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>
41 What happens if no servers exist?
43 char *memcached_get(memcached_st
*ptr
, const char *key
,
47 memcached_return_t
*error
)
49 return memcached_get_by_key(ptr
, NULL
, 0, key
, key_length
, value_length
,
53 static memcached_return_t
memcached_mget_by_key_real(memcached_st
*ptr
,
54 const char *group_key
,
55 size_t group_key_length
,
56 const char * const *keys
,
57 const size_t *key_length
,
58 size_t number_of_keys
,
61 char *memcached_get_by_key(memcached_st
*ptr
,
62 const char *group_key
,
63 size_t group_key_length
,
64 const char *key
, size_t key_length
,
67 memcached_return_t
*error
)
69 memcached_return_t unused
;
78 query_id
= ptr
->query_id
;
82 *error
= memcached_mget_by_key_real(ptr
, group_key
, group_key_length
,
83 (const char * const *)&key
, &key_length
,
87 assert_msg(ptr
->query_id
== query_id
+1, "Programmer error, the query_id was not incremented.");
90 if (memcached_failed(*error
))
94 if (memcached_has_current_error(*ptr
)) // Find the most accurate error
96 *error
= memcached_last_error(ptr
);
108 char *value
= memcached_fetch(ptr
, NULL
, NULL
,
109 value_length
, flags
, error
);
110 assert_msg(ptr
->query_id
== query_id
+1, "Programmer error, the query_id was not incremented.");
112 /* This is for historical reasons */
113 if (*error
== MEMCACHED_END
)
115 *error
= MEMCACHED_NOTFOUND
;
120 if (ptr
->get_key_failure
&& *error
== MEMCACHED_NOTFOUND
)
122 memcached_result_reset(&ptr
->result
);
123 memcached_return_t rc
= ptr
->get_key_failure(ptr
, key
, key_length
, &ptr
->result
);
125 /* On all failure drop to returning NULL */
126 if (rc
== MEMCACHED_SUCCESS
or rc
== MEMCACHED_BUFFERED
)
128 if (rc
== MEMCACHED_BUFFERED
)
130 uint64_t latch
; /* We use latch to track the state of the original socket */
131 latch
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
);
134 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 1);
137 rc
= memcached_set(ptr
, key
, key_length
,
138 (memcached_result_value(&ptr
->result
)),
139 (memcached_result_length(&ptr
->result
)),
141 (memcached_result_flags(&ptr
->result
)));
143 if (rc
== MEMCACHED_BUFFERED
&& latch
== 0)
145 memcached_behavior_set(ptr
, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
, 0);
150 rc
= memcached_set(ptr
, key
, key_length
,
151 (memcached_result_value(&ptr
->result
)),
152 (memcached_result_length(&ptr
->result
)),
154 (memcached_result_flags(&ptr
->result
)));
157 if (rc
== MEMCACHED_SUCCESS
|| rc
== MEMCACHED_BUFFERED
)
160 *value_length
= memcached_result_length(&ptr
->result
);
161 *flags
= memcached_result_flags(&ptr
->result
);
162 return memcached_string_take_value(&ptr
->result
.value
);
166 assert_msg(ptr
->query_id
== query_id
+1, "Programmer error, the query_id was not incremented.");
172 uint32_t dummy_flags
;
173 memcached_return_t dummy_error
;
175 char *dummy_value
= memcached_fetch(ptr
, NULL
, NULL
,
176 &dummy_length
, &dummy_flags
,
178 assert_msg(dummy_value
== 0, "memcached_fetch() returned additional values beyond the single get it expected");
179 assert_msg(dummy_length
== 0, "memcached_fetch() returned additional values beyond the single get it expected");
180 assert_msg(ptr
->query_id
== query_id
+1, "Programmer error, the query_id was not incremented.");
185 memcached_return_t
memcached_mget(memcached_st
*ptr
,
186 const char * const *keys
,
187 const size_t *key_length
,
188 size_t number_of_keys
)
190 return memcached_mget_by_key(ptr
, NULL
, 0, keys
, key_length
, number_of_keys
);
193 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
194 uint32_t master_server_key
,
195 bool is_group_key_set
,
196 const char * const *keys
,
197 const size_t *key_length
,
198 size_t number_of_keys
,
201 static memcached_return_t
memcached_mget_by_key_real(memcached_st
*ptr
,
202 const char *group_key
,
203 size_t group_key_length
,
204 const char * const *keys
,
205 const size_t *key_length
,
206 size_t number_of_keys
,
209 bool failures_occured_in_sending
= false;
210 const char *get_command
= "get ";
211 uint8_t get_command_length
= 4;
212 unsigned int master_server_key
= (unsigned int)-1; /* 0 is a valid server id! */
214 memcached_return_t rc
;
215 if (memcached_failed(rc
= initialize_query(ptr
, true)))
220 if (memcached_is_udp(ptr
))
222 return memcached_set_error(*ptr
, MEMCACHED_NOT_SUPPORTED
, MEMCACHED_AT
);
225 LIBMEMCACHED_MEMCACHED_MGET_START();
227 if (number_of_keys
== 0)
229 return memcached_set_error(*ptr
, MEMCACHED_NOTFOUND
, MEMCACHED_AT
, memcached_literal_param("number_of_keys was zero"));
232 if (memcached_failed(memcached_key_test(*ptr
, keys
, key_length
, number_of_keys
)))
234 return memcached_last_error(ptr
);
237 bool is_group_key_set
= false;
238 if (group_key
and group_key_length
)
240 if (memcached_failed(memcached_key_test(*ptr
, (const char * const *)&group_key
, &group_key_length
, 1)))
242 return memcached_set_error(*ptr
, MEMCACHED_BAD_KEY_PROVIDED
, MEMCACHED_AT
, memcached_literal_param("A bad group key was provided."));
245 master_server_key
= memcached_generate_hash_with_redistribution(ptr
, group_key
, group_key_length
);
246 is_group_key_set
= true;
250 Here is where we pay for the non-block API. We need to remove any data sitting
251 in the queue before we start our get.
253 It might be optimum to bounce the connection if count > some number.
255 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
257 memcached_server_write_instance_st instance
=
258 memcached_server_instance_fetch(ptr
, x
);
260 if (memcached_server_response_count(instance
))
262 char buffer
[MEMCACHED_DEFAULT_COMMAND_SIZE
];
264 if (ptr
->flags
.no_block
)
266 memcached_io_write(instance
);
269 while(memcached_server_response_count(instance
))
271 (void)memcached_response(instance
, buffer
, MEMCACHED_DEFAULT_COMMAND_SIZE
, &ptr
->result
);
276 if (ptr
->flags
.binary_protocol
)
278 return binary_mget_by_key(ptr
, master_server_key
, is_group_key_set
, keys
,
279 key_length
, number_of_keys
, mget_mode
);
282 if (ptr
->flags
.support_cas
)
284 get_command
= "gets ";
285 get_command_length
= 5;
289 If a server fails we warn about errors and start all over with sending keys
292 WATCHPOINT_ASSERT(rc
== MEMCACHED_SUCCESS
);
293 size_t hosts_connected
= 0;
294 for (uint32_t x
= 0; x
< number_of_keys
; x
++)
296 memcached_server_write_instance_st instance
;
299 if (is_group_key_set
)
301 server_key
= master_server_key
;
305 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
308 instance
= memcached_server_instance_fetch(ptr
, server_key
);
310 libmemcached_io_vector_st vector
[]=
312 { get_command
, get_command_length
},
313 { memcached_array_string(ptr
->_namespace
), memcached_array_size(ptr
->_namespace
) },
314 { keys
[x
], key_length
[x
] },
315 { memcached_literal_param(" ") }
319 if (memcached_server_response_count(instance
) == 0)
321 rc
= memcached_connect(instance
);
323 if (memcached_failed(rc
))
325 memcached_set_error(*instance
, rc
, MEMCACHED_AT
);
330 if ((memcached_io_writev(instance
, vector
, 4, false)) == -1)
332 failures_occured_in_sending
= true;
335 WATCHPOINT_ASSERT(instance
->cursor_active
== 0);
336 memcached_server_response_increment(instance
);
337 WATCHPOINT_ASSERT(instance
->cursor_active
== 1);
341 if ((memcached_io_writev(instance
, (vector
+ 1), 3, false)) == -1)
343 memcached_server_response_reset(instance
);
344 failures_occured_in_sending
= true;
350 if (hosts_connected
== 0)
352 LIBMEMCACHED_MEMCACHED_MGET_END();
354 if (memcached_failed(rc
))
359 return memcached_set_error(*ptr
, MEMCACHED_NO_SERVERS
, MEMCACHED_AT
);
364 Should we muddle on if some servers are dead?
366 bool success_happened
= false;
367 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); x
++)
369 memcached_server_write_instance_st instance
=
370 memcached_server_instance_fetch(ptr
, x
);
372 if (memcached_server_response_count(instance
))
374 /* We need to do something about non-connnected hosts in the future */
375 if ((memcached_io_write(instance
, "\r\n", 2, true)) == -1)
377 failures_occured_in_sending
= true;
381 success_happened
= true;
386 LIBMEMCACHED_MEMCACHED_MGET_END();
388 if (failures_occured_in_sending
&& success_happened
)
390 return MEMCACHED_SOME_ERRORS
;
393 if (success_happened
)
394 return MEMCACHED_SUCCESS
;
396 return MEMCACHED_FAILURE
; // Complete failure occurred
399 memcached_return_t
memcached_mget_by_key(memcached_st
*ptr
,
400 const char *group_key
,
401 size_t group_key_length
,
402 const char * const *keys
,
403 const size_t *key_length
,
404 size_t number_of_keys
)
406 return memcached_mget_by_key_real(ptr
, group_key
, group_key_length
, keys
,
407 key_length
, number_of_keys
, true);
410 memcached_return_t
memcached_mget_execute(memcached_st
*ptr
,
411 const char * const *keys
,
412 const size_t *key_length
,
413 size_t number_of_keys
,
414 memcached_execute_fn
*callback
,
416 unsigned int number_of_callbacks
)
418 return memcached_mget_execute_by_key(ptr
, NULL
, 0, keys
, key_length
,
419 number_of_keys
, callback
,
420 context
, number_of_callbacks
);
423 memcached_return_t
memcached_mget_execute_by_key(memcached_st
*ptr
,
424 const char *group_key
,
425 size_t group_key_length
,
426 const char * const *keys
,
427 const size_t *key_length
,
428 size_t number_of_keys
,
429 memcached_execute_fn
*callback
,
431 unsigned int number_of_callbacks
)
433 memcached_return_t rc
;
434 if (memcached_failed(rc
= initialize_query(ptr
, false)))
439 if (memcached_is_udp(ptr
))
441 return memcached_set_error(*ptr
, MEMCACHED_NOT_SUPPORTED
, MEMCACHED_AT
);
444 if (memcached_is_binary(ptr
) == false)
446 return memcached_set_error(*ptr
, MEMCACHED_NOT_SUPPORTED
, MEMCACHED_AT
,
447 memcached_literal_param("ASCII protocol is not supported for memcached_mget_execute_by_key()"));
450 memcached_callback_st
*original_callbacks
= ptr
->callbacks
;
451 memcached_callback_st cb
= {
458 rc
= memcached_mget_by_key(ptr
, group_key
, group_key_length
, keys
,
459 key_length
, number_of_keys
);
460 ptr
->callbacks
= original_callbacks
;
464 static memcached_return_t
simple_binary_mget(memcached_st
*ptr
,
465 uint32_t master_server_key
,
466 bool is_group_key_set
,
467 const char * const *keys
,
468 const size_t *key_length
,
469 size_t number_of_keys
, bool mget_mode
)
471 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
473 bool flush
= (number_of_keys
== 1);
476 If a server fails we warn about errors and start all over with sending keys
479 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
483 if (is_group_key_set
)
485 server_key
= master_server_key
;
489 server_key
= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
492 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, server_key
);
494 if (memcached_server_response_count(instance
) == 0)
496 rc
= memcached_connect(instance
);
497 if (memcached_failed(rc
))
503 protocol_binary_request_getk request
= { }; //= {.bytes= {0}};
504 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
507 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETKQ
;
511 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
514 memcached_return_t vk
;
515 vk
= memcached_validate_key_length(key_length
[x
],
516 ptr
->flags
.binary_protocol
);
517 if (vk
!= MEMCACHED_SUCCESS
)
521 memcached_io_reset(instance
);
527 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + memcached_array_size(ptr
->_namespace
)));
528 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
529 request
.message
.header
.request
.bodylen
= htonl((uint32_t)( key_length
[x
] + memcached_array_size(ptr
->_namespace
)));
531 libmemcached_io_vector_st vector
[]=
533 { request
.bytes
, sizeof(request
.bytes
) },
534 { memcached_array_string(ptr
->_namespace
), memcached_array_size(ptr
->_namespace
) },
535 { keys
[x
], key_length
[x
] }
538 if (memcached_io_writev(instance
, vector
, 3, flush
) == -1)
540 memcached_server_response_reset(instance
);
541 rc
= MEMCACHED_SOME_ERRORS
;
545 /* We just want one pending response per server */
546 memcached_server_response_reset(instance
);
547 memcached_server_response_increment(instance
);
548 if ((x
> 0 && x
== ptr
->io_key_prefetch
) && memcached_flush_buffers(ptr
) != MEMCACHED_SUCCESS
)
550 rc
= MEMCACHED_SOME_ERRORS
;
557 Send a noop command to flush the buffers
559 protocol_binary_request_noop request
= {}; //= {.bytes= {0}};
560 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
561 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_NOOP
;
562 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
564 for (uint32_t x
= 0; x
< memcached_server_count(ptr
); ++x
)
566 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, x
);
568 if (memcached_server_response_count(instance
))
570 if (memcached_io_write(instance
) == false)
572 memcached_server_response_reset(instance
);
573 memcached_io_reset(instance
);
574 rc
= MEMCACHED_SOME_ERRORS
;
577 if (memcached_io_write(instance
, request
.bytes
,
578 sizeof(request
.bytes
), true) == -1)
580 memcached_server_response_reset(instance
);
581 memcached_io_reset(instance
);
582 rc
= MEMCACHED_SOME_ERRORS
;
592 static memcached_return_t
replication_binary_mget(memcached_st
*ptr
,
595 const char *const *keys
,
596 const size_t *key_length
,
597 size_t number_of_keys
)
599 memcached_return_t rc
= MEMCACHED_NOTFOUND
;
601 uint64_t randomize_read
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ
);
604 start
= (uint32_t)random() % (uint32_t)(ptr
->number_of_replicas
+ 1);
606 /* Loop for each replica */
607 for (uint32_t replica
= 0; replica
<= ptr
->number_of_replicas
; ++replica
)
611 for (uint32_t x
= 0; x
< number_of_keys
; ++x
)
613 if (hash
[x
] == memcached_server_count(ptr
))
614 continue; /* Already successfully sent */
616 uint32_t server
= hash
[x
] + replica
;
618 /* In case of randomized reads */
619 if (randomize_read
&& ((server
+ start
) <= (hash
[x
] + ptr
->number_of_replicas
)))
622 while (server
>= memcached_server_count(ptr
))
624 server
-= memcached_server_count(ptr
);
627 if (dead_servers
[server
])
632 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, server
);
634 if (memcached_server_response_count(instance
) == 0)
636 rc
= memcached_connect(instance
);
638 if (memcached_failed(rc
))
640 memcached_io_reset(instance
);
641 dead_servers
[server
]= true;
647 protocol_binary_request_getk request
= {};
648 request
.message
.header
.request
.magic
= PROTOCOL_BINARY_REQ
;
649 request
.message
.header
.request
.opcode
= PROTOCOL_BINARY_CMD_GETK
;
650 request
.message
.header
.request
.keylen
= htons((uint16_t)(key_length
[x
] + memcached_array_size(ptr
->_namespace
)));
651 request
.message
.header
.request
.datatype
= PROTOCOL_BINARY_RAW_BYTES
;
652 request
.message
.header
.request
.bodylen
= htonl((uint32_t)(key_length
[x
] + memcached_array_size(ptr
->_namespace
)));
655 * We need to disable buffering to actually know that the request was
656 * successfully sent to the server (so that we should expect a result
657 * back). It would be nice to do this in buffered mode, but then it
658 * would be complex to handle all error situations if we got to send
659 * some of the messages, and then we failed on writing out some others
660 * and we used the callback interface from memcached_mget_execute so
661 * that we might have processed some of the responses etc. For now,
662 * just make sure we work _correctly_
664 libmemcached_io_vector_st vector
[]=
666 { request
.bytes
, sizeof(request
.bytes
) },
667 { memcached_array_string(ptr
->_namespace
), memcached_array_size(ptr
->_namespace
) },
668 { keys
[x
], key_length
[x
] }
671 if (memcached_io_writev(instance
, vector
, 3, true) == -1)
673 memcached_io_reset(instance
);
674 dead_servers
[server
]= true;
679 memcached_server_response_increment(instance
);
680 hash
[x
]= memcached_server_count(ptr
);
692 static memcached_return_t
binary_mget_by_key(memcached_st
*ptr
,
693 uint32_t master_server_key
,
694 bool is_group_key_set
,
695 const char * const *keys
,
696 const size_t *key_length
,
697 size_t number_of_keys
,
700 if (ptr
->number_of_replicas
== 0)
702 return simple_binary_mget(ptr
, master_server_key
, is_group_key_set
,
703 keys
, key_length
, number_of_keys
, mget_mode
);
706 uint32_t* hash
= libmemcached_xvalloc(ptr
, number_of_keys
, uint32_t);
707 bool* dead_servers
= libmemcached_xcalloc(ptr
, memcached_server_count(ptr
), bool);
709 if (hash
== NULL
|| dead_servers
== NULL
)
711 libmemcached_free(ptr
, hash
);
712 libmemcached_free(ptr
, dead_servers
);
713 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
716 if (is_group_key_set
)
718 for (size_t x
= 0; x
< number_of_keys
; x
++)
720 hash
[x
]= master_server_key
;
725 for (size_t x
= 0; x
< number_of_keys
; x
++)
727 hash
[x
]= memcached_generate_hash_with_redistribution(ptr
, keys
[x
], key_length
[x
]);
731 memcached_return_t rc
= replication_binary_mget(ptr
, hash
, dead_servers
, keys
,
732 key_length
, number_of_keys
);
734 WATCHPOINT_IFERROR(rc
);
735 libmemcached_free(ptr
, hash
);
736 libmemcached_free(ptr
, dead_servers
);
738 return MEMCACHED_SUCCESS
;