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 (rc != MEMCACHED_SUCCESS)
 124         continue;
 125
 126       if ((memcached_io_write(ptr, server_key, get_command, get_command_length, 0)) == -1)
 127       {
 128         rc= MEMCACHED_SOME_ERRORS;
 129         continue;
 130       }
 131       WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 0);
 132       memcached_server_response_increment(ptr, server_key);
 133       WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 1);
 134     }
 135
 136     if ((memcached_io_write(ptr, server_key, keys[x], key_length[x], 0)) == -1)
 137     {
 138       memcached_server_response_reset(ptr, server_key);
 139       rc= MEMCACHED_SOME_ERRORS;
 140       continue;
 141     }
 142
 143     if ((memcached_io_write(ptr, server_key, " ", 1, 0)) == -1)
 144     {
 145       memcached_server_response_reset(ptr, server_key);
 146       rc= MEMCACHED_SOME_ERRORS;
 147       continue;
 148     }
 149   }
 150
 151   /*
 152     Should we muddle on if some servers are dead?
 153   */
 154   for (x= 0; x < ptr->number_of_hosts; x++)
 155   {
 156     if (memcached_server_response_count(ptr, x))
 157     {
 158       /* We need to do something about non-connnected hosts in the future */
 159       if ((memcached_io_write(ptr, x, "\r\n", 2, 1)) == -1)
 160       {
 161         rc= MEMCACHED_SOME_ERRORS;
 162       }
 163     }
 164   }
 165
 166   LIBMEMCACHED_MEMCACHED_MGET_END();
 167   return rc;
 168 }