/// <summary>
/// 解析持久化模型。
/// </summary>
/// <param name="dbContextAccessor">给定的数据库上下文访问器。</param>
/// <returns>返回 <see cref="IModel"/>。</returns>
protected virtual IModel ResolvePersistentModel
(DataDbContextAccessor <TAudit, TAuditProperty, TMigration, TTabulation, TTenant, TGenId, TIncremId, TCreatedBy> dbContextAccessor)
{
return(ExtensionSettings.Preference.RunLocker(() =>
{
var cacheKey = DbContextAccessorHelper.GetMigrationCacheKey(dbContextAccessor);
return MemoryCache.GetOrCreate(cacheKey, entry =>
{
Type snapshotType = null;
// 启用写入分离后，数据库可能会主从同步，因此尝试从数据库获取迁移数据不作连接限制
var lastMigration = dbContextAccessor.Migrations
.FirstOrDefaultByMax(s => s.CreatedTimeTicks);
if (lastMigration.IsNotNull())
{
var buffer = ModelSnapshotCompiler.RestoreAssembly(lastMigration.ModelBody);
var modelAssembly = Assembly.Load(buffer);
snapshotType = modelAssembly.GetType(lastMigration.ModelSnapshotName,
throwOnError: true, ignoreCase: false);
}
if (snapshotType.IsNotNull())
{
return snapshotType.EnsureCreate <ModelSnapshot>().Model;
}
return null;
});
}));
}
protected virtual (byte[] body, string hash) CreateModelSnapshot(DbContextAccessorBase dbContextAccessor,
out TypeNameCombiner modelSnapshotTypeName)
{
var typeName = ModelSnapshotCompiler.GenerateTypeName(dbContextAccessor.CurrentType);
var result = ExtensionSettings.Preference.RunLocker(() =>
{
return(ModelSnapshotCompiler.CompileInMemory(dbContextAccessor,
dbContextAccessor.Model, typeName));
});
modelSnapshotTypeName = typeName;
return(result);
}
