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

   1 /* LibMemcached
   2  * Copyright (C) 2006-2009 Brian Aker
   3  * All rights reserved.
   4  *
   5  * Use and distribution licensed under the BSD license.  See
   6  * the COPYING file in the parent directory for full text.
   7  *
   8  * Summary: memcached_response() is used to determine the return result from an issued command.
   9  *
  10 */
  11
  12 #include "common.h"
  13
  14 static memcached_return_t textual_read_one_response(memcached_server_instance_st *ptr,
  15                                                     char *buffer, size_t buffer_length,
  16                                                     memcached_result_st *result);
  17 static memcached_return_t binary_read_one_response(memcached_server_instance_st *ptr,
  18                                                    char *buffer, size_t buffer_length,
  19                                                    memcached_result_st *result);
  20
  21 memcached_return_t memcached_read_one_response(memcached_server_instance_st *ptr,
  22                                                char *buffer, size_t buffer_length,
  23                                                memcached_result_st *result)
  24 {
  25   memcached_server_response_decrement(ptr);
  26
  27   if (result == NULL)
  28     result = &ptr->root->result;
  29
  30   memcached_return_t rc;
  31   if (ptr->root->flags.binary_protocol)
  32     rc= binary_read_one_response(ptr, buffer, buffer_length, result);
  33   else
  34     rc= textual_read_one_response(ptr, buffer, buffer_length, result);
  35
  36   unlikely(rc == MEMCACHED_UNKNOWN_READ_FAILURE ||
  37            rc == MEMCACHED_PROTOCOL_ERROR ||
  38            rc == MEMCACHED_CLIENT_ERROR ||
  39            rc == MEMCACHED_MEMORY_ALLOCATION_FAILURE)
  40     memcached_io_reset(ptr);
  41
  42   return rc;
  43 }
  44
  45 memcached_return_t memcached_response(memcached_server_instance_st *ptr,
  46                                       char *buffer, size_t buffer_length,
  47                                       memcached_result_st *result)
  48 {
  49   /* We may have old commands in the buffer not set, first purge */
  50   if ((ptr->root->flags.no_block) && (ptr->root->options.is_processing_input == false))
  51   {
  52     (void)memcached_io_write(ptr, NULL, 0, 1);
  53   }
  54
  55   /*
  56    * The previous implementation purged all pending requests and just
  57    * returned the last one. Purge all pending messages to ensure backwards
  58    * compatibility.
  59  */
  60   if (ptr->root->flags.binary_protocol == false)
  61     while (memcached_server_response_count(ptr) > 1)
  62     {
  63       memcached_return_t rc= memcached_read_one_response(ptr, buffer, buffer_length, result);
  64
  65       unlikely (rc != MEMCACHED_END &&
  66                 rc != MEMCACHED_STORED &&
  67                 rc != MEMCACHED_SUCCESS &&
  68                 rc != MEMCACHED_STAT &&
  69                 rc != MEMCACHED_DELETED &&
  70                 rc != MEMCACHED_NOTFOUND &&
  71                 rc != MEMCACHED_NOTSTORED &&
  72                 rc != MEMCACHED_DATA_EXISTS)
  73         return rc;
  74     }
  75
  76   return memcached_read_one_response(ptr, buffer, buffer_length, result);
  77 }
  78
  79 static memcached_return_t textual_value_fetch(memcached_server_instance_st *ptr,
  80                                               char *buffer,
  81                                               memcached_result_st *result)
  82 {
  83   memcached_return_t rc= MEMCACHED_SUCCESS;
  84   char *string_ptr;
  85   char *end_ptr;
  86   char *next_ptr;
  87   size_t value_length;
  88   size_t to_read;
  89   char *value_ptr;
  90   ssize_t read_length= 0;
  91   memcached_return_t rrc;
  92
  93   if (ptr->root->flags.use_udp)
  94     return MEMCACHED_NOT_SUPPORTED;
  95
  96   WATCHPOINT_ASSERT(ptr->root);
  97   end_ptr= buffer + MEMCACHED_DEFAULT_COMMAND_SIZE;
  98
  99   memcached_result_reset(result);
 100
 101   string_ptr= buffer;
 102   string_ptr+= 6; /* "VALUE " */
 103
 104
 105   /* We load the key */
 106   {
 107     char *key;
 108     size_t prefix_length;
 109
 110     key= result->key;
 111     result->key_length= 0;
 112
 113     for (prefix_length= ptr->root->prefix_key_length; !(iscntrl(*string_ptr) || isspace(*string_ptr)) ; string_ptr++)
 114     {
 115       if (prefix_length == 0)
 116       {
 117         *key= *string_ptr;
 118         key++;
 119         result->key_length++;
 120       }
 121       else
 122         prefix_length--;
 123     }
 124     result->key[result->key_length]= 0;
 125   }
 126
 127   if (end_ptr == string_ptr)
 128     goto read_error;
 129
 130   /* Flags fetch move past space */
 131   string_ptr++;
 132   if (end_ptr == string_ptr)
 133     goto read_error;
 134   for (next_ptr= string_ptr; isdigit(*string_ptr); string_ptr++);
 135   result->flags= (uint32_t) strtoul(next_ptr, &string_ptr, 10);
 136
 137   if (end_ptr == string_ptr)
 138     goto read_error;
 139
 140   /* Length fetch move past space*/
 141   string_ptr++;
 142   if (end_ptr == string_ptr)
 143     goto read_error;
 144
 145   for (next_ptr= string_ptr; isdigit(*string_ptr); string_ptr++);
 146   value_length= (size_t)strtoull(next_ptr, &string_ptr, 10);
 147
 148   if (end_ptr == string_ptr)
 149     goto read_error;
 150
 151   /* Skip spaces */
 152   if (*string_ptr == '\r')
 153   {
 154     /* Skip past the \r\n */
 155     string_ptr+= 2;
 156   }
 157   else
 158   {
 159     string_ptr++;
 160     for (next_ptr= string_ptr; isdigit(*string_ptr); string_ptr++);
 161     result->cas= strtoull(next_ptr, &string_ptr, 10);
 162   }
 163
 164   if (end_ptr < string_ptr)
 165     goto read_error;
 166
 167   /* We add two bytes so that we can walk the \r\n */
 168   rc= memcached_string_check(&result->value, value_length+2);
 169   if (rc != MEMCACHED_SUCCESS)
 170   {
 171     value_length= 0;
 172     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 173   }
 174
 175   value_ptr= memcached_string_value(&result->value);
 176   /*
 177     We read the \r\n into the string since not doing so is more
 178     cycles then the waster of memory to do so.
 179
 180     We are null terminating through, which will most likely make
 181     some people lazy about using the return length.
 182   */
 183   to_read= (value_length) + 2;
 184   rrc= memcached_io_read(ptr, value_ptr, to_read, &read_length);
 185   if (rrc != MEMCACHED_SUCCESS)
 186     return rrc;
 187
 188   if (read_length != (ssize_t)(value_length + 2))
 189   {
 190     goto read_error;
 191   }
 192
 193   /* This next bit blows the API, but this is internal....*/
 194   {
 195     char *char_ptr;
 196     char_ptr= memcached_string_value(&result->value);;
 197     char_ptr[value_length]= 0;
 198     char_ptr[value_length + 1]= 0;
 199     memcached_string_set_length(&result->value, value_length);
 200   }
 201
 202   return MEMCACHED_SUCCESS;
 203
 204 read_error:
 205   memcached_io_reset(ptr);
 206
 207   return MEMCACHED_PARTIAL_READ;
 208 }
 209
 210 static memcached_return_t textual_read_one_response(memcached_server_instance_st *ptr,
 211                                                     char *buffer, size_t buffer_length,
 212                                                     memcached_result_st *result)
 213 {
 214   memcached_return_t rc= memcached_io_readline(ptr, buffer, buffer_length);
 215   if (rc != MEMCACHED_SUCCESS)
 216     return rc;
 217
 218   switch(buffer[0])
 219   {
 220   case 'V': /* VALUE || VERSION */
 221     if (buffer[1] == 'A') /* VALUE */
 222     {
 223       /* We add back in one because we will need to search for END */
 224       memcached_server_response_increment(ptr);
 225       return textual_value_fetch(ptr, buffer, result);
 226     }
 227     else if (buffer[1] == 'E') /* VERSION */
 228     {
 229       return MEMCACHED_SUCCESS;
 230     }
 231     else
 232     {
 233       WATCHPOINT_STRING(buffer);
 234       WATCHPOINT_ASSERT(0);
 235       return MEMCACHED_UNKNOWN_READ_FAILURE;
 236     }
 237   case 'O': /* OK */
 238     return MEMCACHED_SUCCESS;
 239   case 'S': /* STORED STATS SERVER_ERROR */
 240     {
 241       if (buffer[2] == 'A') /* STORED STATS */
 242       {
 243         memcached_server_response_increment(ptr);
 244         return MEMCACHED_STAT;
 245       }
 246       else if (buffer[1] == 'E') /* SERVER_ERROR */
 247       {
 248         char *rel_ptr;
 249         char *startptr= buffer + 13, *endptr= startptr;
 250
 251         while (*endptr != '\r' && *endptr != '\n') endptr++;
 252
 253         /*
 254           Yes, we could make this "efficent" but to do that we would need
 255           to maintain more state for the size of the buffer. Why waste
 256           memory in the struct, which is important, for something that
 257           rarely should happen?
 258         */
 259         rel_ptr= (char *)ptr->root->call_realloc(ptr->root,
 260                                                  ptr->cached_server_error,
 261                                                  (size_t) (endptr - startptr + 1));
 262
 263         if (rel_ptr == NULL)
 264         {
 265           /* If we happened to have some memory, we just null it since we don't know the size */
 266           if (ptr->cached_server_error)
 267             ptr->cached_server_error[0]= 0;
 268           return MEMCACHED_SERVER_ERROR;
 269         }
 270         ptr->cached_server_error= rel_ptr;
 271
 272         memcpy(ptr->cached_server_error, startptr, (size_t) (endptr - startptr));
 273         ptr->cached_server_error[endptr - startptr]= 0;
 274         return MEMCACHED_SERVER_ERROR;
 275       }
 276       else if (buffer[1] == 'T')
 277         return MEMCACHED_STORED;
 278       else
 279       {
 280         WATCHPOINT_STRING(buffer);
 281         WATCHPOINT_ASSERT(0);
 282         return MEMCACHED_UNKNOWN_READ_FAILURE;
 283       }
 284     }
 285   case 'D': /* DELETED */
 286     return MEMCACHED_DELETED;
 287   case 'N': /* NOT_FOUND */
 288     {
 289       if (buffer[4] == 'F')
 290         return MEMCACHED_NOTFOUND;
 291       else if (buffer[4] == 'S')
 292         return MEMCACHED_NOTSTORED;
 293       else
 294         return MEMCACHED_UNKNOWN_READ_FAILURE;
 295     }
 296   case 'E': /* PROTOCOL ERROR or END */
 297     {
 298       if (buffer[1] == 'N')
 299         return MEMCACHED_END;
 300       else if (buffer[1] == 'R')
 301         return MEMCACHED_PROTOCOL_ERROR;
 302       else if (buffer[1] == 'X')
 303         return MEMCACHED_DATA_EXISTS;
 304       else
 305         return MEMCACHED_UNKNOWN_READ_FAILURE;
 306     }
 307   case 'I': /* CLIENT ERROR */
 308     /* We add back in one because we will need to search for END */
 309     memcached_server_response_increment(ptr);
 310     return MEMCACHED_ITEM;
 311   case 'C': /* CLIENT ERROR */
 312     return MEMCACHED_CLIENT_ERROR;
 313   default:
 314     {
 315       unsigned long long auto_return_value;
 316
 317       if (sscanf(buffer, "%llu", &auto_return_value) == 1)
 318         return MEMCACHED_SUCCESS;
 319
 320       return MEMCACHED_UNKNOWN_READ_FAILURE;
 321     }
 322   }
 323
 324   /* NOTREACHED */
 325 }
 326
 327 static memcached_return_t binary_read_one_response(memcached_server_instance_st *ptr,
 328                                                    char *buffer, size_t buffer_length,
 329                                                    memcached_result_st *result)
 330 {
 331   protocol_binary_response_header header;
 332
 333   unlikely (memcached_safe_read(ptr, &header.bytes,
 334                                 sizeof(header.bytes)) != MEMCACHED_SUCCESS)
 335     return MEMCACHED_UNKNOWN_READ_FAILURE;
 336
 337   unlikely (header.response.magic != PROTOCOL_BINARY_RES)
 338     return MEMCACHED_PROTOCOL_ERROR;
 339
 340   /*
 341    ** Convert the header to host local endian!
 342  */
 343   header.response.keylen= ntohs(header.response.keylen);
 344   header.response.status= ntohs(header.response.status);
 345   header.response.bodylen= ntohl(header.response.bodylen);
 346   header.response.cas= ntohll(header.response.cas);
 347   uint32_t bodylen= header.response.bodylen;
 348
 349   if (header.response.status == 0)
 350   {
 351     switch (header.response.opcode)
 352     {
 353     case PROTOCOL_BINARY_CMD_GETKQ:
 354       /*
 355        * We didn't increment the response counter for the GETKQ packet
 356        * (only the final NOOP), so we need to increment the counter again.
 357        */
 358       memcached_server_response_increment(ptr);
 359       /* FALLTHROUGH */
 360     case PROTOCOL_BINARY_CMD_GETK:
 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_t 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 }