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/*
* BabelTrace
*
* Format Registry
*
* Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
*
* Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <babeltrace/format.h>
#include <glib.h>
#include <errno.h>
#include <stdio.h>
#include <assert.h>
struct walk_data {
FILE *fp;
int iter;
};
/*
* Format registry hash table contains the registered formats. Format
* registration is typically performed by a format plugin.
*/
static GHashTable *format_registry;
static int format_refcount;
static int init_done;
static __attribute__((constructor)) void format_init(void);
static
void format_refcount_inc(void)
{
format_refcount++;
}
static
void format_cleanup(void)
{
if (format_registry)
g_hash_table_destroy(format_registry);
}
static
void format_refcount_dec(void)
{
if (!--format_refcount)
format_cleanup();
}
struct bt_format *bt_lookup_format(bt_intern_str name)
{
if (!init_done)
return NULL;
return g_hash_table_lookup(format_registry,
(gconstpointer) (unsigned long) name);
}
static void show_format(gpointer key, gpointer value, gpointer user_data)
{
struct walk_data *data = user_data;
fprintf(data->fp, "%s%s", data->iter ? ", " : "",
g_quark_to_string((GQuark) (unsigned long) key));
data->iter++;
}
void bt_fprintf_format_list(FILE *fp)
{
struct walk_data data;
assert(fp);
data.fp = fp;
data.iter = 0;
fprintf(fp, "Formats available: ");
if (!init_done)
return;
g_hash_table_foreach(format_registry, show_format, &data);
if (data.iter == 0)
fprintf(fp, "<none>");
fprintf(fp, ".\n");
}
int bt_register_format(struct bt_format *format)
{
if (!format)
return -EINVAL;
if (!init_done)
format_init();
if (bt_lookup_format(format->name))
return -EEXIST;
format_refcount_inc();
g_hash_table_insert(format_registry,
(gpointer) (unsigned long) format->name,
format);
return 0;
}
void bt_unregister_format(struct bt_format *format)
{
assert(bt_lookup_format(format->name));
g_hash_table_remove(format_registry,
(gpointer) (unsigned long) format->name);
format_refcount_dec();
}
/*
* We cannot assume that the constructor and destructor order will be
* right: another library might be loaded before us, and initialize us
* from bt_register_format(). This is why we use a reference count to
* handle cleanup of this module. The format_finalize destructor
* refcount decrement matches format_init refcount increment.
*/
static __attribute__((constructor))
void format_init(void)
{
if (init_done)
return;
format_refcount_inc();
format_registry = g_hash_table_new(g_direct_hash, g_direct_equal);
assert(format_registry);
init_done = 1;
}
static __attribute__((destructor))
void format_finalize(void)
{
format_refcount_dec();
}
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