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 <stdbool.h>
  17 #include "common/uuid.h"
  18
  19 struct bt_port;
  20 struct bt_graph;
  21
  22 enum bt_message_iterator_state {
  23         /* Iterator is not initialized */
  24         BT_MESSAGE_ITERATOR_STATE_NON_INITIALIZED,
  25
  26         /* Iterator is active, not at the end yet, and not finalized */
  27         BT_MESSAGE_ITERATOR_STATE_ACTIVE,
  28
  29         /*
  30          * Iterator is ended, not finalized yet: the "next" method
  31          * returns BT_MESSAGE_ITERATOR_STATUS_END.
  32          */
  33         BT_MESSAGE_ITERATOR_STATE_ENDED,
  34
  35         /* Iterator is currently being finalized */
  36         BT_MESSAGE_ITERATOR_STATE_FINALIZING,
  37
  38         /* Iterator is finalized */
  39         BT_MESSAGE_ITERATOR_STATE_FINALIZED,
  40
  41         /* Iterator is seeking */
  42         BT_MESSAGE_ITERATOR_STATE_SEEKING,
  43
  44         /* Iterator did seek, but returned `BT_MESSAGE_ITERATOR_STATUS_AGAIN` */
  45         BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN,
  46
  47         /* Iterator did seek, but returned error status */
  48         BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR,
  49 };
  50
  51 typedef enum bt_message_iterator_class_next_method_status
  52 (*bt_message_iterator_next_method)(
  53                 void *, bt_message_array_const, uint64_t, uint64_t *);
  54
  55 typedef enum bt_message_iterator_class_seek_ns_from_origin_method_status
  56 (*bt_message_iterator_seek_ns_from_origin_method)(
  57                 void *, int64_t);
  58
  59 typedef enum bt_message_iterator_class_seek_beginning_method_status
  60 (*bt_message_iterator_seek_beginning_method)(
  61                 void *);
  62
  63 typedef enum bt_message_iterator_class_can_seek_ns_from_origin_method_status
  64 (*bt_message_iterator_can_seek_ns_from_origin_method)(
  65                 void *, int64_t, bt_bool *);
  66
  67 typedef enum bt_message_iterator_class_can_seek_beginning_method_status
  68 (*bt_message_iterator_can_seek_beginning_method)(
  69                 void *, bt_bool *);
  70
  71 struct bt_self_message_iterator_configuration {
  72         bool frozen;
  73         bool can_seek_forward;
  74 };
  75
  76 struct bt_message_iterator {
  77         struct bt_object base;
  78         GPtrArray *msgs;
  79         struct bt_component *upstream_component; /* Weak */
  80         struct bt_port *upstream_port; /* Weak */
  81         struct bt_connection *connection; /* Weak */
  82         struct bt_graph *graph; /* Weak */
  83         struct bt_self_message_iterator_configuration config;
  84
  85         /*
  86          * Array of
  87          * `struct bt_message_iterator *`
  88          * (weak).
  89          *
  90          * This is an array of upstream message iterators on which this
  91          * iterator depends. The references are weak: an upstream
  92          * message iterator is responsible for removing its entry within
  93          * this array on finalization/destruction.
  94          */
  95         GPtrArray *upstream_msg_iters;
  96
  97         /*
  98          * Downstream message iterator which depends on this message
  99          * iterator (weak).
 100          *
 101          * This can be `NULL` if this message iterator's owner is a sink
 102          * component.
 103          */
 104         struct bt_message_iterator *downstream_msg_iter;
 105
 106         struct {
 107                 bt_message_iterator_next_method next;
 108
 109                 /* These two are always both set or both unset. */
 110                 bt_message_iterator_seek_ns_from_origin_method seek_ns_from_origin;
 111                 bt_message_iterator_can_seek_ns_from_origin_method can_seek_ns_from_origin;
 112
 113                 /* These two are always both set or both unset. */
 114                 bt_message_iterator_seek_beginning_method seek_beginning;
 115                 bt_message_iterator_can_seek_beginning_method can_seek_beginning;
 116         } methods;
 117
 118         enum bt_message_iterator_state state;
 119
 120         /*
 121          * Timestamp of the last received message (or INT64_MIN in the
 122          * beginning, or after a seek to beginning).
 123          */
 124         int64_t last_ns_from_origin;
 125
 126         struct {
 127                 enum {
 128                         /* We haven't recorded clock properties yet. */
 129                         CLOCK_EXPECTATION_UNSET,
 130
 131                         /* Expect to have no clock. */
 132                         CLOCK_EXPECTATION_NONE,
 133
 134                         /* Clock with origin_is_unix_epoch true.*/
 135                         CLOCK_EXPECTATION_ORIGIN_UNIX,
 136
 137                         /* Clock with origin_is_unix_epoch false, with a UUID.*/
 138                         CLOCK_EXPECTATION_ORIGIN_OTHER_UUID,
 139
 140                         /* Clock with origin_is_unix_epoch false, without a UUID.*/
 141                         CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID,
 142                 } type;
 143
 144
 145                 union {
 146                         /*
 147                          * Expected UUID of the clock, if `type`is
 148                          * CLOCK_EXPECTATION_ORIGIN_OTHER_UUID.
 149                          *
 150                          * If the clock's origin is the unix epoch, the UUID is
 151                          * irrelevant (as the clock will be correlatable with other
 152                          * clocks having the same origin).
 153                          */
 154                         bt_uuid_t uuid;
 155
 156                         /*
 157                          * Expected clock class, if `type` is
 158                          * CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID.
 159                          *
 160                          * If the first clock class seen has an unknown origin
 161                          * and no UUID, then all subsequent clock classes seen
 162                          * must be the same instance.
 163                          *
 164                          * To make sure that the clock class pointed by this
 165                          * field doesn't get freed and another one reallocated
 166                          * at the same address (which could potentially bypass
 167                          * the clock expectation check), we keep a strong
 168                          * reference, ensuring that the clock class lives at
 169                          * least as long as the iterator.
 170                          */
 171                         const bt_clock_class *clock_class;
 172                 };
 173         } clock_expectation;
 174
 175         BT_IF_DEV_MODE(GHashTable *per_stream_state);
 176
 177         /*
 178          * Data necessary for auto seek (the seek-to-beginning then fast-forward
 179          * seek strategy).
 180          */
 181         struct {
 182                 /*
 183                  * Queue of `const bt_message *` (owned by this queue).
 184                  *
 185                  * When fast-forwarding, we get the messages from upstream in
 186                  * batches. Once we have found the first message with timestamp
 187                  * greater or equal to the seek time, we put it and all of the
 188                  * following message of the batch in this queue.  They will be
 189                  * sent on the next "next" call on this iterator.
 190                  *
 191                  * The messages are in chronological order (i.e. the first to
 192                  * send is the first of the queue).
 193                  */
 194                 GQueue *msgs;
 195
 196                 /*
 197                  * After auto-seeking, we replace the iterator's `next` callback
 198                  * with our own, which returns the contents of the `msgs` queue.
 199                  * This field is where we save the original callback, so we can
 200                  * restore it.
 201                  */
 202                 void *original_next_callback;
 203         } auto_seek;
 204
 205         void *user_data;
 206 };
 207
 208 void bt_message_iterator_try_finalize(
 209                 struct bt_message_iterator *iterator);
 210
 211 void bt_message_iterator_set_connection(
 212                 struct bt_message_iterator *iterator,
 213                 struct bt_connection *connection);
 214
 215 static inline
 216 const char *bt_message_iterator_state_string(
 217                 enum bt_message_iterator_state state)
 218 {
 219         switch (state) {
 220         case BT_MESSAGE_ITERATOR_STATE_ACTIVE:
 221                 return "ACTIVE";
 222         case BT_MESSAGE_ITERATOR_STATE_ENDED:
 223                 return "ENDED";
 224         case BT_MESSAGE_ITERATOR_STATE_FINALIZING:
 225                 return "FINALIZING";
 226         case BT_MESSAGE_ITERATOR_STATE_FINALIZED:
 227                 return "FINALIZED";
 228         case BT_MESSAGE_ITERATOR_STATE_SEEKING:
 229                 return "SEEKING";
 230         case BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN:
 231                 return "LAST_SEEKING_RETURNED_AGAIN";
 232         case BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR:
 233                 return "LAST_SEEKING_RETURNED_ERROR";
 234         default:
 235                 return "(unknown)";
 236         }
 237 };
 238
 239 #endif /* BABELTRACE_GRAPH_MESSAGE_ITERATOR_INTERNAL_H */