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)
135 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 0);
140 rc
= memcached_set(ptr
, key
, key_length
,
141 (memcached_result_value(&ptr
->result
)),
142 (memcached_result_length(&ptr
->result
)),
144 (memcached_result_flags(&ptr
->result
)));
147 if (rc
== MEMCACHED_SUCCESS
|| rc
== MEMCACHED_BUFFERED
)
150 *value_length
= memcached_result_length(&ptr
->result
);
151 *flags
= memcached_result_flags(&ptr
->result
);
152 return memcached_string_take_value(&ptr
->result
.value
);
156 assert(ptr
->query_id
== query_id
+1);
162 uint32_t dummy_flags
;
163 memcached_return_t dummy_error
;
165 char *dummy_value
= memcached_fetch(ptr
, NULL
, NULL
,
166 &dummy_length
, &dummy_flags
,
168 WATCHPOINT_ASSERT(dummy_length
== 0);
169 WATCHPOINT_ASSERT(dummy_value
== 0);
170 assert(ptr
->query_id
== query_id
+1);
175 memcached_return_t
memcached_mget(memcached_st
*ptr
,
176 const char * const *keys
,
177 const size_t *key_length
,
178 size_t number_of_keys
)
180 return memcached_mget_by_key(ptr
, NULL
, 0, keys
, key_length
, number_of_keys
);
183 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
184 uint32_t master_server_key
,
185 bool is_group_key_set
,
186 const char * const *keys
,
187 const size_t *key_length
,
188 size_t number_of_keys
,
191 static memcached_return_t
memcached_mget_by_key_real(memcached_st
*ptr
,
192 const char *group_key
,
193 size_t group_key_length
,
194 const char * const *keys
,
195 const size_t *key_length
,
196 size_t number_of_keys
,
199 bool failures_occured_in_sending
= false;
200 const char *get_command
= "get ";
201 uint8_t get_command_length
= 4;
202 unsigned int master_server_key
= (unsigned int)-1; /* 0 is a valid server id! */
204 memcached_return_t rc
;
205 if (memcached_failed(rc
= initialize_query(ptr
)))
210 unlikely (ptr
->flags
.use_udp
)
212 return memcached_set_error(*ptr
, MEMCACHED_NOT_SUPPORTED
, MEMCACHED_AT
);
215 LIBMEMCACHED_MEMCACHED_MGET_START();
217 if (number_of_keys
== 0)
219 return memcached_set_error(*ptr
, MEMCACHED_NOTFOUND
, MEMCACHED_AT
, memcached_literal_param("number_of_keys was zero"));
222 if (ptr
->flags
.verify_key
&& (memcached_key_test(keys
, key_length
, number_of_keys
) == MEMCACHED_BAD_KEY_PROVIDED
))
224 return memcached_set_error(*ptr
, MEMCACHED_BAD_KEY_PROVIDED
, MEMCACHED_AT
, memcached_literal_param("A bad key value was provided"));
227 bool is_group_key_set
= false;
228 if (group_key
&& group_key_length
)
230 if (ptr
->flags
.verify_key
and (memcached_key_test((const char * const *)&group_key
, &group_key_length
, 1) == MEMCACHED_BAD_KEY_PROVIDED
))
232 return memcached_set_error(*ptr
, MEMCACHED_BAD_KEY_PROVIDED
, MEMCACHED_AT
, memcached_literal_param("A bad group key was provided."));
235 master_server_key
= memcached_generate_hash_with_redistribution(ptr
, group_key
, group_key_length
);
236 is_group_key_set
= true;
240 Here is where we pay for the non-block API. We need to remove any data sitting
241 in the queue before we start our get.
243 It might be optimum to bounce the connection if count > some number.
245 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
247 memcached_server_write_instance_st instance
=
248 memcached_server_instance_fetch(ptr
, x
);
250 if (memcached_server_response_count(instance
))
252 char buffer
[MEMCACHED_DEFAULT_COMMAND_SIZE
];
254 if (ptr
->flags
.no_block
)
255 (void)memcached_io_write(instance
, NULL
, 0, true);
257 while(memcached_server_response_count(instance
))
258 (void)memcached_response(instance
, buffer
, MEMCACHED_DEFAULT_COMMAND_SIZE
, &ptr
->result
);
262 if (ptr
->flags
.binary_protocol
)
264 return binary_mget_by_key(ptr
, master_server_key
, is_group_key_set
, keys
,
265 key_length
, number_of_keys
, mget_mode
);
268 if (ptr
->flags
.support_cas
)
270 get_command
= "gets ";
271 get_command_length
= 5;
275 If a server fails we warn about errors and start all over with sending keys
278 WATCHPOINT_ASSERT(rc
== MEMCACHED_SUCCESS
);
279 size_t hosts_connected
= 0;
280 for (uint32_t x
= 0; x
< number_of_keys
; x
++)
282 memcached_server_write_instance_st instance
;
285 if (is_group_key_set
)
287 server_key
= master_server_key
;
291 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
294 instance
= memcached_server_instance_fetch(ptr
, server_key
);
296 struct libmemcached_io_vector_st vector
[]=
298 { get_command_length
, get_command
},
299 { memcached_array_size(ptr
->prefix_key
), memcached_array_string(ptr
->prefix_key
) },
300 { key_length
[x
], keys
[x
] },
305 if (memcached_server_response_count(instance
) == 0)
307 rc
= memcached_connect(instance
);
309 if (memcached_failed(rc
))
311 memcached_set_error(*instance
, rc
, MEMCACHED_AT
);
316 if ((memcached_io_writev(instance
, vector
, 4, false)) == -1)
318 failures_occured_in_sending
= true;
321 WATCHPOINT_ASSERT(instance
->cursor_active
== 0);
322 memcached_server_response_increment(instance
);
323 WATCHPOINT_ASSERT(instance
->cursor_active
== 1);
327 if ((memcached_io_writev(instance
, (vector
+ 1), 3, false)) == -1)
329 memcached_server_response_reset(instance
);
330 failures_occured_in_sending
= true;
336 if (hosts_connected
== 0)
338 LIBMEMCACHED_MEMCACHED_MGET_END();
340 if (memcached_failed(rc
))
343 return memcached_set_error(*ptr
, MEMCACHED_NO_SERVERS
, MEMCACHED_AT
);
348 Should we muddle on if some servers are dead?
350 bool success_happened
= false;
351 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
353 memcached_server_write_instance_st instance
=
354 memcached_server_instance_fetch(ptr
, x
);
356 if (memcached_server_response_count(instance
))
358 /* We need to do something about non-connnected hosts in the future */
359 if ((memcached_io_write(instance
, "\r\n", 2, true)) == -1)
361 failures_occured_in_sending
= true;
365 success_happened
= true;
370 LIBMEMCACHED_MEMCACHED_MGET_END();
372 if (failures_occured_in_sending
&& success_happened
)
374 return MEMCACHED_SOME_ERRORS
;
377 if (success_happened
)
378 return MEMCACHED_SUCCESS
;
380 return MEMCACHED_FAILURE
; // Complete failure occurred
383 memcached_return_t
memcached_mget_by_key(memcached_st
*ptr
,
384 const char *group_key
,
385 size_t group_key_length
,
386 const char * const *keys
,
387 const size_t *key_length
,
388 size_t number_of_keys
)
390 return memcached_mget_by_key_real(ptr
, group_key
, group_key_length
, keys
,
391 key_length
, number_of_keys
, true);
394 memcached_return_t
memcached_mget_execute(memcached_st
*ptr
,
395 const char * const *keys
,
396 const size_t *key_length
,
397 size_t number_of_keys
,
398 memcached_execute_fn
*callback
,
400 unsigned int number_of_callbacks
)
402 return memcached_mget_execute_by_key(ptr
, NULL
, 0, keys
, key_length
,
403 number_of_keys
, callback
,
404 context
, number_of_callbacks
);
407 memcached_return_t
memcached_mget_execute_by_key(memcached_st
*ptr
,
408 const char *group_key
,
409 size_t group_key_length
,
410 const char * const *keys
,
411 const size_t *key_length
,
412 size_t number_of_keys
,
413 memcached_execute_fn
*callback
,
415 unsigned int number_of_callbacks
)
417 if ((ptr
->flags
.binary_protocol
) == 0)
418 return MEMCACHED_NOT_SUPPORTED
;
420 memcached_return_t rc
;
421 memcached_callback_st
*original_callbacks
= ptr
->callbacks
;
422 memcached_callback_st cb
= {
429 rc
= memcached_mget_by_key(ptr
, group_key
, group_key_length
, keys
,
430 key_length
, number_of_keys
);
431 ptr
->callbacks
= original_callbacks
;
435 static memcached_return_t
simple_binary_mget(memcached_st
*ptr
,
436 uint32_t master_server_key
,
437 bool is_group_key_set
,
438 const char * const *keys
,
439 const size_t *key_length
,
440 size_t number_of_keys
, bool mget_mode
)
442 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
444 bool flush
= (number_of_keys
== 1);
447 If a server fails we warn about errors and start all over with sending keys
450 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
454 if (is_group_key_set
)
456 server_key
= master_server_key
;
460 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
463 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, server_key
);
465 if (memcached_server_response_count(instance
) == 0)
467 rc
= memcached_connect(instance
);
468 if (memcached_failed(rc
))
472 protocol_binary_request_getk request
= { }; //= {.bytes= {0}};
473 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
475 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETKQ
;
477 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
479 memcached_return_t vk
;
480 vk
= memcached_validate_key_length(key_length
[x
],
481 ptr
->flags
.binary_protocol
);
482 unlikely (vk
!= MEMCACHED_SUCCESS
)
486 memcached_io_reset(instance
);
492 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
493 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
494 request
.message
.header
.request
.bodylen
= htonl((uint32_t)( key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
496 struct libmemcached_io_vector_st vector
[]=
498 { sizeof(request
.bytes
), request
.bytes
},
499 { memcached_array_size(ptr
->prefix_key
), memcached_array_string(ptr
->prefix_key
) },
500 { key_length
[x
], keys
[x
] }
503 if (memcached_io_writev(instance
, vector
, 3, flush
) == -1)
505 memcached_server_response_reset(instance
);
506 rc
= MEMCACHED_SOME_ERRORS
;
510 /* We just want one pending response per server */
511 memcached_server_response_reset(instance
);
512 memcached_server_response_increment(instance
);
513 if ((x
> 0 && x
== ptr
->io_key_prefetch
) && memcached_flush_buffers(ptr
) != MEMCACHED_SUCCESS
)
515 rc
= MEMCACHED_SOME_ERRORS
;
522 Send a noop command to flush the buffers
524 protocol_binary_request_noop request
= {}; //= {.bytes= {0}};
525 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
526 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_NOOP
;
527 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
529 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); ++x
)
531 memcached_server_write_instance_st instance
=
532 memcached_server_instance_fetch(ptr
, x
);
534 if (memcached_server_response_count(instance
))
536 if (memcached_io_write(instance
, NULL
, 0, true) == -1)
538 memcached_server_response_reset(instance
);
539 memcached_io_reset(instance
);
540 rc
= MEMCACHED_SOME_ERRORS
;
543 if (memcached_io_write(instance
, request
.bytes
,
544 sizeof(request
.bytes
), true) == -1)
546 memcached_server_response_reset(instance
);
547 memcached_io_reset(instance
);
548 rc
= MEMCACHED_SOME_ERRORS
;
558 static memcached_return_t
replication_binary_mget(memcached_st
*ptr
,
561 const char *const *keys
,
562 const size_t *key_length
,
563 size_t number_of_keys
)
565 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
567 uint64_t randomize_read
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ
);
570 start
= (uint32_t)random() % (uint32_t)(ptr
->number_of_replicas
+ 1);
572 /* Loop for each replica */
573 for (uint32_t replica
= 0; replica
<= ptr
->number_of_replicas
; ++replica
)
577 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
579 if (hash
[x
] == memcached_server_count(ptr
))
580 continue; /* Already successfully sent */
582 uint32_t server
= hash
[x
] + replica
;
584 /* In case of randomized reads */
585 if (randomize_read
&& ((server
+ start
) <= (hash
[x
] + ptr
->number_of_replicas
)))
588 while (server
>= memcached_server_count(ptr
))
589 server
-= memcached_server_count(ptr
);
591 if (dead_servers
[server
])
594 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, server
);
596 if (memcached_server_response_count(instance
) == 0)
598 rc
= memcached_connect(instance
);
599 if (memcached_failed(rc
))
601 memcached_io_reset(instance
);
602 dead_servers
[server
]= true;
608 protocol_binary_request_getk request
= {};
609 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
610 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
611 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
612 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
613 request
.message
.header
.request
.bodylen
= htonl((uint32_t)(key_length
[x
] + memcached_array_size(ptr
->prefix_key
)));
616 * We need to disable buffering to actually know that the request was
617 * successfully sent to the server (so that we should expect a result
618 * back). It would be nice to do this in buffered mode, but then it
619 * would be complex to handle all error situations if we got to send
620 * some of the messages, and then we failed on writing out some others
621 * and we used the callback interface from memcached_mget_execute so
622 * that we might have processed some of the responses etc. For now,
623 * just make sure we work _correctly_
625 struct libmemcached_io_vector_st vector
[]=
627 { sizeof(request
.bytes
), request
.bytes
},
628 { memcached_array_size(ptr
->prefix_key
), memcached_array_string(ptr
->prefix_key
) },
629 { key_length
[x
], keys
[x
] }
632 if (memcached_io_writev(instance
, vector
, 3, true) == -1)
634 memcached_io_reset(instance
);
635 dead_servers
[server
]= true;
640 memcached_server_response_increment(instance
);
641 hash
[x
]= memcached_server_count(ptr
);
651 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
652 uint32_t master_server_key
,
653 bool is_group_key_set
,
654 const char * const *keys
,
655 const size_t *key_length
,
656 size_t number_of_keys
,
659 if (ptr
->number_of_replicas
== 0)
661 return simple_binary_mget(ptr
, master_server_key
, is_group_key_set
,
662 keys
, key_length
, number_of_keys
, mget_mode
);
665 uint32_t* hash
= static_cast<uint32_t*>(libmemcached_malloc(ptr
, sizeof(uint32_t) * number_of_keys
));
666 bool* dead_servers
= static_cast<bool*>(libmemcached_calloc(ptr
, memcached_server_count(ptr
), sizeof(bool)));
668 if (hash
== NULL
|| dead_servers
== NULL
)
670 libmemcached_free(ptr
, hash
);
671 libmemcached_free(ptr
, dead_servers
);
672 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
675 if (is_group_key_set
)
677 for (size_t x
= 0; x
< number_of_keys
; x
++)
679 hash
[x
]= master_server_key
;
684 for (size_t x
= 0; x
< number_of_keys
; x
++)
686 hash
[x
]= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
690 memcached_return_t rc
= replication_binary_mget(ptr
, hash
, dead_servers
, keys
,
691 key_length
, number_of_keys
);
693 WATCHPOINT_IFERROR(rc
);
694 libmemcached_free(ptr
, hash
);
695 libmemcached_free(ptr
, dead_servers
);
697 return MEMCACHED_SUCCESS
;