formats/registry.c

   1 /*
   2  * BabelTrace
   3  *
   4  * Format Registry
   5  *
   6  * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  */
  18
  19 #include <babeltrace/format.h>
  20 #include <glib.h>
  21 #include <errno.h>
  22 #include <stdio.h>
  23
  24 static int init_done;
  25 void __attribute__((constructor)) format_init(void);
  26 void __attribute__((destructor)) format_finalize(void);
  27
  28 /*
  29  * Format registry hash table contains the registered formats. Format
  30  * registration is typically performed by a format plugin.
  31  * TODO: support plugin unload (unregistration of formats).
  32  */
  33 GHashTable *format_registry;
  34
  35 struct format *bt_lookup_format(GQuark qname)
  36 {
  37         if (!init_done)
  38                 return NULL;
  39         return g_hash_table_lookup(format_registry,
  40                                    (gconstpointer) (unsigned long) qname);
  41 }
  42
  43 static void show_format(gpointer key, gpointer value, gpointer user_data)
  44 {
  45         FILE *fp = user_data;
  46
  47         fprintf(fp, "format: %s\n",
  48                 g_quark_to_string((GQuark) (unsigned long) key));
  49 }
  50
  51 void bt_fprintf_format_list(FILE *fp)
  52 {
  53         fprintf(fp, "Formats available:\n");
  54         if (!init_done)
  55                 return;
  56         g_hash_table_foreach(format_registry, show_format, fp);
  57         fprintf(fp, "End of formats available.\n");
  58 }
  59
  60 int bt_register_format(struct format *format)
  61 {
  62         if (!init_done)
  63                 format_init();
  64
  65         if (bt_lookup_format(format->name))
  66                 return -EEXIST;
  67
  68         g_hash_table_insert(format_registry,
  69                             (gpointer) (unsigned long) format->name,
  70                             format);
  71         return 0;
  72 }
  73
  74 void format_init(void)
  75 {
  76         if (init_done)
  77                 return;
  78         format_registry = g_hash_table_new(g_direct_hash, g_direct_equal);
  79         assert(format_registry);
  80         init_done = 1;
  81 }
  82
  83 void format_finalize(void)
  84 {
  85         g_hash_table_destroy(format_registry);
  86 }