Module format and executor: 027's stage 3, nested stored state: a stored or a transient list's records may hold lists (a message's rows not, nor as a key); such a list's cell holds the value in its items' stored form (PURE_CELL_LIST, held as bytes are: each item's fields in order, 8 bytes a number, bool or i64, a u32le length and bytes a text or a list, a list's in this form again), read into one of the event's lists by ITEM_GET (counted in the event's room) and written from one by LIST_APPEND, LIST_INSERT and ITEM_SET, APPEND_IN reading, appending and writing back (undone with the event): images, the log, undoing, readers' shares and commits hold it as a text's bytes, so nothing new is stored or recovered; a list image's header names its record graph (a list field's items' record by its number, the graph's other records after the fields: a record holds itself through a list), and starting or replacing moves the items of the lists in fields by field name down the graph (PureLayout, pure_list_migrate); an event's lists keep the event's lists' numbers; a view lets go the lists a view before it read in; no FIND joined to a list field's read; pure-run shows a kept list's lists; unit tests (an event changing a number and a stored item's list, the process dying at the tree's four stages and the log's two, failed commits changing nothing; a replacement moving a stored and a transient list's lists, their items' record gaining a field and the board's fields changing places; under ASan and UBSan too)

1 files changed, 22 insertions, 7 deletions

diff --git a/core/module-save.h b/core/module-save.h
index 5c81504..281854b 100644
--- a/core/module-save.h
+++ b/core/module-save.h
@@ -74,12 +74,27 @@ uint32_t pure_fields_lay_out(PureField *fields, uint32_t count);
 PureResult pure_send_recast(const PureField *from, uint32_t from_count, const PureField *to, uint32_t to_count,
                             PureSpan payload, unsigned char **out, size_t *size);
 
-/* A record field's kind in a list, as a stored list names it too (PURE_CELL_...). */
+/* A record field's kind in a list kept past an event, as a stored list names it too (PURE_CELL_...: a list field's
+ * PURE_CELL_LIST; an event's list holds one of the event's lists' numbers there instead, an integer). */
 uint8_t pure_record_kind(const PureModule *, uint32_t field);
-/* A list with record's fields, taking from `from` (its fields' names and
- * kinds) each field of the same name and kind, or a number, a bool and an
- * i64 from each other when the value fits (pure_cell_as), and giving the
- * others their defaults (module.c). */
-PureResult pure_list_migrate(PureList **out, const PureList *from, const char *const *names,
-                             const uint8_t *kinds, unsigned count, const PureModule *m, uint32_t record);
+/* A record graph as a list kept past an event names it (027's stage 3): its records, from the list's own (0) on in the
+ * order its list fields first meet them, each its fields' kinds (PURE_CELL_...) and names, and a list field's items'
+ * record by its number here. A module's graph knows each record's number in the module too. */
+typedef struct {
+    unsigned records;
+    struct {
+        unsigned count;
+        uint8_t kinds[PURE_RECORD_FIELDS], items[PURE_RECORD_FIELDS];
+        char names[PURE_RECORD_FIELDS][PURE_MODULE_NAME];
+    } record[PURE_MODULE_RECORDS];
+    uint16_t module_record[PURE_MODULE_RECORDS];
+} PureLayout;
+void pure_layout_of(const PureModule *, uint32_t record, PureLayout *out);
+bool pure_layout_same(const PureLayout *, const PureLayout *);
+/* A list with record's fields, taking from `from` (laid out as from_layout's record 0) each field of the same name and
+ * kind, or a number, a bool and an i64 from each other when the value fits (pure_cell_as), and giving the others their
+ * defaults (module.c); a list field's values move so too, item by item (kept: a list kept past an event, holding
+ * them in their stored form, else an event's, holding none yet). */
+PureResult pure_list_migrate(PureList **out, const PureList *from, const PureLayout *from_layout, const PureModule *m,
+                             uint32_t record, bool kept);
 #endif