| /* |
| * 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.openers; |
| |
| import com.google.android.libraries.mobiledatadownload.file.Behavior; |
| import com.google.android.libraries.mobiledatadownload.file.OpenContext; |
| import com.google.android.libraries.mobiledatadownload.file.Opener; |
| import java.io.BufferedInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.util.List; |
| |
| /** An opener that returns a simple InputStream opened for read. */ |
| public final class ReadStreamOpener implements Opener<InputStream> { |
| |
| private boolean bufferIo = false; |
| private Behavior[] behaviors; |
| |
| private ReadStreamOpener() {} |
| |
| public static ReadStreamOpener create() { |
| return new ReadStreamOpener(); |
| } |
| |
| public ReadStreamOpener withBehaviors(Behavior... behaviors) { |
| this.behaviors = behaviors; |
| return this; |
| } |
| |
| /** |
| * If enabled, uses {@link BufferedInputStream} to buffer IO from the backend. Depending on the |
| * situation this can help or hurt performance, so please contact <internal> before using it. |
| * |
| * <p>Encouraged: zip files. |
| * |
| * <p>Discouraged: protos (already buffered internally). |
| */ |
| public ReadStreamOpener withBufferedIo() { |
| this.bufferIo = true; |
| return this; |
| } |
| |
| @Override |
| public InputStream open(OpenContext openContext) throws IOException { |
| InputStream backendInput = openContext.backend().openForRead(openContext.encodedUri()); |
| if (bufferIo) { |
| backendInput = new BufferedInputStream(backendInput); |
| } |
| List<InputStream> chain = openContext.chainTransformsForRead(backendInput); |
| if (behaviors != null) { |
| for (Behavior behavior : behaviors) { |
| behavior.forInputChain(chain); |
| } |
| } |
| return chain.get(0); |
| } |
| } |