/eet-1.4.1/src/examples/eet-data-file_descriptor.c

#include <Eina.h>
#include <Eet.h>
#include <stdio.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

// complex real-world structures based on elmdentica database
typedef struct
{
   const char * screen_name;
   const char * name;
   const char * message;
   unsigned int id;
   unsigned int status_id;
   unsigned int date;
   unsigned int timeline;
} My_Message;

typedef struct
{
   const char * dm_to;
   const char * message;
} My_Post;

typedef struct
{
   unsigned int id;
   const char * name;
   Eina_List *  messages;
   Eina_List *  posts;
} My_Account;

typedef struct
{
   unsigned int version; // it is recommended to use versioned configuration!
   Eina_List *  accounts;
} My_Cache;

// string that represents the entry in eet file, you might like to have
// different profiles or so in the same file, this is possible with
// different strings
static const char MY_CACHE_FILE_ENTRY[] = "cache";

// keep the descriptor static global, so it can be
// shared by different functions (load/save) of this and only this
// file.
static Eet_Data_Descriptor * _my_cache_descriptor;
static Eet_Data_Descriptor * _my_account_descriptor;
static Eet_Data_Descriptor * _my_message_descriptor;
static Eet_Data_Descriptor * _my_post_descriptor;

// keep file handle alive, so mmap()ed strings are all alive as well
static Eet_File * _my_cache_file = NULL;
static Eet_Dictionary * _my_cache_dict = NULL;

static void
_my_cache_descriptor_init(void)
{
   Eet_Data_Descriptor_Class eddc;

   // The FILE variant is good for caches and things that are just
   // appended, but needs to take care when changing strings and files must
   // be kept open so mmap()ed strings will be kept alive.
   EET_EINA_FILE_DATA_DESCRIPTOR_CLASS_SET(&eddc, My_Cache);
   _my_cache_descriptor = eet_data_descriptor_file_new(&eddc);

   EET_EINA_FILE_DATA_DESCRIPTOR_CLASS_SET(&eddc, My_Account);
   _my_account_descriptor = eet_data_descriptor_file_new(&eddc);

   EET_EINA_FILE_DATA_DESCRIPTOR_CLASS_SET(&eddc, My_Message);
   _my_message_descriptor = eet_data_descriptor_file_new(&eddc);

   EET_EINA_FILE_DATA_DESCRIPTOR_CLASS_SET(&eddc, My_Post);
   _my_post_descriptor = eet_data_descriptor_file_new(&eddc);

   // Describe the members to be saved:
   // Use a temporary macro so we don't type a lot, also avoid errors:

#define ADD_BASIC(member, eet_type)\
   EET_DATA_DESCRIPTOR_ADD_BASIC\
      (_my_message_descriptor, My_Message, # member, member, eet_type)
   ADD_BASIC(screen_name, EET_T_STRING);
   ADD_BASIC(name,        EET_T_STRING);
   ADD_BASIC(message,     EET_T_STRING);
   ADD_BASIC(id,          EET_T_UINT);
   ADD_BASIC(status_id,   EET_T_UINT);
   ADD_BASIC(date,        EET_T_UINT);
   ADD_BASIC(timeline,    EET_T_UINT);
#undef ADD_BASIC

#define ADD_BASIC(member, eet_type)\
   EET_DATA_DESCRIPTOR_ADD_BASIC\
      (_my_post_descriptor, My_Post, # member, member, eet_type)
   ADD_BASIC(dm_to,   EET_T_STRING);
   ADD_BASIC(message, EET_T_STRING);
#undef ADD_BASIC

#define ADD_BASIC(member, eet_type)\
   EET_DATA_DESCRIPTOR_ADD_BASIC\
      (_my_account_descriptor, My_Account, # member, member, eet_type)
   ADD_BASIC(name, EET_T_STRING);
   ADD_BASIC(id,   EET_T_UINT);
#undef ADD_BASIC

   EET_DATA_DESCRIPTOR_ADD_LIST
      (_my_account_descriptor, My_Account, "messages", messages,
      _my_message_descriptor);
   EET_DATA_DESCRIPTOR_ADD_LIST
      (_my_account_descriptor, My_Account, "posts",    posts,
      _my_post_descriptor);

#define ADD_BASIC(member, eet_type)\
   EET_DATA_DESCRIPTOR_ADD_BASIC\
      (_my_cache_descriptor, My_Cache, # member, member, eet_type)
   ADD_BASIC(version, EET_T_UINT);
#undef ADD_BASIC

   EET_DATA_DESCRIPTOR_ADD_LIST
      (_my_cache_descriptor, My_Cache, "accounts", accounts,
      _my_account_descriptor);
} /* _my_cache_descriptor_init */

static void
_my_cache_descriptor_shutdown(void)
{
   eet_data_descriptor_free(_my_cache_descriptor);
   eet_data_descriptor_free(_my_account_descriptor);
   eet_data_descriptor_free(_my_message_descriptor);
   eet_data_descriptor_free(_my_post_descriptor);
} /* _my_cache_descriptor_shutdown */

// need to check if the pointer came from mmaped area in eet_dictionary
// or it was allocated with eina_stringshare_add()
static void
_eet_string_free(const char * str)
{
   if (!str)
      return;

   if ((_my_cache_dict) && (eet_dictionary_string_check(_my_cache_dict, str)))
      return;

   eina_stringshare_del(str);
} /* _eet_string_free */

static My_Message *
_my_message_new(const char * message)
{
   My_Message * msg = calloc(1, sizeof(My_Message));
   if (!msg)
     {
        fprintf(stderr, "ERROR: could not calloc My_Message\n");
        return NULL;
     }

   msg->message = eina_stringshare_add(message);
   return msg;
} /* _my_message_new */

static void
_my_message_free(My_Message * msg)
{
   _eet_string_free(msg->screen_name);
   _eet_string_free(msg->name);
   _eet_string_free(msg->message);
   free(msg);
} /* _my_message_free */

static My_Post *
_my_post_new(const char * message)
{
   My_Post * post = calloc(1, sizeof(My_Post));
   if (!post)
     {
        fprintf(stderr, "ERROR: could not calloc My_Post\n");
        return NULL;
     }

   post->message = eina_stringshare_add(message);
   return post;
} /* _my_post_new */

static void
_my_post_free(My_Post * post)
{
   _eet_string_free(post->dm_to);
   _eet_string_free(post->message);
   free(post);
} /* _my_post_free */

static My_Account *
_my_account_new(const char * name)
{
   My_Account * acc = calloc(1, sizeof(My_Account));
   if (!acc)
     {
        fprintf(stderr, "ERROR: could not calloc My_Account\n");
        return NULL;
     }

   acc->name = eina_stringshare_add(name);
   return acc;
} /* _my_account_new */

static void
_my_account_free(My_Account * acc)
{
   My_Message * m;
   My_Post * p;

   _eet_string_free(acc->name);

   EINA_LIST_FREE(acc->messages, m)
   _my_message_free(m);

   EINA_LIST_FREE(acc->posts, p)
   _my_post_free(p);

   free(acc);
} /* _my_account_free */

static My_Cache *
_my_cache_new(void)
{
   My_Cache * my_cache = calloc(1, sizeof(My_Cache));
   if (!my_cache)
     {
        fprintf(stderr, "ERROR: could not calloc My_Cache\n");
        return NULL;
     }

   my_cache->version = 1;
   return my_cache;
} /* _my_cache_new */

static void
_my_cache_free(My_Cache * my_cache)
{
   My_Account * acc;
   EINA_LIST_FREE(my_cache->accounts, acc)
   _my_account_free(acc);
   free(my_cache);
} /* _my_cache_free */

static My_Account *
_my_cache_account_find(My_Cache * my_cache, const char * name)
{
   My_Account * acc;
   Eina_List * l;
   EINA_LIST_FOREACH(my_cache->accounts, l, acc)
   if (strcmp(acc->name, name) == 0)
      return acc;

   return NULL;
} /* _my_cache_account_find */

static My_Cache *
_my_cache_load(const char * filename)
{
   My_Cache * my_cache;
   Eet_File * ef = eet_open(filename, EET_FILE_MODE_READ);
   if (!ef)
     {
        fprintf(stderr, "ERROR: could not open '%s' for read\n", filename);
        return NULL;
     }

   my_cache = eet_data_read(ef, _my_cache_descriptor, MY_CACHE_FILE_ENTRY);
   if (!my_cache)
     {
        eet_close(ef);
        return NULL;
     }

   if (my_cache->version < 1)
     {
        fprintf(stderr,
                "WARNING: version %#x was too old, upgrading it to %#x\n",
                my_cache->version, 1);

        my_cache->version = 1;
     }

   if (_my_cache_file)
      eet_close(_my_cache_file);

   _my_cache_file = ef;
   _my_cache_dict = eet_dictionary_get(ef);

   return my_cache;
} /* _my_cache_load */

static Eina_Bool
_my_cache_save(const My_Cache * my_cache, const char * filename)
{
   char tmp[PATH_MAX];
   Eet_File * ef;
   Eina_Bool ret;
   unsigned int i, len;
   struct stat st;

   len = eina_strlcpy(tmp, filename, sizeof(tmp));
   if (len + 12 >= (int)sizeof(tmp))
     {
        fprintf(stderr, "ERROR: file name is too big: %s\n", filename);
        return EINA_FALSE;
     }

   i = 0;
   do
     {
        snprintf(tmp + len, 12, ".%u", i);
        i++;
     }
   while (stat(tmp, &st) == 0);

   ef = eet_open(tmp, EET_FILE_MODE_WRITE);
   if (!ef)
     {
        fprintf(stderr, "ERROR: could not open '%s' for write\n", tmp);
        return EINA_FALSE;
     }

   ret = eet_data_write
         (ef, _my_cache_descriptor, MY_CACHE_FILE_ENTRY, my_cache, EINA_TRUE);

   // VERY IMPORTANT NOTE:
   // after eet_close(), all strings mmaped from file will be GONE, invalid!
   // you'll need to free the old cache and open the new one.
   // For cache this is okay, as you should be saving not so often or just
   // at end.
   //
   // This is a trade off, you save memory by using mmap()ed strings, but
   // you have to care about this.
   eet_close(ef);

   if (ret)
     {
        unlink(filename);
        rename(tmp, filename);
     }

   return ret;
} /* _my_cache_save */

int main(int argc, char * argv[])
{
   My_Cache * my_cache;
   const Eina_List * l_acc;
   My_Account * acc;
   int ret = 0;

   if (argc < 3)
     {
        fprintf(stderr,
                "Usage:\n\t%s <input> <output> [action] [action-params]\n\n"
                "Where actions and their parameters:\n"
                "\tacc <name>\n"
                "\tpost <account-name> <message>\n"
                "\tmessage <account-name> <message>\n"
                "\n",
                argv[0]);
        return -1;
     }

   eina_init();
   eet_init();
   _my_cache_descriptor_init();

   my_cache = _my_cache_load(argv[1]);
   if (!my_cache)
     {
        printf("creating new cache.\n");
        my_cache = _my_cache_new();
        if (!my_cache)
          {
             ret = -2;
             goto end;
          }
     }

   if (argc > 3)
     {
        if (strcmp(argv[3], "acc") == 0)
          {
             if (argc == 5)
               {
                  My_Account * acc = _my_cache_account_find(my_cache, argv[4]);
                  if (!acc)
                    {
                       acc = _my_account_new(argv[4]);
                       my_cache->accounts = eina_list_append
                             (my_cache->accounts, acc);
                    }
                  else
                     fprintf(stderr, "ERROR: account '%s' already exists.\n",
                             argv[4]);
               }
             else
                fprintf(stderr,
                        "ERROR: wrong number of parameters (%d).\n",
                        argc);
          }
        else if (strcmp(argv[3], "post") == 0)
          {
             if (argc == 6)
               {
                  My_Account * acc = _my_cache_account_find(my_cache, argv[4]);
                  if (acc)
                    {
                       My_Post * post = _my_post_new(argv[5]);
                       acc->posts = eina_list_append(acc->posts, post);
                    }
                  else
                     fprintf(stderr, "ERROR: unknown account: '%s'\n", argv[4]);
               }
             else
                fprintf(stderr,
                        "ERROR: wrong number of parameters (%d).\n",
                        argc);
          }
        else if (strcmp(argv[3], "message") == 0)
          {
             if (argc == 6)
               {
                  My_Account * acc = _my_cache_account_find(my_cache, argv[4]);
                  if (acc)
                    {
                       My_Message * msg = _my_message_new(argv[5]);
                       acc->messages = eina_list_append(acc->messages, msg);
                    }
                  else
                     fprintf(stderr, "ERROR: unknown account: '%s'\n", argv[4]);
               }
             else
                fprintf(stderr,
                        "ERROR: wrong number of parameters (%d).\n",
                        argc);
          }
        else
           fprintf(stderr, "ERROR: unknown action '%s'\n", argv[2]);
     }

   printf("My_Cache:\n"
          "\tversion.: %#x\n"
          "\taccounts: %u\n",
          my_cache->version,
          eina_list_count(my_cache->accounts));
   EINA_LIST_FOREACH(my_cache->accounts, l_acc, acc)
   {
      const My_Post * post;

      printf("\t  > %-#8x '%.20s' stats: m=%u, p=%u\n",
             acc->id, acc->name ? acc->name : "",
             eina_list_count(acc->messages),
             eina_list_count(acc->posts));

      if (eina_list_count(acc->messages))
        {
           const Eina_List * l;
           const My_Message * msg;
           printf("\t  |messages:\n");

           EINA_LIST_FOREACH(acc->messages, l, msg)
           {
              printf("\t  |   %-8x '%s' [%s]: '%.20s'\n",
                     msg->id,
                     msg->name ? msg->name : "",
                     msg->screen_name ? msg->screen_name : "",
                     msg->message ? msg->message : "");
           }
        }

      if (eina_list_count(acc->posts))
        {
           const Eina_List * l;
           const My_Post * post;
           printf("\t  |posts:\n");

           EINA_LIST_FOREACH(acc->posts, l, post)
           {
              if (post->dm_to)
                 printf("\t  |  @%s: '%.20s'\n", post->dm_to, post->message);
              else
                 printf("\t  |  '%.20s'\n",      post->message);
           }
        }

      printf("\n");
   }

   if (!_my_cache_save(my_cache, argv[2]))
      ret = -3;

   _my_cache_free(my_cache);

end:
   _my_cache_descriptor_shutdown();
   eet_shutdown();
   eina_shutdown();

   return ret;
} /* main */