+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
+ * Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ */
+
+#ifndef BABELTRACE_GRAPH_MESSAGE_ITERATOR_INTERNAL_H
+#define BABELTRACE_GRAPH_MESSAGE_ITERATOR_INTERNAL_H
+
+#include "common/macros.h"
+#include "lib/object.h"
+#include <babeltrace2/graph/connection.h>
+#include <babeltrace2/graph/message.h>
+#include <babeltrace2/types.h>
+#include "common/assert.h"
+#include <stdbool.h>
+#include "common/uuid.h"
+
+struct bt_port;
+struct bt_graph;
+
+enum bt_message_iterator_state {
+ /* Iterator is not initialized */
+ BT_MESSAGE_ITERATOR_STATE_NON_INITIALIZED,
+
+ /* Iterator is active, not at the end yet, and not finalized */
+ BT_MESSAGE_ITERATOR_STATE_ACTIVE,
+
+ /*
+ * Iterator is ended, not finalized yet: the "next" method
+ * returns BT_MESSAGE_ITERATOR_STATUS_END.
+ */
+ BT_MESSAGE_ITERATOR_STATE_ENDED,
+
+ /* Iterator is currently being finalized */
+ BT_MESSAGE_ITERATOR_STATE_FINALIZING,
+
+ /* Iterator is finalized */
+ BT_MESSAGE_ITERATOR_STATE_FINALIZED,
+
+ /* Iterator is seeking */
+ BT_MESSAGE_ITERATOR_STATE_SEEKING,
+
+ /* Iterator did seek, but returned `BT_MESSAGE_ITERATOR_STATUS_AGAIN` */
+ BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN,
+
+ /* Iterator did seek, but returned error status */
+ BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR,
+};
+
+typedef enum bt_message_iterator_class_next_method_status
+(*bt_message_iterator_next_method)(
+ void *, bt_message_array_const, uint64_t, uint64_t *);
+
+typedef enum bt_message_iterator_class_seek_ns_from_origin_method_status
+(*bt_message_iterator_seek_ns_from_origin_method)(
+ void *, int64_t);
+
+typedef enum bt_message_iterator_class_seek_beginning_method_status
+(*bt_message_iterator_seek_beginning_method)(
+ void *);
+
+typedef enum bt_message_iterator_class_can_seek_ns_from_origin_method_status
+(*bt_message_iterator_can_seek_ns_from_origin_method)(
+ void *, int64_t, bt_bool *);
+
+typedef enum bt_message_iterator_class_can_seek_beginning_method_status
+(*bt_message_iterator_can_seek_beginning_method)(
+ void *, bt_bool *);
+
+struct bt_self_message_iterator_configuration {
+ bool frozen;
+ bool can_seek_forward;
+};
+
+struct bt_message_iterator {
+ struct bt_object base;
+ GPtrArray *msgs;
+ struct bt_component *upstream_component; /* Weak */
+ struct bt_port *upstream_port; /* Weak */
+ struct bt_connection *connection; /* Weak */
+ struct bt_graph *graph; /* Weak */
+ struct bt_self_message_iterator_configuration config;
+
+ /*
+ * Array of
+ * `struct bt_message_iterator *`
+ * (weak).
+ *
+ * This is an array of upstream message iterators on which this
+ * iterator depends. The references are weak: an upstream
+ * message iterator is responsible for removing its entry within
+ * this array on finalization/destruction.
+ */
+ GPtrArray *upstream_msg_iters;
+
+ /*
+ * Downstream message iterator which depends on this message
+ * iterator (weak).
+ *
+ * This can be `NULL` if this message iterator's owner is a sink
+ * component.
+ */
+ struct bt_message_iterator *downstream_msg_iter;
+
+ struct {
+ bt_message_iterator_next_method next;
+
+ /* These two are always both set or both unset. */
+ bt_message_iterator_seek_ns_from_origin_method seek_ns_from_origin;
+ bt_message_iterator_can_seek_ns_from_origin_method can_seek_ns_from_origin;
+
+ /* These two are always both set or both unset. */
+ bt_message_iterator_seek_beginning_method seek_beginning;
+ bt_message_iterator_can_seek_beginning_method can_seek_beginning;
+ } methods;
+
+ enum bt_message_iterator_state state;
+
+ /*
+ * Timestamp of the last received message (or INT64_MIN in the
+ * beginning, or after a seek to beginning).
+ */
+ int64_t last_ns_from_origin;
+
+ struct {
+ enum {
+ /* We haven't recorded clock properties yet. */
+ CLOCK_EXPECTATION_UNSET,
+
+ /* Expect to have no clock. */
+ CLOCK_EXPECTATION_NONE,
+
+ /* Clock with origin_is_unix_epoch true.*/
+ CLOCK_EXPECTATION_ORIGIN_UNIX,
+
+ /* Clock with origin_is_unix_epoch false, with a UUID.*/
+ CLOCK_EXPECTATION_ORIGIN_OTHER_UUID,
+
+ /* Clock with origin_is_unix_epoch false, without a UUID.*/
+ CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID,
+ } type;
+
+ /*
+ * Expected UUID of the clock, if `type`is CLOCK_EXPECTATION_ORIGIN_OTHER_UUID.
+ *
+ * If the clock's origin is the unix epoch, the UUID is
+ * irrelevant (as the clock will be correlatable with other
+ * clocks having the same origin).
+ */
+ bt_uuid_t uuid;
+ } clock_expectation;
+
+ BT_IF_DEV_MODE(GHashTable *per_stream_state);
+
+ /*
+ * Data necessary for auto seek (the seek-to-beginning then fast-forward
+ * seek strategy).
+ */
+ struct {
+ /*
+ * Queue of `const bt_message *` (owned by this queue).
+ *
+ * When fast-forwarding, we get the messages from upstream in
+ * batches. Once we have found the first message with timestamp
+ * greater or equal to the seek time, we put it and all of the
+ * following message of the batch in this queue. They will be
+ * sent on the next "next" call on this iterator.
+ *
+ * The messages are in chronological order (i.e. the first to
+ * send is the first of the queue).
+ */
+ GQueue *msgs;
+
+ /*
+ * After auto-seeking, we replace the iterator's `next` callback
+ * with our own, which returns the contents of the `msgs` queue.
+ * This field is where we save the original callback, so we can
+ * restore it.
+ */
+ void *original_next_callback;
+ } auto_seek;
+
+ void *user_data;
+};
+
+void bt_message_iterator_try_finalize(
+ struct bt_message_iterator *iterator);
+
+void bt_message_iterator_set_connection(
+ struct bt_message_iterator *iterator,
+ struct bt_connection *connection);
+
+static inline
+const char *bt_message_iterator_state_string(
+ enum bt_message_iterator_state state)
+{
+ switch (state) {
+ case BT_MESSAGE_ITERATOR_STATE_ACTIVE:
+ return "ACTIVE";
+ case BT_MESSAGE_ITERATOR_STATE_ENDED:
+ return "ENDED";
+ case BT_MESSAGE_ITERATOR_STATE_FINALIZING:
+ return "FINALIZING";
+ case BT_MESSAGE_ITERATOR_STATE_FINALIZED:
+ return "FINALIZED";
+ case BT_MESSAGE_ITERATOR_STATE_SEEKING:
+ return "SEEKING";
+ case BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN:
+ return "LAST_SEEKING_RETURNED_AGAIN";
+ case BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR:
+ return "LAST_SEEKING_RETURNED_ERROR";
+ default:
+ return "(unknown)";
+ }
+};
+
+#endif /* BABELTRACE_GRAPH_MESSAGE_ITERATOR_INTERNAL_H */