53 lines
2.1 KiB
Ruby
53 lines
2.1 KiB
Ruby
# Some migrations have been present in glitch-soc for a long time and have then
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# been merged in upstream Mastodon, under a different version number.
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#
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# This puts us in an uneasy situation in which if we remove upstream's
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# migration file, people migrating from upstream will end up having a conflict
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# with their already-ran migration.
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#
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# On the other hand, if we keep upstream's migration and remove our own,
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# any current glitch-soc user will have a conflict during migration.
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#
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# For lack of a better solution, as those migrations are indeed identical,
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# we decided monkey-patching Rails' Migrator to completely ignore the duplicate,
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# keeping only the one that has run, or an arbitrary one.
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ALLOWED_DUPLICATES = [20180410220657, 20180831171112].freeze
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module ActiveRecord
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class Migrator
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def self.new(direction, migrations, target_version = nil)
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migrated = Set.new(Base.connection.migration_context.get_all_versions)
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migrations.group_by(&:name).each do |name, duplicates|
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if duplicates.length > 1 && duplicates.all? { |m| ALLOWED_DUPLICATES.include?(m.version) }
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# We have a set of allowed duplicates. Keep the migrated one, if any.
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non_migrated = duplicates.reject { |m| migrated.include?(m.version.to_i) }
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if duplicates.length == non_migrated.length || non_migrated.length == 0
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# There weren't any migrated one, so we have to pick one “canonical” migration
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migrations = migrations - duplicates[1..-1]
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else
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# Just reject every duplicate which hasn't been migrated yet
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migrations = migrations - non_migrated
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end
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end
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end
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super(direction, migrations, target_version)
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end
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end
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class MigrationContext
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def needs_migration?
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# A set of duplicated migrations is considered migrated if at least one of
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# them is migrated.
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migrated = get_all_versions
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migrations.group_by(&:name).each do |name, duplicates|
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return true unless duplicates.any? { |m| migrated.include?(m.version.to_i) }
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end
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return false
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end
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end
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end
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