Fix: Make sure we have all the metadata streams before adding new traces
[babeltrace.git] / lib / registry.c
CommitLineData
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1/*
2 * BabelTrace
3 *
4 * Format Registry
5 *
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6 * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
7 *
8 * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
fc93b2bd 9 *
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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:
fc93b2bd 16 *
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17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
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19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
23 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
26 * SOFTWARE.
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27 */
28
4c8bfb7e 29#include <babeltrace/format.h>
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30#include <glib.h>
31#include <errno.h>
7fb21036 32#include <stdio.h>
3122e6f0 33#include <assert.h>
fc93b2bd 34
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35struct walk_data {
36 FILE *fp;
37 int iter;
38};
39
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40/*
41 * Format registry hash table contains the registered formats. Format
42 * registration is typically performed by a format plugin.
fc93b2bd 43 */
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44static GHashTable *format_registry;
45static int format_refcount;
46static int init_done;
47
48static __attribute__((constructor)) void format_init(void);
49
50static
51void format_refcount_inc(void)
52{
53 format_refcount++;
54}
55
56static
57void format_cleanup(void)
58{
59 if (format_registry)
60 g_hash_table_destroy(format_registry);
61}
62
63static
64void format_refcount_dec(void)
65{
66 if (!--format_refcount)
67 format_cleanup();
68}
fc93b2bd 69
37b99bdb 70struct bt_format *bt_lookup_format(bt_intern_str name)
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71{
72 if (!init_done)
73 return NULL;
7f89ddce 74
fc93b2bd 75 return g_hash_table_lookup(format_registry,
34861b9d 76 (gconstpointer) (unsigned long) name);
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77}
78
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79static void show_format(gpointer key, gpointer value, gpointer user_data)
80{
d2b8ea6b 81 struct walk_data *data = user_data;
7fb21036 82
d2b8ea6b 83 fprintf(data->fp, "%s%s", data->iter ? ", " : "",
7fb21036 84 g_quark_to_string((GQuark) (unsigned long) key));
d2b8ea6b 85 data->iter++;
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86}
87
88void bt_fprintf_format_list(FILE *fp)
89{
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90 struct walk_data data;
91
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92 assert(fp);
93
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94 data.fp = fp;
95 data.iter = 0;
96
97 fprintf(fp, "Formats available: ");
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98 if (!init_done)
99 return;
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100 g_hash_table_foreach(format_registry, show_format, &data);
101 if (data.iter == 0)
102 fprintf(fp, "<none>");
103 fprintf(fp, ".\n");
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104}
105
37b99bdb 106int bt_register_format(struct bt_format *format)
fc93b2bd 107{
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108 if (!format)
109 return -EINVAL;
110
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111 if (!init_done)
112 format_init();
113
4c8bfb7e 114 if (bt_lookup_format(format->name))
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115 return -EEXIST;
116
95febab3 117 format_refcount_inc();
fc93b2bd 118 g_hash_table_insert(format_registry,
4c8bfb7e 119 (gpointer) (unsigned long) format->name,
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120 format);
121 return 0;
122}
123
37b99bdb 124void bt_unregister_format(struct bt_format *format)
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125{
126 assert(bt_lookup_format(format->name));
127 g_hash_table_remove(format_registry,
128 (gpointer) (unsigned long) format->name);
129 format_refcount_dec();
130}
131
132/*
133 * We cannot assume that the constructor and destructor order will be
134 * right: another library might be loaded before us, and initialize us
135 * from bt_register_format(). This is why we use a reference count to
136 * handle cleanup of this module. The format_finalize destructor
137 * refcount decrement matches format_init refcount increment.
138 */
139static __attribute__((constructor))
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140void format_init(void)
141{
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142 if (init_done)
143 return;
95febab3 144 format_refcount_inc();
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145 format_registry = g_hash_table_new(g_direct_hash, g_direct_equal);
146 assert(format_registry);
147 init_done = 1;
148}
149
95febab3 150static __attribute__((destructor))
4c8bfb7e 151void format_finalize(void)
fc93b2bd 152{
95febab3 153 format_refcount_dec();
fc93b2bd 154}
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