git.m6w6.name Git - m6w6/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_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT,
  35                                    memcached_literal_param("snprintf(MEMCACHED_DEFAULT_COMMAND_SIZE)"));
  36       }
  37
  38       rc= memcached_do(instance, buffer, (size_t)send_length, true);
  39
  40       unlikely (rc != MEMCACHED_SUCCESS)
  41         goto error;
  42
  43       while (1)
  44       {
  45         uint32_t callback_counter;
  46         rc= memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, NULL);
  47
  48         if (rc == MEMCACHED_ITEM)
  49         {
  50           char *string_ptr, *end_ptr;
  51           char *key;
  52
  53           string_ptr= buffer;
  54           string_ptr+= 5; /* Move past ITEM */
  55           for (end_ptr= string_ptr; isgraph(*end_ptr); end_ptr++) {} ;
  56           key= string_ptr;
  57           key[(size_t)(end_ptr-string_ptr)]= 0;
  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               break;
  63           }
  64         }
  65         else if (rc == MEMCACHED_END)
  66           break;
  67         else if (rc == MEMCACHED_SERVER_ERROR || rc == MEMCACHED_CLIENT_ERROR)
  68         {
  69           /* If we try to request stats cachedump for a slab class that is too big
  70            * the server will return an incorrect error message:
  71            * "MEMCACHED_SERVER_ERROR failed to allocate memory"
  72            * This isn't really a fatal error, so let's just skip it. I want to
  73            * fix the return value from the memcached server to a CLIENT_ERROR,
  74            * so let's add support for that as well right now.
  75            */
  76           rc= MEMCACHED_END;
  77           break;
  78         }
  79         else
  80           goto error;
  81       }
  82     }
  83   }
  84
  85 error:
  86   if (rc == MEMCACHED_END)
  87     return MEMCACHED_SUCCESS;
  88   else
  89     return rc;
  90 }
  91
  92 memcached_return_t memcached_dump(memcached_st *ptr, memcached_dump_fn *callback, void *context, uint32_t number_of_callbacks)
  93 {
  94   memcached_return_t rc;
  95   if ((rc= initialize_query(ptr)) != MEMCACHED_SUCCESS)
  96   {
  97     return rc;
  98   }
  99
 100   /*
 101     No support for Binary protocol yet
 102     @todo Fix this so that we just flush, switch to ascii, and then go back to binary.
 103   */
 104   if (ptr->flags.binary_protocol)
 105     return MEMCACHED_FAILURE;
 106
 107   return ascii_dump(ptr, callback, context, number_of_callbacks);
 108 }