[ltt-dev] [BABELTRACE PATCH] Basic seek support

[Mathieu Desnoyers]

* Julien Desfossez (julien.desfossez at polymtl.ca) wrote:
> For now just mimic the previous behaviour of babeltrace but with a basic
> seek structure.
> 
> Signed-off-by: Julien Desfossez <julien.desfossez at polymtl.ca>
> ---
>  converter/babeltrace-lib.c |   33 +++++++++++++++++++++++++--------
>  1 files changed, 25 insertions(+), 8 deletions(-)
> 
> diff --git a/converter/babeltrace-lib.c b/converter/babeltrace-lib.c
> index d078a69..76e5093 100644
> --- a/converter/babeltrace-lib.c
> +++ b/converter/babeltrace-lib.c
> @@ -156,7 +156,6 @@ int stream_compare(void *a, void *b)
>  		return 0;
>  }
>  
> -/* TODO: use begin_pos/end_pos */
>  struct babeltrace_iter *babeltrace_iter_create(struct trace_collection *tc,
>  		struct trace_collection_pos *begin_pos,
>  		struct trace_collection_pos *end_pos)
> @@ -170,6 +169,7 @@ struct babeltrace_iter *babeltrace_iter_create(struct trace_collection *tc,
>  		goto error_malloc;
>  	iter->stream_heap = g_new(struct ptr_heap, 1);
>  	iter->tc = tc;
> +	iter->end_pos = end_pos;
>  
>  	ret = heap_init(iter->stream_heap, 0, stream_compare);
>  	if (ret < 0)
> @@ -198,12 +198,27 @@ struct babeltrace_iter *babeltrace_iter_create(struct trace_collection *tc,
>  				file_stream = g_ptr_array_index(stream->streams,
>  						filenr);
>  
> -				ret = stream_read_event(file_stream);
> -				if (ret == EOF) {
> -					ret = 0;
> -					continue;
> -				} else if (ret) {
> -					goto error;
> +				if (begin_pos) {
> +					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.cur_index = 0;

Shouldn't you just call ctf_move_pos_slow(&file_stream->pos, 0, SEEK_SET); here ?

Otherwise the current mapping is not updated, nor is the offset
position.

Thanks,

Mathieu

> +						ret = stream_read_event(file_stream);
> +						if (ret == EOF) {
> +							ret = 0;
> +							continue;
> +						} else if (ret) {
> +							goto error;
> +						}
> +						break;
> +					case BT_SEEK_TIME:
> +					case BT_SEEK_RESTORE:
> +					case BT_SEEK_END:
> +					default:
> +						assert(0); /* Not yet defined */
> +					}
>  				}
>  				/* Add to heap */
>  				ret = heap_insert(iter->stream_heap, file_stream);
> @@ -286,12 +301,14 @@ int convert_trace(struct trace_descriptor *td_write,
>  	struct ctf_stream *stream;
>  	struct ctf_stream_event *event;
>  	struct ctf_text_stream_pos *sout;
> +	struct trace_collection_pos begin_pos;
>  	int ret = 0;
>  
>  	sout = container_of(td_write, struct ctf_text_stream_pos,
>  			trace_descriptor);
>  
> -	iter = babeltrace_iter_create(trace_collection_read, NULL, NULL);
> +	begin_pos.type = BT_SEEK_BEGIN;
> +	iter = babeltrace_iter_create(trace_collection_read, &begin_pos, NULL);
>  	while (babeltrace_iter_read_event(iter, &stream, &event) == 0) {
>  		ret = sout->parent.event_cb(&sout->parent, stream);
>  		if (ret) {
> -- 
> 1.7.4.1
> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com