/* GStreamer

 * Copyright (C) 2016 Stefan Sauer <ensonic@users.sf.net>

 *

 * gsttracerrecord.c: tracer log record class

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public

 * License along with this library; if not, write to the

 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

/**

 * SECTION:gsttracerrecord

 * @title: GstTracerRecord

 * @short_description: Trace log entry class

 *

 * Tracing modules will create instances of this class to announce the data they

 * will log and create a log formatter.

 *

 * Since: 1.8

 */

#define GST_USE_UNSTABLE_API

#include "gst_private.h"

#include "gstenumtypes.h"

#include "gstinfo.h"

#include "gststructure.h"

#include "gsttracerrecord.h"

#include "gstvalue.h"

#include <gobject/gvaluecollector.h>

GST_DEBUG_CATEGORY_EXTERN (tracer_debug);

#define GST_CAT_DEFAULT tracer_debug

struct _GstTracerRecord

{

  GstObject parent;

  GstStructure *spec;

  gchar *format;

};

struct _GstTracerRecordClass

{

  GstObjectClass parent_class;

};

#define gst_tracer_record_parent_class parent_class

G_DEFINE_TYPE (GstTracerRecord, gst_tracer_record, GST_TYPE_OBJECT);

static gboolean

build_field_template (GQuark field_id, const GValue * value, gpointer user_data)

{

  GString *s = (GString *) user_data;

  const GstStructure *sub;

  GValue template_value = { 0, };

  GType type = G_TYPE_INVALID;

  GstTracerValueFlags flags = GST_TRACER_VALUE_FLAGS_NONE;

  gboolean res;

  if (G_VALUE_TYPE (value) != GST_TYPE_STRUCTURE) {

    GST_WARNING ("expected field of type GstStructure, but %s is %s",

        g_quark_to_string (field_id), G_VALUE_TYPE_NAME (value));

    return FALSE;

  }

  sub = gst_value_get_structure (value);

  gst_structure_get (sub, "type", G_TYPE_GTYPE, &type, "flags",

      GST_TYPE_TRACER_VALUE_FLAGS, &flags, NULL);

  if (flags & GST_TRACER_VALUE_FLAGS_OPTIONAL) {

    gchar *opt_name = g_strconcat ("have-", g_quark_to_string (field_id), NULL);

    /* add a boolean field, that indicates the presence of the next field */

    g_value_init (&template_value, G_TYPE_BOOLEAN);

    priv__gst_structure_append_template_to_gstring (g_quark_from_string

        (opt_name), &template_value, s);

    g_value_unset (&template_value);

    g_free (opt_name);

  }

  g_value_init (&template_value, type);

  res = priv__gst_structure_append_template_to_gstring (field_id,

      &template_value, s);

  g_value_unset (&template_value);

  return res;

}

static void

gst_tracer_record_build_format (GstTracerRecord * self)

{

  GstStructure *structure = self->spec;

  GString *s;

  gchar *name = (gchar *) g_quark_to_string (structure->name);

  gchar *p;

  g_return_if_fail (g_str_has_suffix (name, ".class"));

  /* announce the format */

  GST_TRACE ("%" GST_PTR_FORMAT, structure);

  /* cut off '.class' suffix */

  name = g_strdup (name);

  p = strrchr (name, '.');

  g_assert (p != NULL);

  *p = '\0';

  s = g_string_sized_new (STRUCTURE_ESTIMATED_STRING_LEN (structure));

  g_string_append (s, name);

  gst_structure_foreach (structure, build_field_template, s);

  g_string_append_c (s, ';');

  self->format = g_string_free (s, FALSE);

  GST_DEBUG ("new format string: %s", self->format);

  g_free (name);

}

static void

gst_tracer_record_dispose (GObject * object)

{

  GstTracerRecord *self = GST_TRACER_RECORD (object);

  if (self->spec) {

    gst_structure_free (self->spec);

    self->spec = NULL;

  }

  g_free (self->format);

  self->format = NULL;

}

static void

gst_tracer_record_class_init (GstTracerRecordClass * klass)

{

  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->dispose = gst_tracer_record_dispose;

}

static void

gst_tracer_record_init (GstTracerRecord * self)

{

}

/**

 * gst_tracer_record_new:

 * @name: name of new record, must end on ".class".

 * @firstfield: name of first field to set

 * @...: additional arguments

 *

 * Create a new tracer record. The record instance can be used to efficiently

 * log entries using gst_tracer_record_log().

 *

 * The @name without the ".class" suffix will be used for the log records.

 * There must be fields for each value that gets logged where the field name is

 * the value name. The field must be a #GstStructure describing the value. The

 * sub structure must contain a field called 'type' of %G_TYPE_GTYPE that

 * contains the GType of the value. The resulting #GstTracerRecord will take

 * ownership of the field structures.

 *

 * The way to deal with optional values is to log an additional boolean before

 * the optional field, that if %TRUE signals that the optional field is valid

 * and %FALSE signals that the optional field should be ignored. One must still

 * log a placeholder value for the optional field though. Please also note, that

 * pointer type values must not be NULL - the underlying serialisation can not

 * handle that right now.

 *

 * > Please note that this is still under discussion and subject to change.

 *

 * Returns: (transfer full): a new #GstTracerRecord

 */

GstTracerRecord *

gst_tracer_record_new (const gchar * name, const gchar * firstfield, ...)

{

  GstTracerRecord *self;

  GstStructure *structure;

  va_list varargs;

  gchar *err = NULL;

  GType type;

  GQuark id;

  va_start (varargs, firstfield);

  structure = gst_structure_new_empty (name);

  while (firstfield) {

    GValue val = { 0, };

    id = g_quark_from_string (firstfield);

    type = va_arg (varargs, GType);

    /* all fields passed here must be GstStructures which we take over */

    if (type != GST_TYPE_STRUCTURE) {

      GST_WARNING ("expected field of type GstStructure, but %s is %s",

          firstfield, g_type_name (type));

    }

    G_VALUE_COLLECT_INIT (&val, type, varargs, G_VALUE_NOCOPY_CONTENTS, &err;;

    if (G_UNLIKELY (err)) {

      g_critical ("%s", err);

      break;

    }

    /* see boxed_proxy_collect_value */

    val.data[1].v_uint &= ~G_VALUE_NOCOPY_CONTENTS;

    gst_structure_id_take_value (structure, id, &val;;

    firstfield = va_arg (varargs, gchar *);

  }

  va_end (varargs);

  self = g_object_new (GST_TYPE_TRACER_RECORD, NULL);

  /* Clear floating flag */

  gst_object_ref_sink (self);

  self->spec = structure;

  gst_tracer_record_build_format (self);

  return self;

}

#ifndef GST_DISABLE_GST_DEBUG

/**

 * gst_tracer_record_log:

 * @self: the tracer-record

 * @...: the args as described in the spec-

 *

 * Serialzes the trace event into the log.

 *

 * Right now this is using the gstreamer debug log with the level TRACE (7) and

 * the category "GST_TRACER".

 *

 * > Please note that this is still under discussion and subject to change.

 */

void

gst_tracer_record_log (GstTracerRecord * self, ...)

{

  va_list var_args;

  /*

   * does it make sense to use the {file, line, func} from the tracer hook?

   * a)

   * - we'd need to pass them in the macros to gst_tracer_dispatch()

   * - and each tracer needs to grab them from the va_list and pass them here

   * b)

   * - we create a context in dispatch, pass that to the tracer

   * - and the tracer will pass that here

   * ideally we also use *our* ts instead of the one that

   * gst_debug_log_default() will pick

   */

  va_start (var_args, self);

  if (G_LIKELY (GST_LEVEL_TRACE <= _gst_debug_min)) {

    gst_debug_log_valist (GST_CAT_DEFAULT, GST_LEVEL_TRACE, "", "", 0, NULL,

        self->format, var_args);

  }

  va_end (var_args);

}

#endif