce the connection if count > some number.
181 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
183 memcached_server_write_instance_st instance
=
184 memcached_server_instance_fetch(ptr
, x
);
186 if (memcached_server_response_count(instance
))
188 char buffer
[MEMCACHED_DEFAULT_COMMAND_SIZE
];
190 if (ptr
->flags
.no_block
)
191 (void)memcached_io_write(instance
, NULL
, 0, true);
193 while(memcached_server_response_count(instance
))
194 (void)memcached_response(instance
, buffer
, MEMCACHED_DEFAULT_COMMAND_SIZE
, &ptr
->result
);
198 if (ptr
->flags
.binary_protocol
)
200 return binary_mget_by_key(ptr
, master_server_key
, is_master_key_set
, keys
,
201 key_length
, number_of_keys
, mget_mode
);
204 if (ptr
->flags
.support_cas
)
206 get_command
= "gets ";
207 get_command_length
= 5;
211 If a server fails we warn about errors and start all over with sending keys
214 for (uint32_t x
= 0; x
< number_of_keys
; x
++)
216 memcached_server_write_instance_st instance
;
219 if (is_master_key_set
)
221 server_key
= master_server_key
;
225 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
228 instance
= memcached_server_instance_fetch(ptr
, server_key
);
230 struct libmemcached_io_vector_st vector
[]=
232 { .length
= get_command_length
, .buffer
= get_command
},
233 { .length
= ptr
->prefix_key_length
, .buffer
= ptr
->prefix_key
},
234 { .length
= key_length
[x
], .buffer
= keys
[x
] },
235 { .length
= 1, .buffer
= " " }
239 if (memcached_server_response_count(instance
) == 0)
241 rc
= memcached_connect(instance
);
243 if (rc
!= MEMCACHED_SUCCESS
)
246 if ((memcached_io_writev(instance
, vector
, 4, false)) == -1)
248 fprintf(stderr
, "%s:%d (%s)\n", __FILE__
, __LINE__
,__func__
);fflush(stdout
);
249 rc
= MEMCACHED_SOME_ERRORS
;
252 WATCHPOINT_ASSERT(instance
->cursor_active
== 0);
253 memcached_server_response_increment(instance
);
254 WATCHPOINT_ASSERT(instance
->cursor_active
== 1);
258 if ((memcached_io_writev(instance
, (vector
+ 1), 3, false)) == -1)
260 memcached_server_response_reset(instance
);
261 fprintf(stderr
, "%s:%d (%s)\n", __FILE__
, __LINE__
,__func__
);fflush(stdout
);
262 rc
= MEMCACHED_SOME_ERRORS
;
269 Should we muddle on if some servers are dead?
271 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
273 memcached_server_write_instance_st instance
=
274 memcached_server_instance_fetch(ptr
, x
);
276 if (memcached_server_response_count(instance
))
278 /* We need to do something about non-connnected hosts in the future */
279 if ((memcached_io_write(instance
, "\r\n", 2, true)) == -1)
281 fprintf(stderr
, "%s:%d (%s)\n", __FILE__
, __LINE__
,__func__
);fflush(stdout
);
282 rc
= MEMCACHED_SOME_ERRORS
;
287 LIBMEMCACHED_MEMCACHED_MGET_END();
291 memcached_return_t
memcached_mget_by_key(memcached_st
*ptr
,
292 const char *master_key
,
293 size_t master_key_length
,
294 const char * const *keys
,
295 const size_t *key_length
,
296 size_t number_of_keys
)
298 return memcached_mget_by_key_real(ptr
, master_key
, master_key_length
, keys
,
299 key_length
, number_of_keys
, true);
302 memcached_return_t
memcached_mget_execute(memcached_st
*ptr
,
303 const char * const *keys
,
304 const size_t *key_length
,
305 size_t number_of_keys
,
306 memcached_execute_fn
*callback
,
308 unsigned int number_of_callbacks
)
310 return memcached_mget_execute_by_key(ptr
, NULL
, 0, keys
, key_length
,
311 number_of_keys
, callback
,
312 context
, number_of_callbacks
);
315 memcached_return_t
memcached_mget_execute_by_key(memcached_st
*ptr
,
316 const char *master_key
,
317 size_t master_key_length
,
318 const char * const *keys
,
319 const size_t *key_length
,
320 size_t number_of_keys
,
321 memcached_execute_fn
*callback
,
323 unsigned int number_of_callbacks
)
325 if ((ptr
->flags
.binary_protocol
) == 0)
326 return MEMCACHED_NOT_SUPPORTED
;
328 memcached_return_t rc
;
329 memcached_callback_st
*original_callbacks
= ptr
->callbacks
;
330 memcached_callback_st cb
= {
333 .number_of_callback
= number_of_callbacks
337 rc
= memcached_mget_by_key(ptr
, master_key
, master_key_length
, keys
,
338 key_length
, number_of_keys
);
339 ptr
->callbacks
= original_callbacks
;
343 static memcached_return_t
simple_binary_mget(memcached_st
*ptr
,
344 uint32_t master_server_key
,
345 bool is_master_key_set
,
346 const char * const *keys
,
347 const size_t *key_length
,
348 size_t number_of_keys
, bool mget_mode
)
350 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
352 int flush
= number_of_keys
== 1;
355 If a server fails we warn about errors and start all over with sending keys
358 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
361 memcached_server_write_instance_st instance
;
363 if (is_master_key_set
)
365 server_key
= master_server_key
;
369 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
372 instance
= memcached_server_instance_fetch(ptr
, server_key
);
374 if (memcached_server_response_count(instance
) == 0)
376 rc
= memcached_connect(instance
);
377 if (rc
!= MEMCACHED_SUCCESS
)
381 protocol_binary_request_getk request
= {.bytes
= {0}};
382 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
384 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETKQ
;
386 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
388 memcached_return_t vk
;
389 vk
= memcached_validate_key_length(key_length
[x
],
390 ptr
->flags
.binary_protocol
);
391 unlikely (vk
!= MEMCACHED_SUCCESS
)
395 memcached_io_reset(instance
);
401 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + ptr
->prefix_key_length
));
402 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
403 request
.message
.header
.request
.bodylen
= htonl((uint32_t)( key_length
[x
] + ptr
->prefix_key_length
));
405 struct libmemcached_io_vector_st vector
[]=
407 { .length
= sizeof(request
.bytes
), .buffer
= request
.bytes
},
408 { .length
= ptr
->prefix_key_length
, .buffer
= ptr
->prefix_key
},
409 { .length
= key_length
[x
], .buffer
= keys
[x
] }
412 if (memcached_io_writev(instance
, vector
, 3, flush
) == -1)
414 memcached_server_response_reset(instance
);
415 fprintf(stderr
, "%s:%d (%s)\n", __FILE__
, __LINE__
,__func__
);fflush(stdout
);
416 rc
= MEMCACHED_SOME_ERRORS
;
420 /* We just want one pending response per server */
421 memcached_server_response_reset(instance
);
422 memcached_server_response_increment(instance
);
423 if ((x
> 0 && x
== ptr
->io_key_prefetch
) && memcached_flush_buffers(ptr
) != MEMCACHED_SUCCESS
)
425 fprintf(stderr
, "%s:%d (%s)\n", __FILE__
, __LINE__
,__func__
);fflush(stdout
);
426 rc
= MEMCACHED_SOME_ERRORS
;
433 * Send a noop command to flush the buffers
435 protocol_binary_request_noop request
= {.bytes
= {0}};
436 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
437 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_NOOP
;
438 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
440 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); ++x
)
442 memcached_server_write_instance_st instance
=
443 memcached_server_instance_fetch(ptr
, x
);
445 if (memcached_server_response_count(instance
))
447 if (memcached_io_write(instance
, NULL
, 0, true) == -1)
449 memcached_server_response_reset(instance
);
450 memcached_io_reset(instance
);
451 fprintf(stderr
, "%s:%d (%s)\n", __FILE__
, __LINE__
,__func__
);fflush(stdout
);
452 rc
= MEMCACHED_SOME_ERRORS
;
455 if (memcached_io_write(instance
, request
.bytes
,
456 sizeof(request
.bytes
), true) == -1)
458 memcached_server_response_reset(instance
);
459 memcached_io_reset(instance
);
460 fprintf(stderr
, "%s:%d (%s)\n", __FILE__
, __LINE__
,__func__
);fflush(stdout
);
461 rc
= MEMCACHED_SOME_ERRORS
;
471 static memcached_return_t
replication_binary_mget(memcached_st
*ptr
,
474 const char *const *keys
,
475 const size_t *key_length
,
476 size_t number_of_keys
)
478 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
480 uint64_t randomize_read
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ
);
483 start
= (uint32_t)random() % (uint32_t)(ptr
->number_of_replicas
+ 1);
485 /* Loop for each replica */
486 for (uint32_t replica
= 0; replica
<= ptr
->number_of_replicas
; ++replica
)
490 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
492 memcached_server_write_instance_st instance
;
494 if (hash
[x
] == memcached_server_count(ptr
))
495 continue; /* Already successfully sent */
497 uint32_t server
= hash
[x
] + replica
;
499 /* In case of randomized reads */
500 if (randomize_read
&& ((server
+ start
) <= (hash
[x
] + ptr
->number_of_replicas
)))
503 while (server
>= memcached_server_count(ptr
))
504 server
-= memcached_server_count(ptr
);
506 if (dead_servers
[server
])
509 instance
= memcached_server_instance_fetch(ptr
, server
);
511 if (memcached_server_response_count(instance
) == 0)
513 rc
= memcached_connect(instance
);
514 if (rc
!= MEMCACHED_SUCCESS
)
516 memcached_io_reset(instance
);
517 dead_servers
[server
]= true;
523 protocol_binary_request_getk request
= {
524 .message
.header
.request
= {
525 .magic
= PROTOCOL_BINARY_REQ
,
526 .opcode
= PROTOCOL_BINARY_CMD_GETK
,
527 .keylen
= htons((uint16_t)(key_length
[x
] + ptr
->prefix_key_length
)),
528 .datatype
= PROTOCOL_BINARY_RAW_BYTES
,
529 .bodylen
= htonl((uint32_t)(key_length
[x
] + ptr
->prefix_key_length
))
534 * We need to disable buffering to actually know that the request was
535 * successfully sent to the server (so that we should expect a result
536 * back). It would be nice to do this in buffered mode, but then it
537 * would be complex to handle all error situations if we got to send
538 * some of the messages, and then we failed on writing out some others
539 * and we used the callback interface from memcached_mget_execute so
540 * that we might have processed some of the responses etc. For now,
541 * just make sure we work _correctly_
543 struct libmemcached_io_vector_st vector
[]=
545 { .length
= sizeof(request
.bytes
), .buffer
= request
.bytes
},
546 { .length
= ptr
->prefix_key_length
, .buffer
= ptr
->prefix_key
},
547 { .length
= key_length
[x
], .buffer
= keys
[x
] }
550 if (memcached_io_writev(instance
, vector
, 3, true) == -1)
552 memcached_io_reset(instance
);
553 dead_servers
[server
]= true;
558 memcached_server_response_increment(instance
);
559 hash
[x
]= memcached_server_count(ptr
);
569 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
570 uint32_t master_server_key
,
571 bool is_master_key_set
,
572 const char * const *keys
,
573 const size_t *key_length
,
574 size_t number_of_keys
,
577 memcached_return_t rc
;
579 if (ptr
->number_of_replicas
== 0)
581 rc
= simple_binary_mget(ptr
, master_server_key
, is_master_key_set
,
582 keys
, key_length
, number_of_keys
, mget_mode
);
589 hash
= libmemcached_malloc(ptr
, sizeof(uint32_t) * number_of_keys
);
590 dead_servers
= libmemcached_calloc(ptr
, memcached_server_count(ptr
), sizeof(bool));
592 if (hash
== NULL
|| dead_servers
== NULL
)
594 libmemcached_free(ptr
, hash
);
595 libmemcached_free(ptr
, dead_servers
);
596 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
599 if (is_master_key_set
)
601 for (size_t x
= 0; x
< number_of_keys
; x
++)
603 hash
[x
]= master_server_key
;
608 for (size_t x
= 0; x
< number_of_keys
; x
++)
610 hash
[x
]= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
614 rc
= replication_binary_mget(ptr
, hash
, dead_servers
, keys
,
615 key_length
, number_of_keys
);
617 libmemcached_free(ptr
, hash
);
618 libmemcached_free(ptr
, dead_servers
);
620 return MEMCACHED_SUCCESS
;