git.m6w6.name Git - awesomized/libmemcached/blob - src/libmemcached/exist.cc

   1 /*
   2     +--------------------------------------------------------------------+
   3     | libmemcached-awesome - C/C++ Client Library for memcached          |
   4     +--------------------------------------------------------------------+
   5     | Redistribution and use in source and binary forms, with or without |
   6     | modification, are permitted under the terms of the BSD license.    |
   7     | You should have received a copy of the license in a bundled file   |
   8     | named LICENSE; in case you did not receive a copy you can review   |
   9     | the terms online at: https://opensource.org/licenses/BSD-3-Clause  |
  10     +--------------------------------------------------------------------+
  11     | Copyright (c) 2006-2014 Brian Aker   https://datadifferential.com/ |
  12     | Copyright (c) 2020-2021 Michael Wallner        https://awesome.co/ |
  13     +--------------------------------------------------------------------+
  14 */
  15
  16 #include "libmemcached/common.h"
  17
  18 static memcached_return_t ascii_exist(Memcached *memc, memcached_instance_st *instance,
  19                                       const char *key, size_t key_length) {
  20   libmemcached_io_vector_st vector[] = {
  21       {NULL, 0},
  22       {memcached_literal_param("add ")},
  23       {memcached_array_string(memc->_namespace), memcached_array_size(memc->_namespace)},
  24       {key, key_length},
  25       {memcached_literal_param(" 0")},
  26       {memcached_literal_param(" 2678400")},
  27       {memcached_literal_param(" 0")},
  28       {memcached_literal_param("\r\n")},
  29       {memcached_literal_param("\r\n")}};
  30
  31   /* Send command header */
  32   memcached_return_t rc;
  33   if (memcached_fatal(rc = memcached_vdo(instance, vector, 9, true))) {
  34     return rc;
  35   }
  36
  37   char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
  38   rc = memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, NULL);
  39
  40   if (rc == MEMCACHED_NOTSTORED) {
  41     rc = MEMCACHED_SUCCESS;
  42   }
  43
  44   if (rc == MEMCACHED_STORED) {
  45     rc = MEMCACHED_NOTFOUND;
  46   }
  47
  48   return rc;
  49 }
  50
  51 static memcached_return_t binary_exist(Memcached *memc, memcached_instance_st *instance,
  52                                        const char *key, size_t key_length) {
  53   protocol_binary_request_set request = {};
  54   size_t send_length = sizeof(request.bytes);
  55
  56   initialize_binary_request(instance, request.message.header);
  57
  58   request.message.header.request.opcode = PROTOCOL_BINARY_CMD_ADD;
  59   request.message.header.request.keylen =
  60       htons((uint16_t)(key_length + memcached_array_size(memc->_namespace)));
  61   request.message.header.request.datatype = PROTOCOL_BINARY_RAW_BYTES;
  62   request.message.header.request.extlen = 8;
  63   request.message.body.flags = 0;
  64   request.message.body.expiration = htonl(2678400);
  65
  66   request.message.header.request.bodylen = htonl((uint32_t)(
  67       key_length + memcached_array_size(memc->_namespace) + request.message.header.request.extlen));
  68
  69   libmemcached_io_vector_st vector[] = {
  70       {NULL, 0},
  71       {request.bytes, send_length},
  72       {memcached_array_string(memc->_namespace), memcached_array_size(memc->_namespace)},
  73       {key, key_length}};
  74
  75   /* write the header */
  76   memcached_return_t rc;
  77   if (memcached_fatal(rc = memcached_vdo(instance, vector, 4, true))) {
  78     return rc;
  79   }
  80
  81   rc = memcached_response(instance, NULL, 0, NULL);
  82
  83   if (rc == MEMCACHED_SUCCESS) {
  84     rc = MEMCACHED_NOTFOUND;
  85   }
  86
  87   if (rc == MEMCACHED_DATA_EXISTS) {
  88     rc = MEMCACHED_SUCCESS;
  89   }
  90
  91   return rc;
  92 }
  93
  94 memcached_return_t memcached_exist(memcached_st *memc, const char *key, size_t key_length) {
  95   return memcached_exist_by_key(memc, key, key_length, key, key_length);
  96 }
  97
  98 memcached_return_t memcached_exist_by_key(memcached_st *shell, const char *group_key,
  99                                           size_t group_key_length, const char *key,
 100                                           size_t key_length) {
 101   Memcached *memc = memcached2Memcached(shell);
 102   memcached_return_t rc;
 103   if (memcached_failed(rc = initialize_query(memc, true))) {
 104     return rc;
 105   }
 106
 107   if (memcached_is_udp(memc)) {
 108     return memcached_set_error(*memc, MEMCACHED_NOT_SUPPORTED, MEMCACHED_AT);
 109   }
 110
 111   uint32_t server_key =
 112       memcached_generate_hash_with_redistribution(memc, group_key, group_key_length);
 113   memcached_instance_st *instance = memcached_instance_fetch(memc, server_key);
 114
 115   if (memcached_is_binary(memc)) {
 116     rc = binary_exist(memc, instance, key, key_length);
 117   } else {
 118     rc = ascii_exist(memc, instance, key, key_length);
 119   }
 120
 121   return rc;
 122 }