/*
* babeltrace_filestream_seek: seek a filestream to given position.
*
* The stream_id parameter is only useful for BT_SEEK_RESTORE.
*/
static int babeltrace_filestream_seek(struct ctf_file_stream *file_stream,
const struct bt_iter_pos *begin_pos,
unsigned long stream_id)
{
int ret = 0;
if (!file_stream || !begin_pos)
return -EINVAL;
switch (begin_pos->type) {
case BT_SEEK_CUR:
/*
* just insert into the heap we should already know
* the timestamps
*/
break;
case BT_SEEK_BEGIN:
file_stream->pos.packet_seek(&file_stream->pos.parent,
0, SEEK_SET);
ret = stream_read_event(file_stream);
break;
case BT_SEEK_TIME:
case BT_SEEK_RESTORE:
default:
assert(0); /* Not yet defined */
}
return ret;
}
/*
* seek_file_stream_by_timestamp
*
* Browse a filestream by index, if an index contains the timestamp passed in
* argument, seek inside the corresponding packet it until we find the event we
* are looking for (either the exact timestamp or the event just after the
* timestamp).
*
* Return 0 if the seek succeded, EOF if we didn't find any packet
* containing the timestamp, or a positive integer for error.
*
* TODO: this should be turned into a binary search! It is currently
* doing a linear search in the packets. This is a O(n) operation on a
* very frequent code path.
*/
static int seek_file_stream_by_timestamp(struct ctf_file_stream *cfs,
uint64_t timestamp)
{
struct ctf_stream_pos *stream_pos;
struct packet_index *index;
int i, ret;
stream_pos = &cfs->pos;
for (i = 0; i < stream_pos->packet_index->len; i++) {
index = &g_array_index(stream_pos->packet_index,
struct packet_index, i);
if (index->ts_real.timestamp_end < timestamp)
continue;
stream_pos->packet_seek(&stream_pos->parent, i, SEEK_SET);
do {
ret = stream_read_event(cfs);
} while (cfs->parent.real_timestamp < timestamp && ret == 0);
/* Can return either EOF, 0, or error (> 0). */
return ret;
}
/*
* Cannot find the timestamp within the stream packets, return
* EOF.
*/
return EOF;
}
int bt_iter_next(struct bt_iter *iter)
{
struct ctf_file_stream *file_stream, *removed;
int ret;
bool event_outside_interval = false;
if (!iter)
return -EINVAL;
file_stream = bt_heap_maximum(iter->stream_heap);
if (!file_stream) {
/* end of file for all streams */
ret = 0;
goto end;
}
ret = stream_read_event(file_stream);
if (file_stream->pos.parent.trace &&
file_stream->pos.parent.trace->interval_set) {
event_outside_interval =
file_stream->parent.real_timestamp >
file_stream->pos.parent.trace->interval_real.timestamp_end;
}
if (ret == EOF || event_outside_interval) {
removed = bt_heap_remove(iter->stream_heap);
assert(removed == file_stream);
ret = 0;
goto end;
} else if (ret == EAGAIN) {
/*
* Live streaming: the stream is inactive for now, we
* just updated the timestamp_end to skip over this
* stream up to a certain point in time.
*
* Since we can't guarantee that a stream will ever have
* any activity, we can't rely on the fact that
* bt_iter_next will be called for each stream and deal
* with inactive streams. So instead, we return 0 here
* to the caller and let the read API handle the
* retry case.
*/
ret = 0;
goto reinsert;
} else if (ret) {
goto end;
}
reinsert:
/* Reinsert the file stream into the heap, and rebalance. */
removed = bt_heap_replace_max(iter->stream_heap, file_stream);
assert(removed == file_stream);
end:
return ret;
}
/*
* Find timestamp of last event in the stream.
*
* Return value: 0 if OK, positive error value on error, EOF if no
* events were found.
*/
static int find_max_timestamp_ctf_file_stream(struct ctf_file_stream *cfs,
uint64_t *timestamp_end)
{
int ret, count = 0, i;
uint64_t timestamp = 0;
struct ctf_stream_pos *stream_pos;
stream_pos = &cfs->pos;
/*
* We start by the last packet, and iterate backwards until we
* either find at least one event, or we reach the first packet
* (some packets can be empty).
*/
for (i = stream_pos->packet_index->len - 1; i >= 0; i--) {
stream_pos->packet_seek(&stream_pos->parent, i, SEEK_SET);
count = 0;
/* read each event until we reach the end of the stream */
do {
ret = stream_read_event(cfs);
if (ret == 0) {
count++;
timestamp = cfs->parent.real_timestamp;
}
} while (ret == 0);
/* Error */
if (ret > 0)
goto end;
assert(ret == EOF);
if (count)
break;
}
if (count) {
*timestamp_end = timestamp;
ret = 0;
} else {
/* Return EOF if no events were found */
ret = EOF;
}
end:
return ret;
}
int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
{
struct trace_collection *tc;
int i, ret;
if (!iter || !iter_pos)
return -EINVAL;
switch (iter_pos->type) {
case BT_SEEK_RESTORE:
if (!iter_pos->u.restore)
return -EINVAL;
bt_heap_free(iter->stream_heap);
ret = bt_heap_init(iter->stream_heap, 0, stream_compare);
if (ret < 0)
goto error_heap_init;
for (i = 0; i < iter_pos->u.restore->stream_saved_pos->len;
i++) {
struct stream_saved_pos *saved_pos;
struct ctf_stream_pos *stream_pos;
struct ctf_stream_definition *stream;
saved_pos = &g_array_index(
iter_pos->u.restore->stream_saved_pos,
struct stream_saved_pos, i);
stream = &saved_pos->file_stream->parent;
stream_pos = &saved_pos->file_stream->pos;
stream_pos->packet_seek(&stream_pos->parent,
saved_pos->cur_index, SEEK_SET);
/*
* the timestamp needs to be restored after
* packet_seek, because this function resets
* the timestamp to the beginning of the packet
*/
stream->real_timestamp = saved_pos->current_real_timestamp;
stream->cycles_timestamp = saved_pos->current_cycles_timestamp;
stream_pos->offset = saved_pos->offset;
stream_pos->last_offset = LAST_OFFSET_POISON;
stream->current.real.begin = 0;
stream->current.real.end = 0;
stream->current.cycles.begin = 0;
stream->current.cycles.end = 0;
stream->prev.real.begin = 0;
stream->prev.real.end = 0;
stream->prev.cycles.begin = 0;
stream->prev.cycles.end = 0;
printf_debug("restored to cur_index = %" PRId64 " and "
"offset = %" PRId64 ", timestamp = %" PRIu64 "\n",
stream_pos->cur_index,
stream_pos->offset, stream->real_timestamp);
ret = stream_read_event(saved_pos->file_stream);
if (ret != 0) {
goto error;
}
/* Add to heap */
ret = bt_heap_insert(iter->stream_heap,
saved_pos->file_stream);
if (ret)
goto error;
}
return 0;
case BT_SEEK_TIME:
tc = iter->ctx->tc;
bt_heap_free(iter->stream_heap);
ret = bt_heap_init(iter->stream_heap, 0, stream_compare);
if (ret < 0)
goto error_heap_init;
/* for each trace in the trace_collection */
for (i = 0; i < tc->array->len; i++) {
struct ctf_trace *tin;
struct bt_trace_descriptor *td_read;
td_read = g_ptr_array_index(tc->array, i);
if (!td_read)
continue;
tin = container_of(td_read, struct ctf_trace, parent);
ret = seek_ctf_trace_by_timestamp(tin,
iter_pos->u.seek_time,
iter->stream_heap);
/*
* Positive errors are failure. Negative value
* is EOF (for which we continue with other
* traces). 0 is success. Note: on EOF, it just
* means that no stream has been added to the
* iterator for that trace, which is fine.
*/
if (ret != 0 && ret != EOF)
goto error;
}
return 0;
case BT_SEEK_BEGIN:
tc = iter->ctx->tc;
bt_heap_free(iter->stream_heap);
ret = bt_heap_init(iter->stream_heap, 0, stream_compare);
if (ret < 0)
goto error_heap_init;
for (i = 0; i < tc->array->len; i++) {
struct ctf_trace *tin;
struct bt_trace_descriptor *td_read;
int stream_id;
td_read = g_ptr_array_index(tc->array, i);
if (!td_read)
continue;
tin = container_of(td_read, struct ctf_trace, parent);
/* Populate heap with each stream */
for (stream_id = 0; stream_id < tin->streams->len;
stream_id++) {
struct ctf_stream_declaration *stream;
int filenr;
stream = g_ptr_array_index(tin->streams,
stream_id);
if (!stream)
continue;
for (filenr = 0; filenr < stream->streams->len;
filenr++) {
struct ctf_file_stream *file_stream;
file_stream = g_ptr_array_index(
stream->streams,
filenr);
if (!file_stream)
continue;
ret = babeltrace_filestream_seek(
file_stream, iter_pos,
stream_id);
if (ret != 0 && ret != EOF) {
goto error;
}
if (ret == EOF) {
/* Do not add EOF streams */
continue;
}
ret = bt_heap_insert(iter->stream_heap, file_stream);
if (ret)
goto error;
}
}
}
break;
case BT_SEEK_LAST:
{
struct ctf_file_stream *cfs = NULL;
tc = iter->ctx->tc;
ret = seek_last_ctf_trace_collection(tc, &cfs);
if (ret != 0 || !cfs)
goto error;
/* remove all streams from the heap */
bt_heap_free(iter->stream_heap);
/* Create a new empty heap */
ret = bt_heap_init(iter->stream_heap, 0, stream_compare);
if (ret < 0)
goto error;
/* Insert the stream that contains the last event */
ret = bt_heap_insert(iter->stream_heap, cfs);
if (ret)
goto error;
break;
}
default:
/* not implemented */
return -EINVAL;
}
return 0;
error:
bt_heap_free(iter->stream_heap);
error_heap_init:
if (bt_heap_init(iter->stream_heap, 0, stream_compare) < 0) {
bt_heap_free(iter->stream_heap);
g_free(iter->stream_heap);
iter->stream_heap = NULL;
ret = -ENOMEM;
}
return ret;
}
