src/lib/graph/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                 union {
 147                         /*
 148                          * Expected UUID of the clock, if `type`is
 149                          * CLOCK_EXPECTATION_ORIGIN_OTHER_UUID.
 150                          *
 151                          * If the clock's origin is the unix epoch, the UUID is
 152                          * irrelevant (as the clock will be correlatable with other
 153                          * clocks having the same origin).
 154                          */
 155                         bt_uuid_t uuid;
 156
 157                         /*
 158                          * Expected clock class, if `type` is
 159                          * CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID.
 160                          *
 161                          * If the first clock class seen has an unknown origin
 162                          * and no UUID, then all subsequent clock classes seen
 163                          * must be the same instance.
 164                          *
 165                          * To make sure that the clock class pointed by this
 166                          * field doesn't get freed and another one reallocated
 167                          * at the same address (which could potentially bypass
 168                          * the clock expectation check), we keep a strong
 169                          * reference, ensuring that the clock class lives at
 170                          * least as long as the iterator.
 171                          */
 172                         const bt_clock_class *clock_class;
 173                 };
 174         } clock_expectation;
 175
 176         BT_IF_DEV_MODE(GHashTable *per_stream_state);
 177
 178         /*
 179          * Data necessary for auto seek (the seek-to-beginning then fast-forward
 180          * seek strategy).
 181          */
 182         struct {
 183                 /*
 184                  * Queue of `const bt_message *` (owned by this queue).
 185                  *
 186                  * When fast-forwarding, we get the messages from upstream in
 187                  * batches. Once we have found the first message with timestamp
 188                  * greater or equal to the seek time, we put it and all of the
 189                  * following message of the batch in this queue.  They will be
 190                  * sent on the next "next" call on this iterator.
 191                  *
 192                  * The messages are in chronological order (i.e. the first to
 193                  * send is the first of the queue).
 194                  */
 195                 GQueue *msgs;
 196
 197                 /*
 198                  * After auto-seeking, we replace the iterator's `next` callback
 199                  * with our own, which returns the contents of the `msgs` queue.
 200                  * This field is where we save the original callback, so we can
 201                  * restore it.
 202                  */
 203                 void *original_next_callback;
 204         } auto_seek;
 205
 206         void *user_data;
 207 };
 208
 209 void bt_message_iterator_try_finalize(
 210                 struct bt_message_iterator *iterator);
 211
 212 void bt_message_iterator_set_connection(
 213                 struct bt_message_iterator *iterator,
 214                 struct bt_connection *connection);
 215
 216 static inline
 217 const char *bt_message_iterator_state_string(
 218                 enum bt_message_iterator_state state)
 219 {
 220         switch (state) {
 221         case BT_MESSAGE_ITERATOR_STATE_ACTIVE:
 222                 return "ACTIVE";
 223         case BT_MESSAGE_ITERATOR_STATE_ENDED:
 224                 return "ENDED";
 225         case BT_MESSAGE_ITERATOR_STATE_FINALIZING:
 226                 return "FINALIZING";
 227         case BT_MESSAGE_ITERATOR_STATE_FINALIZED:
 228                 return "FINALIZED";
 229         case BT_MESSAGE_ITERATOR_STATE_SEEKING:
 230                 return "SEEKING";
 231         case BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN:
 232                 return "LAST_SEEKING_RETURNED_AGAIN";
 233         case BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR:
 234                 return "LAST_SEEKING_RETURNED_ERROR";
 235         default:
 236                 return "(unknown)";
 237         }
 238 };
 239
 240 #endif /* BABELTRACE_GRAPH_MESSAGE_ITERATOR_INTERNAL_H */