Class: ActiveRecord::Tasks::VirgodbDatabaseTasks

Inherits:
SQLiteDatabaseTasks
  • Object
show all
Defined in:
lib/activerecord-virgodb-adapter.rb

Overview

ActiveRecord::Tasks::SQLiteDatabaseTasks#structure_dump just shells out to the real sqlite3 CLI (.schema --nosys, or a raw SELECT sql FROM sqlite_master when a host app has any ActiveRecord::SchemaDumper.ignore_tables configured -- e.g. excluding tables owned by a separate replication/backup mechanism) against the configured database file -- DDL only. ActiveRecord::Tasks::DatabaseTasks.dump_schema then special-cases exactly one table on top of that: if schema_migrations exists, it appends that table's real row data (connection .dump_schema_versions) to the same dump file, because Rails' own migration bookkeeping needs those rows to survive a db:schema:load/ structure_load, not just the table shape.

schema_versions (this adapter's own bookkeeping table, plural, distinct from Rails' singular schema_migrations) needs exactly the same treatment and doesn't get it for free: it holds real data (the versioned column list compact::schema_from_columns on the Rust side depends on), not just structure, and Rails has no way to know that a table it didn't create needs the same row-preserving special case. Confirmed empirically: without this, a fresh database prepared via structure_load (which Rails does automatically whenever a db:migrate invocation for a later environment/connection finds an existing, version-matching dump already on disk from an earlier one -- not something this adapter can opt out of) ends up with the real host-app table but an EMPTY schema_versions, so Manifest::current_schema_version() on the Rust side returns None even though the SQLite table itself is correct.

Class Attribute Summary collapse

Instance Method Summary collapse

Class Attribute Details

.table_layout_provider ⇒ Object

Optional host-app hook: ->(sql_table_name) { {sort_by:, key_column:, partition_column:} or nil }. Purely a documentation comment written above CREATE TABLE at dump time -- nothing on the Rust or Ruby side ever reads it back. This adapter gem stays host-app-agnostic (see the class doc comment above: "lets any Rails app..."), so it can't hardcode any one host app's sort_by/key_column config (that's app/services/virgodb/registry.rb's job, which already has this exact data for real -- passed to Virgodb.start_maintenance on every boot). A host app that wants it surfaced sets this once, e.g. in an initializer; left nil, structure_dump behaves exactly as before.



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# File 'lib/activerecord-virgodb-adapter.rb', line 257

def table_layout_provider
  @table_layout_provider
end

Instance Method Details

#structure_dump(filename, extra_flags) ⇒ Object 



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# File 'lib/activerecord-virgodb-adapter.rb', line 260

def structure_dump(filename, extra_flags)
  super
  reformat_create_table_statements!(filename)
  annotate_physical_layout!(filename)
  dump_schema_versions!(filename)
end