X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=blobdiff_plain;f=lib%2Fiterator.c;h=927444f47931885ea166be040b5133a8261827fe;hp=4b5b453fae609ba5a025c3527461b977f4ccaf6e;hb=b4b292cc76e04e9efda111e492251d8e7aefe451;hpb=3394d22e104e2f6511b656773ef4e74506842f3e

diff --git a/lib/iterator.c b/lib/iterator.c
index 4b5b453f..927444f4 100644
--- a/lib/iterator.c
+++ b/lib/iterator.c
@@ -20,12 +20,18 @@
 
 #include <stdlib.h>
 #include <babeltrace/babeltrace.h>
-#include <babeltrace/callbacks-internal.h>
 #include <babeltrace/context.h>
-#include <babeltrace/ctf/metadata.h>
+#include <babeltrace/context-internal.h>
 #include <babeltrace/iterator-internal.h>
 #include <babeltrace/iterator.h>
 #include <babeltrace/prio_heap.h>
+#include <babeltrace/ctf/metadata.h>
+#include <babeltrace/ctf/events.h>
+#include <inttypes.h>
+
+static int babeltrace_filestream_seek(struct ctf_file_stream *file_stream,
+		const struct bt_iter_pos *begin_pos,
+		unsigned long stream_id);
 
 struct stream_saved_pos {
 	/*
@@ -35,9 +41,11 @@ struct stream_saved_pos {
 	struct ctf_file_stream *file_stream;
 	size_t cur_index;	/* current index in packet index */
 	ssize_t offset;		/* offset from base, in bits. EOF for end of file. */
+	uint64_t current_real_timestamp;
+	uint64_t current_cycles_timestamp;
 };
 
-struct babeltrace_saved_pos {
+struct bt_saved_pos {
 	struct trace_collection *tc;
 	GArray *stream_saved_pos;	/* Contains struct stream_saved_pos */
 };
@@ -59,27 +67,550 @@ static int stream_read_event(struct ctf_file_stream *sin)
 /*
  * returns true if a < b, false otherwise.
  */
-int stream_compare(void *a, void *b)
+static int stream_compare(void *a, void *b)
 {
 	struct ctf_file_stream *s_a = a, *s_b = b;
 
-	if (s_a->parent.timestamp < s_b->parent.timestamp)
+	if (s_a->parent.real_timestamp < s_b->parent.real_timestamp)
 		return 1;
 	else
 		return 0;
 }
 
+void bt_iter_free_pos(struct bt_iter_pos *iter_pos)
+{
+	if (!iter_pos)
+		return;
+
+	if (iter_pos->type == BT_SEEK_RESTORE && iter_pos->u.restore) {
+		if (iter_pos->u.restore->stream_saved_pos) {
+			g_array_free(
+				iter_pos->u.restore->stream_saved_pos,
+				TRUE);
+		}
+		g_free(iter_pos->u.restore);
+	}
+	g_free(iter_pos);
+}
+
+/*
+ * 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_real_index->len; i++) {
+		index = &g_array_index(stream_pos->packet_real_index,
+				struct packet_index, i);
+		if (index->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;
+}
+
+/*
+ * seek_ctf_trace_by_timestamp : for each file stream, seek to the event with
+ * the corresponding timestamp
+ *
+ * Return 0 on success.
+ * If the timestamp is not part of any file stream, return EOF to inform the
+ * user the timestamp is out of the scope.
+ * On other errors, return positive value.
+ */
+static int seek_ctf_trace_by_timestamp(struct ctf_trace *tin,
+		uint64_t timestamp, struct ptr_heap *stream_heap)
+{
+	int i, j, ret;
+	int found = 0;
+
+	/* for each stream_class */
+	for (i = 0; i < tin->streams->len; i++) {
+		struct ctf_stream_declaration *stream_class;
+
+		stream_class = g_ptr_array_index(tin->streams, i);
+		if (!stream_class)
+			continue;
+		/* for each file_stream */
+		for (j = 0; j < stream_class->streams->len; j++) {
+			struct ctf_stream_definition *stream;
+			struct ctf_file_stream *cfs;
+
+			stream = g_ptr_array_index(stream_class->streams, j);
+			if (!stream)
+				continue;
+			cfs = container_of(stream, struct ctf_file_stream,
+					parent);
+			ret = seek_file_stream_by_timestamp(cfs, timestamp);
+			if (ret == 0) {
+				/* Add to heap */
+				ret = heap_insert(stream_heap, cfs);
+				if (ret) {
+					/* Return positive error. */
+					return -ret;
+				}
+				found = 1;
+			} else if (ret > 0) {
+				/*
+				 * Error in seek (not EOF), failure.
+				 */
+				return ret;
+			}
+			/* on EOF just do not put stream into heap. */
+		}
+	}
+
+	return found ? 0 : EOF;
+}
+
+/*
+ * 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_real_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;
+}
+
+/*
+ * Find the stream within a stream class that contains the event with
+ * the largest timestamp, and save that timestamp.
+ *
+ * Return 0 if OK, EOF if no events were found in the streams, or
+ * positive value on error.
+ */
+static int find_max_timestamp_ctf_stream_class(
+		struct ctf_stream_declaration *stream_class,
+		struct ctf_file_stream **cfsp,
+		uint64_t *max_timestamp)
+{
+	int ret = EOF, i;
+
+	for (i = 0; i < stream_class->streams->len; i++) {
+		struct ctf_stream_definition *stream;
+		struct ctf_file_stream *cfs;
+		uint64_t current_max_ts = 0;
+
+		stream = g_ptr_array_index(stream_class->streams, i);
+		if (!stream)
+			continue;
+		cfs = container_of(stream, struct ctf_file_stream, parent);
+		ret = find_max_timestamp_ctf_file_stream(cfs, &current_max_ts);
+		if (ret == EOF)
+			continue;
+		if (ret != 0)
+			break;
+		if (current_max_ts >= *max_timestamp) {
+			*max_timestamp = current_max_ts;
+			*cfsp = cfs;
+		}
+	}
+	assert(ret >= 0 || ret == EOF);
+	return ret;
+}
+
+/*
+ * seek_last_ctf_trace_collection: seek trace collection to last event.
+ *
+ * Return 0 if OK, EOF if no events were found, or positive error value
+ * on error.
+ */
+static int seek_last_ctf_trace_collection(struct trace_collection *tc,
+		struct ctf_file_stream **cfsp)
+{
+	int i, j, ret;
+	int found = 0;
+	uint64_t max_timestamp = 0;
+
+	if (!tc)
+		return 1;
+
+	/* For each trace in the trace_collection */
+	for (i = 0; i < tc->array->len; i++) {
+		struct ctf_trace *tin;
+		struct 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);
+		/* For each stream_class in the trace */
+		for (j = 0; j < tin->streams->len; j++) {
+			struct ctf_stream_declaration *stream_class;
+
+			stream_class = g_ptr_array_index(tin->streams, j);
+			if (!stream_class)
+				continue;
+			ret = find_max_timestamp_ctf_stream_class(stream_class,
+					cfsp, &max_timestamp);
+			if (ret > 0)
+				goto end;
+			if (ret == 0)
+				found = 1;
+			assert(ret == EOF || ret == 0);
+		}
+	}
+	/*
+	 * Now we know in which file stream the last event is located,
+	 * and we know its timestamp.
+	 */
+	if (!found) {
+		ret = EOF;
+	} else {
+		ret = seek_file_stream_by_timestamp(*cfsp, max_timestamp);
+		assert(ret == 0);
+	}
+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;
+
+		heap_free(iter->stream_heap);
+		ret = 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->prev_real_timestamp = 0;
+			stream->prev_real_timestamp_end = 0;
+			stream->prev_cycles_timestamp = 0;
+			stream->prev_cycles_timestamp_end = 0;
+
+			printf_debug("restored to cur_index = %zd and "
+				"offset = %zd, 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 = heap_insert(iter->stream_heap,
+					saved_pos->file_stream);
+			if (ret)
+				goto error;
+		}
+		return 0;
+	case BT_SEEK_TIME:
+		tc = iter->ctx->tc;
+
+		heap_free(iter->stream_heap);
+		ret = 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 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;
+		heap_free(iter->stream_heap);
+		ret = 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 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;
+					}
+					ret = heap_insert(iter->stream_heap, file_stream);
+					if (ret)
+						goto error;
+				}
+			}
+		}
+		break;
+	case BT_SEEK_LAST:
+	{
+		struct ctf_file_stream *cfs;
+
+		tc = iter->ctx->tc;
+		ret = seek_last_ctf_trace_collection(tc, &cfs);
+		if (ret != 0)
+			goto error;
+		/* remove all streams from the heap */
+		heap_free(iter->stream_heap);
+		/* Create a new empty heap */
+		ret = heap_init(iter->stream_heap, 0, stream_compare);
+		if (ret < 0)
+			goto error;
+		/* Insert the stream that contains the last event */
+		ret = heap_insert(iter->stream_heap, cfs);
+		if (ret)
+			goto error;
+		break;
+	}
+	default:
+		/* not implemented */
+		return -EINVAL;
+	}
+
+	return 0;
+
+error:
+	heap_free(iter->stream_heap);
+error_heap_init:
+	if (heap_init(iter->stream_heap, 0, stream_compare) < 0) {
+		heap_free(iter->stream_heap);
+		g_free(iter->stream_heap);
+		iter->stream_heap = NULL;
+		ret = -ENOMEM;
+	}
+
+	return ret;
+}
+
+struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter)
+{
+	struct bt_iter_pos *pos;
+	struct trace_collection *tc;
+	struct ctf_file_stream *file_stream = NULL, *removed;
+	struct ptr_heap iter_heap_copy;
+	int ret;
+
+	if (!iter)
+		return NULL;
+
+	tc = iter->ctx->tc;
+	pos = g_new0(struct bt_iter_pos, 1);
+	pos->type = BT_SEEK_RESTORE;
+	pos->u.restore = g_new0(struct bt_saved_pos, 1);
+	pos->u.restore->tc = tc;
+	pos->u.restore->stream_saved_pos = g_array_new(FALSE, TRUE,
+			sizeof(struct stream_saved_pos));
+	if (!pos->u.restore->stream_saved_pos)
+		goto error;
+
+	ret = heap_copy(&iter_heap_copy, iter->stream_heap);
+	if (ret < 0)
+		goto error_heap;
+
+	/* iterate over each stream in the heap */
+	file_stream = heap_maximum(&iter_heap_copy);
+	while (file_stream != NULL) {
+		struct stream_saved_pos saved_pos;
+
+		assert(file_stream->pos.last_offset != LAST_OFFSET_POISON);
+		saved_pos.offset = file_stream->pos.last_offset;
+		saved_pos.file_stream = file_stream;
+		saved_pos.cur_index = file_stream->pos.cur_index;
+
+		saved_pos.current_real_timestamp = file_stream->parent.real_timestamp;
+		saved_pos.current_cycles_timestamp = file_stream->parent.cycles_timestamp;
+
+		g_array_append_val(
+				pos->u.restore->stream_saved_pos,
+				saved_pos);
+
+		printf_debug("stream : %" PRIu64 ", cur_index : %zd, "
+				"offset : %zd, "
+				"timestamp = %" PRIu64 "\n",
+				file_stream->parent.stream_id,
+				saved_pos.cur_index, saved_pos.offset,
+				saved_pos.current_real_timestamp);
+
+		/* remove the stream from the heap copy */
+		removed = heap_remove(&iter_heap_copy);
+		assert(removed == file_stream);
+
+		file_stream = heap_maximum(&iter_heap_copy);
+	}
+	heap_free(&iter_heap_copy);
+	return pos;
+
+error_heap:
+	g_array_free(pos->u.restore->stream_saved_pos, TRUE);
+error:
+	g_free(pos);
+	return NULL;
+}
+
+struct bt_iter_pos *bt_iter_create_time_pos(struct bt_iter *iter,
+		uint64_t timestamp)
+{
+	struct bt_iter_pos *pos;
+
+	if (!iter)
+		return NULL;
+
+	pos = g_new0(struct bt_iter_pos, 1);
+	pos->type = BT_SEEK_TIME;
+	pos->u.seek_time = timestamp;
+	return pos;
+}
+
 /*
  * 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 trace_collection_pos *begin_pos,
+		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:
 		/*
@@ -88,7 +619,8 @@ static int babeltrace_filestream_seek(struct ctf_file_stream *file_stream,
 		 */
 		break;
 	case BT_SEEK_BEGIN:
-		file_stream->pos.move_pos_slow(&file_stream->pos, 0, SEEK_SET);
+		file_stream->pos.packet_seek(&file_stream->pos.parent,
+				0, SEEK_SET);
 		ret = stream_read_event(file_stream);
 		break;
 	case BT_SEEK_TIME:
@@ -101,66 +633,25 @@ static int babeltrace_filestream_seek(struct ctf_file_stream *file_stream,
 	return ret;
 }
 
-/*
- * babeltrace_iter_seek: seek iterator to given position.
- */
-int babeltrace_iter_seek(struct babeltrace_iter *iter,
-		const struct trace_collection_pos *begin_pos)
+int bt_iter_init(struct bt_iter *iter,
+		struct bt_context *ctx,
+		const struct bt_iter_pos *begin_pos,
+		const struct bt_iter_pos *end_pos)
 {
 	int i, stream_id;
 	int ret = 0;
-	struct trace_collection *tc = iter->ctx->tc;
 
-	for (i = 0; i < tc->array->len; i++) {
-		struct ctf_trace *tin;
-		struct trace_descriptor *td_read;
-
-		td_read = g_ptr_array_index(tc->array, i);
-		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_class *stream;
-			int filenr;
+	if (!iter || !ctx)
+		return -EINVAL;
 
-			stream = g_ptr_array_index(tin->streams, stream_id);
-			for (filenr = 0; filenr < stream->streams->len;
-					filenr++) {
-				struct ctf_file_stream *file_stream;
-
-				file_stream = g_ptr_array_index(stream->streams,
-						filenr);
-				ret = babeltrace_filestream_seek(file_stream, begin_pos,
-						stream_id);
-				if (ret < 0)
-					goto end;
-			}
-		}
+	if (ctx->current_iterator) {
+		ret = -1;
+		goto error_ctx;
 	}
-end:
-	return ret;
-}
 
-struct babeltrace_iter *babeltrace_iter_create(struct bt_context *ctx,
-		struct trace_collection_pos *begin_pos,
-		struct trace_collection_pos *end_pos)
-{
-	int i, stream_id;
-	int ret = 0;
-	struct babeltrace_iter *iter;
-
-	iter = malloc(sizeof(struct babeltrace_iter));
-	if (!iter)
-		goto error_malloc;
 	iter->stream_heap = g_new(struct ptr_heap, 1);
 	iter->end_pos = end_pos;
-	iter->callbacks = g_array_new(0, 1, sizeof(struct bt_stream_callbacks));
-	iter->recalculate_dep_graph = 0;
-	iter->main_callbacks.callback = NULL;
-	iter->dep_gc = g_ptr_array_new();
-	if (bt_context_get(ctx) != 0)
-		goto error_ctx;
+	bt_context_get(ctx);
 	iter->ctx = ctx;
 
 	ret = heap_init(iter->stream_heap, 0, stream_compare);
@@ -172,12 +663,14 @@ struct babeltrace_iter *babeltrace_iter_create(struct bt_context *ctx,
 		struct trace_descriptor *td_read;
 
 		td_read = g_ptr_array_index(ctx->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_class *stream;
+			struct ctf_stream_declaration *stream;
 			int filenr;
 
 			stream = g_ptr_array_index(tin->streams, stream_id);
@@ -189,16 +682,25 @@ struct babeltrace_iter *babeltrace_iter_create(struct bt_context *ctx,
 
 				file_stream = g_ptr_array_index(stream->streams,
 						filenr);
-
+				if (!file_stream)
+					continue;
 				if (begin_pos) {
-				    ret = babeltrace_filestream_seek(file_stream, begin_pos,
+					ret = babeltrace_filestream_seek(
+							file_stream,
+							begin_pos,
+							stream_id);
+				} else {
+					struct bt_iter_pos pos;
+					pos.type = BT_SEEK_BEGIN;
+					ret = babeltrace_filestream_seek(
+							file_stream, &pos,
 							stream_id);
-				    if (ret == EOF) {
-					   ret = 0;
-					   continue;
-				    } else if (ret) {
-					   goto error;
-				    }
+				}
+				if (ret == EOF) {
+					ret = 0;
+					continue;
+				} else if (ret) {
+					goto error;
 				}
 				/* Add to heap */
 				ret = heap_insert(iter->stream_heap, file_stream);
@@ -208,57 +710,63 @@ struct babeltrace_iter *babeltrace_iter_create(struct bt_context *ctx,
 		}
 	}
 
-	return iter;
+	ctx->current_iterator = iter;
+	return 0;
 
 error:
 	heap_free(iter->stream_heap);
 error_heap_init:
 	g_free(iter->stream_heap);
+	iter->stream_heap = NULL;
 error_ctx:
-	free(iter);
-error_malloc:
-	return NULL;
+	return ret;
 }
 
-void babeltrace_iter_destroy(struct babeltrace_iter *iter)
+struct bt_iter *bt_iter_create(struct bt_context *ctx,
+		const struct bt_iter_pos *begin_pos,
+		const struct bt_iter_pos *end_pos)
 {
-	struct bt_stream_callbacks *bt_stream_cb;
-	struct bt_callback_chain *bt_chain;
-	int i, j;
-
-	heap_free(iter->stream_heap);
-	g_free(iter->stream_heap);
+	struct bt_iter *iter;
+	int ret;
 
-	/* free all events callbacks */
-	if (iter->main_callbacks.callback)
-		g_array_free(iter->main_callbacks.callback, TRUE);
+	if (!ctx)
+		return NULL;
 
-	/* free per-event callbacks */
-	for (i = 0; i < iter->callbacks->len; i++) {
-		bt_stream_cb = &g_array_index(iter->callbacks,
-				struct bt_stream_callbacks, i);
-		if (!bt_stream_cb || !bt_stream_cb->per_id_callbacks)
-			continue;
-		for (j = 0; j < bt_stream_cb->per_id_callbacks->len; j++) {
-			bt_chain = &g_array_index(bt_stream_cb->per_id_callbacks,
-					struct bt_callback_chain, j);
-			if (bt_chain->callback) {
-				g_array_free(bt_chain->callback, TRUE);
-			}
-		}
-		g_array_free(bt_stream_cb->per_id_callbacks, TRUE);
+	iter = g_new0(struct bt_iter, 1);
+	ret = bt_iter_init(iter, ctx, begin_pos, end_pos);
+	if (ret) {
+		g_free(iter);
+		return NULL;
 	}
+	return iter;
+}
 
+void bt_iter_fini(struct bt_iter *iter)
+{
+	assert(iter);
+	if (iter->stream_heap) {
+		heap_free(iter->stream_heap);
+		g_free(iter->stream_heap);
+	}
+	iter->ctx->current_iterator = NULL;
 	bt_context_put(iter->ctx);
+}
 
-	free(iter);
+void bt_iter_destroy(struct bt_iter *iter)
+{
+	assert(iter);
+	bt_iter_fini(iter);
+	g_free(iter);
 }
 
-int babeltrace_iter_next(struct babeltrace_iter *iter)
+int bt_iter_next(struct bt_iter *iter)
 {
 	struct ctf_file_stream *file_stream, *removed;
 	int ret;
 
+	if (!iter)
+		return -EINVAL;
+
 	file_stream = heap_maximum(iter->stream_heap);
 	if (!file_stream) {
 		/* end of file for all streams */
@@ -282,28 +790,3 @@ int babeltrace_iter_next(struct babeltrace_iter *iter)
 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);
-
-	if ((*stream)->stream_id > iter->callbacks->len)
-		goto end;
-
-	process_callbacks(iter, *stream);
-
-end:
-	return ret;
-}