50 lines
1.7 KiB
C#
50 lines
1.7 KiB
C#
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namespace Theriapolis.Core.Persistence.SaveMigrations;
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/// <summary>
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/// Registry + chain runner for SaveBody migrations. Phase 4 is the v4 baseline;
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/// older versions are not supported because nothing earlier shipped. As we
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/// bump the schema in Phase 5+, register migrations here.
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///
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/// The registry seeds itself with every built-in migration on first use, so
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/// callers don't need to remember to <see cref="Register"/> them at startup.
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/// </summary>
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public static class Migrations
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{
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private static readonly List<ISaveMigration> _registry = new();
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private static bool _seeded;
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public static void Register(ISaveMigration m)
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{
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EnsureSeeded();
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_registry.Add(m);
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}
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private static void EnsureSeeded()
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{
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if (_seeded) return;
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_seeded = true;
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// Built-in migrations registered in version order:
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_registry.Add(new V5ToV6Migration());
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_registry.Add(new V6ToV7Migration());
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_registry.Add(new V7ToV8Migration());
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}
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/// <summary>
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/// Walk migrations from header.Version up to C.SAVE_SCHEMA_VERSION. Returns
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/// false if no chain exists; the caller decides whether to hard-block or
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/// best-effort the load (see SaveCodec docs).
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/// </summary>
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public static bool MigrateUp(SaveHeader header, SaveBody body)
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{
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EnsureSeeded();
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while (header.Version < C.SAVE_SCHEMA_VERSION)
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{
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var step = _registry.FirstOrDefault(m => m.FromVersion == header.Version);
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if (step is null) return false;
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step.Apply(header, body);
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header.Version = step.ToVersion;
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}
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return header.Version == C.SAVE_SCHEMA_VERSION;
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}
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}
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