/// <summary>
/// 从给定的题目句柄对象创建 NativeProblemDataProvider 对象。
/// </summary>
/// <param name="handle">题目句柄对象。</param>
/// <param name="isReadonly">一个值，该值指示创建的 NativeProblemDataProvider 对象是否处于只读模式。</param>
/// <returns>从给定题目句柄创建的 NativeProblemDataProvider 对象。</returns>
/// <exception cref="ArgumentNullException"/>
/// <exception cref="InvalidProblemException"/>
/// <exception cref="ProblemNotExistException"/>
public static NativeProblemDataProvider Create(ProblemHandle handle, bool isReadonly)
{
if (handle == null)
{
throw new ArgumentNullException(nameof(handle));
}
if (!handle.IsNativeProblem)
{
throw new InvalidProblemException(handle, "给定的题目句柄不是 BITOJ 本地题目。");
}
// 尝试从题目句柄中解析出题目ID。
if (!int.TryParse(handle.ProblemId.Substring(3), out int id))
{
throw new InvalidProblemException(handle, "给定的题目句柄非法。");
}
// 从底层数据库中查询题目实体对象。
ProblemEntity entity = ProblemArchieveManager.Default.DataContext.GetProblemEntityById(id);
if (entity == null)
{
throw new ProblemNotExistException(handle);
}
// 创建底层题目数据访问器对象。
ProblemAccessHandle entryHandle = new ProblemAccessHandle(entity.ProblemDirectory);
return(new NativeProblemDataProvider()
{
m_entity = entity,
m_accessHandle = entryHandle,
m_readonly = isReadonly
});
}
/// <summary>
/// 初始化 NativeProblemDataProvider 类的新实例。
/// </summary>
private NativeProblemDataProvider()
{
m_entity = null;
m_accessHandle = null;
m_readonly = true;
m_disposed = false;
}
/// <summary>
/// 从给定的题目句柄对象创建 NativeProblemDataProvider 对象。
/// </summary>
/// <param name="handle">题目句柄对象。</param>
/// <param name="isReadonly">一个值，该值指示创建的 NativeProblemDataProvider 对象是否处于只读模式。</param>
/// <returns>从给定题目句柄创建的 NativeProblemDataProvider 对象。</returns>
/// <exception cref="ArgumentNullException"/>
/// <exception cref="InvalidProblemException"/>
/// <exception cref="ProblemNotExistException"/>
public static ProblemDataProvider Create(ProblemHandle handle, bool isReadonly)
{
if (handle == null)
{
throw new ArgumentNullException(nameof(handle));
}
if (!handle.IsNativeProblem)
{
throw new InvalidProblemException(handle, "给定的题目句柄不是 BITOJ 本地题目。");
}
// 从底层数据库中查询题目实体对象。
ProblemDataContext context = new ProblemDataContextFactory().CreateContext();
ProblemEntity entity = context.GetProblemEntityById(handle.ProblemId);
if (entity == null)
{
context.Dispose();
throw new ProblemNotExistException(handle);
}
// 创建底层题目数据访问器对象。
ProblemAccessHandle entryHandle = new ProblemAccessHandle(entity);
return(new ProblemDataProvider()
{
m_context = context,
m_entity = entity,
m_accessHandle = entryHandle,
m_readonly = isReadonly
});
}
