src/lib/graph/message/iterator.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   5  * Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   6  */
   7
   8 #ifndef BABELTRACE_GRAPH_MESSAGE_ITERATOR_INTERNAL_H
   9 #define BABELTRACE_GRAPH_MESSAGE_ITERATOR_INTERNAL_H
  10
  11 #include "common/macros.h"
  12 #include "lib/object.h"
  13 #include <babeltrace2/graph/connection.h>
  14 #include <babeltrace2/graph/message.h>
  15 #include <babeltrace2/types.h>
  16 #include "common/assert.h"
  17 #include <stdbool.h>
  18 #include "common/uuid.h"
  19
  20 struct bt_port;
  21 struct bt_graph;
  22
  23 enum bt_message_iterator_state {
  24         /* Iterator is not initialized */
  25         BT_MESSAGE_ITERATOR_STATE_NON_INITIALIZED,
  26
  27         /* Iterator is active, not at the end yet, and not finalized */
  28         BT_MESSAGE_ITERATOR_STATE_ACTIVE,
  29
  30         /*
  31          * Iterator is ended, not finalized yet: the "next" method
  32          * returns BT_MESSAGE_ITERATOR_STATUS_END.
  33          */
  34         BT_MESSAGE_ITERATOR_STATE_ENDED,
  35
  36         /* Iterator is currently being finalized */
  37         BT_MESSAGE_ITERATOR_STATE_FINALIZING,
  38
  39         /* Iterator is finalized */
  40         BT_MESSAGE_ITERATOR_STATE_FINALIZED,
  41
  42         /* Iterator is seeking */
  43         BT_MESSAGE_ITERATOR_STATE_SEEKING,
  44
  45         /* Iterator did seek, but returned `BT_MESSAGE_ITERATOR_STATUS_AGAIN` */
  46         BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN,
  47
  48         /* Iterator did seek, but returned error status */
  49         BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR,
  50 };
  51
  52 typedef enum bt_message_iterator_class_next_method_status
  53 (*bt_message_iterator_next_method)(
  54                 void *, bt_message_array_const, uint64_t, uint64_t *);
  55
  56 typedef enum bt_message_iterator_class_seek_ns_from_origin_method_status
  57 (*bt_message_iterator_seek_ns_from_origin_method)(
  58                 void *, int64_t);
  59
  60 typedef enum bt_message_iterator_class_seek_beginning_method_status
  61 (*bt_message_iterator_seek_beginning_method)(
  62                 void *);
  63
  64 typedef enum bt_message_iterator_class_can_seek_ns_from_origin_method_status
  65 (*bt_message_iterator_can_seek_ns_from_origin_method)(
  66                 void *, int64_t, bt_bool *);
  67
  68 typedef enum bt_message_iterator_class_can_seek_beginning_method_status
  69 (*bt_message_iterator_can_seek_beginning_method)(
  70                 void *, bt_bool *);
  71
  72 struct bt_self_message_iterator_configuration {
  73         bool frozen;
  74         bool can_seek_forward;
  75 };
  76
  77 struct bt_message_iterator {
  78         struct bt_object base;
  79         GPtrArray *msgs;
  80         struct bt_component *upstream_component; /* Weak */
  81         struct bt_port *upstream_port; /* Weak */
  82         struct bt_connection *connection; /* Weak */
  83         struct bt_graph *graph; /* Weak */
  84         struct bt_self_message_iterator_configuration config;
  85
  86         /*
  87          * Array of
  88          * `struct bt_message_iterator *`
  89          * (weak).
  90          *
  91          * This is an array of upstream message iterators on which this
  92          * iterator depends. The references are weak: an upstream
  93          * message iterator is responsible for removing its entry within
  94          * this array on finalization/destruction.
  95          */
  96         GPtrArray *upstream_msg_iters;
  97
  98         /*
  99          * Downstream message iterator which depends on this message
 100          * iterator (weak).
 101          *
 102          * This can be `NULL` if this message iterator's owner is a sink
 103          * component.
 104          */
 105         struct bt_message_iterator *downstream_msg_iter;
 106
 107         struct {
 108                 bt_message_iterator_next_method next;
 109
 110                 /* These two are always both set or both unset. */
 111                 bt_message_iterator_seek_ns_from_origin_method seek_ns_from_origin;
 112                 bt_message_iterator_can_seek_ns_from_origin_method can_seek_ns_from_origin;
 113
 114                 /* These two are always both set or both unset. */
 115                 bt_message_iterator_seek_beginning_method seek_beginning;
 116                 bt_message_iterator_can_seek_beginning_method can_seek_beginning;
 117         } methods;
 118
 119         enum bt_message_iterator_state state;
 120
 121         /*
 122          * Timestamp of the last received message (or INT64_MIN in the
 123          * beginning, or after a seek to beginning).
 124          */
 125         int64_t last_ns_from_origin;
 126
 127         struct {
 128                 enum {
 129                         /* We haven't recorded clock properties yet. */
 130                         CLOCK_EXPECTATION_UNSET,
 131
 132                         /* Expect to have no clock. */
 133                         CLOCK_EXPECTATION_NONE,
 134
 135                         /* Clock with origin_is_unix_epoch true.*/
 136                         CLOCK_EXPECTATION_ORIGIN_UNIX,
 137
 138                         /* Clock with origin_is_unix_epoch false, with a UUID.*/
 139                         CLOCK_EXPECTATION_ORIGIN_OTHER_UUID,
 140
 141                         /* Clock with origin_is_unix_epoch false, without a UUID.*/
 142                         CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID,
 143                 } type;
 144
 145                 /*
 146                  * Expected UUID of the clock, if `type`is CLOCK_EXPECTATION_ORIGIN_OTHER_UUID.
 147                  *
 148                  * If the clock's origin is the unix epoch, the UUID is
 149                  * irrelevant (as the clock will be correlatable with other
 150                  * clocks having the same origin).
 151                  */
 152                 bt_uuid_t uuid;
 153         } clock_expectation;
 154
 155         /*
 156          * Data necessary for auto seek (the seek-to-beginning then fast-forward
 157          * seek strategy).
 158          */
 159         struct {
 160                 /*
 161                  * Queue of `const bt_message *` (owned by this queue).
 162                  *
 163                  * When fast-forwarding, we get the messages from upstream in
 164                  * batches. Once we have found the first message with timestamp
 165                  * greater or equal to the seek time, we put it and all of the
 166                  * following message of the batch in this queue.  They will be
 167                  * sent on the next "next" call on this iterator.
 168                  *
 169                  * The messages are in chronological order (i.e. the first to
 170                  * send is the first of the queue).
 171                  */
 172                 GQueue *msgs;
 173
 174                 /*
 175                  * After auto-seeking, we replace the iterator's `next` callback
 176                  * with our own, which returns the contents of the `msgs` queue.
 177                  * This field is where we save the original callback, so we can
 178                  * restore it.
 179                  */
 180                 void *original_next_callback;
 181         } auto_seek;
 182
 183         void *user_data;
 184 };
 185
 186 BT_HIDDEN
 187 void bt_message_iterator_try_finalize(
 188                 struct bt_message_iterator *iterator);
 189
 190 BT_HIDDEN
 191 void bt_message_iterator_set_connection(
 192                 struct bt_message_iterator *iterator,
 193                 struct bt_connection *connection);
 194
 195 static inline
 196 const char *bt_message_iterator_state_string(
 197                 enum bt_message_iterator_state state)
 198 {
 199         switch (state) {
 200         case BT_MESSAGE_ITERATOR_STATE_ACTIVE:
 201                 return "ACTIVE";
 202         case BT_MESSAGE_ITERATOR_STATE_ENDED:
 203                 return "ENDED";
 204         case BT_MESSAGE_ITERATOR_STATE_FINALIZING:
 205                 return "FINALIZING";
 206         case BT_MESSAGE_ITERATOR_STATE_FINALIZED:
 207                 return "FINALIZED";
 208         case BT_MESSAGE_ITERATOR_STATE_SEEKING:
 209                 return "SEEKING";
 210         case BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN:
 211                 return "LAST_SEEKING_RETURNED_AGAIN";
 212         case BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR:
 213                 return "LAST_SEEKING_RETURNED_ERROR";
 214         default:
 215                 return "(unknown)";
 216         }
 217 };
 218
 219 #endif /* BABELTRACE_GRAPH_MESSAGE_ITERATOR_INTERNAL_H */