[ltt-dev] [BABELTRACE PATCH] Babeltrace public API
Mathieu Desnoyers
compudj at krystal.dyndns.org
Fri Aug 12 18:44:58 EDT 2011
* Julien Desfossez (julien.desfossez at polymtl.ca) wrote:
> Add a new library to allow external tools to read traces.
> Updated convert_trace to use this API.
Merged and pushed (with minor edit).
Thanks!
Mathieu
>
> Signed-off-by: Julien Desfossez <julien.desfossez at polymtl.ca>
> ---
> converter/babeltrace-api.h | 95 ++++++++++++++++++++++++++++++
> converter/babeltrace-lib.c | 137 +++++++++++++++++++++++++++++++-------------
> 2 files changed, 193 insertions(+), 39 deletions(-)
> create mode 100644 converter/babeltrace-api.h
>
> diff --git a/converter/babeltrace-api.h b/converter/babeltrace-api.h
> new file mode 100644
> index 0000000..d95f091
> --- /dev/null
> +++ b/converter/babeltrace-api.h
> @@ -0,0 +1,95 @@
> +#ifndef _BABELTRACE_LIB_H
> +#define _BABELTRACE_LIB_H
> +
> +/*
> + * BabelTrace API
> + *
> + * Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers at 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.
> + */
> +
> +#include <babeltrace/types.h>
> +#include <babeltrace/format.h>
> +#include <babeltrace/ctf/types.h>
> +#include <babeltrace/ctf-ir/metadata.h>
> +
> +/*
> + * struct babeltrace_iter: data structure representing an iterator on a trace
> + * collection.
> + */
> +struct babeltrace_iter {
> + struct ptr_heap *stream_heap;
> + struct trace_collection *tc;
> +};
> +
> +struct babeltrace_iter_pos {
> + GPtrArray *pos; /* struct babeltrace_iter_stream_pos */
> +};
> +
> +struct babeltrace_iter_stream_pos {
> + struct stream_pos parent;
> + ssize_t offset;
> + size_t cur_index;
> +};
> +
> +/*
> + * Initialization/teardown.
> + */
> +struct babeltrace_iter *babeltrace_iter_create(struct trace_collection *tc);
> +void babeltrace_iter_destroy(struct babeltrace_iter *iter);
> +
> +/*
> + * Move within the trace.
> + */
> +/*
> + * babeltrace_iter_next: Move stream position to the next event.
> + *
> + * Does *not* read the event.
> + * Returns 0 on success, a negative value on error
> + * 0: success, event is ready.
> + */
> +int babeltrace_iter_next(struct babeltrace_iter *iter);
> +
> +/* Get the current position for each stream of the trace */
> +struct babeltrace_iter_pos *
> +babeltrace_iter_get_pos(struct babeltrace_iter *iter);
> +
> +/* The position needs to be freed after use */
> +void babeltrace_iter_free_pos(struct babeltrace_iter_pos *pos);
> +
> +/* Seek the trace to the position */
> +int babeltrace_iter_seek_pos(struct babeltrace_iter *iter,
> + struct babeltrace_iter_pos *pos);
> +
> +/*
> + * babeltrace_iter_seek_time: Seek the trace to the given timestamp.
> + *
> + * Return EOF if timestamp is after the last event of the trace.
> + * Return other negative value for other errors.
> + * Return 0 for success.
> + */
> +int babeltrace_iter_seek_time(struct babeltrace_iter *iter,
> + uint64_t timestamp);
> +
> +/*
> + * babeltrace_iter_read_event: Read the current event data.
> + *
> + * @iter: trace iterator (input)
> + * @stream: stream containing event at current position (output)
> + * @event: current event (output)
> + * Return 0 on success, negative error value on error.
> + */
> +int babeltrace_iter_read_event(struct babeltrace_iter *iter,
> + struct ctf_stream **stream,
> + struct ctf_stream_event **event);
> +
> +#endif /* _BABELTRACE_LIB_H */
> diff --git a/converter/babeltrace-lib.c b/converter/babeltrace-lib.c
> index 3f9369b..b07d1e3 100644
> --- a/converter/babeltrace-lib.c
> +++ b/converter/babeltrace-lib.c
> @@ -29,7 +29,9 @@
> #include <babeltrace/ctf-text/types.h>
> #include <babeltrace/prio_heap.h>
>
> -static int read_event(struct ctf_file_stream *sin)
> +#include "babeltrace-api.h"
> +
> +static int stream_read_event(struct ctf_file_stream *sin)
> {
> int ret;
>
> @@ -56,24 +58,23 @@ int stream_compare(void *a, void *b)
> return 0;
> }
>
> -int convert_trace(struct trace_descriptor *td_write,
> - struct trace_collection *trace_collection_read)
> +struct babeltrace_iter *babeltrace_iter_create(struct trace_collection *tc)
> {
> - struct ptr_heap *stream_heap;
> - struct ctf_text_stream_pos *sout;
> int i, stream_id;
> int ret = 0;
> + struct babeltrace_iter *iter;
>
> - stream_heap = g_new(struct ptr_heap, 1);
> - heap_init(stream_heap, 0, stream_compare);
> - sout = container_of(td_write, struct ctf_text_stream_pos,
> - trace_descriptor);
> + iter = malloc(sizeof(struct babeltrace_iter));
> + iter->stream_heap = g_new(struct ptr_heap, 1);
> + iter->tc = tc;
> +
> + heap_init(iter->stream_heap, 0, stream_compare);
>
> - for (i = 0; i < trace_collection_read->array->len; i++) {
> + for (i = 0; i < tc->array->len; i++) {
> struct ctf_trace *tin;
> struct trace_descriptor *td_read;
>
> - td_read = g_ptr_array_index(trace_collection_read->array, i);
> + td_read = g_ptr_array_index(tc->array, i);
> tin = container_of(td_read, struct ctf_trace, parent);
>
> /* Populate heap with each stream */
> @@ -92,54 +93,112 @@ int convert_trace(struct trace_descriptor *td_write,
> file_stream = g_ptr_array_index(stream->streams,
> filenr);
>
> - ret = read_event(file_stream);
> + ret = stream_read_event(file_stream);
> if (ret == EOF) {
> ret = 0;
> continue;
> } else if (ret) {
> - goto end;
> + goto error;
> }
> /* Add to heap */
> - ret = heap_insert(stream_heap, file_stream);
> + ret = heap_insert(iter->stream_heap, file_stream);
> if (ret) {
> fprintf(stdout,
> - "[error] Out of memory.\n");
> - goto end;
> + "[error] Out of memory.\n");
> + goto error;
> }
> }
> }
> }
>
> - /* Replace heap entries until EOF for each stream (heap empty) */
> - for (;;) {
> - struct ctf_file_stream *file_stream, *removed;
> + return iter;
>
> - file_stream = heap_maximum(stream_heap);
> - if (!file_stream) {
> - /* end of file for all streams */
> - ret = 0;
> - break;
> - }
> - ret = sout->parent.event_cb(&sout->parent, &file_stream->parent);
> +error:
> + heap_free(iter->stream_heap);
> + g_free(iter->stream_heap);
> + free(iter);
> + return NULL;
> +}
> +
> +void babeltrace_iter_destroy(struct babeltrace_iter *iter)
> +{
> + heap_free(iter->stream_heap);
> + g_free(iter->stream_heap);
> + free(iter);
> +}
> +
> +int babeltrace_iter_next(struct babeltrace_iter *iter)
> +{
> + struct ctf_file_stream *file_stream, *removed;
> + int ret;
> +
> + file_stream = 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 (ret == EOF) {
> + removed = heap_remove(iter->stream_heap);
> + assert(removed == file_stream);
> + ret = 0;
> + goto end;
> + } else if (ret) {
> + goto end;
> + }
> + /* Reinsert the file stream into the heap, and rebalance. */
> + removed = heap_replace_max(iter->stream_heap, file_stream);
> + assert(removed == file_stream);
> +
> +end:
> + return ret;
> +}
> +
> +int babeltrace_iter_read_event(struct babeltrace_iter *iter,
> + struct ctf_stream **stream,
> + struct ctf_stream_event **event)
> +{
> + struct ctf_file_stream *file_stream;
> + int ret = 0;
> +
> + file_stream = heap_maximum(iter->stream_heap);
> + if (!file_stream) {
> + /* end of file for all streams */
> + ret = EOF;
> + goto end;
> + }
> + *stream = &file_stream->parent;
> + *event = g_ptr_array_index((*stream)->events_by_id, (*stream)->event_id);
> +end:
> + return ret;
> +}
> +
> +int convert_trace(struct trace_descriptor *td_write,
> + struct trace_collection *trace_collection_read)
> +{
> + struct babeltrace_iter *iter;
> + struct ctf_stream *stream;
> + struct ctf_stream_event *event;
> + struct ctf_text_stream_pos *sout;
> + int ret = 0;
> +
> + sout = container_of(td_write, struct ctf_text_stream_pos,
> + trace_descriptor);
> +
> + iter = babeltrace_iter_create(trace_collection_read);
> + while (babeltrace_iter_read_event(iter, &stream, &event) == 0) {
> + ret = sout->parent.event_cb(&sout->parent, stream);
> if (ret) {
> fprintf(stdout, "[error] Writing event failed.\n");
> goto end;
> }
> - ret = read_event(file_stream);
> - if (ret == EOF) {
> - removed = heap_remove(stream_heap);
> - assert(removed == file_stream);
> - ret = 0;
> - continue;
> - } else if (ret)
> + ret = babeltrace_iter_next(iter);
> + if (ret < 0)
> goto end;
> - /* Reinsert the file stream into the heap, and rebalance. */
> - removed = heap_replace_max(stream_heap, file_stream);
> - assert(removed == file_stream);
> }
> -
> end:
> - heap_free(stream_heap);
> - g_free(stream_heap);
> + babeltrace_iter_destroy(iter);
> return ret;
> }
> --
> 1.7.4.1
>
>
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> ltt-dev at lists.casi.polymtl.ca
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>
--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
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