/// <summary>
/// Initializes a new instance of the <see cref="MergeBuilder"/> class.
/// </summary>
internal MergeBuilder(MigrationPlan plan)
{
_plan = plan;
}
/// <summary>
/// Executes the plan.
/// </summary>
/// <param name="scope">A scope.</param>
/// <param name="fromState">The state to start execution at.</param>
/// <param name="migrationBuilder">A migration builder.</param>
/// <param name="logger">A logger.</param>
/// <param name="loggerFactory"></param>
/// <returns>The final state.</returns>
/// <remarks>The plan executes within the scope, which must then be completed.</remarks>
public string Execute(MigrationPlan plan, string fromState)
{
plan.Validate();
_logger.LogInformation("Starting '{MigrationName}'...", plan.Name);
fromState ??= string.Empty;
var nextState = fromState;
_logger.LogInformation("At {OrigState}", string.IsNullOrWhiteSpace(nextState) ? "origin" : nextState);
if (!plan.Transitions.TryGetValue(nextState, out MigrationPlan.Transition? transition))
{
plan.ThrowOnUnknownInitialState(nextState);
}
using (ICoreScope scope = _scopeProvider.CreateCoreScope(autoComplete: true))
{
// We want to suppress scope (service, etc...) notifications during a migration plan
// execution. This is because if a package that doesn't have their migration plan
// executed is listening to service notifications to perform some persistence logic,
// that packages notification handlers may explode because that package isn't fully installed yet.
using (scope.Notifications.Suppress())
{
var context = new MigrationContext(plan, _scopeAccessor.AmbientScope?.Database, _loggerFactory.CreateLogger <MigrationContext>());
while (transition != null)
{
_logger.LogInformation("Execute {MigrationType}", transition.MigrationType.Name);
var migration = _migrationBuilder.Build(transition.MigrationType, context);
migration.Run();
nextState = transition.TargetState;
_logger.LogInformation("At {OrigState}", nextState);
// throw a raw exception here: this should never happen as the plan has
// been validated - this is just a paranoid safety test
if (!plan.Transitions.TryGetValue(nextState, out transition))
{
throw new InvalidOperationException($"Unknown state \"{nextState}\".");
}
}
// prepare and de-duplicate post-migrations, only keeping the 1st occurence
var temp = new HashSet <Type>();
var postMigrationTypes = context.PostMigrations
.Where(x => !temp.Contains(x))
.Select(x => { temp.Add(x); return(x); });
// run post-migrations
foreach (var postMigrationType in postMigrationTypes)
{
_logger.LogInformation($"PostMigration: {postMigrationType.FullName}.");
var postMigration = _migrationBuilder.Build(postMigrationType, context);
postMigration.Run();
}
}
}
_logger.LogInformation("Done (pending scope completion).");
// safety check - again, this should never happen as the plan has been validated,
// and this is just a paranoid safety test
var finalState = plan.FinalState;
if (nextState != finalState)
{
throw new InvalidOperationException($"Internal error, reached state {nextState} which is not final state {finalState}");
}
return(nextState);
}
public ExecutedMigrationPlan(MigrationPlan plan, string initialState, string finalState)
{
Plan = plan;
InitialState = initialState ?? throw new ArgumentNullException(nameof(initialState));
FinalState = finalState ?? throw new ArgumentNullException(nameof(finalState));
}