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