blob: 0093edcbcf6042c352e3a2bc32d5c707b3619f8e [file] [log] [blame]
/*
* Copyright 2022 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.android.libraries.mobiledatadownload.file.common;
import java.io.IOException;
import javax.annotation.Nullable;
/** Interface for accessing the size of a data behind a stream. */
public interface Sizable {
/**
* Return the logical size of the stream or null if it is unknown. The logical size is defined as
* the total number of bytes required to store all of the data in the stream after applying the
* transform. This is expected to be an efficient operation. In particular, if it is O(filesize)
* to compute the logical size, implementor should return null rather than perform that
* calculation.
*/
@Nullable
Long size() throws IOException;
}