git.m6w6.name Git - awesomized/libmemcached/blob - lib/memcached_get.c

   1 #include "common.h"
   2 #include "memcached_io.h"
   3
   4 /*
   5   What happens if no servers exist?
   6 */
   7 char *memcached_get(memcached_st *ptr, char *key, size_t key_length,
   8                     size_t *value_length,
   9                     uint32_t *flags,
  10                     memcached_return *error)
  11 {
  12   return memcached_get_by_key(ptr, NULL, 0, key, key_length, value_length,
  13                               flags, error);
  14 }
  15
  16 char *memcached_get_by_key(memcached_st *ptr,
  17                            char *master_key, size_t master_key_length,
  18                            char *key, size_t key_length,
  19                            size_t *value_length,
  20                            uint32_t *flags,
  21                            memcached_return *error)
  22 {
  23   char *value;
  24   size_t dummy_length;
  25   uint32_t dummy_flags;
  26   memcached_return dummy_error;
  27
  28   /* Request the key */
  29   *error= memcached_mget_by_key(ptr,
  30                                 master_key,
  31                                 master_key_length,
  32                                 &key, &key_length, 1);
  33
  34   value= memcached_fetch(ptr, NULL, NULL,
  35                          value_length, flags, error);
  36   /* This is for historical reasons */
  37   if (*error == MEMCACHED_END)
  38     *error= MEMCACHED_NOTFOUND;
  39
  40   if (value == NULL)
  41     return NULL;
  42
  43   (void)memcached_fetch(ptr, NULL, NULL,
  44                         &dummy_length, &dummy_flags,
  45                         &dummy_error);
  46
  47   return value;
  48 }
  49
  50 memcached_return memcached_mget(memcached_st *ptr,
  51                                 char **keys, size_t *key_length,
  52                                 unsigned int number_of_keys)
  53 {
  54   return memcached_mget_by_key(ptr, NULL, 0, keys, key_length, number_of_keys);
  55 }
  56
  57 memcached_return memcached_mget_by_key(memcached_st *ptr,
  58                                        char *master_key, size_t master_key_length,
  59                                        char **keys, size_t *key_length,
  60                                        unsigned int number_of_keys)
  61 {
  62   unsigned int x;
  63   memcached_return rc= MEMCACHED_NOTFOUND;
  64   char *get_command= "get ";
  65   uint8_t get_command_length= 4;
  66   unsigned int master_server_key= 0;
  67
  68   LIBMEMCACHED_MEMCACHED_MGET_START();
  69   ptr->cursor_server= 0;
  70
  71   if (number_of_keys == 0)
  72     return MEMCACHED_NOTFOUND;
  73
  74   if (ptr->number_of_hosts == 0)
  75     return MEMCACHED_NO_SERVERS;
  76
  77   if (ptr->flags & MEM_SUPPORT_CAS)
  78   {
  79     get_command= "gets ";
  80     get_command_length= 5;
  81   }
  82
  83   if (master_key && master_key_length)
  84     master_server_key= memcached_generate_hash(ptr, master_key, master_key_length);
  85
  86   /*
  87     Here is where we pay for the non-block API. We need to remove any data sitting
  88     in the queue before we start our get.
  89
  90     It might be optimum to bounce the connection if count > some number.
  91   */
  92   for (x= 0; x < ptr->number_of_hosts; x++)
  93   {
  94     if (memcached_server_response_count(ptr, x))
  95     {
  96       char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
  97
  98       if (ptr->flags & MEM_NO_BLOCK)
  99         (void)memcached_io_write(ptr, x, NULL, 0, 1);
 100
 101       while(memcached_server_response_count(ptr, x))
 102         (void)memcached_response(ptr, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, &ptr->result, x);
 103     }
 104   }
 105
 106   /*
 107     If a server fails we warn about errors and start all over with sending keys
 108     to the server.
 109   */
 110   for (x= 0; x < number_of_keys; x++)
 111   {
 112     unsigned int server_key;
 113
 114     if (master_server_key)
 115       server_key= master_server_key;
 116     else
 117       server_key= memcached_generate_hash(ptr, keys[x], key_length[x]);
 118
 119     if (memcached_server_response_count(ptr, server_key) == 0)
 120     {
 121       rc= memcached_connect(ptr, server_key);
 122
 123       if ((memcached_io_write(ptr, server_key, get_command, get_command_length, 0)) == -1)
 124       {
 125         rc= MEMCACHED_SOME_ERRORS;
 126         continue;
 127       }
 128       WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 0);
 129       memcached_server_response_increment(ptr, server_key);
 130       WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 1);
 131     }
 132
 133     if ((memcached_io_write(ptr, server_key, keys[x], key_length[x], 0)) == -1)
 134     {
 135       memcached_server_response_reset(ptr, server_key);
 136       rc= MEMCACHED_SOME_ERRORS;
 137       continue;
 138     }
 139
 140     if ((memcached_io_write(ptr, server_key, " ", 1, 0)) == -1)
 141     {
 142       memcached_server_response_reset(ptr, server_key);
 143       rc= MEMCACHED_SOME_ERRORS;
 144       continue;
 145     }
 146   }
 147
 148   /*
 149     Should we muddle on if some servers are dead?
 150   */
 151   for (x= 0; x < ptr->number_of_hosts; x++)
 152   {
 153     if (memcached_server_response_count(ptr, x))
 154     {
 155       /* We need to do something about non-connnected hosts in the future */
 156       if ((memcached_io_write(ptr, x, "\r\n", 2, 1)) == -1)
 157       {
 158         rc= MEMCACHED_SOME_ERRORS;
 159       }
 160     }
 161   }
 162
 163   LIBMEMCACHED_MEMCACHED_MGET_END();
 164   return rc;
 165 }