git.m6w6.name Git - awesomized/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= 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 != (size_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')
 241         return MEMCACHED_SERVER_ERROR;
 242       else if (buffer[1] == 'T')
 243         return MEMCACHED_STORED;
 244       else
 245       {
 246         WATCHPOINT_STRING(buffer);
 247         WATCHPOINT_ASSERT(0);
 248         return MEMCACHED_UNKNOWN_READ_FAILURE;
 249       }
 250     }
 251   case 'D': /* DELETED */
 252     return MEMCACHED_DELETED;
 253   case 'N': /* NOT_FOUND */
 254     {
 255       if (buffer[4] == 'F')
 256         return MEMCACHED_NOTFOUND;
 257       else if (buffer[4] == 'S')
 258         return MEMCACHED_NOTSTORED;
 259       else
 260         return MEMCACHED_UNKNOWN_READ_FAILURE;
 261     }
 262   case 'E': /* PROTOCOL ERROR or END */
 263     {
 264       if (buffer[1] == 'N')
 265         return MEMCACHED_END;
 266       else if (buffer[1] == 'R')
 267         return MEMCACHED_PROTOCOL_ERROR;
 268       else if (buffer[1] == 'X')
 269         return MEMCACHED_DATA_EXISTS;
 270       else
 271         return MEMCACHED_UNKNOWN_READ_FAILURE;
 272     }
 273   case 'C': /* CLIENT ERROR */
 274     return MEMCACHED_CLIENT_ERROR;
 275   default:
 276     {
 277       unsigned long long auto_return_value;
 278
 279       if (sscanf(buffer, "%llu", &auto_return_value) == 1)
 280         return MEMCACHED_SUCCESS;
 281
 282       return MEMCACHED_UNKNOWN_READ_FAILURE;
 283     }
 284   }
 285
 286   /* NOTREACHED */
 287 }
 288
 289 char *memcached_result_value(memcached_result_st *ptr)
 290 {
 291   memcached_string_st *sptr= &ptr->value;
 292   return memcached_string_value(sptr);
 293 }
 294
 295 size_t memcached_result_length(memcached_result_st *ptr)
 296 {
 297   memcached_string_st *sptr= &ptr->value;
 298   return memcached_string_length(sptr);
 299 }
 300
 301 static memcached_return binary_read_one_response(memcached_server_st *ptr,
 302                                                  char *buffer, size_t buffer_length,
 303                                                  memcached_result_st *result)
 304 {
 305   protocol_binary_response_header header;
 306
 307   unlikely (memcached_safe_read(ptr, &header.bytes,
 308                                 sizeof(header.bytes)) != MEMCACHED_SUCCESS)
 309     return MEMCACHED_UNKNOWN_READ_FAILURE;
 310
 311   unlikely (header.response.magic != PROTOCOL_BINARY_RES)
 312     return MEMCACHED_PROTOCOL_ERROR;
 313
 314   /*
 315   ** Convert the header to host local endian!
 316   */
 317   header.response.keylen= ntohs(header.response.keylen);
 318   header.response.status= ntohs(header.response.status);
 319   header.response.bodylen= ntohl(header.response.bodylen);
 320   header.response.cas= ntohll(header.response.cas);
 321   uint32_t bodylen= header.response.bodylen;
 322
 323   if (header.response.status == 0)
 324   {
 325     switch (header.response.opcode)
 326     {
 327     case PROTOCOL_BINARY_CMD_GETK:
 328     case PROTOCOL_BINARY_CMD_GETKQ:
 329       {
 330         uint16_t keylen= header.response.keylen;
 331         memcached_result_reset(result);
 332         result->cas= header.response.cas;
 333
 334         if (memcached_safe_read(ptr, &result->flags,
 335                                 sizeof (result->flags)) != MEMCACHED_SUCCESS)
 336           return MEMCACHED_UNKNOWN_READ_FAILURE;
 337
 338         result->flags= ntohl(result->flags);
 339         bodylen -= header.response.extlen;
 340
 341         result->key_length= keylen;
 342         if (memcached_safe_read(ptr, result->key, keylen) != MEMCACHED_SUCCESS)
 343           return MEMCACHED_UNKNOWN_READ_FAILURE;
 344
 345         bodylen -= keylen;
 346         if (memcached_string_check(&result->value,
 347                                    bodylen) != MEMCACHED_SUCCESS)
 348           return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 349
 350         char *vptr= memcached_string_value(&result->value);
 351         if (memcached_safe_read(ptr, vptr, bodylen) != MEMCACHED_SUCCESS)
 352           return MEMCACHED_UNKNOWN_READ_FAILURE;
 353
 354         memcached_string_set_length(&result->value, bodylen);
 355       }
 356       break;
 357     case PROTOCOL_BINARY_CMD_INCREMENT:
 358     case PROTOCOL_BINARY_CMD_DECREMENT:
 359       {
 360         if (bodylen != sizeof(uint64_t) || buffer_length != sizeof(uint64_t))
 361           return MEMCACHED_PROTOCOL_ERROR;
 362
 363         WATCHPOINT_ASSERT(bodylen == buffer_length);
 364         uint64_t val;
 365         if (memcached_safe_read(ptr, &val, sizeof(val)) != MEMCACHED_SUCCESS)
 366           return MEMCACHED_UNKNOWN_READ_FAILURE;
 367
 368         val= ntohll(val);
 369         memcpy(buffer, &val, sizeof(val));
 370       }
 371       break;
 372     case PROTOCOL_BINARY_CMD_VERSION:
 373       {
 374         memset(buffer, 0, buffer_length);
 375         if (bodylen >= buffer_length)
 376           /* not enough space in buffer.. should not happen... */
 377           return MEMCACHED_UNKNOWN_READ_FAILURE;
 378         else if (memcached_safe_read(ptr, buffer, bodylen) != MEMCACHED_SUCCESS)
 379           return MEMCACHED_UNKNOWN_READ_FAILURE;
 380       }
 381       break;
 382     case PROTOCOL_BINARY_CMD_FLUSH:
 383     case PROTOCOL_BINARY_CMD_QUIT:
 384     case PROTOCOL_BINARY_CMD_SET:
 385     case PROTOCOL_BINARY_CMD_ADD:
 386     case PROTOCOL_BINARY_CMD_REPLACE:
 387     case PROTOCOL_BINARY_CMD_APPEND:
 388     case PROTOCOL_BINARY_CMD_PREPEND:
 389     case PROTOCOL_BINARY_CMD_DELETE:
 390       {
 391         WATCHPOINT_ASSERT(bodylen == 0);
 392         return MEMCACHED_SUCCESS;
 393       }
 394       break;
 395     case PROTOCOL_BINARY_CMD_NOOP:
 396       {
 397         WATCHPOINT_ASSERT(bodylen == 0);
 398         return MEMCACHED_END;
 399       }
 400       break;
 401     case PROTOCOL_BINARY_CMD_STAT:
 402       {
 403         if (bodylen == 0)
 404           return MEMCACHED_END;
 405         else if (bodylen + 1 > buffer_length)
 406           /* not enough space in buffer.. should not happen... */
 407           return MEMCACHED_UNKNOWN_READ_FAILURE;
 408         else
 409         {
 410           size_t keylen= header.response.keylen;
 411           memset(buffer, 0, buffer_length);
 412           if (memcached_safe_read(ptr, buffer, keylen) != MEMCACHED_SUCCESS ||
 413               memcached_safe_read(ptr, buffer + keylen + 1,
 414                                   bodylen - keylen) != MEMCACHED_SUCCESS)
 415             return MEMCACHED_UNKNOWN_READ_FAILURE;
 416         }
 417       }
 418       break;
 419     default:
 420       {
 421         /* Command not implemented yet! */
 422         WATCHPOINT_ASSERT(0);
 423         return MEMCACHED_PROTOCOL_ERROR;
 424       }
 425     }
 426   }
 427   else if (header.response.bodylen)
 428   {
 429      /* What should I do with the error message??? just discard it for now */
 430     char hole[SMALL_STRING_LEN];
 431     while (bodylen > 0)
 432     {
 433       size_t nr= (bodylen > SMALL_STRING_LEN) ? SMALL_STRING_LEN : bodylen;
 434       if (memcached_safe_read(ptr, hole, nr) != MEMCACHED_SUCCESS)
 435         return MEMCACHED_UNKNOWN_READ_FAILURE;
 436       bodylen -= nr;
 437     }
 438
 439     /* This might be an error from one of the quiet commands.. if
 440      * so, just throw it away and get the next one. What about creating
 441      * a callback to the user with the error information?
 442      */
 443     switch (header.response.opcode)
 444     {
 445     case PROTOCOL_BINARY_CMD_SETQ:
 446     case PROTOCOL_BINARY_CMD_ADDQ:
 447     case PROTOCOL_BINARY_CMD_REPLACEQ:
 448     case PROTOCOL_BINARY_CMD_APPENDQ:
 449     case PROTOCOL_BINARY_CMD_PREPENDQ:
 450       return binary_read_one_response(ptr, buffer, buffer_length, result);
 451     default:
 452       break;
 453     }
 454   }
 455
 456   memcached_return rc= MEMCACHED_SUCCESS;
 457   unlikely(header.response.status != 0)
 458     switch (header.response.status)
 459     {
 460     case PROTOCOL_BINARY_RESPONSE_KEY_ENOENT:
 461       rc= MEMCACHED_NOTFOUND;
 462       break;
 463     case PROTOCOL_BINARY_RESPONSE_KEY_EEXISTS:
 464       rc= MEMCACHED_DATA_EXISTS;
 465       break;
 466     case PROTOCOL_BINARY_RESPONSE_E2BIG:
 467     case PROTOCOL_BINARY_RESPONSE_EINVAL:
 468     case PROTOCOL_BINARY_RESPONSE_NOT_STORED:
 469     case PROTOCOL_BINARY_RESPONSE_UNKNOWN_COMMAND:
 470     case PROTOCOL_BINARY_RESPONSE_ENOMEM:
 471     default:
 472       /* @todo fix the error mappings */
 473       rc= MEMCACHED_PROTOCOL_ERROR;
 474       break;
 475     }
 476
 477   return rc;
 478 }