git.m6w6.name Git - m6w6/libmemcached/blob - libmemcached/memcached_response.c

   1 /*
   2   Memcached library
   3
   4   memcached_response() is used to determine the return result
   5   from an issued command.
   6 */
   7
   8 #include "common.h"
   9 #include "memcached_io.h"
  10
  11 static memcached_return_t textual_read_one_response(memcached_server_st *ptr,
  12                                                   char *buffer, size_t buffer_length,
  13                                                   memcached_result_st *result);
  14 static memcached_return_t binary_read_one_response(memcached_server_st *ptr,
  15                                                  char *buffer, size_t buffer_length,
  16                                                  memcached_result_st *result);
  17
  18 memcached_return_t memcached_read_one_response(memcached_server_st *ptr,
  19                                              char *buffer, size_t buffer_length,
  20                                              memcached_result_st *result)
  21 {
  22   memcached_server_response_decrement(ptr);
  23
  24   if (result == NULL)
  25     result = &ptr->root->result;
  26
  27   memcached_return_t rc;
  28   if (ptr->root->flags.binary_protocol)
  29     rc= binary_read_one_response(ptr, buffer, buffer_length, result);
  30   else
  31     rc= textual_read_one_response(ptr, buffer, buffer_length, result);
  32
  33   unlikely(rc == MEMCACHED_UNKNOWN_READ_FAILURE ||
  34            rc == MEMCACHED_PROTOCOL_ERROR ||
  35            rc == MEMCACHED_CLIENT_ERROR ||
  36            rc == MEMCACHED_MEMORY_ALLOCATION_FAILURE)
  37      memcached_io_reset(ptr);
  38
  39   return rc;
  40 }
  41
  42 memcached_return_t memcached_response(memcached_server_st *ptr,
  43                                     char *buffer, size_t buffer_length,
  44                                     memcached_result_st *result)
  45 {
  46   /* We may have old commands in the buffer not set, first purge */
  47   if (ptr->root->flags.no_block)
  48     (void)memcached_io_write(ptr, NULL, 0, 1);
  49
  50   /*
  51    * The previous implementation purged all pending requests and just
  52    * returned the last one. Purge all pending messages to ensure backwards
  53    * compatibility.
  54    */
  55   if (ptr->root->flags.binary_protocol == false)
  56     while (memcached_server_response_count(ptr) > 1)
  57     {
  58       memcached_return_t rc= memcached_read_one_response(ptr, buffer, buffer_length, result);
  59
  60       unlikely (rc != MEMCACHED_END &&
  61                 rc != MEMCACHED_STORED &&
  62                 rc != MEMCACHED_SUCCESS &&
  63                 rc != MEMCACHED_STAT &&
  64                 rc != MEMCACHED_DELETED &&
  65                 rc != MEMCACHED_NOTFOUND &&
  66                 rc != MEMCACHED_NOTSTORED &&
  67                 rc != MEMCACHED_DATA_EXISTS)
  68         return rc;
  69     }
  70
  71   return memcached_read_one_response(ptr, buffer, buffer_length, result);
  72 }
  73
  74 static memcached_return_t textual_value_fetch(memcached_server_st *ptr,
  75                                             char *buffer,
  76                                             memcached_result_st *result)
  77 {
  78   memcached_return_t rc= MEMCACHED_SUCCESS;
  79   char *string_ptr;
  80   char *end_ptr;
  81   char *next_ptr;
  82   size_t value_length;
  83   size_t to_read;
  84   char *value_ptr;
  85
  86   if (ptr->root->flags.use_udp)
  87     return MEMCACHED_NOT_SUPPORTED;
  88
  89   WATCHPOINT_ASSERT(ptr->root);
  90   end_ptr= buffer + MEMCACHED_DEFAULT_COMMAND_SIZE;
  91
  92   memcached_result_reset(result);
  93
  94   string_ptr= buffer;
  95   string_ptr+= 6; /* "VALUE " */
  96
  97
  98   /* We load the key */
  99   {
 100     char *key;
 101     size_t prefix_length;
 102
 103     key= result->key;
 104     result->key_length= 0;
 105
 106     for (prefix_length= ptr->root->prefix_key_length; !(iscntrl(*string_ptr) || isspace(*string_ptr)) ; string_ptr++)
 107     {
 108       if (prefix_length == 0)
 109       {
 110         *key= *string_ptr;
 111         key++;
 112         result->key_length++;
 113       }
 114       else
 115         prefix_length--;
 116     }
 117     result->key[result->key_length]= 0;
 118   }
 119
 120   if (end_ptr == string_ptr)
 121     goto read_error;
 122
 123   /* Flags fetch move past space */
 124   string_ptr++;
 125   if (end_ptr == string_ptr)
 126     goto read_error;
 127   for (next_ptr= string_ptr; isdigit(*string_ptr); string_ptr++);
 128   result->flags= (uint32_t) strtoul(next_ptr, &string_ptr, 10);
 129
 130   if (end_ptr == string_ptr)
 131     goto read_error;
 132
 133   /* Length fetch move past space*/
 134   string_ptr++;
 135   if (end_ptr == string_ptr)
 136     goto read_error;
 137
 138   for (next_ptr= string_ptr; isdigit(*string_ptr); string_ptr++);
 139   value_length= (size_t)strtoull(next_ptr, &string_ptr, 10);
 140
 141   if (end_ptr == string_ptr)
 142     goto read_error;
 143
 144   /* Skip spaces */
 145   if (*string_ptr == '\r')
 146   {
 147     /* Skip past the \r\n */
 148     string_ptr+= 2;
 149   }
 150   else
 151   {
 152     string_ptr++;
 153     for (next_ptr= string_ptr; isdigit(*string_ptr); string_ptr++);
 154     result->cas= strtoull(next_ptr, &string_ptr, 10);
 155   }
 156
 157   if (end_ptr < string_ptr)
 158     goto read_error;
 159
 160   /* We add two bytes so that we can walk the \r\n */
 161   rc= memcached_string_check(&result->value, value_length+2);
 162   if (rc != MEMCACHED_SUCCESS)
 163   {
 164     value_length= 0;
 165     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 166   }
 167
 168   value_ptr= memcached_string_value(&result->value);
 169   /*
 170     We read the \r\n into the string since not doing so is more
 171     cycles then the waster of memory to do so.
 172
 173     We are null terminating through, which will most likely make
 174     some people lazy about using the return length.
 175   */
 176   to_read= (value_length) + 2;
 177   ssize_t read_length= 0;
 178   memcached_return_t rrc= memcached_io_read(ptr, value_ptr, to_read, &read_length);
 179   if (rrc != MEMCACHED_SUCCESS)
 180     return rrc;
 181
 182   if (read_length != (ssize_t)(value_length + 2))
 183   {
 184     goto read_error;
 185   }
 186
 187 /* This next bit blows the API, but this is internal....*/
 188   {
 189     char *char_ptr;
 190     char_ptr= memcached_string_value(&result->value);;
 191     char_ptr[value_length]= 0;
 192     char_ptr[value_length + 1]= 0;
 193     memcached_string_set_length(&result->value, value_length);
 194   }
 195
 196   return MEMCACHED_SUCCESS;
 197
 198 read_error:
 199   memcached_io_reset(ptr);
 200
 201   return MEMCACHED_PARTIAL_READ;
 202 }
 203
 204 static memcached_return_t textual_read_one_response(memcached_server_st *ptr,
 205                                                   char *buffer, size_t buffer_length,
 206                                                   memcached_result_st *result)
 207 {
 208   memcached_return_t rc= memcached_io_readline(ptr, buffer, buffer_length);
 209   if (rc != MEMCACHED_SUCCESS)
 210     return rc;
 211
 212   switch(buffer[0])
 213   {
 214   case 'V': /* VALUE || VERSION */
 215     if (buffer[1] == 'A') /* VALUE */
 216     {
 217       /* We add back in one because we will need to search for END */
 218       memcached_server_response_increment(ptr);
 219       return textual_value_fetch(ptr, buffer, result);
 220     }
 221     else if (buffer[1] == 'E') /* VERSION */
 222     {
 223       return MEMCACHED_SUCCESS;
 224     }
 225     else
 226     {
 227       WATCHPOINT_STRING(buffer);
 228       WATCHPOINT_ASSERT(0);
 229       return MEMCACHED_UNKNOWN_READ_FAILURE;
 230     }
 231   case 'O': /* OK */
 232     return MEMCACHED_SUCCESS;
 233   case 'S': /* STORED STATS SERVER_ERROR */
 234     {
 235       if (buffer[2] == 'A') /* STORED STATS */
 236       {
 237         memcached_server_response_increment(ptr);
 238         return MEMCACHED_STAT;
 239       }
 240       else if (buffer[1] == 'E') /* SERVER_ERROR */
 241         {
 242           char *rel_ptr;
 243           char *startptr= buffer + 13, *endptr= startptr;
 244
 245           while (*endptr != '\r' && *endptr != '\n') endptr++;
 246
 247           /*
 248             Yes, we could make this "efficent" but to do that we would need
 249             to maintain more state for the size of the buffer. Why waste
 250             memory in the struct, which is important, for something that
 251             rarely should happen?
 252           */
 253           rel_ptr= (char *)ptr->root->call_realloc(ptr->root,
 254                                                    ptr->cached_server_error,
 255                                                    (size_t) (endptr - startptr + 1));
 256
 257           if (rel_ptr == NULL)
 258           {
 259             /* If we happened to have some memory, we just null it since we don't know the size */
 260             if (ptr->cached_server_error)
 261               ptr->cached_server_error[0]= 0;
 262             return MEMCACHED_SERVER_ERROR;
 263           }
 264           ptr->cached_server_error= rel_ptr;
 265
 266           memcpy(ptr->cached_server_error, startptr, (size_t) (endptr - startptr));
 267           ptr->cached_server_error[endptr - startptr]= 0;
 268           return MEMCACHED_SERVER_ERROR;
 269         }
 270       else if (buffer[1] == 'T')
 271         return MEMCACHED_STORED;
 272       else
 273       {
 274         WATCHPOINT_STRING(buffer);
 275         WATCHPOINT_ASSERT(0);
 276         return MEMCACHED_UNKNOWN_READ_FAILURE;
 277       }
 278     }
 279   case 'D': /* DELETED */
 280     return MEMCACHED_DELETED;
 281   case 'N': /* NOT_FOUND */
 282     {
 283       if (buffer[4] == 'F')
 284         return MEMCACHED_NOTFOUND;
 285       else if (buffer[4] == 'S')
 286         return MEMCACHED_NOTSTORED;
 287       else
 288         return MEMCACHED_UNKNOWN_READ_FAILURE;
 289     }
 290   case 'E': /* PROTOCOL ERROR or END */
 291     {
 292       if (buffer[1] == 'N')
 293         return MEMCACHED_END;
 294       else if (buffer[1] == 'R')
 295         return MEMCACHED_PROTOCOL_ERROR;
 296       else if (buffer[1] == 'X')
 297         return MEMCACHED_DATA_EXISTS;
 298       else
 299         return MEMCACHED_UNKNOWN_READ_FAILURE;
 300     }
 301   case 'I': /* CLIENT ERROR */
 302       /* We add back in one because we will need to search for END */
 303       memcached_server_response_increment(ptr);
 304     return MEMCACHED_ITEM;
 305   case 'C': /* CLIENT ERROR */
 306     return MEMCACHED_CLIENT_ERROR;
 307   default:
 308     {
 309       unsigned long long auto_return_value;
 310
 311       if (sscanf(buffer, "%llu", &auto_return_value) == 1)
 312         return MEMCACHED_SUCCESS;
 313
 314       return MEMCACHED_UNKNOWN_READ_FAILURE;
 315     }
 316   }
 317
 318   /* NOTREACHED */
 319 }
 320
 321 char *memcached_result_value(memcached_result_st *ptr)
 322 {
 323   memcached_string_st *sptr= &ptr->value;
 324   return memcached_string_value(sptr);
 325 }
 326
 327 size_t memcached_result_length(memcached_result_st *ptr)
 328 {
 329   memcached_string_st *sptr= &ptr->value;
 330   return memcached_string_length(sptr);
 331 }
 332
 333 static memcached_return_t binary_read_one_response(memcached_server_st *ptr,
 334                                                  char *buffer, size_t buffer_length,
 335                                                  memcached_result_st *result)
 336 {
 337   protocol_binary_response_header header;
 338
 339   unlikely (memcached_safe_read(ptr, &header.bytes,
 340                                 sizeof(header.bytes)) != MEMCACHED_SUCCESS)
 341     return MEMCACHED_UNKNOWN_READ_FAILURE;
 342
 343   unlikely (header.response.magic != PROTOCOL_BINARY_RES)
 344     return MEMCACHED_PROTOCOL_ERROR;
 345
 346   /*
 347   ** Convert the header to host local endian!
 348   */
 349   header.response.keylen= ntohs(header.response.keylen);
 350   header.response.status= ntohs(header.response.status);
 351   header.response.bodylen= ntohl(header.response.bodylen);
 352   header.response.cas= ntohll(header.response.cas);
 353   uint32_t bodylen= header.response.bodylen;
 354
 355   if (header.response.status == 0)
 356   {
 357     switch (header.response.opcode)
 358     {
 359     case PROTOCOL_BINARY_CMD_GETKQ:
 360       /*
 361        * We didn't increment the response counter for the GETKQ packet
 362        * (only the final NOOP), so we need to increment the counter again.
 363        */
 364       memcached_server_response_increment(ptr);
 365       /* FALLTHROUGH */
 366     case PROTOCOL_BINARY_CMD_GETK:
 367       {
 368         uint16_t keylen= header.response.keylen;
 369         memcached_result_reset(result);
 370         result->cas= header.response.cas;
 371
 372         if (memcached_safe_read(ptr, &result->flags,
 373                                 sizeof (result->flags)) != MEMCACHED_SUCCESS)
 374           return MEMCACHED_UNKNOWN_READ_FAILURE;
 375
 376         result->flags= ntohl(result->flags);
 377         bodylen -= header.response.extlen;
 378
 379         result->key_length= keylen;
 380         if (memcached_safe_read(ptr, result->key, keylen) != MEMCACHED_SUCCESS)
 381           return MEMCACHED_UNKNOWN_READ_FAILURE;
 382
 383         bodylen -= keylen;
 384         if (memcached_string_check(&result->value,
 385                                    bodylen) != MEMCACHED_SUCCESS)
 386           return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 387
 388         char *vptr= memcached_string_value(&result->value);
 389         if (memcached_safe_read(ptr, vptr, bodylen) != MEMCACHED_SUCCESS)
 390           return MEMCACHED_UNKNOWN_READ_FAILURE;
 391
 392         memcached_string_set_length(&result->value, bodylen);
 393       }
 394       break;
 395     case PROTOCOL_BINARY_CMD_INCREMENT:
 396     case PROTOCOL_BINARY_CMD_DECREMENT:
 397       {
 398         if (bodylen != sizeof(uint64_t) || buffer_length != sizeof(uint64_t))
 399           return MEMCACHED_PROTOCOL_ERROR;
 400
 401         WATCHPOINT_ASSERT(bodylen == buffer_length);
 402         uint64_t val;
 403         if (memcached_safe_read(ptr, &val, sizeof(val)) != MEMCACHED_SUCCESS)
 404           return MEMCACHED_UNKNOWN_READ_FAILURE;
 405
 406         val= ntohll(val);
 407         memcpy(buffer, &val, sizeof(val));
 408       }
 409       break;
 410     case PROTOCOL_BINARY_CMD_VERSION:
 411       {
 412         memset(buffer, 0, buffer_length);
 413         if (bodylen >= buffer_length)
 414           /* not enough space in buffer.. should not happen... */
 415           return MEMCACHED_UNKNOWN_READ_FAILURE;
 416         else if (memcached_safe_read(ptr, buffer, bodylen) != MEMCACHED_SUCCESS)
 417           return MEMCACHED_UNKNOWN_READ_FAILURE;
 418       }
 419       break;
 420     case PROTOCOL_BINARY_CMD_FLUSH:
 421     case PROTOCOL_BINARY_CMD_QUIT:
 422     case PROTOCOL_BINARY_CMD_SET:
 423     case PROTOCOL_BINARY_CMD_ADD:
 424     case PROTOCOL_BINARY_CMD_REPLACE:
 425     case PROTOCOL_BINARY_CMD_APPEND:
 426     case PROTOCOL_BINARY_CMD_PREPEND:
 427     case PROTOCOL_BINARY_CMD_DELETE:
 428       {
 429         WATCHPOINT_ASSERT(bodylen == 0);
 430         return MEMCACHED_SUCCESS;
 431       }
 432     case PROTOCOL_BINARY_CMD_NOOP:
 433       {
 434         WATCHPOINT_ASSERT(bodylen == 0);
 435         return MEMCACHED_END;
 436       }
 437     case PROTOCOL_BINARY_CMD_STAT:
 438       {
 439         if (bodylen == 0)
 440           return MEMCACHED_END;
 441         else if (bodylen + 1 > buffer_length)
 442           /* not enough space in buffer.. should not happen... */
 443           return MEMCACHED_UNKNOWN_READ_FAILURE;
 444         else
 445         {
 446           size_t keylen= header.response.keylen;
 447           memset(buffer, 0, buffer_length);
 448           if (memcached_safe_read(ptr, buffer, keylen) != MEMCACHED_SUCCESS ||
 449               memcached_safe_read(ptr, buffer + keylen + 1,
 450                                   bodylen - keylen) != MEMCACHED_SUCCESS)
 451             return MEMCACHED_UNKNOWN_READ_FAILURE;
 452         }
 453       }
 454       break;
 455     default:
 456       {
 457         /* Command not implemented yet! */
 458         WATCHPOINT_ASSERT(0);
 459         return MEMCACHED_PROTOCOL_ERROR;
 460       }
 461     }
 462   }
 463   else if (header.response.bodylen)
 464   {
 465      /* What should I do with the error message??? just discard it for now */
 466     char hole[SMALL_STRING_LEN];
 467     while (bodylen > 0)
 468     {
 469       size_t nr= (bodylen > SMALL_STRING_LEN) ? SMALL_STRING_LEN : bodylen;
 470       if (memcached_safe_read(ptr, hole, nr) != MEMCACHED_SUCCESS)
 471         return MEMCACHED_UNKNOWN_READ_FAILURE;
 472       bodylen-= (uint32_t) nr;
 473     }
 474
 475     /* This might be an error from one of the quiet commands.. if
 476      * so, just throw it away and get the next one. What about creating
 477      * a callback to the user with the error information?
 478      */
 479     switch (header.response.opcode)
 480     {
 481     case PROTOCOL_BINARY_CMD_SETQ:
 482     case PROTOCOL_BINARY_CMD_ADDQ:
 483     case PROTOCOL_BINARY_CMD_REPLACEQ:
 484     case PROTOCOL_BINARY_CMD_APPENDQ:
 485     case PROTOCOL_BINARY_CMD_PREPENDQ:
 486       return binary_read_one_response(ptr, buffer, buffer_length, result);
 487     default:
 488       break;
 489     }
 490   }
 491
 492   memcached_return_t rc= MEMCACHED_SUCCESS;
 493   unlikely(header.response.status != 0)
 494     switch (header.response.status)
 495     {
 496     case PROTOCOL_BINARY_RESPONSE_KEY_ENOENT:
 497       rc= MEMCACHED_NOTFOUND;
 498       break;
 499     case PROTOCOL_BINARY_RESPONSE_KEY_EEXISTS:
 500       rc= MEMCACHED_DATA_EXISTS;
 501       break;
 502     case PROTOCOL_BINARY_RESPONSE_NOT_STORED:
 503       rc= MEMCACHED_NOTSTORED;
 504       break;
 505     case PROTOCOL_BINARY_RESPONSE_E2BIG:
 506       rc= MEMCACHED_E2BIG;
 507       break;
 508     case PROTOCOL_BINARY_RESPONSE_ENOMEM:
 509       rc= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 510       break;
 511     case PROTOCOL_BINARY_RESPONSE_EINVAL:
 512     case PROTOCOL_BINARY_RESPONSE_UNKNOWN_COMMAND:
 513     default:
 514       /* @todo fix the error mappings */
 515       rc= MEMCACHED_PROTOCOL_ERROR;
 516       break;
 517     }
 518
 519   return rc;
 520 }