git.m6w6.name Git - awesomized/libmemcached/blob - libmemcached/dump.cc

   1 /*
   2   We use this to dump all keys.
   3
   4   At this point we only support a callback method. This could be optimized by first
   5   calling items and finding active slabs. For the moment though we just loop through
   6   all slabs on servers and "grab" the keys.
   7 */
   8
   9 #include <libmemcached/common.h>
  10
  11 static memcached_return_t ascii_dump(memcached_st *ptr, memcached_dump_fn *callback, void *context, uint32_t number_of_callbacks)
  12 {
  13   memcached_return_t rc= MEMCACHED_SUCCESS;
  14
  15   for (uint32_t server_key= 0; server_key < memcached_server_count(ptr); server_key++)
  16   {
  17     memcached_server_write_instance_st instance;
  18     instance= memcached_server_instance_fetch(ptr, server_key);
  19
  20     /* 256 I BELIEVE is the upper limit of slabs */
  21     for (uint32_t x= 0; x < 256; x++)
  22     {
  23       char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
  24       int send_length;
  25       send_length= snprintf(buffer, MEMCACHED_DEFAULT_COMMAND_SIZE,
  26                             "stats cachedump %u 0 0\r\n", x);
  27
  28       if (send_length >= MEMCACHED_DEFAULT_COMMAND_SIZE || send_length < 0)
  29       {
  30         return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT,
  31                                    memcached_literal_param("snprintf(MEMCACHED_DEFAULT_COMMAND_SIZE)"));
  32       }
  33
  34       rc= memcached_do(instance, buffer, (size_t)send_length, true);
  35
  36       if (rc != MEMCACHED_SUCCESS)
  37       {
  38         goto error;
  39       }
  40
  41       while (1)
  42       {
  43         uint32_t callback_counter;
  44         rc= memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, NULL);
  45
  46         if (rc == MEMCACHED_ITEM)
  47         {
  48           char *string_ptr, *end_ptr;
  49
  50           string_ptr= buffer;
  51           string_ptr+= 5; /* Move past ITEM */
  52
  53           for (end_ptr= string_ptr; isgraph(*end_ptr); end_ptr++) {} ;
  54
  55           char *key= string_ptr;
  56           key[(size_t)(end_ptr-string_ptr)]= 0;
  57
  58           for (callback_counter= 0; callback_counter < number_of_callbacks; callback_counter++)
  59           {
  60             rc= (*callback[callback_counter])(ptr, key, (size_t)(end_ptr-string_ptr), context);
  61             if (rc != MEMCACHED_SUCCESS)
  62             {
  63               break;
  64             }
  65           }
  66         }
  67         else if (rc == MEMCACHED_END)
  68         {
  69           break;
  70         }
  71         else if (rc == MEMCACHED_SERVER_ERROR or rc == MEMCACHED_CLIENT_ERROR)
  72         {
  73           /* If we try to request stats cachedump for a slab class that is too big
  74            * the server will return an incorrect error message:
  75            * "MEMCACHED_SERVER_ERROR failed to allocate memory"
  76            * This isn't really a fatal error, so let's just skip it. I want to
  77            * fix the return value from the memcached server to a CLIENT_ERROR,
  78            * so let's add support for that as well right now.
  79            */
  80           rc= MEMCACHED_END;
  81           break;
  82         }
  83         else
  84         {
  85           goto error;
  86         }
  87       }
  88     }
  89   }
  90
  91 error:
  92   if (rc == MEMCACHED_END)
  93   {
  94     return MEMCACHED_SUCCESS;
  95   }
  96   else
  97   {
  98     return rc;
  99   }
 100 }
 101
 102 memcached_return_t memcached_dump(memcached_st *ptr, memcached_dump_fn *callback, void *context, uint32_t number_of_callbacks)
 103 {
 104   memcached_return_t rc;
 105   if ((rc= initialize_query(ptr)) != MEMCACHED_SUCCESS)
 106   {
 107     return rc;
 108   }
 109
 110   /*
 111     No support for Binary protocol yet
 112     @todo Fix this so that we just flush, switch to ascii, and then go back to binary.
 113   */
 114   if (ptr->flags.binary_protocol)
 115   {
 116     return MEMCACHED_FAILURE;
 117   }
 118
 119   return ascii_dump(ptr, callback, context, number_of_callbacks);
 120 }