git.m6w6.name Git - m6w6/libmemcached/blob - lib/memcached_get.c

   1 #include <memcached.h>
   2
   3 char *memcached_get(memcached_st *ptr, char *key, size_t key_length,
   4                     size_t *value_length,
   5                     uint16_t *flags,
   6                     memcached_return *error)
   7 {
   8   size_t send_length, sent_length;
   9   char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
  10   char *string_ptr;
  11   unsigned int server_key;
  12
  13   *value_length= 0;
  14   *error= memcached_connect(ptr);
  15
  16   if (*error != MEMCACHED_SUCCESS)
  17     return NULL;
  18
  19   server_key= memcached_generate_hash(key, key_length) % ptr->number_of_hosts;
  20
  21   send_length= snprintf(buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, "get %.*s\r\n",
  22                         (int)key_length, key);
  23
  24   if (send_length >= MEMCACHED_DEFAULT_COMMAND_SIZE)
  25     return MEMCACHED_WRITE_FAILURE;
  26
  27   if ((sent_length = write(ptr->hosts[server_key].fd, buffer, send_length) == -1))
  28   {
  29     *error= MEMCACHED_WRITE_FAILURE;
  30     return NULL;
  31   }
  32   if (sent_length != send_length) {
  33     *error= MEMCACHED_WRITE_FAILURE;
  34     return NULL;
  35   }
  36
  37   memset(buffer, 0, MEMCACHED_DEFAULT_COMMAND_SIZE);
  38   *error= memcached_response(ptr, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, server_key);
  39
  40   if (*error == MEMCACHED_SUCCESS)
  41   {
  42     char *end_ptr;
  43
  44     string_ptr= buffer;
  45     string_ptr+= 6; /* "VALUE " */
  46
  47     /* We do nothing with the key, since we only asked for one key */
  48     for (end_ptr= string_ptr; *end_ptr != ' '; end_ptr++);
  49
  50     /* Flags fetch */
  51     string_ptr= end_ptr + 1;
  52     for (end_ptr= string_ptr; *end_ptr != ' '; end_ptr++);
  53     *flags= (uint16_t)strtol(string_ptr, &end_ptr, 10);
  54
  55     /* Length fetch */
  56     string_ptr= end_ptr + 1;
  57     for (end_ptr= string_ptr; *end_ptr != ' '; end_ptr++);
  58     *value_length= strtoll(string_ptr, &end_ptr, 10);
  59
  60     /* Skip past the \r\n */
  61     string_ptr= end_ptr +2;
  62
  63     if (*value_length)
  64     {
  65       size_t need_to_copy;
  66       char *pos_ptr;
  67       char *value;
  68
  69       value= (char *)malloc(*value_length * sizeof(char));
  70
  71       if (!value)
  72       {
  73         *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
  74         return NULL;
  75       }
  76
  77       need_to_copy= (*value_length < (size_t)(buffer-string_ptr))
  78         ? *value_length
  79         : (size_t)(buffer-string_ptr) ;
  80
  81       pos_ptr= memcpy(value, string_ptr, need_to_copy);
  82
  83       if ( need_to_copy > *value_length)
  84       {
  85         size_t read_length;
  86         size_t need_to_read;
  87
  88         need_to_read= *value_length - need_to_copy;
  89
  90         read_length= read(ptr->hosts[server_key].fd, pos_ptr, need_to_read);
  91         if (read_length != need_to_read)
  92         {
  93           free(value);
  94           *error= MEMCACHED_PARTIAL_READ;
  95
  96           return NULL;
  97         }
  98       }
  99
 100       return value;
 101     }
 102   }
 103
 104   return NULL;
 105 }