1 /* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
5 * Copyright (C) 2011 Data Differential, http://datadifferential.com/
6 * Copyright (C) 2006-2009 Brian Aker All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are
12 * * Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
15 * * Redistributions in binary form must reproduce the above
16 * copyright notice, this list of conditions and the following disclaimer
17 * in the documentation and/or other materials provided with the
20 * * The names of its contributors may not be used to endorse or
21 * promote products derived from this software without specific prior
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
28 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
30 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
34 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 #include <libmemcached/common.h>
42 What happens if no servers exist?
44 char *memcached_get(memcached_st
*ptr
, const char *key
,
48 memcached_return_t
*error
)
50 return memcached_get_by_key(ptr
, NULL
, 0, key
, key_length
, value_length
,
54 static memcached_return_t
memcached_mget_by_key_real(memcached_st
*ptr
,
55 const char *group_key
,
56 size_t group_key_length
,
57 const char * const *keys
,
58 const size_t *key_length
,
59 size_t number_of_keys
,
62 char *memcached_get_by_key(memcached_st
*ptr
,
63 const char *group_key
,
64 size_t group_key_length
,
65 const char *key
, size_t key_length
,
68 memcached_return_t
*error
)
70 unlikely (ptr
->flags
.use_udp
)
75 *error
= memcached_set_error(*ptr
, MEMCACHED_NOT_SUPPORTED
, MEMCACHED_AT
);
79 uint64_t query_id
= ptr
->query_id
;
83 *error
= memcached_mget_by_key_real(ptr
, group_key
, group_key_length
,
84 (const char * const *)&key
,
85 &key_length
, 1, false);
86 assert(ptr
->query_id
== query_id
+1);
89 if (memcached_failed(*error
))
91 if (memcached_has_current_error(*ptr
)) // Find the most accurate error
93 *error
= memcached_last_error(ptr
);
102 char *value
= memcached_fetch(ptr
, NULL
, NULL
,
103 value_length
, flags
, error
);
104 assert(ptr
->query_id
== query_id
+1);
106 /* This is for historical reasons */
107 if (*error
== MEMCACHED_END
)
108 *error
= MEMCACHED_NOTFOUND
;
112 if (ptr
->get_key_failure
&& *error
== MEMCACHED_NOTFOUND
)
115 memcached_result_reset(&ptr
->result
);
116 memcached_return_t rc
= ptr
->get_key_failure(ptr
, key
, key_length
, &ptr
->result
);
118 /* On all failure drop to returning NULL */
119 if (rc
== MEMCACHED_SUCCESS
|| rc
== MEMCACHED_BUFFERED
)
121 if (rc
== MEMCACHED_BUFFERED
)
123 uint64_t latch
; /* We use latch to track the state of the original socket */
124 latch
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
);
126 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 1);
128 rc
= memcached_set(ptr
, key
, key_length
,
129 (memcached_result_value(&ptr
->result
)),
130 (memcached_result_length(&ptr
->result
)),
132 (memcached_result_flags(&ptr
->result
)));
134 if (rc
== MEMCACHED_BUFFERED
&& latch
== 0)
135 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 0);
139 rc
= memcached_set(ptr
, key
, key_length
,
140 (memcached_result_value(&ptr
->result
)),
141 (memcached_result_length(&ptr
->result
)),
143 (memcached_result_flags(&ptr
->result
)));
146 if (rc
== MEMCACHED_SUCCESS
|| rc
== MEMCACHED_BUFFERED
)
149 *value_length
= memcached_result_length(&ptr
->result
);
150 *flags
= memcached_result_flags(&ptr
->result
);
151 return memcached_string_c_copy(&ptr
->result
.value
);
155 assert(ptr
->query_id
== query_id
+1);
161 uint32_t dummy_flags
;
162 memcached_return_t dummy_error
;
164 char *dummy_value
= memcached_fetch(ptr
, NULL
, NULL
,
165 &dummy_length
, &dummy_flags
,
167 WATCHPOINT_ASSERT(dummy_length
== 0);
168 WATCHPOINT_ASSERT(dummy_value
== 0);
169 assert(ptr
->query_id
== query_id
+1);
174 memcached_return_t
memcached_mget(memcached_st
*ptr
,
175 const char * const *keys
,
176 const size_t *key_length
,
177 size_t number_of_keys
)
179 return memcached_mget_by_key(ptr
, NULL
, 0, keys
, key_length
, number_of_keys
);
182 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
183 uint32_t master_server_key
,
184 bool is_group_key_set
,
185 const char * const *keys
,
186 const size_t *key_length
,
187 size_t number_of_keys
,
190 static memcached_return_t
memcached_mget_by_key_real(memcached_st
*ptr
,
191 const char *group_key
,
192 size_t group_key_length
,
193 const char * const *keys
,
194 const size_t *key_length
,
195 size_t number_of_keys
,
198 bool failures_occured_in_sending
= false;
199 const char *get_command
= "get ";
200 uint8_t get_command_length
= 4;
201 unsigned int master_server_key
= (unsigned int)-1; /* 0 is a valid server id! */
203 memcached_return_t rc
;
204 if (memcached_failed(rc
= initialize_query(ptr
)))
209 unlikely (ptr
->flags
.use_udp
)
211 return memcached_set_error(*ptr
, MEMCACHED_NOT_SUPPORTED
, MEMCACHED_AT
);
214 LIBMEMCACHED_MEMCACHED_MGET_START();
216 if (number_of_keys
== 0)
218 return memcached_set_error(*ptr
, MEMCACHED_NOTFOUND
, MEMCACHED_AT
, memcached_literal_param("number_of_keys was zero"));
221 if (ptr
->flags
.verify_key
&& (memcached_key_test(keys
, key_length
, number_of_keys
) == MEMCACHED_BAD_KEY_PROVIDED
))
223 return memcached_set_error(*ptr
, MEMCACHED_BAD_KEY_PROVIDED
, MEMCACHED_AT
, memcached_literal_param("A bad key value was provided"));
226 bool is_group_key_set
= false;
227 if (group_key
&& group_key_length
)
229 if (ptr
->flags
.verify_key
and (memcached_key_test((const char * const *)&group_key
, &group_key_length
, 1) == MEMCACHED_BAD_KEY_PROVIDED
))
231 return memcached_set_error(*ptr
, MEMCACHED_BAD_KEY_PROVIDED
, MEMCACHED_AT
, memcached_literal_param("A bad group key was provided."));
234 master_server_key
= memcached_generate_hash_with_redistribution(ptr
, group_key
, group_key_length
);
235 is_group_key_set
= true;
239 Here is where we pay for the non-block API. We need to remove any data sitting
240 in the queue before we start our get.
242 It might be optimum to bounce the connection if count > some number.
244 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
246 memcached_server_write_instance_st instance
=
247 memcached_server_instance_fetch(ptr
, x
);
249 if (memcached_server_response_count(instance
))
251 char buffer
[MEMCACHED_DEFAULT_COMMAND_SIZE
];
253 if (ptr
->flags
.no_block
)
254 (void)memcached_io_write(instance
, NULL
, 0, true);
256 while(memcached_server_response_count(instance
))
257 (void)memcached_response(instance
, buffer
, MEMCACHED_DEFAULT_COMMAND_SIZE
, &ptr
->result
);
261 if (ptr
->flags
.binary_protocol
)
263 return binary_mget_by_key(ptr
, master_server_key
, is_group_key_set
, keys
,
264 key_length
, number_of_keys
, mget_mode
);
267 if (ptr
->flags
.support_cas
)
269 get_command
= "gets ";
270 get_command_length
= 5;
274 If a server fails we warn about errors and start all over with sending keys
277 WATCHPOINT_ASSERT(rc
== MEMCACHED_SUCCESS
);
278 size_t hosts_connected
= 0;
279 for (uint32_t x
= 0; x
< number_of_keys
; x
++)
281 memcached_server_write_instance_st instance
;
284 if (is_group_key_set
)
286 server_key
= master_server_key
;
290 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
293 instance
= memcached_server_instance_fetch(ptr
, server_key
);
295 struct libmemcached_io_vector_st vector
[]=
297 { get_command_length
, get_command
},
298 { memcached_array_size(ptr
->prefix_key
), memcached_array_string(ptr
->prefix_key
) },
299 { key_length
[x
], keys
[x
] },
304 if (memcached_server_response_count(instance
) == 0)
306 rc
= memcached_connect(instance
);
308 if (memcached_failed(rc
))
310 memcached_set_error(*instance
, rc
, MEMCACHED_AT
);
315 if ((memcached_io_writev(instance
, vector
, 4, false)) == -1)
317 failures_occured_in_sending
= true;
320 WATCHPOINT_ASSERT(instance
->cursor_active
== 0);
321 memcached_server_response_increment(instance
);
322 WATCHPOINT_ASSERT(instance
->cursor_active
== 1);
326 if ((memcached_io_writev(instance
, (vector
+ 1), 3, false)) == -1)
328 memcached_server_response_reset(instance
);
329 failures_occured_in_sending
= true;
335 if (hosts_connected
== 0)
337 LIBMEMCACHED_MEMCACHED_MGET_END();
339 if (memcached_failed(rc
))
342 return memcached_set_error(*ptr
, MEMCACHED_NO_SERVERS
, MEMCACHED_AT
);
347 Should we muddle on if some servers are dead?
349 bool success_happened
= false;
350 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
352 memcached_server_write_instance_st instance
=
353 memcached_server_instance_fetch(ptr
, x
);
355 if (memcached_server_response_count(instance
))
357 /* We need to do something about non-connnected hosts in the future */
358 if ((memcached_io_write(instance
, "\r\n", 2, true)) == -1)
360 failures_occured_in_sending
= true;
364 success_happened
= true;
369 LIBMEMCACHED_MEMCACHED_MGET_END();
371 if (failures_occured_in_sending
&& success_happened
)
373 return MEMCACHED_SOME_ERRORS
;
376 if (success_happened
)
377 return MEMCACHED_SUCCESS
;
379 return MEMCACHED_FAILURE
; // Complete failure occurred
382 memcached_return_t
memcached_mget_by_key(memcached_st
*ptr
,
383 const char *group_key
,
384 size_t group_key_length
,
385 const char * const *keys
,
386 const size_t *key_length
,
387 size_t number_of_keys
)
389 return memcached_mget_by_key_real(ptr
, group_key
, group_key_length
, keys
,
390 key_length
, number_of_keys
, true);
393 memcached_return_t
memcached_mget_execute(memcached_st
*ptr
,
394 const char * const *keys
,
395 const size_t *key_length
,
396 size_t number_of_keys
,
397 memcached_execute_fn
*callback
,
399 unsigned int number_of_callbacks
)
401 return memcached_mget_execute_by_key(ptr
, NULL
, 0, keys
, key_length
,
402 number_of_keys
, callback
,
403 context
, number_of_callbacks
);
406 memcached_return_t
memcached_mget_execute_by_key(memcached_st
*ptr
,
407 const char *group_key
,
408 size_t group_key_length
,
409 const char * const *keys
,
410 const size_t *key_length
,
411 size_t number_of_keys
,
412 memcached_execute_fn
*callback
,
414 unsigned int number_of_callbacks
)
416 if ((ptr
->flags
.binary_protocol
) == 0)
417 return MEMCACHED_NOT_SUPPORTED
;
419 memcached_return_t rc
;
420 memcached_callback_st
*original_callbacks
= ptr
->callbacks
;
421 memcached_callback_st cb
= {
428 rc
= memcached_mget_by_key(ptr
, group_key
, group_key_length
, keys
,
429 key_length
, number_of_keys
);
430 ptr
->callbacks
= original_callbacks
;
434 static memcached_return_t
simple_binary_mget(memcached_st
*ptr
,
435 uint32_t master_server_key
,
436 bool is_group_key_set
,
437 const char * const *keys
,
438 const size_t *key_length
,
439 size_t number_of_keys
, bool mget_mode
)
441 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
443 bool flush
= (number_of_keys
== 1);
446 If a server fails we warn about errors and start all over with sending keys
449 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
453 if (is_group_key_set
)
455 server_key
= master_server_key
;
459 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
462 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, server_key
);
464 if (memcached_server_response_count(instance
) == 0)
466 rc
= memcached_connect(instance
);
467 if (memcached_failed(rc
))
471 protocol_binary_request_getk request
= { }; //= {.bytes= {0}};
472 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
474 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETKQ
;
476 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
478 memcached_return_t vk
;
479 vk
= memcached_validate_key_length(key_length
[x
],
480 ptr
->flags
.binary_protocol
);
481 unlikely (vk
!= MEMCACHED_SUCCESS
)
485 memcached_io_reset(instance
);
491 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
492 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
493 request
.message
.header
.request
.bodylen
= htonl((uint32_t)( key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
495 struct libmemcached_io_vector_st vector
[]=
497 { sizeof(request
.bytes
), request
.bytes
},
498 { memcached_array_size(ptr
->prefix_key
), memcached_array_string(ptr
->prefix_key
) },
499 { key_length
[x
], keys
[x
] }
502 if (memcached_io_writev(instance
, vector
, 3, flush
) == -1)
504 memcached_server_response_reset(instance
);
505 rc
= MEMCACHED_SOME_ERRORS
;
509 /* We just want one pending response per server */
510 memcached_server_response_reset(instance
);
511 memcached_server_response_increment(instance
);
512 if ((x
> 0 && x
== ptr
->io_key_prefetch
) && memcached_flush_buffers(ptr
) != MEMCACHED_SUCCESS
)
514 rc
= MEMCACHED_SOME_ERRORS
;
521 Send a noop command to flush the buffers
523 protocol_binary_request_noop request
= {}; //= {.bytes= {0}};
524 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
525 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_NOOP
;
526 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
528 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); ++x
)
530 memcached_server_write_instance_st instance
=
531 memcached_server_instance_fetch(ptr
, x
);
533 if (memcached_server_response_count(instance
))
535 if (memcached_io_write(instance
, NULL
, 0, true) == -1)
537 memcached_server_response_reset(instance
);
538 memcached_io_reset(instance
);
539 rc
= MEMCACHED_SOME_ERRORS
;
542 if (memcached_io_write(instance
, request
.bytes
,
543 sizeof(request
.bytes
), true) == -1)
545 memcached_server_response_reset(instance
);
546 memcached_io_reset(instance
);
547 rc
= MEMCACHED_SOME_ERRORS
;
557 static memcached_return_t
replication_binary_mget(memcached_st
*ptr
,
560 const char *const *keys
,
561 const size_t *key_length
,
562 size_t number_of_keys
)
564 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
566 uint64_t randomize_read
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ
);
569 start
= (uint32_t)random() % (uint32_t)(ptr
->number_of_replicas
+ 1);
571 /* Loop for each replica */
572 for (uint32_t replica
= 0; replica
<= ptr
->number_of_replicas
; ++replica
)
576 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
578 if (hash
[x
] == memcached_server_count(ptr
))
579 continue; /* Already successfully sent */
581 uint32_t server
= hash
[x
] + replica
;
583 /* In case of randomized reads */
584 if (randomize_read
&& ((server
+ start
) <= (hash
[x
] + ptr
->number_of_replicas
)))
587 while (server
>= memcached_server_count(ptr
))
588 server
-= memcached_server_count(ptr
);
590 if (dead_servers
[server
])
593 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, server
);
595 if (memcached_server_response_count(instance
) == 0)
597 rc
= memcached_connect(instance
);
598 if (memcached_failed(rc
))
600 memcached_io_reset(instance
);
601 dead_servers
[server
]= true;
607 protocol_binary_request_getk request
= {};
608 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
609 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
610 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
611 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
612 request
.message
.header
.request
.bodylen
= htonl((uint32_t)(key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
615 * We need to disable buffering to actually know that the request was
616 * successfully sent to the server (so that we should expect a result
617 * back). It would be nice to do this in buffered mode, but then it
618 * would be complex to handle all error situations if we got to send
619 * some of the messages, and then we failed on writing out some others
620 * and we used the callback interface from memcached_mget_execute so
621 * that we might have processed some of the responses etc. For now,
622 * just make sure we work _correctly_
624 struct libmemcached_io_vector_st vector
[]=
626 { sizeof(request
.bytes
), request
.bytes
},
627 { memcached_array_size(ptr
->prefix_key
), memcached_array_string(ptr
->prefix_key
) },
628 { key_length
[x
], keys
[x
] }
631 if (memcached_io_writev(instance
, vector
, 3, true) == -1)
633 memcached_io_reset(instance
);
634 dead_servers
[server
]= true;
639 memcached_server_response_increment(instance
);
640 hash
[x
]= memcached_server_count(ptr
);
650 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
651 uint32_t master_server_key
,
652 bool is_group_key_set
,
653 const char * const *keys
,
654 const size_t *key_length
,
655 size_t number_of_keys
,
658 if (ptr
->number_of_replicas
== 0)
660 return simple_binary_mget(ptr
, master_server_key
, is_group_key_set
,
661 keys
, key_length
, number_of_keys
, mget_mode
);
664 uint32_t* hash
= static_cast<uint32_t*>(libmemcached_malloc(ptr
, sizeof(uint32_t) * number_of_keys
));
665 bool* dead_servers
= static_cast<bool*>(libmemcached_calloc(ptr
, memcached_server_count(ptr
), sizeof(bool)));
667 if (hash
== NULL
|| dead_servers
== NULL
)
669 libmemcached_free(ptr
, hash
);
670 libmemcached_free(ptr
, dead_servers
);
671 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
674 if (is_group_key_set
)
676 for (size_t x
= 0; x
< number_of_keys
; x
++)
678 hash
[x
]= master_server_key
;
683 for (size_t x
= 0; x
< number_of_keys
; x
++)
685 hash
[x
]= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
689 memcached_return_t rc
= replication_binary_mget(ptr
, hash
, dead_servers
, keys
,
690 key_length
, number_of_keys
);
692 WATCHPOINT_IFERROR(rc
);
693 libmemcached_free(ptr
, hash
);
694 libmemcached_free(ptr
, dead_servers
);
696 return MEMCACHED_SUCCESS
;