formats/registry.c

   1 /*
   2  * BabelTrace
   3  *
   4  * Format Registry
   5  *
   6  * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
   7  *
   8  * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  */
  20
  21 #include <babeltrace/format.h>
  22 #include <glib.h>
  23 #include <errno.h>
  24 #include <stdio.h>
  25
  26 struct walk_data {
  27         FILE *fp;
  28         int iter;
  29 };
  30
  31 static int init_done;
  32 void __attribute__((constructor)) format_init(void);
  33 void __attribute__((destructor)) format_finalize(void);
  34
  35 /*
  36  * Format registry hash table contains the registered formats. Format
  37  * registration is typically performed by a format plugin.
  38  * TODO: support plugin unload (unregistration of formats).
  39  */
  40 GHashTable *format_registry;
  41
  42 struct format *bt_lookup_format(GQuark qname)
  43 {
  44         if (!init_done)
  45                 return NULL;
  46         return g_hash_table_lookup(format_registry,
  47                                    (gconstpointer) (unsigned long) qname);
  48 }
  49
  50 static void show_format(gpointer key, gpointer value, gpointer user_data)
  51 {
  52         struct walk_data *data = user_data;
  53
  54         fprintf(data->fp, "%s%s", data->iter ? ", " : "",
  55                 g_quark_to_string((GQuark) (unsigned long) key));
  56         data->iter++;
  57 }
  58
  59 void bt_fprintf_format_list(FILE *fp)
  60 {
  61         struct walk_data data;
  62
  63         data.fp = fp;
  64         data.iter = 0;
  65
  66         fprintf(fp, "Formats available: ");
  67         if (!init_done)
  68                 return;
  69         g_hash_table_foreach(format_registry, show_format, &data);
  70         if (data.iter == 0)
  71                 fprintf(fp, "<none>");
  72         fprintf(fp, ".\n");
  73 }
  74
  75 int bt_register_format(struct format *format)
  76 {
  77         if (!init_done)
  78                 format_init();
  79
  80         if (bt_lookup_format(format->name))
  81                 return -EEXIST;
  82
  83         g_hash_table_insert(format_registry,
  84                             (gpointer) (unsigned long) format->name,
  85                             format);
  86         return 0;
  87 }
  88
  89 void format_init(void)
  90 {
  91         if (init_done)
  92                 return;
  93         format_registry = g_hash_table_new(g_direct_hash, g_direct_equal);
  94         assert(format_registry);
  95         init_done = 1;
  96 }
  97
  98 void format_finalize(void)
  99 {
 100         g_hash_table_destroy(format_registry);
 101 }