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 memcached_return_t unused
;
74 unlikely (ptr
->flags
.use_udp
)
79 *error
= memcached_set_error(*ptr
, MEMCACHED_NOT_SUPPORTED
, MEMCACHED_AT
);
83 uint64_t query_id
= ptr
->query_id
;
87 *error
= memcached_mget_by_key_real(ptr
, group_key
, group_key_length
,
88 (const char * const *)&key
, &key_length
,
90 assert(ptr
->query_id
== query_id
+1);
93 if (memcached_failed(*error
))
95 if (memcached_has_current_error(*ptr
)) // Find the most accurate error
97 *error
= memcached_last_error(ptr
);
106 char *value
= memcached_fetch(ptr
, NULL
, NULL
,
107 value_length
, flags
, error
);
108 assert(ptr
->query_id
== query_id
+1);
110 /* This is for historical reasons */
111 if (*error
== MEMCACHED_END
)
112 *error
= MEMCACHED_NOTFOUND
;
116 if (ptr
->get_key_failure
&& *error
== MEMCACHED_NOTFOUND
)
118 memcached_result_reset(&ptr
->result
);
119 memcached_return_t rc
= ptr
->get_key_failure(ptr
, key
, key_length
, &ptr
->result
);
121 /* On all failure drop to returning NULL */
122 if (rc
== MEMCACHED_SUCCESS
|| rc
== MEMCACHED_BUFFERED
)
124 if (rc
== MEMCACHED_BUFFERED
)
126 uint64_t latch
; /* We use latch to track the state of the original socket */
127 latch
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
);
129 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 1);
131 rc
= memcached_set(ptr
, key
, key_length
,
132 (memcached_result_value(&ptr
->result
)),
133 (memcached_result_length(&ptr
->result
)),
135 (memcached_result_flags(&ptr
->result
)));
137 if (rc
== MEMCACHED_BUFFERED
&& latch
== 0)
139 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 0);
144 rc
= memcached_set(ptr
, key
, key_length
,
145 (memcached_result_value(&ptr
->result
)),
146 (memcached_result_length(&ptr
->result
)),
148 (memcached_result_flags(&ptr
->result
)));
151 if (rc
== MEMCACHED_SUCCESS
|| rc
== MEMCACHED_BUFFERED
)
154 *value_length
= memcached_result_length(&ptr
->result
);
155 *flags
= memcached_result_flags(&ptr
->result
);
156 return memcached_string_take_value(&ptr
->result
.value
);
160 assert(ptr
->query_id
== query_id
+1);
166 uint32_t dummy_flags
;
167 memcached_return_t dummy_error
;
169 char *dummy_value
= memcached_fetch(ptr
, NULL
, NULL
,
170 &dummy_length
, &dummy_flags
,
172 WATCHPOINT_ASSERT(dummy_length
== 0);
173 WATCHPOINT_ASSERT(dummy_value
== 0);
174 assert(ptr
->query_id
== query_id
+1);
179 memcached_return_t
memcached_mget(memcached_st
*ptr
,
180 const char * const *keys
,
181 const size_t *key_length
,
182 size_t number_of_keys
)
184 return memcached_mget_by_key(ptr
, NULL
, 0, keys
, key_length
, number_of_keys
);
187 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
188 uint32_t master_server_key
,
189 bool is_group_key_set
,
190 const char * const *keys
,
191 const size_t *key_length
,
192 size_t number_of_keys
,
195 static memcached_return_t
memcached_mget_by_key_real(memcached_st
*ptr
,
196 const char *group_key
,
197 size_t group_key_length
,
198 const char * const *keys
,
199 const size_t *key_length
,
200 size_t number_of_keys
,
203 bool failures_occured_in_sending
= false;
204 const char *get_command
= "get ";
205 uint8_t get_command_length
= 4;
206 unsigned int master_server_key
= (unsigned int)-1; /* 0 is a valid server id! */
208 memcached_return_t rc
;
209 if (memcached_failed(rc
= initialize_query(ptr
)))
214 unlikely (ptr
->flags
.use_udp
)
216 return memcached_set_error(*ptr
, MEMCACHED_NOT_SUPPORTED
, MEMCACHED_AT
);
219 LIBMEMCACHED_MEMCACHED_MGET_START();
221 if (number_of_keys
== 0)
223 return memcached_set_error(*ptr
, MEMCACHED_NOTFOUND
, MEMCACHED_AT
, memcached_literal_param("number_of_keys was zero"));
226 if (memcached_failed(memcached_key_test(*ptr
, keys
, key_length
, number_of_keys
)))
228 return memcached_set_error(*ptr
, MEMCACHED_BAD_KEY_PROVIDED
, MEMCACHED_AT
, memcached_literal_param("A bad key value was provided"));
231 bool is_group_key_set
= false;
232 if (group_key
&& group_key_length
)
234 if (memcached_failed(memcached_key_test(*ptr
, (const char * const *)&group_key
, &group_key_length
, 1)))
236 return memcached_set_error(*ptr
, MEMCACHED_BAD_KEY_PROVIDED
, MEMCACHED_AT
, memcached_literal_param("A bad group key was provided."));
239 master_server_key
= memcached_generate_hash_with_redistribution(ptr
, group_key
, group_key_length
);
240 is_group_key_set
= true;
244 Here is where we pay for the non-block API. We need to remove any data sitting
245 in the queue before we start our get.
247 It might be optimum to bounce the connection if count > some number.
249 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
251 memcached_server_write_instance_st instance
=
252 memcached_server_instance_fetch(ptr
, x
);
254 if (memcached_server_response_count(instance
))
256 char buffer
[MEMCACHED_DEFAULT_COMMAND_SIZE
];
258 if (ptr
->flags
.no_block
)
259 (void)memcached_io_write(instance
, NULL
, 0, true);
261 while(memcached_server_response_count(instance
))
262 (void)memcached_response(instance
, buffer
, MEMCACHED_DEFAULT_COMMAND_SIZE
, &ptr
->result
);
266 if (ptr
->flags
.binary_protocol
)
268 return binary_mget_by_key(ptr
, master_server_key
, is_group_key_set
, keys
,
269 key_length
, number_of_keys
, mget_mode
);
272 if (ptr
->flags
.support_cas
)
274 get_command
= "gets ";
275 get_command_length
= 5;
279 If a server fails we warn about errors and start all over with sending keys
282 WATCHPOINT_ASSERT(rc
== MEMCACHED_SUCCESS
);
283 size_t hosts_connected
= 0;
284 for (uint32_t x
= 0; x
< number_of_keys
; x
++)
286 memcached_server_write_instance_st instance
;
289 if (is_group_key_set
)
291 server_key
= master_server_key
;
295 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
298 instance
= memcached_server_instance_fetch(ptr
, server_key
);
300 struct libmemcached_io_vector_st vector
[]=
302 { get_command_length
, get_command
},
303 { memcached_array_size(ptr
->_namespace
), memcached_array_string(ptr
->_namespace
) },
304 { key_length
[x
], keys
[x
] },
309 if (memcached_server_response_count(instance
) == 0)
311 rc
= memcached_connect(instance
);
313 if (memcached_failed(rc
))
315 memcached_set_error(*instance
, rc
, MEMCACHED_AT
);
320 if ((memcached_io_writev(instance
, vector
, 4, false)) == -1)
322 failures_occured_in_sending
= true;
325 WATCHPOINT_ASSERT(instance
->cursor_active
== 0);
326 memcached_server_response_increment(instance
);
327 WATCHPOINT_ASSERT(instance
->cursor_active
== 1);
331 if ((memcached_io_writev(instance
, (vector
+ 1), 3, false)) == -1)
333 memcached_server_response_reset(instance
);
334 failures_occured_in_sending
= true;
340 if (hosts_connected
== 0)
342 LIBMEMCACHED_MEMCACHED_MGET_END();
344 if (memcached_failed(rc
))
347 return memcached_set_error(*ptr
, MEMCACHED_NO_SERVERS
, MEMCACHED_AT
);
352 Should we muddle on if some servers are dead?
354 bool success_happened
= false;
355 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
357 memcached_server_write_instance_st instance
=
358 memcached_server_instance_fetch(ptr
, x
);
360 if (memcached_server_response_count(instance
))
362 /* We need to do something about non-connnected hosts in the future */
363 if ((memcached_io_write(instance
, "\r\n", 2, true)) == -1)
365 failures_occured_in_sending
= true;
369 success_happened
= true;
374 LIBMEMCACHED_MEMCACHED_MGET_END();
376 if (failures_occured_in_sending
&& success_happened
)
378 return MEMCACHED_SOME_ERRORS
;
381 if (success_happened
)
382 return MEMCACHED_SUCCESS
;
384 return MEMCACHED_FAILURE
; // Complete failure occurred
387 memcached_return_t
memcached_mget_by_key(memcached_st
*ptr
,
388 const char *group_key
,
389 size_t group_key_length
,
390 const char * const *keys
,
391 const size_t *key_length
,
392 size_t number_of_keys
)
394 return memcached_mget_by_key_real(ptr
, group_key
, group_key_length
, keys
,
395 key_length
, number_of_keys
, true);
398 memcached_return_t
memcached_mget_execute(memcached_st
*ptr
,
399 const char * const *keys
,
400 const size_t *key_length
,
401 size_t number_of_keys
,
402 memcached_execute_fn
*callback
,
404 unsigned int number_of_callbacks
)
406 return memcached_mget_execute_by_key(ptr
, NULL
, 0, keys
, key_length
,
407 number_of_keys
, callback
,
408 context
, number_of_callbacks
);
411 memcached_return_t
memcached_mget_execute_by_key(memcached_st
*ptr
,
412 const char *group_key
,
413 size_t group_key_length
,
414 const char * const *keys
,
415 const size_t *key_length
,
416 size_t number_of_keys
,
417 memcached_execute_fn
*callback
,
419 unsigned int number_of_callbacks
)
421 if ((ptr
->flags
.binary_protocol
) == 0)
422 return MEMCACHED_NOT_SUPPORTED
;
424 memcached_return_t rc
;
425 memcached_callback_st
*original_callbacks
= ptr
->callbacks
;
426 memcached_callback_st cb
= {
433 rc
= memcached_mget_by_key(ptr
, group_key
, group_key_length
, keys
,
434 key_length
, number_of_keys
);
435 ptr
->callbacks
= original_callbacks
;
439 static memcached_return_t
simple_binary_mget(memcached_st
*ptr
,
440 uint32_t master_server_key
,
441 bool is_group_key_set
,
442 const char * const *keys
,
443 const size_t *key_length
,
444 size_t number_of_keys
, bool mget_mode
)
446 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
448 bool flush
= (number_of_keys
== 1);
451 If a server fails we warn about errors and start all over with sending keys
454 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
458 if (is_group_key_set
)
460 server_key
= master_server_key
;
464 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
467 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, server_key
);
469 if (memcached_server_response_count(instance
) == 0)
471 rc
= memcached_connect(instance
);
472 if (memcached_failed(rc
))
476 protocol_binary_request_getk request
= { }; //= {.bytes= {0}};
477 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
479 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETKQ
;
481 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
483 memcached_return_t vk
;
484 vk
= memcached_validate_key_length(key_length
[x
],
485 ptr
->flags
.binary_protocol
);
486 unlikely (vk
!= MEMCACHED_SUCCESS
)
490 memcached_io_reset(instance
);
496 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + memcached_array_size(ptr
->_namespace
)));
497 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
498 request
.message
.header
.request
.bodylen
= htonl((uint32_t)( key_length
[x
] + memcached_array_size(ptr
->_namespace
)));
500 struct libmemcached_io_vector_st vector
[]=
502 { sizeof(request
.bytes
), request
.bytes
},
503 { memcached_array_size(ptr
->_namespace
), memcached_array_string(ptr
->_namespace
) },
504 { key_length
[x
], keys
[x
] }
507 if (memcached_io_writev(instance
, vector
, 3, flush
) == -1)
509 memcached_server_response_reset(instance
);
510 rc
= MEMCACHED_SOME_ERRORS
;
514 /* We just want one pending response per server */
515 memcached_server_response_reset(instance
);
516 memcached_server_response_increment(instance
);
517 if ((x
> 0 && x
== ptr
->io_key_prefetch
) && memcached_flush_buffers(ptr
) != MEMCACHED_SUCCESS
)
519 rc
= MEMCACHED_SOME_ERRORS
;
526 Send a noop command to flush the buffers
528 protocol_binary_request_noop request
= {}; //= {.bytes= {0}};
529 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
530 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_NOOP
;
531 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
533 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); ++x
)
535 memcached_server_write_instance_st instance
=
536 memcached_server_instance_fetch(ptr
, x
);
538 if (memcached_server_response_count(instance
))
540 if (memcached_io_write(instance
, NULL
, 0, true) == -1)
542 memcached_server_response_reset(instance
);
543 memcached_io_reset(instance
);
544 rc
= MEMCACHED_SOME_ERRORS
;
547 if (memcached_io_write(instance
, request
.bytes
,
548 sizeof(request
.bytes
), true) == -1)
550 memcached_server_response_reset(instance
);
551 memcached_io_reset(instance
);
552 rc
= MEMCACHED_SOME_ERRORS
;
562 static memcached_return_t
replication_binary_mget(memcached_st
*ptr
,
565 const char *const *keys
,
566 const size_t *key_length
,
567 size_t number_of_keys
)
569 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
571 uint64_t randomize_read
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ
);
574 start
= (uint32_t)random() % (uint32_t)(ptr
->number_of_replicas
+ 1);
576 /* Loop for each replica */
577 for (uint32_t replica
= 0; replica
<= ptr
->number_of_replicas
; ++replica
)
581 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
583 if (hash
[x
] == memcached_server_count(ptr
))
584 continue; /* Already successfully sent */
586 uint32_t server
= hash
[x
] + replica
;
588 /* In case of randomized reads */
589 if (randomize_read
&& ((server
+ start
) <= (hash
[x
] + ptr
->number_of_replicas
)))
592 while (server
>= memcached_server_count(ptr
))
593 server
-= memcached_server_count(ptr
);
595 if (dead_servers
[server
])
598 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, server
);
600 if (memcached_server_response_count(instance
) == 0)
602 rc
= memcached_connect(instance
);
603 if (memcached_failed(rc
))
605 memcached_io_reset(instance
);
606 dead_servers
[server
]= true;
612 protocol_binary_request_getk request
= {};
613 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
614 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
615 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + memcached_array_size(ptr
->_namespace
)));
616 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
617 request
.message
.header
.request
.bodylen
= htonl((uint32_t)(key_length
[x
] + memcached_array_size(ptr
->_namespace
)));
620 * We need to disable buffering to actually know that the request was
621 * successfully sent to the server (so that we should expect a result
622 * back). It would be nice to do this in buffered mode, but then it
623 * would be complex to handle all error situations if we got to send
624 * some of the messages, and then we failed on writing out some others
625 * and we used the callback interface from memcached_mget_execute so
626 * that we might have processed some of the responses etc. For now,
627 * just make sure we work _correctly_
629 struct libmemcached_io_vector_st vector
[]=
631 { sizeof(request
.bytes
), request
.bytes
},
632 { memcached_array_size(ptr
->_namespace
), memcached_array_string(ptr
->_namespace
) },
633 { key_length
[x
], keys
[x
] }
636 if (memcached_io_writev(instance
, vector
, 3, true) == -1)
638 memcached_io_reset(instance
);
639 dead_servers
[server
]= true;
644 memcached_server_response_increment(instance
);
645 hash
[x
]= memcached_server_count(ptr
);
655 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
656 uint32_t master_server_key
,
657 bool is_group_key_set
,
658 const char * const *keys
,
659 const size_t *key_length
,
660 size_t number_of_keys
,
663 if (ptr
->number_of_replicas
== 0)
665 return simple_binary_mget(ptr
, master_server_key
, is_group_key_set
,
666 keys
, key_length
, number_of_keys
, mget_mode
);
669 uint32_t* hash
= static_cast<uint32_t*>(libmemcached_malloc(ptr
, sizeof(uint32_t) * number_of_keys
));
670 bool* dead_servers
= static_cast<bool*>(libmemcached_calloc(ptr
, memcached_server_count(ptr
), sizeof(bool)));
672 if (hash
== NULL
|| dead_servers
== NULL
)
674 libmemcached_free(ptr
, hash
);
675 libmemcached_free(ptr
, dead_servers
);
676 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
679 if (is_group_key_set
)
681 for (size_t x
= 0; x
< number_of_keys
; x
++)
683 hash
[x
]= master_server_key
;
688 for (size_t x
= 0; x
< number_of_keys
; x
++)
690 hash
[x
]= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
694 memcached_return_t rc
= replication_binary_mget(ptr
, hash
, dead_servers
, keys
,
695 key_length
, number_of_keys
);
697 WATCHPOINT_IFERROR(rc
);
698 libmemcached_free(ptr
, hash
);
699 libmemcached_free(ptr
, dead_servers
);
701 return MEMCACHED_SUCCESS
;