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 textual_read_one_response(memcached_server_st *ptr,
  12                                                   char *buffer, size_t buffer_length,
  13                                                   memcached_result_st *result);
  14 static memcached_return binary_read_one_response(memcached_server_st *ptr,
  15                                                  char *buffer, size_t buffer_length,
  16                                                  memcached_result_st *result);
  17
  18 memcached_return 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 rc;
  28   if (ptr->root->flags & MEM_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 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 & MEM_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 & MEM_BINARY_PROTOCOL) == 0)
  56     while (memcached_server_response_count(ptr) > 1)
  57     {
  58       memcached_return 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 textual_value_fetch(memcached_server_st *ptr,
  75                                             char *buffer,
  76                                             memcached_result_st *result)
  77 {
  78   memcached_return 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 & MEM_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 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 textual_read_one_response(memcached_server_st *ptr,
 205                                                   char *buffer, size_t buffer_length,
 206                                                   memcached_result_st *result)
 207 {
 208   memcached_return 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 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_GETK:
 360     case PROTOCOL_BINARY_CMD_GETKQ:
 361       {
 362         uint16_t keylen= header.response.keylen;
 363         memcached_result_reset(result);
 364         result->cas= header.response.cas;
 365
 366         if (memcached_safe_read(ptr, &result->flags,
 367                                 sizeof (result->flags)) != MEMCACHED_SUCCESS)
 368           return MEMCACHED_UNKNOWN_READ_FAILURE;
 369
 370         result->flags= ntohl(result->flags);
 371         bodylen -= header.response.extlen;
 372
 373         result->key_length= keylen;
 374         if (memcached_safe_read(ptr, result->key, keylen) != MEMCACHED_SUCCESS)
 375           return MEMCACHED_UNKNOWN_READ_FAILURE;
 376
 377         bodylen -= keylen;
 378         if (memcached_string_check(&result->value,
 379                                    bodylen) != MEMCACHED_SUCCESS)
 380           return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 381
 382         char *vptr= memcached_string_value(&result->value);
 383         if (memcached_safe_read(ptr, vptr, bodylen) != MEMCACHED_SUCCESS)
 384           return MEMCACHED_UNKNOWN_READ_FAILURE;
 385
 386         memcached_string_set_length(&result->value, bodylen);
 387       }
 388       break;
 389     case PROTOCOL_BINARY_CMD_INCREMENT:
 390     case PROTOCOL_BINARY_CMD_DECREMENT:
 391       {
 392         if (bodylen != sizeof(uint64_t) || buffer_length != sizeof(uint64_t))
 393           return MEMCACHED_PROTOCOL_ERROR;
 394
 395         WATCHPOINT_ASSERT(bodylen == buffer_length);
 396         uint64_t val;
 397         if (memcached_safe_read(ptr, &val, sizeof(val)) != MEMCACHED_SUCCESS)
 398           return MEMCACHED_UNKNOWN_READ_FAILURE;
 399
 400         val= ntohll(val);
 401         memcpy(buffer, &val, sizeof(val));
 402       }
 403       break;
 404     case PROTOCOL_BINARY_CMD_VERSION:
 405       {
 406         memset(buffer, 0, buffer_length);
 407         if (bodylen >= buffer_length)
 408           /* not enough space in buffer.. should not happen... */
 409           return MEMCACHED_UNKNOWN_READ_FAILURE;
 410         else if (memcached_safe_read(ptr, buffer, bodylen) != MEMCACHED_SUCCESS)
 411           return MEMCACHED_UNKNOWN_READ_FAILURE;
 412       }
 413       break;
 414     case PROTOCOL_BINARY_CMD_FLUSH:
 415     case PROTOCOL_BINARY_CMD_QUIT:
 416     case PROTOCOL_BINARY_CMD_SET:
 417     case PROTOCOL_BINARY_CMD_ADD:
 418     case PROTOCOL_BINARY_CMD_REPLACE:
 419     case PROTOCOL_BINARY_CMD_APPEND:
 420     case PROTOCOL_BINARY_CMD_PREPEND:
 421     case PROTOCOL_BINARY_CMD_DELETE:
 422       {
 423         WATCHPOINT_ASSERT(bodylen == 0);
 424         return MEMCACHED_SUCCESS;
 425       }
 426     case PROTOCOL_BINARY_CMD_NOOP:
 427       {
 428         WATCHPOINT_ASSERT(bodylen == 0);
 429         return MEMCACHED_END;
 430       }
 431     case PROTOCOL_BINARY_CMD_STAT:
 432       {
 433         if (bodylen == 0)
 434           return MEMCACHED_END;
 435         else if (bodylen + 1 > buffer_length)
 436           /* not enough space in buffer.. should not happen... */
 437           return MEMCACHED_UNKNOWN_READ_FAILURE;
 438         else
 439         {
 440           size_t keylen= header.response.keylen;
 441           memset(buffer, 0, buffer_length);
 442           if (memcached_safe_read(ptr, buffer, keylen) != MEMCACHED_SUCCESS ||
 443               memcached_safe_read(ptr, buffer + keylen + 1,
 444                                   bodylen - keylen) != MEMCACHED_SUCCESS)
 445             return MEMCACHED_UNKNOWN_READ_FAILURE;
 446         }
 447       }
 448       break;
 449     default:
 450       {
 451         /* Command not implemented yet! */
 452         WATCHPOINT_ASSERT(0);
 453         return MEMCACHED_PROTOCOL_ERROR;
 454       }
 455     }
 456   }
 457   else if (header.response.bodylen)
 458   {
 459      /* What should I do with the error message??? just discard it for now */
 460     char hole[SMALL_STRING_LEN];
 461     while (bodylen > 0)
 462     {
 463       size_t nr= (bodylen > SMALL_STRING_LEN) ? SMALL_STRING_LEN : bodylen;
 464       if (memcached_safe_read(ptr, hole, nr) != MEMCACHED_SUCCESS)
 465         return MEMCACHED_UNKNOWN_READ_FAILURE;
 466       bodylen-= (uint32_t) nr;
 467     }
 468
 469     /* This might be an error from one of the quiet commands.. if
 470      * so, just throw it away and get the next one. What about creating
 471      * a callback to the user with the error information?
 472      */
 473     switch (header.response.opcode)
 474     {
 475     case PROTOCOL_BINARY_CMD_SETQ:
 476     case PROTOCOL_BINARY_CMD_ADDQ:
 477     case PROTOCOL_BINARY_CMD_REPLACEQ:
 478     case PROTOCOL_BINARY_CMD_APPENDQ:
 479     case PROTOCOL_BINARY_CMD_PREPENDQ:
 480       return binary_read_one_response(ptr, buffer, buffer_length, result);
 481     default:
 482       break;
 483     }
 484   }
 485
 486   memcached_return rc= MEMCACHED_SUCCESS;
 487   unlikely(header.response.status != 0)
 488     switch (header.response.status)
 489     {
 490     case PROTOCOL_BINARY_RESPONSE_KEY_ENOENT:
 491       rc= MEMCACHED_NOTFOUND;
 492       break;
 493     case PROTOCOL_BINARY_RESPONSE_KEY_EEXISTS:
 494       rc= MEMCACHED_DATA_EXISTS;
 495       break;
 496     case PROTOCOL_BINARY_RESPONSE_NOT_STORED:
 497       rc= MEMCACHED_NOTSTORED;
 498       break;
 499     case PROTOCOL_BINARY_RESPONSE_E2BIG:
 500       rc= MEMCACHED_E2BIG;
 501       break;
 502     case PROTOCOL_BINARY_RESPONSE_ENOMEM:
 503       rc= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 504       break;
 505     case PROTOCOL_BINARY_RESPONSE_EINVAL:
 506     case PROTOCOL_BINARY_RESPONSE_UNKNOWN_COMMAND:
 507     default:
 508       /* @todo fix the error mappings */
 509       rc= MEMCACHED_PROTOCOL_ERROR;
 510       break;
 511     }
 512
 513   return rc;
 514 }