git.m6w6.name Git - m6w6/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   WATCHPOINT_ASSERT(dummy_length == 0);
  47
  48   return value;
  49 }
  50
  51 memcached_return memcached_mget(memcached_st *ptr,
  52                                 char **keys, size_t *key_length,
  53                                 unsigned int number_of_keys)
  54 {
  55   return memcached_mget_by_key(ptr, NULL, 0, keys, key_length, number_of_keys);
  56 }
  57
  58 memcached_return memcached_mget_by_key(memcached_st *ptr,
  59                                        char *master_key, size_t master_key_length,
  60                                        char **keys, size_t *key_length,
  61                                        unsigned int number_of_keys)
  62 {
  63   unsigned int x;
  64   memcached_return rc= MEMCACHED_NOTFOUND;
  65   char *get_command= "get ";
  66   uint8_t get_command_length= 4;
  67   unsigned int master_server_key= 0;
  68
  69   LIBMEMCACHED_MEMCACHED_MGET_START();
  70   ptr->cursor_server= 0;
  71
  72   if (number_of_keys == 0)
  73     return MEMCACHED_NOTFOUND;
  74
  75   if (ptr->number_of_hosts == 0)
  76     return MEMCACHED_NO_SERVERS;
  77
  78   if (ptr->flags & MEM_SUPPORT_CAS)
  79   {
  80     get_command= "gets ";
  81     get_command_length= 5;
  82   }
  83
  84   if (master_key && master_key_length)
  85     master_server_key= memcached_generate_hash(ptr, master_key, master_key_length);
  86
  87   /*
  88     Here is where we pay for the non-block API. We need to remove any data sitting
  89     in the queue before we start our get.
  90
  91     It might be optimum to bounce the connection if count > some number.
  92   */
  93   for (x= 0; x < ptr->number_of_hosts; x++)
  94   {
  95     if (memcached_server_response_count(&ptr->hosts[x]))
  96     {
  97       char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
  98
  99       if (ptr->flags & MEM_NO_BLOCK)
 100         (void)memcached_io_write(&ptr->hosts[x], NULL, 0, 1);
 101
 102       while(memcached_server_response_count(&ptr->hosts[x]))
 103         (void)memcached_response(&ptr->hosts[x], buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, &ptr->result);
 104     }
 105   }
 106
 107   /*
 108     If a server fails we warn about errors and start all over with sending keys
 109     to the server.
 110   */
 111   for (x= 0; x < number_of_keys; x++)
 112   {
 113     unsigned int server_key;
 114
 115     if (master_server_key)
 116       server_key= master_server_key;
 117     else
 118       server_key= memcached_generate_hash(ptr, keys[x], key_length[x]);
 119
 120     if (memcached_server_response_count(&ptr->hosts[server_key]) == 0)
 121     {
 122       rc= memcached_connect(&ptr->hosts[server_key]);
 123
 124       if (rc != MEMCACHED_SUCCESS)
 125         continue;
 126
 127       if ((memcached_io_write(&ptr->hosts[server_key], get_command, get_command_length, 0)) == -1)
 128       {
 129         rc= MEMCACHED_SOME_ERRORS;
 130         continue;
 131       }
 132       WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 0);
 133       memcached_server_response_increment(&ptr->hosts[server_key]);
 134       WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 1);
 135     }
 136
 137     if ((memcached_io_write(&ptr->hosts[server_key], keys[x], key_length[x], 0)) == -1)
 138     {
 139       memcached_server_response_reset(&ptr->hosts[server_key]);
 140       rc= MEMCACHED_SOME_ERRORS;
 141       continue;
 142     }
 143
 144     if ((memcached_io_write(&ptr->hosts[server_key], " ", 1, 0)) == -1)
 145     {
 146       memcached_server_response_reset(&ptr->hosts[server_key]);
 147       rc= MEMCACHED_SOME_ERRORS;
 148       continue;
 149     }
 150   }
 151
 152   /*
 153     Should we muddle on if some servers are dead?
 154   */
 155   for (x= 0; x < ptr->number_of_hosts; x++)
 156   {
 157     if (memcached_server_response_count(&ptr->hosts[x]))
 158     {
 159       /* We need to do something about non-connnected hosts in the future */
 160       if ((memcached_io_write(&ptr->hosts[x], "\r\n", 2, 1)) == -1)
 161       {
 162         rc= MEMCACHED_SOME_ERRORS;
 163       }
 164     }
 165   }
 166
 167   LIBMEMCACHED_MEMCACHED_MGET_END();
 168   return rc;
 169 }