[babeltrace.git] / lib / ctf-ir / packet.c

/*
 * packet.c
 *
 * Babeltrace CTF IR - Stream packet
 *
 * Copyright 2016 Philippe Proulx <pproulx@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.
 */

#define BT_LOG_TAG "PACKET"
#include <babeltrace/lib-logging-internal.h>

#include <babeltrace/assert-pre-internal.h>
#include <babeltrace/ctf-ir/fields-internal.h>
#include <babeltrace/ctf-ir/packet.h>
#include <babeltrace/ctf-ir/packet-internal.h>
#include <babeltrace/ctf-ir/field-wrapper-internal.h>
#include <babeltrace/ctf-ir/trace.h>
#include <babeltrace/ctf-ir/stream-class-internal.h>
#include <babeltrace/ctf-ir/stream-class.h>
#include <babeltrace/ctf-ir/stream.h>
#include <babeltrace/ctf-ir/stream-internal.h>
#include <babeltrace/ctf-ir/trace-internal.h>
#include <babeltrace/object-internal.h>
#include <babeltrace/ref.h>
#include <babeltrace/assert-internal.h>
#include <inttypes.h>

struct bt_stream *bt_packet_borrow_stream(struct bt_packet *packet)
{
	BT_ASSERT_PRE_NON_NULL(packet, "Packet");
	return packet->stream;
}

struct bt_field *bt_packet_borrow_header(struct bt_packet *packet)
{
	BT_ASSERT_PRE_NON_NULL(packet, "Packet");
	return packet->header ? (void *) packet->header->field : NULL;
}

struct bt_field *bt_packet_borrow_context(struct bt_packet *packet)
{
	BT_ASSERT_PRE_NON_NULL(packet, "Packet");
	return packet->context ? (void *) packet->context->field : NULL;
}

BT_HIDDEN
void _bt_packet_freeze(struct bt_packet *packet)
{
	if (!packet || packet->frozen) {
		return;
	}

	BT_LOGD("Freezing packet: addr=%p", packet);

	if (packet->header) {
		BT_LOGD_STR("Freezing packet's header field.");
		bt_field_set_is_frozen_recursive((void *) packet->header->field, true);
	}

	if (packet->context) {
		BT_LOGD_STR("Freezing packet's context field.");
		bt_field_set_is_frozen_recursive((void *) packet->context->field, true);
	}

	packet->frozen = 1;
}

static inline
void bt_packet_reset(struct bt_packet *packet)
{
	BT_ASSERT(packet);
	packet->frozen = false;

	if (packet->header) {
		bt_field_set_is_frozen_recursive(
			(void *) packet->header->field, false);
		bt_field_reset_recursive((void *) packet->header->field);
	}

	if (packet->context) {
		bt_field_set_is_frozen_recursive(
			(void *) packet->context->field, false);
		bt_field_reset_recursive((void *) packet->context->field);
	}
}

static
void bt_packet_header_field_recycle(struct bt_field_wrapper *header_field,
		struct bt_trace *trace)
{
	BT_ASSERT(header_field);
	BT_LIB_LOGD("Recycling packet header field: "
		"addr=%p, %![trace-]+t, %![field-]+f", header_field,
		trace, header_field->field);
	bt_object_pool_recycle_object(&trace->packet_header_field_pool,
		header_field);
}

static
void bt_packet_context_field_recycle(struct bt_field_wrapper *context_field,
		struct bt_stream_class *stream_class)
{
	BT_ASSERT(context_field);
	BT_LIB_LOGD("Recycling packet context field: "
		"addr=%p, %![sc-]+S, %![field-]+f", context_field,
		stream_class, context_field->field);
	bt_object_pool_recycle_object(&stream_class->packet_context_field_pool,
		context_field);
}

BT_HIDDEN
void bt_packet_recycle(struct bt_packet *packet)
{
	struct bt_stream *stream;

	BT_ASSERT(packet);
	BT_LIB_LOGD("Recycling packet: %!+a", packet);

	/*
	 * Those are the important ordered steps:
	 *
	 * 1. Reset the packet object (put any permanent reference it
	 *    has, unfreeze it and its fields in developer mode, etc.),
	 *    but do NOT put its stream's reference. This stream
	 *    contains the pool to which we're about to recycle this
	 *    packet object, so we must guarantee its existence thanks
	 *    to this existing reference.
	 *
	 * 2. Move the stream reference to our `stream`
	 *    variable so that we can set the packet's stream member
	 *    to NULL before recycling it. We CANNOT do this after
	 *    we put the stream reference because this bt_put()
	 *    could destroy the stream, also destroying its
	 *    packet pool, thus also destroying our packet object (this
	 *    would result in an invalid write access).
	 *
	 * 3. Recycle the packet object.
	 *
	 * 4. Put our stream reference.
	 */
	bt_packet_reset(packet);
	stream = packet->stream;
	BT_ASSERT(stream);
	packet->stream = NULL;
	bt_object_pool_recycle_object(&stream->packet_pool, packet);
	bt_put(stream);
}

BT_HIDDEN
void bt_packet_destroy(struct bt_packet *packet)
{
	BT_LOGD("Destroying packet: addr=%p", packet);
	BT_LOGD_STR("Destroying packet's header field.");

	if (packet->header) {
		if (packet->stream) {
			BT_LOGD_STR("Recycling packet's header field.");
			bt_packet_header_field_recycle(packet->header,
				bt_stream_class_borrow_trace(
					bt_stream_borrow_class(packet->stream)));
		} else {
			bt_field_wrapper_destroy(packet->header);
		}
	}

	if (packet->context) {
		if (packet->stream) {
			BT_LOGD_STR("Recycling packet's context field.");
			bt_packet_context_field_recycle(packet->context,
				bt_stream_borrow_class(packet->stream));
		} else {
			bt_field_wrapper_destroy(packet->context);
		}
	}

	BT_LOGD_STR("Putting packet's stream.");
	bt_put(packet->stream);
	g_free(packet);
}

BT_HIDDEN
struct bt_packet *bt_packet_new(struct bt_stream *stream)
{
	struct bt_packet *packet = NULL;
	struct bt_stream_class *stream_class = NULL;
	struct bt_trace *trace = NULL;

	BT_ASSERT(stream);
	BT_LOGD("Creating packet object: stream-addr=%p, "
		"stream-name=\"%s\", stream-class-addr=%p, "
		"stream-class-name=\"%s\", stream-class-id=%" PRId64,
		stream, bt_stream_get_name(stream),
		stream->common.stream_class,
		bt_stream_class_common_get_name(stream->common.stream_class),
		bt_stream_class_common_get_id(stream->common.stream_class));
	stream_class = bt_stream_borrow_class(stream);
	BT_ASSERT(stream_class);
	trace = bt_stream_class_borrow_trace(stream_class);
	BT_ASSERT(trace);
	packet = g_new0(struct bt_packet, 1);
	if (!packet) {
		BT_LOGE_STR("Failed to allocate one packet object.");
		goto end;
	}

	bt_object_init(packet, (bt_object_release_func) bt_packet_recycle);
	packet->stream = bt_get(stream);

	if (trace->common.packet_header_field_type) {
		BT_LOGD("Creating initial packet header field: ft-addr=%p",
			trace->common.packet_header_field_type);
		packet->header = bt_field_wrapper_create(
			&trace->packet_header_field_pool,
			(void *) trace->common.packet_header_field_type);
		if (!packet->header) {
			BT_LOGE("Cannot create packet header field wrapper.");
			BT_PUT(packet);
			goto end;
		}
	}

	if (stream->common.stream_class->packet_context_field_type) {
		BT_LOGD("Creating initial packet context field: ft-addr=%p",
			stream->common.stream_class->packet_context_field_type);
		packet->context = bt_field_wrapper_create(
			&stream_class->packet_context_field_pool,
			(void *) stream->common.stream_class->packet_context_field_type);
		if (!packet->context) {
			BT_LOGE("Cannot create packet context field wrapper.");
			BT_PUT(packet);
			goto end;
		}
	}

	BT_LOGD("Created packet object: addr=%p", packet);

end:
	return packet;
}

struct bt_packet *bt_packet_create(struct bt_stream *stream)
{
	struct bt_packet *packet = NULL;

	BT_ASSERT_PRE_NON_NULL(stream, "Stream");
	packet = bt_object_pool_create_object(&stream->packet_pool);
	if (!packet) {
		BT_LIB_LOGE("Cannot allocate one packet from stream's packet pool: "
			"%![stream-]+s", stream);
		goto error;
	}

	if (!packet->stream) {
		packet->stream = bt_get(stream);
	}

	goto end;

error:
	if (packet) {
		bt_packet_recycle(packet);
		packet = NULL;
	}

end:
	return packet;
}

int bt_packet_move_header(struct bt_packet *packet,
		struct bt_packet_header_field *header_field)
{
	struct bt_trace *trace;
	struct bt_field_wrapper *field_wrapper = (void *) header_field;

	BT_ASSERT_PRE_NON_NULL(packet, "Event");
	BT_ASSERT_PRE_NON_NULL(field_wrapper, "Header field");
	BT_ASSERT_PRE_HOT(packet, "Packet", ": +%!+a", packet);
	trace = bt_stream_class_borrow_trace(
		bt_stream_borrow_class(packet->stream));
	BT_ASSERT_PRE(trace->common.packet_header_field_type,
		"Trace has no packet header field type: %!+t",
		trace);

	/* TODO: compare field types (precondition) */

	/* Recycle current header field: always exists */
	BT_ASSERT(packet->header);
	bt_packet_header_field_recycle(packet->header, trace);

	/* Move new field */
	packet->header = field_wrapper;
	return 0;
}

int bt_packet_move_context(struct bt_packet *packet,
		struct bt_packet_context_field *context_field)
{
	struct bt_stream_class *stream_class;
	struct bt_field_wrapper *field_wrapper = (void *) context_field;

	BT_ASSERT_PRE_NON_NULL(packet, "Event");
	BT_ASSERT_PRE_NON_NULL(field_wrapper, "Context field");
	BT_ASSERT_PRE_HOT(packet, "Packet", ": +%!+a", packet);
	stream_class = bt_stream_borrow_class(packet->stream);
	BT_ASSERT_PRE(stream_class->common.packet_context_field_type,
		"Stream class has no packet context field type: %!+S",
		stream_class);

	/* TODO: compare field types (precondition) */

	/* Recycle current context field: always exists */
	BT_ASSERT(packet->context);
	bt_packet_context_field_recycle(packet->context, stream_class);

	/* Move new field */
	packet->context = field_wrapper;
	return 0;
}
Commit	Line	Data
f79cf0f0 PP	1	/*
	2	* packet.c
	3	*
	4	* Babeltrace CTF IR - Stream packet
	5	*
	6	* Copyright 2016 Philippe Proulx <pproulx@efficios.com>
	7	*
	8	* Permission is hereby granted, free of charge, to any person obtaining a copy
	9	* of this software and associated documentation files (the "Software"), to deal
	10	* in the Software without restriction, including without limitation the rights
	11	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	12	* copies of the Software, and to permit persons to whom the Software is
	13	* furnished to do so, subject to the following conditions:
	14	*
	15	* The above copyright notice and this permission notice shall be included in
	16	* all copies or substantial portions of the Software.
	17	*
	18	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	19	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	20	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	21	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	22	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	23	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	24	* SOFTWARE.
	25	*/
	26
8ea705f0	27	#define BT_LOG_TAG "PACKET"
be514b0c	28	#include <babeltrace/lib-logging-internal.h>
8ea705f0	29
3dca2276	30	#include <babeltrace/assert-pre-internal.h>
f79cf0f0 PP	31	#include <babeltrace/ctf-ir/fields-internal.h>
	32	#include <babeltrace/ctf-ir/packet.h>
	33	#include <babeltrace/ctf-ir/packet-internal.h>
312c056a	34	#include <babeltrace/ctf-ir/field-wrapper-internal.h>
f79cf0f0 PP	35	#include <babeltrace/ctf-ir/trace.h>
	36	#include <babeltrace/ctf-ir/stream-class-internal.h>
	37	#include <babeltrace/ctf-ir/stream-class.h>
	38	#include <babeltrace/ctf-ir/stream.h>
	39	#include <babeltrace/ctf-ir/stream-internal.h>
	40	#include <babeltrace/ctf-ir/trace-internal.h>
	41	#include <babeltrace/object-internal.h>
	42	#include <babeltrace/ref.h>
f6ccaed9	43	#include <babeltrace/assert-internal.h>
be514b0c	44	#include <inttypes.h>
f79cf0f0	45
094ff7c0	46	struct bt_stream bt_packet_borrow_stream(struct bt_packet packet)
f79cf0f0	47	{
f6ccaed9	48	BT_ASSERT_PRE_NON_NULL(packet, "Packet");
094ff7c0	49	return packet->stream;
f79cf0f0 PP	50	}
f79cf0f0 PP	51
312c056a	52	struct bt_field bt_packet_borrow_header(struct bt_packet packet)
f79cf0f0	53	{
f6ccaed9	54	BT_ASSERT_PRE_NON_NULL(packet, "Packet");
312c056a	55	return packet->header ? (void *) packet->header->field : NULL;
f79cf0f0 PP	56	}
f79cf0f0 PP	57
312c056a	58	struct bt_field bt_packet_borrow_context(struct bt_packet packet)
f79cf0f0	59	{
312c056a PP	60	BT_ASSERT_PRE_NON_NULL(packet, "Packet");
	61	return packet->context ? (void *) packet->context->field : NULL;
	62	}
c5c82c6e	63
312c056a PP	64	BT_HIDDEN
	65	void _bt_packet_freeze(struct bt_packet *packet)
	66	{
	67	if (!packet \|\| packet->frozen) {
	68	return;
c5c82c6e PP	69	}
c5c82c6e PP	70
312c056a PP	71	BT_LOGD("Freezing packet: addr=%p", packet);
	72
	73	if (packet->header) {
	74	BT_LOGD_STR("Freezing packet's header field.");
	75	bt_field_set_is_frozen_recursive((void *) packet->header->field, true);
f79cf0f0 PP	76	}
f79cf0f0 PP	77
312c056a PP	78	if (packet->context) {
	79	BT_LOGD_STR("Freezing packet's context field.");
	80	bt_field_set_is_frozen_recursive((void *) packet->context->field, true);
	81	}
	82
	83	packet->frozen = 1;
f6ccaed9 PP	84	}
f6ccaed9 PP	85
312c056a PP	86	static inline
312c056a PP	87	void bt_packet_reset(struct bt_packet *packet)
f6ccaed9	88	{
312c056a PP	89	BT_ASSERT(packet);
	90	packet->frozen = false;
	91
	92	if (packet->header) {
	93	bt_field_set_is_frozen_recursive(
	94	(void *) packet->header->field, false);
	95	bt_field_reset_recursive((void *) packet->header->field);
	96	}
	97
	98	if (packet->context) {
	99	bt_field_set_is_frozen_recursive(
	100	(void *) packet->context->field, false);
	101	bt_field_reset_recursive((void *) packet->context->field);
	102	}
f79cf0f0 PP	103	}
f79cf0f0 PP	104
312c056a PP	105	static
	106	void bt_packet_header_field_recycle(struct bt_field_wrapper *header_field,
	107	struct bt_trace *trace)
f79cf0f0	108	{
312c056a PP	109	BT_ASSERT(header_field);
	110	BT_LIB_LOGD("Recycling packet header field: "
	111	"addr=%p, %![trace-]+t, %![field-]+f", header_field,
	112	trace, header_field->field);
	113	bt_object_pool_recycle_object(&trace->packet_header_field_pool,
	114	header_field);
f79cf0f0 PP	115	}
f79cf0f0 PP	116
312c056a PP	117	static
	118	void bt_packet_context_field_recycle(struct bt_field_wrapper *context_field,
	119	struct bt_stream_class *stream_class)
f79cf0f0	120	{
312c056a PP	121	BT_ASSERT(context_field);
	122	BT_LIB_LOGD("Recycling packet context field: "
	123	"addr=%p, %![sc-]+S, %![field-]+f", context_field,
	124	stream_class, context_field->field);
	125	bt_object_pool_recycle_object(&stream_class->packet_context_field_pool,
	126	context_field);
f79cf0f0 PP	127	}
	128
	129	BT_HIDDEN
312c056a	130	void bt_packet_recycle(struct bt_packet *packet)
f79cf0f0	131	{
312c056a	132	struct bt_stream *stream;
f79cf0f0	133
312c056a PP	134	BT_ASSERT(packet);
	135	BT_LIB_LOGD("Recycling packet: %!+a", packet);
	136
	137	/*
	138	* Those are the important ordered steps:
	139	*
	140	* 1. Reset the packet object (put any permanent reference it
	141	* has, unfreeze it and its fields in developer mode, etc.),
	142	* but do NOT put its stream's reference. This stream
	143	* contains the pool to which we're about to recycle this
	144	* packet object, so we must guarantee its existence thanks
	145	* to this existing reference.
	146	*
	147	* 2. Move the stream reference to our `stream`
	148	* variable so that we can set the packet's stream member
	149	* to NULL before recycling it. We CANNOT do this after
	150	* we put the stream reference because this bt_put()
	151	* could destroy the stream, also destroying its
	152	* packet pool, thus also destroying our packet object (this
	153	* would result in an invalid write access).
	154	*
	155	* 3. Recycle the packet object.
	156	*
	157	* 4. Put our stream reference.
	158	*/
	159	bt_packet_reset(packet);
	160	stream = packet->stream;
	161	BT_ASSERT(stream);
	162	packet->stream = NULL;
	163	bt_object_pool_recycle_object(&stream->packet_pool, packet);
	164	bt_put(stream);
f79cf0f0 PP	165	}
f79cf0f0 PP	166
312c056a PP	167	BT_HIDDEN
312c056a PP	168	void bt_packet_destroy(struct bt_packet *packet)
f79cf0f0	169	{
8ea705f0	170	BT_LOGD("Destroying packet: addr=%p", packet);
312c056a PP	171	BT_LOGD_STR("Destroying packet's header field.");
	172
	173	if (packet->header) {
	174	if (packet->stream) {
	175	BT_LOGD_STR("Recycling packet's header field.");
	176	bt_packet_header_field_recycle(packet->header,
	177	bt_stream_class_borrow_trace(
	178	bt_stream_borrow_class(packet->stream)));
	179	} else {
	180	bt_field_wrapper_destroy(packet->header);
	181	}
	182	}
	183
	184	if (packet->context) {
	185	if (packet->stream) {
	186	BT_LOGD_STR("Recycling packet's context field.");
	187	bt_packet_context_field_recycle(packet->context,
	188	bt_stream_borrow_class(packet->stream));
	189	} else {
	190	bt_field_wrapper_destroy(packet->context);
	191	}
	192	}
	193
d409daba	194	BT_LOGD_STR("Putting packet's stream.");
f79cf0f0 PP	195	bt_put(packet->stream);
	196	g_free(packet);
	197	}
	198
312c056a PP	199	BT_HIDDEN
312c056a PP	200	struct bt_packet bt_packet_new(struct bt_stream stream)
f79cf0f0	201	{
50842bdc PP	202	struct bt_packet *packet = NULL;
	203	struct bt_stream_class *stream_class = NULL;
	204	struct bt_trace *trace = NULL;
f79cf0f0	205
312c056a	206	BT_ASSERT(stream);
be514b0c PP	207	BT_LOGD("Creating packet object: stream-addr=%p, "
	208	"stream-name=\"%s\", stream-class-addr=%p, "
	209	"stream-class-name=\"%s\", stream-class-id=%" PRId64,
50842bdc	210	stream, bt_stream_get_name(stream),
3dca2276 PP	211	stream->common.stream_class,
	212	bt_stream_class_common_get_name(stream->common.stream_class),
	213	bt_stream_class_common_get_id(stream->common.stream_class));
094ff7c0	214	stream_class = bt_stream_borrow_class(stream);
f6ccaed9	215	BT_ASSERT(stream_class);
094ff7c0	216	trace = bt_stream_class_borrow_trace(stream_class);
f6ccaed9	217	BT_ASSERT(trace);
50842bdc	218	packet = g_new0(struct bt_packet, 1);
f79cf0f0	219	if (!packet) {
8ea705f0	220	BT_LOGE_STR("Failed to allocate one packet object.");
f79cf0f0 PP	221	goto end;
	222	}
	223
312c056a	224	bt_object_init(packet, (bt_object_release_func) bt_packet_recycle);
f79cf0f0	225	packet->stream = bt_get(stream);
be514b0c	226
3dca2276	227	if (trace->common.packet_header_field_type) {
be514b0c	228	BT_LOGD("Creating initial packet header field: ft-addr=%p",
3dca2276	229	trace->common.packet_header_field_type);
312c056a PP	230	packet->header = bt_field_wrapper_create(
	231	&trace->packet_header_field_pool,
	232	(void *) trace->common.packet_header_field_type);
be514b0c	233	if (!packet->header) {
312c056a	234	BT_LOGE("Cannot create packet header field wrapper.");
be514b0c PP	235	BT_PUT(packet);
	236	goto end;
	237	}
f79cf0f0 PP	238	}
f79cf0f0 PP	239
3dca2276	240	if (stream->common.stream_class->packet_context_field_type) {
be514b0c	241	BT_LOGD("Creating initial packet context field: ft-addr=%p",
3dca2276	242	stream->common.stream_class->packet_context_field_type);
312c056a PP	243	packet->context = bt_field_wrapper_create(
	244	&stream_class->packet_context_field_pool,
	245	(void *) stream->common.stream_class->packet_context_field_type);
be514b0c	246	if (!packet->context) {
312c056a	247	BT_LOGE("Cannot create packet context field wrapper.");
be514b0c PP	248	BT_PUT(packet);
	249	goto end;
	250	}
f79cf0f0 PP	251	}
f79cf0f0 PP	252
8ea705f0 PP	253	BT_LOGD("Created packet object: addr=%p", packet);
8ea705f0 PP	254
f79cf0f0	255	end:
f79cf0f0 PP	256	return packet;
f79cf0f0 PP	257	}
312c056a PP	258
	259	struct bt_packet bt_packet_create(struct bt_stream stream)
	260	{
	261	struct bt_packet *packet = NULL;
	262
	263	BT_ASSERT_PRE_NON_NULL(stream, "Stream");
	264	packet = bt_object_pool_create_object(&stream->packet_pool);
	265	if (!packet) {
	266	BT_LIB_LOGE("Cannot allocate one packet from stream's packet pool: "
	267	"%![stream-]+s", stream);
	268	goto error;
	269	}
	270
	271	if (!packet->stream) {
	272	packet->stream = bt_get(stream);
	273	}
	274
	275	goto end;
	276
	277	error:
	278	if (packet) {
	279	bt_packet_recycle(packet);
	280	packet = NULL;
	281	}
	282
	283	end:
	284	return packet;
	285	}
	286
	287	int bt_packet_move_header(struct bt_packet *packet,
	288	struct bt_packet_header_field *header_field)
	289	{
	290	struct bt_trace *trace;
	291	struct bt_field_wrapper field_wrapper = (void ) header_field;
	292
	293	BT_ASSERT_PRE_NON_NULL(packet, "Event");
	294	BT_ASSERT_PRE_NON_NULL(field_wrapper, "Header field");
	295	BT_ASSERT_PRE_HOT(packet, "Packet", ": +%!+a", packet);
	296	trace = bt_stream_class_borrow_trace(
	297	bt_stream_borrow_class(packet->stream));
	298	BT_ASSERT_PRE(trace->common.packet_header_field_type,
	299	"Trace has no packet header field type: %!+t",
	300	trace);
	301
	302	/* TODO: compare field types (precondition) */
	303
	304	/* Recycle current header field: always exists */
	305	BT_ASSERT(packet->header);
	306	bt_packet_header_field_recycle(packet->header, trace);
	307
	308	/* Move new field */
	309	packet->header = field_wrapper;
	310	return 0;
	311	}
	312
	313	int bt_packet_move_context(struct bt_packet *packet,
	314	struct bt_packet_context_field *context_field)
	315	{
	316	struct bt_stream_class *stream_class;
	317	struct bt_field_wrapper field_wrapper = (void ) context_field;
	318
	319	BT_ASSERT_PRE_NON_NULL(packet, "Event");
	320	BT_ASSERT_PRE_NON_NULL(field_wrapper, "Context field");
	321	BT_ASSERT_PRE_HOT(packet, "Packet", ": +%!+a", packet);
322	stream_class = bt_stream_borrow_class(packet->stream);
323	BT_ASSERT_PRE(stream_class->common.packet_context_field_type,
324	"Stream class has no packet context field type: %!+S",
325	stream_class);
326
327	/* TODO: compare field types (precondition) */
328
329	/* Recycle current context field: always exists */
330	BT_ASSERT(packet->context);
331	bt_packet_context_field_recycle(packet->context, stream_class);
332
333	/* Move new field */
334	packet->context = field_wrapper;
335	return 0;
336	}