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
)
114 memcached_result_reset(&ptr
->result
);
115 memcached_return_t rc
= ptr
->get_key_failure(ptr
, key
, key_length
, &ptr
->result
);
117 /* On all failure drop to returning NULL */
118 if (rc
== MEMCACHED_SUCCESS
|| rc
== MEMCACHED_BUFFERED
)
120 if (rc
== MEMCACHED_BUFFERED
)
122 uint64_t latch
; /* We use latch to track the state of the original socket */
123 latch
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
);
125 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 1);
127 rc
= memcached_set(ptr
, key
, key_length
,
128 (memcached_result_value(&ptr
->result
)),
129 (memcached_result_length(&ptr
->result
)),
131 (memcached_result_flags(&ptr
->result
)));
133 if (rc
== MEMCACHED_BUFFERED
&& latch
== 0)
134 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 0);
138 rc
= memcached_set(ptr
, key
, key_length
,
139 (memcached_result_value(&ptr
->result
)),
140 (memcached_result_length(&ptr
->result
)),
142 (memcached_result_flags(&ptr
->result
)));
145 if (rc
== MEMCACHED_SUCCESS
|| rc
== MEMCACHED_BUFFERED
)
148 *value_length
= memcached_result_length(&ptr
->result
);
149 *flags
= memcached_result_flags(&ptr
->result
);
150 return memcached_string_take_value(&ptr
->result
.value
);
154 assert(ptr
->query_id
== query_id
+1);
160 uint32_t dummy_flags
;
161 memcached_return_t dummy_error
;
163 char *dummy_value
= memcached_fetch(ptr
, NULL
, NULL
,
164 &dummy_length
, &dummy_flags
,
166 WATCHPOINT_ASSERT(dummy_length
== 0);
167 WATCHPOINT_ASSERT(dummy_value
== 0);
168 assert(ptr
->query_id
== query_id
+1);
173 memcached_return_t
memcached_mget(memcached_st
*ptr
,
174 const char * const *keys
,
175 const size_t *key_length
,
176 size_t number_of_keys
)
178 return memcached_mget_by_key(ptr
, NULL
, 0, keys
, key_length
, number_of_keys
);
181 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
182 uint32_t master_server_key
,
183 bool is_group_key_set
,
184 const char * const *keys
,
185 const size_t *key_length
,
186 size_t number_of_keys
,
189 static memcached_return_t
memcached_mget_by_key_real(memcached_st
*ptr
,
190 const char *group_key
,
191 size_t group_key_length
,
192 const char * const *keys
,
193 const size_t *key_length
,
194 size_t number_of_keys
,
197 bool failures_occured_in_sending
= false;
198 const char *get_command
= "get ";
199 uint8_t get_command_length
= 4;
200 unsigned int master_server_key
= (unsigned int)-1; /* 0 is a valid server id! */
202 memcached_return_t rc
;
203 if (memcached_failed(rc
= initialize_query(ptr
)))
208 unlikely (ptr
->flags
.use_udp
)
210 return memcached_set_error(*ptr
, MEMCACHED_NOT_SUPPORTED
, MEMCACHED_AT
);
213 LIBMEMCACHED_MEMCACHED_MGET_START();
215 if (number_of_keys
== 0)
217 return memcached_set_error(*ptr
, MEMCACHED_NOTFOUND
, MEMCACHED_AT
, memcached_literal_param("number_of_keys was zero"));
220 if (ptr
->flags
.verify_key
&& (memcached_key_test(keys
, key_length
, number_of_keys
) == MEMCACHED_BAD_KEY_PROVIDED
))
222 return memcached_set_error(*ptr
, MEMCACHED_BAD_KEY_PROVIDED
, MEMCACHED_AT
, memcached_literal_param("A bad key value was provided"));
225 bool is_group_key_set
= false;
226 if (group_key
&& group_key_length
)
228 if (ptr
->flags
.verify_key
and (memcached_key_test((const char * const *)&group_key
, &group_key_length
, 1) == MEMCACHED_BAD_KEY_PROVIDED
))
230 return memcached_set_error(*ptr
, MEMCACHED_BAD_KEY_PROVIDED
, MEMCACHED_AT
, memcached_literal_param("A bad group key was provided."));
233 master_server_key
= memcached_generate_hash_with_redistribution(ptr
, group_key
, group_key_length
);
234 is_group_key_set
= true;
238 Here is where we pay for the non-block API. We need to remove any data sitting
239 in the queue before we start our get.
241 It might be optimum to bounce the connection if count > some number.
243 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
245 memcached_server_write_instance_st instance
=
246 memcached_server_instance_fetch(ptr
, x
);
248 if (memcached_server_response_count(instance
))
250 char buffer
[MEMCACHED_DEFAULT_COMMAND_SIZE
];
252 if (ptr
->flags
.no_block
)
253 (void)memcached_io_write(instance
, NULL
, 0, true);
255 while(memcached_server_response_count(instance
))
256 (void)memcached_response(instance
, buffer
, MEMCACHED_DEFAULT_COMMAND_SIZE
, &ptr
->result
);
260 if (ptr
->flags
.binary_protocol
)
262 return binary_mget_by_key(ptr
, master_server_key
, is_group_key_set
, keys
,
263 key_length
, number_of_keys
, mget_mode
);
266 if (ptr
->flags
.support_cas
)
268 get_command
= "gets ";
269 get_command_length
= 5;
273 If a server fails we warn about errors and start all over with sending keys
276 WATCHPOINT_ASSERT(rc
== MEMCACHED_SUCCESS
);
277 size_t hosts_connected
= 0;
278 for (uint32_t x
= 0; x
< number_of_keys
; x
++)
280 memcached_server_write_instance_st instance
;
283 if (is_group_key_set
)
285 server_key
= master_server_key
;
289 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
292 instance
= memcached_server_instance_fetch(ptr
, server_key
);
294 struct libmemcached_io_vector_st vector
[]=
296 { get_command_length
, get_command
},
297 { memcached_array_size(ptr
->prefix_key
), memcached_array_string(ptr
->prefix_key
) },
298 { key_length
[x
], keys
[x
] },
303 if (memcached_server_response_count(instance
) == 0)
305 rc
= memcached_connect(instance
);
307 if (memcached_failed(rc
))
309 memcached_set_error(*instance
, rc
, MEMCACHED_AT
);
314 if ((memcached_io_writev(instance
, vector
, 4, false)) == -1)
316 failures_occured_in_sending
= true;
319 WATCHPOINT_ASSERT(instance
->cursor_active
== 0);
320 memcached_server_response_increment(instance
);
321 WATCHPOINT_ASSERT(instance
->cursor_active
== 1);
325 if ((memcached_io_writev(instance
, (vector
+ 1), 3, false)) == -1)
327 memcached_server_response_reset(instance
);
328 failures_occured_in_sending
= true;
334 if (hosts_connected
== 0)
336 LIBMEMCACHED_MEMCACHED_MGET_END();
338 if (memcached_failed(rc
))
341 return memcached_set_error(*ptr
, MEMCACHED_NO_SERVERS
, MEMCACHED_AT
);
346 Should we muddle on if some servers are dead?
348 bool success_happened
= false;
349 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
351 memcached_server_write_instance_st instance
=
352 memcached_server_instance_fetch(ptr
, x
);
354 if (memcached_server_response_count(instance
))
356 /* We need to do something about non-connnected hosts in the future */
357 if ((memcached_io_write(instance
, "\r\n", 2, true)) == -1)
359 failures_occured_in_sending
= true;
363 success_happened
= true;
368 LIBMEMCACHED_MEMCACHED_MGET_END();
370 if (failures_occured_in_sending
&& success_happened
)
372 return MEMCACHED_SOME_ERRORS
;
375 if (success_happened
)
376 return MEMCACHED_SUCCESS
;
378 return MEMCACHED_FAILURE
; // Complete failure occurred
381 memcached_return_t
memcached_mget_by_key(memcached_st
*ptr
,
382 const char *group_key
,
383 size_t group_key_length
,
384 const char * const *keys
,
385 const size_t *key_length
,
386 size_t number_of_keys
)
388 return memcached_mget_by_key_real(ptr
, group_key
, group_key_length
, keys
,
389 key_length
, number_of_keys
, true);
392 memcached_return_t
memcached_mget_execute(memcached_st
*ptr
,
393 const char * const *keys
,
394 const size_t *key_length
,
395 size_t number_of_keys
,
396 memcached_execute_fn
*callback
,
398 unsigned int number_of_callbacks
)
400 return memcached_mget_execute_by_key(ptr
, NULL
, 0, keys
, key_length
,
401 number_of_keys
, callback
,
402 context
, number_of_callbacks
);
405 memcached_return_t
memcached_mget_execute_by_key(memcached_st
*ptr
,
406 const char *group_key
,
407 size_t group_key_length
,
408 const char * const *keys
,
409 const size_t *key_length
,
410 size_t number_of_keys
,
411 memcached_execute_fn
*callback
,
413 unsigned int number_of_callbacks
)
415 if ((ptr
->flags
.binary_protocol
) == 0)
416 return MEMCACHED_NOT_SUPPORTED
;
418 memcached_return_t rc
;
419 memcached_callback_st
*original_callbacks
= ptr
->callbacks
;
420 memcached_callback_st cb
= {
427 rc
= memcached_mget_by_key(ptr
, group_key
, group_key_length
, keys
,
428 key_length
, number_of_keys
);
429 ptr
->callbacks
= original_callbacks
;
433 static memcached_return_t
simple_binary_mget(memcached_st
*ptr
,
434 uint32_t master_server_key
,
435 bool is_group_key_set
,
436 const char * const *keys
,
437 const size_t *key_length
,
438 size_t number_of_keys
, bool mget_mode
)
440 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
442 bool flush
= (number_of_keys
== 1);
445 If a server fails we warn about errors and start all over with sending keys
448 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
452 if (is_group_key_set
)
454 server_key
= master_server_key
;
458 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
461 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, server_key
);
463 if (memcached_server_response_count(instance
) == 0)
465 rc
= memcached_connect(instance
);
466 if (memcached_failed(rc
))
470 protocol_binary_request_getk request
= { }; //= {.bytes= {0}};
471 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
473 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETKQ
;
475 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
477 memcached_return_t vk
;
478 vk
= memcached_validate_key_length(key_length
[x
],
479 ptr
->flags
.binary_protocol
);
480 unlikely (vk
!= MEMCACHED_SUCCESS
)
484 memcached_io_reset(instance
);
490 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
491 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
492 request
.message
.header
.request
.bodylen
= htonl((uint32_t)( key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
494 struct libmemcached_io_vector_st vector
[]=
496 { sizeof(request
.bytes
), request
.bytes
},
497 { memcached_array_size(ptr
->prefix_key
), memcached_array_string(ptr
->prefix_key
) },
498 { key_length
[x
], keys
[x
] }
501 if (memcached_io_writev(instance
, vector
, 3, flush
) == -1)
503 memcached_server_response_reset(instance
);
504 rc
= MEMCACHED_SOME_ERRORS
;
508 /* We just want one pending response per server */
509 memcached_server_response_reset(instance
);
510 memcached_server_response_increment(instance
);
511 if ((x
> 0 && x
== ptr
->io_key_prefetch
) && memcached_flush_buffers(ptr
) != MEMCACHED_SUCCESS
)
513 rc
= MEMCACHED_SOME_ERRORS
;
520 Send a noop command to flush the buffers
522 protocol_binary_request_noop request
= {}; //= {.bytes= {0}};
523 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
524 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_NOOP
;
525 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
527 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); ++x
)
529 memcached_server_write_instance_st instance
=
530 memcached_server_instance_fetch(ptr
, x
);
532 if (memcached_server_response_count(instance
))
534 if (memcached_io_write(instance
, NULL
, 0, true) == -1)
536 memcached_server_response_reset(instance
);
537 memcached_io_reset(instance
);
538 rc
= MEMCACHED_SOME_ERRORS
;
541 if (memcached_io_write(instance
, request
.bytes
,
542 sizeof(request
.bytes
), true) == -1)
544 memcached_server_response_reset(instance
);
545 memcached_io_reset(instance
);
546 rc
= MEMCACHED_SOME_ERRORS
;
556 static memcached_return_t
replication_binary_mget(memcached_st
*ptr
,
559 const char *const *keys
,
560 const size_t *key_length
,
561 size_t number_of_keys
)
563 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
565 uint64_t randomize_read
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ
);
568 start
= (uint32_t)random() % (uint32_t)(ptr
->number_of_replicas
+ 1);
570 /* Loop for each replica */
571 for (uint32_t replica
= 0; replica
<= ptr
->number_of_replicas
; ++replica
)
575 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
577 if (hash
[x
] == memcached_server_count(ptr
))
578 continue; /* Already successfully sent */
580 uint32_t server
= hash
[x
] + replica
;
582 /* In case of randomized reads */
583 if (randomize_read
&& ((server
+ start
) <= (hash
[x
] + ptr
->number_of_replicas
)))
586 while (server
>= memcached_server_count(ptr
))
587 server
-= memcached_server_count(ptr
);
589 if (dead_servers
[server
])
592 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, server
);
594 if (memcached_server_response_count(instance
) == 0)
596 rc
= memcached_connect(instance
);
597 if (memcached_failed(rc
))
599 memcached_io_reset(instance
);
600 dead_servers
[server
]= true;
606 protocol_binary_request_getk request
= {};
607 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
608 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
609 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
610 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
611 request
.message
.header
.request
.bodylen
= htonl((uint32_t)(key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
614 * We need to disable buffering to actually know that the request was
615 * successfully sent to the server (so that we should expect a result
616 * back). It would be nice to do this in buffered mode, but then it
617 * would be complex to handle all error situations if we got to send
618 * some of the messages, and then we failed on writing out some others
619 * and we used the callback interface from memcached_mget_execute so
620 * that we might have processed some of the responses etc. For now,
621 * just make sure we work _correctly_
623 struct libmemcached_io_vector_st vector
[]=
625 { sizeof(request
.bytes
), request
.bytes
},
626 { memcached_array_size(ptr
->prefix_key
), memcached_array_string(ptr
->prefix_key
) },
627 { key_length
[x
], keys
[x
] }
630 if (memcached_io_writev(instance
, vector
, 3, true) == -1)
632 memcached_io_reset(instance
);
633 dead_servers
[server
]= true;
638 memcached_server_response_increment(instance
);
639 hash
[x
]= memcached_server_count(ptr
);
649 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
650 uint32_t master_server_key
,
651 bool is_group_key_set
,
652 const char * const *keys
,
653 const size_t *key_length
,
654 size_t number_of_keys
,
657 if (ptr
->number_of_replicas
== 0)
659 return simple_binary_mget(ptr
, master_server_key
, is_group_key_set
,
660 keys
, key_length
, number_of_keys
, mget_mode
);
663 uint32_t* hash
= static_cast<uint32_t*>(libmemcached_malloc(ptr
, sizeof(uint32_t) * number_of_keys
));
664 bool* dead_servers
= static_cast<bool*>(libmemcached_calloc(ptr
, memcached_server_count(ptr
), sizeof(bool)));
666 if (hash
== NULL
|| dead_servers
== NULL
)
668 libmemcached_free(ptr
, hash
);
669 libmemcached_free(ptr
, dead_servers
);
670 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
673 if (is_group_key_set
)
675 for (size_t x
= 0; x
< number_of_keys
; x
++)
677 hash
[x
]= master_server_key
;
682 for (size_t x
= 0; x
< number_of_keys
; x
++)
684 hash
[x
]= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
688 memcached_return_t rc
= replication_binary_mget(ptr
, hash
, dead_servers
, keys
,
689 key_length
, number_of_keys
);
691 WATCHPOINT_IFERROR(rc
);
692 libmemcached_free(ptr
, hash
);
693 libmemcached_free(ptr
, dead_servers
);
695 return MEMCACHED_SUCCESS
;