| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * 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.exoplayer2.upstream; |
| |
| import android.net.Uri; |
| import androidx.annotation.Nullable; |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.Map; |
| |
| /** {@link DataSource} wrapper allowing just-in-time resolution of {@link DataSpec DataSpecs}. */ |
| public final class ResolvingDataSource implements DataSource { |
| |
| /** Resolves {@link DataSpec DataSpecs}. */ |
| public interface Resolver { |
| |
| /** |
| * Resolves a {@link DataSpec} before forwarding it to the wrapped {@link DataSource}. This |
| * method is allowed to block until the {@link DataSpec} has been resolved. |
| * |
| * <p>Note that this method is called for every new connection, so caching of results is |
| * recommended, especially if network operations are involved. |
| * |
| * @param dataSpec The original {@link DataSpec}. |
| * @return The resolved {@link DataSpec}. |
| * @throws IOException If an {@link IOException} occurred while resolving the {@link DataSpec}. |
| */ |
| DataSpec resolveDataSpec(DataSpec dataSpec) throws IOException; |
| |
| /** |
| * Resolves a URI reported by {@link DataSource#getUri()} for event reporting and caching |
| * purposes. |
| * |
| * <p>Implementations do not need to overwrite this method unless they want to change the |
| * reported URI. |
| * |
| * <p>This method is <em>not</em> allowed to block. |
| * |
| * @param uri The URI as reported by {@link DataSource#getUri()}. |
| * @return The resolved URI used for event reporting and caching. |
| */ |
| default Uri resolveReportedUri(Uri uri) { |
| return uri; |
| } |
| } |
| |
| /** {@link DataSource.Factory} for {@link ResolvingDataSource} instances. */ |
| public static final class Factory implements DataSource.Factory { |
| |
| private final DataSource.Factory upstreamFactory; |
| private final Resolver resolver; |
| |
| /** |
| * @param upstreamFactory The wrapped {@link DataSource.Factory} for handling resolved {@link |
| * DataSpec DataSpecs}. |
| * @param resolver The {@link Resolver} to resolve the {@link DataSpec DataSpecs}. |
| */ |
| public Factory(DataSource.Factory upstreamFactory, Resolver resolver) { |
| this.upstreamFactory = upstreamFactory; |
| this.resolver = resolver; |
| } |
| |
| @Override |
| public ResolvingDataSource createDataSource() { |
| return new ResolvingDataSource(upstreamFactory.createDataSource(), resolver); |
| } |
| } |
| |
| private final DataSource upstreamDataSource; |
| private final Resolver resolver; |
| |
| private boolean upstreamOpened; |
| |
| /** |
| * @param upstreamDataSource The wrapped {@link DataSource}. |
| * @param resolver The {@link Resolver} to resolve the {@link DataSpec DataSpecs}. |
| */ |
| public ResolvingDataSource(DataSource upstreamDataSource, Resolver resolver) { |
| this.upstreamDataSource = upstreamDataSource; |
| this.resolver = resolver; |
| } |
| |
| @Override |
| public void addTransferListener(TransferListener transferListener) { |
| upstreamDataSource.addTransferListener(transferListener); |
| } |
| |
| @Override |
| public long open(DataSpec dataSpec) throws IOException { |
| DataSpec resolvedDataSpec = resolver.resolveDataSpec(dataSpec); |
| upstreamOpened = true; |
| return upstreamDataSource.open(resolvedDataSpec); |
| } |
| |
| @Override |
| public int read(byte[] buffer, int offset, int readLength) throws IOException { |
| return upstreamDataSource.read(buffer, offset, readLength); |
| } |
| |
| @Override |
| @Nullable |
| public Uri getUri() { |
| @Nullable Uri reportedUri = upstreamDataSource.getUri(); |
| return reportedUri == null ? null : resolver.resolveReportedUri(reportedUri); |
| } |
| |
| @Override |
| public Map<String, List<String>> getResponseHeaders() { |
| return upstreamDataSource.getResponseHeaders(); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| if (upstreamOpened) { |
| upstreamOpened = false; |
| upstreamDataSource.close(); |
| } |
| } |
| } |