git.m6w6.name Git - awesomized/libmemcached/blob - libmemcached/exist.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
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   9  *  met:
  10  *
  11  *      * Redistributions of source code must retain the above copyright
  12  *  notice, this list of conditions and the following disclaimer.
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  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
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  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
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  33  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  *
  35  */
  36
  37 #include <libmemcached/common.h>
  38
  39 static memcached_return_t ascii_exist(memcached_st *memc, memcached_server_write_instance_st instance, const char *key, size_t key_length)
  40 {
  41   struct libmemcached_io_vector_st vector[]=
  42   {
  43     { memcached_literal_param("add ") },
  44     { memcached_array_string(memc->_namespace), memcached_array_size(memc->_namespace) },
  45     { key, key_length },
  46     { memcached_literal_param(" 0") },
  47     { memcached_literal_param(" 2678400") },
  48     { memcached_literal_param(" 0") },
  49     { memcached_literal_param("\r\n") },
  50     { memcached_literal_param("\r\n") }
  51   };
  52
  53   /* Send command header */
  54   memcached_return_t rc=  memcached_vdo(instance, vector, 8, true);
  55   if (rc == MEMCACHED_SUCCESS)
  56   {
  57     char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
  58     rc= memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, NULL);
  59
  60     if (rc == MEMCACHED_NOTSTORED)
  61     {
  62       rc= MEMCACHED_SUCCESS;
  63     }
  64
  65     if (rc == MEMCACHED_STORED)
  66     {
  67       rc= MEMCACHED_NOTFOUND;
  68     }
  69   }
  70
  71   if (rc == MEMCACHED_WRITE_FAILURE)
  72   {
  73     memcached_io_reset(instance);
  74   }
  75
  76   return rc;
  77 }
  78
  79 static memcached_return_t binary_exist(memcached_st *memc, memcached_server_write_instance_st instance, const char *key, size_t key_length)
  80 {
  81   protocol_binary_request_set request= {};
  82   size_t send_length= sizeof(request.bytes);
  83
  84   request.message.header.request.magic= PROTOCOL_BINARY_REQ;
  85   request.message.header.request.opcode= PROTOCOL_BINARY_CMD_ADD;
  86   request.message.header.request.keylen= htons((uint16_t)(key_length + memcached_array_size(memc->_namespace)));
  87   request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
  88   request.message.header.request.extlen= 8;
  89   request.message.body.flags= 0;
  90   request.message.body.expiration= htonl(2678400);
  91
  92   request.message.header.request.bodylen= htonl((uint32_t) (key_length
  93                                                             +memcached_array_size(memc->_namespace)
  94                                                             +request.message.header.request.extlen));
  95
  96   struct libmemcached_io_vector_st vector[]=
  97   {
  98     { request.bytes, send_length },
  99     { memcached_array_string(memc->_namespace), memcached_array_size(memc->_namespace) },
 100     { key, key_length }
 101   };
 102
 103   /* write the header */
 104   memcached_return_t rc;
 105   if ((rc= memcached_vdo(instance, vector, 3, true)) != MEMCACHED_SUCCESS)
 106   {
 107     memcached_io_reset(instance);
 108     return (rc == MEMCACHED_SUCCESS) ? MEMCACHED_WRITE_FAILURE : rc;
 109   }
 110
 111   rc= memcached_response(instance, NULL, 0, NULL);
 112
 113   if (rc == MEMCACHED_SUCCESS)
 114     rc= MEMCACHED_NOTFOUND;
 115
 116   if (rc == MEMCACHED_DATA_EXISTS)
 117     rc= MEMCACHED_SUCCESS;
 118
 119   return rc;
 120 }
 121
 122 memcached_return_t memcached_exist(memcached_st *memc, const char *key, size_t key_length)
 123 {
 124   return memcached_exist_by_key(memc, key, key_length, key, key_length);
 125 }
 126
 127 memcached_return_t memcached_exist_by_key(memcached_st *memc,
 128                                           const char *group_key, size_t group_key_length,
 129                                           const char *key, size_t key_length)
 130 {
 131   memcached_return_t rc;
 132   if (memcached_failed(rc= initialize_query(memc)))
 133   {
 134     return rc;
 135   }
 136
 137   if (memc->flags.use_udp)
 138   {
 139     return MEMCACHED_NOT_SUPPORTED;
 140   }
 141
 142
 143   uint32_t server_key= memcached_generate_hash_with_redistribution(memc, group_key, group_key_length);
 144   memcached_server_write_instance_st instance;
 145   instance= memcached_server_instance_fetch(memc, server_key);
 146
 147   if (memc->flags.binary_protocol)
 148   {
 149     return binary_exist(memc, instance, key, key_length);
 150   }
 151   else
 152   {
 153     return ascii_exist(memc, instance, key, key_length);
 154   }
 155 }