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

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