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

   1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   2  *
   3  *  Libmemcached library
   4  *
   5  *  Copyright (C) 2011 Data Differential, http://datadifferential.com/
   6  *
   7  *  Redistribution and use in source and binary forms, with or without
   8  *  modification, are permitted provided that the following conditions are
   9  *  met:
  10  *
  11  *      * Redistributions of source code must retain the above copyright
  12  *  notice, this list of conditions and the following disclaimer.
  13  *
  14  *      * Redistributions in binary form must reproduce the above
  15  *  copyright notice, this list of conditions and the following disclaimer
  16  *  in the documentation and/or other materials provided with the
  17  *  distribution.
  18  *
  19  *      * The names of its contributors may not be used to endorse or
  20  *  promote products derived from this software without specific prior
  21  *  written permission.
  22  *
  23  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  26  *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  27  *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  28  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  29  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  30  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  31  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  32  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  33  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  *
  35  */
  36
  37 /*
  38   We use this to dump all keys.
  39
  40   At this point we only support a callback method. This could be optimized by first
  41   calling items and finding active slabs. For the moment though we just loop through
  42   all slabs on servers and "grab" the keys.
  43 */
  44
  45 #include <libmemcached/common.h>
  46
  47 static memcached_return_t ascii_dump(memcached_st *ptr, memcached_dump_fn *callback, void *context, uint32_t number_of_callbacks)
  48 {
  49   memcached_return_t rc= MEMCACHED_SUCCESS;
  50
  51   for (uint32_t server_key= 0; server_key < memcached_server_count(ptr); server_key++)
  52   {
  53     memcached_server_write_instance_st instance;
  54     instance= memcached_server_instance_fetch(ptr, server_key);
  55
  56     /* 256 I BELIEVE is the upper limit of slabs */
  57     for (uint32_t x= 0; x < 256; x++)
  58     {
  59       char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
  60       int buffer_length= snprintf(buffer, sizeof(buffer), "%u", x);
  61       if (buffer_length >= MEMCACHED_DEFAULT_COMMAND_SIZE or buffer_length < 0)
  62       {
  63         return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT,
  64                                    memcached_literal_param("snprintf(MEMCACHED_DEFAULT_COMMAND_SIZE)"));
  65       }
  66
  67       libmemcached_io_vector_st vector[]=
  68       {
  69         { memcached_literal_param("stats cachedump ") },
  70         { buffer, buffer_length },
  71         { memcached_literal_param(" 0 0\r\n") }
  72       };
  73
  74       rc= memcached_vdo(instance, vector, 3, true);
  75
  76       if (rc != MEMCACHED_SUCCESS)
  77       {
  78         goto error;
  79       }
  80
  81       while (1)
  82       {
  83         uint32_t callback_counter;
  84         rc= memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, NULL);
  85
  86         if (rc == MEMCACHED_ITEM)
  87         {
  88           char *string_ptr, *end_ptr;
  89
  90           string_ptr= buffer;
  91           string_ptr+= 5; /* Move past ITEM */
  92
  93           for (end_ptr= string_ptr; isgraph(*end_ptr); end_ptr++) {} ;
  94
  95           char *key= string_ptr;
  96           key[(size_t)(end_ptr-string_ptr)]= 0;
  97
  98           for (callback_counter= 0; callback_counter < number_of_callbacks; callback_counter++)
  99           {
 100             rc= (*callback[callback_counter])(ptr, key, (size_t)(end_ptr-string_ptr), context);
 101             if (rc != MEMCACHED_SUCCESS)
 102             {
 103               break;
 104             }
 105           }
 106         }
 107         else if (rc == MEMCACHED_END)
 108         {
 109           break;
 110         }
 111         else if (rc == MEMCACHED_SERVER_ERROR or rc == MEMCACHED_CLIENT_ERROR)
 112         {
 113           /* If we try to request stats cachedump for a slab class that is too big
 114            * the server will return an incorrect error message:
 115            * "MEMCACHED_SERVER_ERROR failed to allocate memory"
 116            * This isn't really a fatal error, so let's just skip it. I want to
 117            * fix the return value from the memcached server to a CLIENT_ERROR,
 118            * so let's add support for that as well right now.
 119          */
 120           rc= MEMCACHED_END;
 121           break;
 122         }
 123         else
 124         {
 125           goto error;
 126         }
 127       }
 128     }
 129   }
 130
 131 error:
 132   if (rc == MEMCACHED_END)
 133   {
 134     return MEMCACHED_SUCCESS;
 135   }
 136   else
 137   {
 138     return rc;
 139   }
 140 }
 141
 142 memcached_return_t memcached_dump(memcached_st *ptr, memcached_dump_fn *callback, void *context, uint32_t number_of_callbacks)
 143 {
 144   memcached_return_t rc;
 145   if (memcached_failed(rc= initialize_query(ptr, true)))
 146   {
 147     return rc;
 148   }
 149
 150   /*
 151     No support for Binary protocol yet
 152     @todo Fix this so that we just flush, switch to ascii, and then go back to binary.
 153   */
 154   if (ptr->flags.binary_protocol)
 155   {
 156     return MEMCACHED_FAILURE;
 157   }
 158
 159   return ascii_dump(ptr, callback, context, number_of_callbacks);
 160 }