1 /* GStreamer
2 * Copyright (C) 2016 Stefan Sauer <ensonic@users.sf.net>
3 *
4 * gsttracerrecord.c: tracer log record class
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 */
21
22 /**
23 * SECTION:gsttracerrecord
24 * @title: GstTracerRecord
25 * @short_description: Trace log entry class
26 *
27 * Tracing modules will create instances of this class to announce the data they
28 * will log and create a log formatter.
29 *
30 * Since: 1.8
31 */
32
33 #include "gst_private.h"
34 #include "gstenumtypes.h"
35 #include "gstinfo.h"
36 #include "gststructure.h"
37 #include "gsttracerrecord.h"
38 #include "gstvalue.h"
39 #include <gobject/gvaluecollector.h>
40
41 GST_DEBUG_CATEGORY_EXTERN (tracer_debug);
42 #define GST_CAT_DEFAULT tracer_debug
43
44 struct _GstTracerRecord
45 {
46 GstObject parent;
47
48 GstStructure *spec;
49 gchar *format;
50 };
51
52 struct _GstTracerRecordClass
53 {
54 GstObjectClass parent_class;
55 };
56
57 #define gst_tracer_record_parent_class parent_class
58 G_DEFINE_TYPE (GstTracerRecord, gst_tracer_record, GST_TYPE_OBJECT);
59
60 static gboolean
build_field_template(GQuark field_id,const GValue * value,gpointer user_data)61 build_field_template (GQuark field_id, const GValue * value, gpointer user_data)
62 {
63 GString *s = (GString *) user_data;
64 const GstStructure *sub;
65 GValue template_value = { 0, };
66 GType type = G_TYPE_INVALID;
67 GstTracerValueFlags flags = GST_TRACER_VALUE_FLAGS_NONE;
68 gboolean res;
69
70 if (G_VALUE_TYPE (value) != GST_TYPE_STRUCTURE) {
71 GST_ERROR ("expected field of type GstStructure, but %s is %s",
72 g_quark_to_string (field_id), G_VALUE_TYPE_NAME (value));
73 return FALSE;
74 }
75
76 sub = gst_value_get_structure (value);
77 gst_structure_get (sub, "type", G_TYPE_GTYPE, &type, "flags",
78 GST_TYPE_TRACER_VALUE_FLAGS, &flags, NULL);
79
80 if (flags & GST_TRACER_VALUE_FLAGS_OPTIONAL) {
81 gchar *opt_name = g_strconcat ("have-", g_quark_to_string (field_id), NULL);
82
83 /* add a boolean field, that indicates the presence of the next field */
84 g_value_init (&template_value, G_TYPE_BOOLEAN);
85 priv__gst_structure_append_template_to_gstring (g_quark_from_string
86 (opt_name), &template_value, s);
87 g_value_unset (&template_value);
88 g_free (opt_name);
89 }
90
91 g_value_init (&template_value, type);
92 res = priv__gst_structure_append_template_to_gstring (field_id,
93 &template_value, s);
94 g_value_unset (&template_value);
95 return res;
96 }
97
98 static void
gst_tracer_record_build_format(GstTracerRecord * self)99 gst_tracer_record_build_format (GstTracerRecord * self)
100 {
101 GstStructure *structure = self->spec;
102 GString *s;
103 gchar *name = (gchar *) g_quark_to_string (structure->name);
104 gchar *p;
105
106 g_return_if_fail (g_str_has_suffix (name, ".class"));
107
108 /* announce the format */
109 GST_TRACE ("%" GST_PTR_FORMAT, structure);
110
111 /* cut off '.class' suffix */
112 name = g_strdup (name);
113 p = strrchr (name, '.');
114 g_assert (p != NULL);
115 *p = '\0';
116
117 s = g_string_sized_new (STRUCTURE_ESTIMATED_STRING_LEN (structure));
118 g_string_append (s, name);
119 gst_structure_foreach (structure, build_field_template, s);
120 g_string_append_c (s, ';');
121
122 self->format = g_string_free (s, FALSE);
123 GST_DEBUG ("new format string: %s", self->format);
124 g_free (name);
125 }
126
127 static void
gst_tracer_record_dispose(GObject * object)128 gst_tracer_record_dispose (GObject * object)
129 {
130 GstTracerRecord *self = GST_TRACER_RECORD (object);
131
132 if (self->spec) {
133 gst_structure_free (self->spec);
134 self->spec = NULL;
135 }
136 g_free (self->format);
137 self->format = NULL;
138 }
139
140 static void
gst_tracer_record_class_init(GstTracerRecordClass * klass)141 gst_tracer_record_class_init (GstTracerRecordClass * klass)
142 {
143 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
144
145 gobject_class->dispose = gst_tracer_record_dispose;
146 }
147
148 static void
gst_tracer_record_init(GstTracerRecord * self)149 gst_tracer_record_init (GstTracerRecord * self)
150 {
151 }
152
153 /**
154 * gst_tracer_record_new:
155 * @name: name of new record, must end on ".class".
156 * @firstfield: name of first field to set
157 * @...: additional arguments
158
159 *
160 * Create a new tracer record. The record instance can be used to efficiently
161 * log entries using gst_tracer_record_log().
162 * %NULL terminator required after the last argument.
163 *
164 * The @name without the ".class" suffix will be used for the log records.
165 * There must be fields for each value that gets logged where the field name is
166 * the value name. The field must be a #GstStructure describing the value. The
167 * sub structure must contain a field called 'type' of %G_TYPE_GTYPE that
168 * contains the GType of the value. The resulting #GstTracerRecord will take
169 * ownership of the field structures.
170 *
171 * The way to deal with optional values is to log an additional boolean before
172 * the optional field, that if %TRUE signals that the optional field is valid
173 * and %FALSE signals that the optional field should be ignored. One must still
174 * log a placeholder value for the optional field though. Please also note, that
175 * pointer type values must not be NULL - the underlying serialisation can not
176 * handle that right now.
177 *
178 * > Please note that this is still under discussion and subject to change.
179 *
180 * Returns: (transfer full): a new #GstTracerRecord
181 *
182 * Since: 1.8
183 */
184 GstTracerRecord *
gst_tracer_record_new(const gchar * name,const gchar * firstfield,...)185 gst_tracer_record_new (const gchar * name, const gchar * firstfield, ...)
186 {
187 GstTracerRecord *self;
188 GstStructure *structure;
189 va_list varargs;
190 gchar *err = NULL;
191 GType type;
192 GQuark id;
193
194 va_start (varargs, firstfield);
195 structure = gst_structure_new_empty (name);
196
197 while (firstfield) {
198 GValue val = { 0, };
199
200 id = g_quark_from_string (firstfield);
201 type = va_arg (varargs, GType);
202
203 /* all fields passed here must be GstStructures which we take over */
204 if (type != GST_TYPE_STRUCTURE) {
205 GST_ERROR ("expected field of type GstStructure, but %s is %s",
206 firstfield, g_type_name (type));
207 va_end (varargs);
208 gst_structure_free (structure);
209 return NULL;
210 }
211
212 G_VALUE_COLLECT_INIT (&val, type, varargs, G_VALUE_NOCOPY_CONTENTS, &err);
213 if (G_UNLIKELY (err)) {
214 g_critical ("%s", err);
215 g_free (err);
216 break;
217 }
218 /* give ownership of the GstStructure "value" collected from varargs
219 * to this structure by unsetting the NOCOPY_CONTENTS collect-flag.
220 * see boxed_proxy_collect_value in glib's gobject/gboxed.c */
221 val.data[1].v_uint &= ~G_VALUE_NOCOPY_CONTENTS;
222 gst_structure_id_take_value (structure, id, &val);
223
224 firstfield = va_arg (varargs, gchar *);
225 }
226 va_end (varargs);
227
228 self = g_object_new (GST_TYPE_TRACER_RECORD, NULL);
229
230 /* Clear floating flag */
231 gst_object_ref_sink (self);
232
233 self->spec = structure;
234 gst_tracer_record_build_format (self);
235
236 return self;
237 }
238
239 #ifndef GST_DISABLE_GST_DEBUG
240 /**
241 * gst_tracer_record_log:
242 * @self: the tracer-record
243 * @...: the args as described in the spec-
244 *
245 * Serialzes the trace event into the log.
246 *
247 * Right now this is using the gstreamer debug log with the level TRACE (7) and
248 * the category "GST_TRACER".
249 *
250 * > Please note that this is still under discussion and subject to change.
251 *
252 * Since: 1.8
253 */
254 void
gst_tracer_record_log(GstTracerRecord * self,...)255 gst_tracer_record_log (GstTracerRecord * self, ...)
256 {
257 va_list var_args;
258
259 /*
260 * does it make sense to use the {file, line, func} from the tracer hook?
261 * a)
262 * - we'd need to pass them in the macros to gst_tracer_dispatch()
263 * - and each tracer needs to grab them from the va_list and pass them here
264 * b)
265 * - we create a context in dispatch, pass that to the tracer
266 * - and the tracer will pass that here
267 * ideally we also use *our* ts instead of the one that
268 * gst_debug_log_default() will pick
269 */
270
271 va_start (var_args, self);
272 if (G_LIKELY (GST_LEVEL_TRACE <= _gst_debug_min)) {
273 gst_debug_log_valist (GST_CAT_DEFAULT, GST_LEVEL_TRACE, "", "", 0, NULL,
274 self->format, var_args);
275 }
276 va_end (var_args);
277 }
278 #endif
279