Add a DefaultHttpDataSource contract test

Also add a MockWebServer Dispatcher that can be customised with
different resources and behaviours for different paths.

PiperOrigin-RevId: 348759662

library/core/src/test/java/com/google/android/exoplayer2/upstream/DefaultHttpDataSourceContractTest.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2020 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
+ *
+ *      https://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.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.testutil.DataSourceContractTest;
+import com.google.android.exoplayer2.testutil.TestUtil;
+import com.google.android.exoplayer2.testutil.WebServerDispatcher;
+import com.google.common.collect.ImmutableList;
+import okhttp3.mockwebserver.MockWebServer;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.runner.RunWith;
+
+/** {@link DataSource} contract tests for {@link DefaultHttpDataSource}. */
+@RunWith(AndroidJUnit4.class)
+public class DefaultHttpDataSourceContractTest extends DataSourceContractTest {
+
+  private static int seed = 0;
+  private static final WebServerDispatcher.Resource RANGE_SUPPORTED =
+      new WebServerDispatcher.Resource.Builder()
+          .setPath("/supports/range-requests")
+          .setData(TestUtil.buildTestData(/* length= */ 20, seed++))
+          .supportsRangeRequests(true)
+          .build();
+
+  private static final WebServerDispatcher.Resource RANGE_SUPPORTED_LENGTH_UNKNOWN =
+      new WebServerDispatcher.Resource.Builder()
+          .setPath("/supports/range-requests-length-unknown")
+          .setData(TestUtil.buildTestData(/* length= */ 20, seed++))
+          .supportsRangeRequests(true)
+          .resolvesToUnknownLength(true)
+          .build();
+
+  private static final WebServerDispatcher.Resource RANGE_NOT_SUPPORTED =
+      new WebServerDispatcher.Resource.Builder()
+          .setPath("/doesnt/support/range-requests")
+          .setData(TestUtil.buildTestData(/* length= */ 20, seed++))
+          .supportsRangeRequests(false)
+          .build();
+
+  private static final WebServerDispatcher.Resource RANGE_NOT_SUPPORTED_LENGTH_UNKNOWN =
+      new WebServerDispatcher.Resource.Builder()
+          .setPath("/doesnt/support/range-requests-length-unknown")
+          .setData(TestUtil.buildTestData(/* length= */ 20, seed++))
+          .supportsRangeRequests(false)
+          .resolvesToUnknownLength(true)
+          .build();
+
+  private final MockWebServer mockWebServer = new MockWebServer();
+
+  @Before
+  public void startServer() throws Exception {
+    mockWebServer.start();
+    mockWebServer.setDispatcher(
+        WebServerDispatcher.forResources(
+            ImmutableList.of(
+                RANGE_SUPPORTED,
+                RANGE_SUPPORTED_LENGTH_UNKNOWN,
+                RANGE_NOT_SUPPORTED,
+                RANGE_NOT_SUPPORTED_LENGTH_UNKNOWN)));
+  }
+
+  @After
+  public void shutdownServer() throws Exception {
+    mockWebServer.shutdown();
+  }
+
+  @Override
+  protected DataSource createDataSource() {
+    return new DefaultHttpDataSource.Factory().createDataSource();
+  }
+
+  @Override
+  protected ImmutableList<TestResource> getTestResources() {
+    return ImmutableList.of(
+        toTestResource("range supported", RANGE_SUPPORTED),
+        toTestResource("range supported, length unknown", RANGE_SUPPORTED_LENGTH_UNKNOWN),
+        toTestResource("range not supported", RANGE_NOT_SUPPORTED),
+        toTestResource("range not supported, length unknown", RANGE_NOT_SUPPORTED_LENGTH_UNKNOWN));
+  }
+
+  @Override
+  protected Uri getNotFoundUri() {
+    return Uri.parse(mockWebServer.url("/not/a/real/path").toString());
+  }
+
+  private TestResource toTestResource(String name, WebServerDispatcher.Resource resource) {
+    return new TestResource.Builder()
+        .setName(name)
+        .setUri(Uri.parse(mockWebServer.url(resource.getPath()).toString()))
+        .setExpectedBytes(resource.getData())
+        .setResolvesToUnknownLength(resource.resolvesToUnknownLength())
+        .setEndOfInputExpected(!resource.resolvesToUnknownLength())
+        .build();
+  }
+}

testutils/build.gradle

@@ -23,6 +23,7 @@ dependencies {
     compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
+    implementation 'com.squareup.okhttp3:mockwebserver:' + mockWebServerVersion
     implementation project(modulePrefix + 'library-core')
     testImplementation 'org.robolectric:robolectric:' + robolectricVersion
 }

testutils/src/main/java/com/google/android/exoplayer2/testutil/WebServerDispatcher.java

@@ -0,0 +1,257 @@
+/*
+ * Copyright (C) 2020 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
+ *
+ *      https://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.testutil;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+import static java.lang.Math.max;
+import static java.lang.Math.min;
+
+import android.util.Pair;
+import androidx.annotation.Nullable;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Maps;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import okhttp3.mockwebserver.Dispatcher;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.RecordedRequest;
+import okio.Buffer;
+import org.checkerframework.checker.nullness.compatqual.NullableType;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/**
+ * A {@link Dispatcher} for {@link okhttp3.mockwebserver.MockWebServer} that allows per-path
+ * customisation of the static data served.
+ */
+public class WebServerDispatcher extends Dispatcher {
+
+  /** A resource served by {@link WebServerDispatcher}. */
+  public static class Resource {
+
+    /** Builder for {@link Resource}. */
+    public static class Builder {
+      private @MonotonicNonNull String path;
+      private byte @MonotonicNonNull [] data;
+      private boolean supportsRangeRequests;
+      private boolean resolvesToUnknownLength;
+
+      /**
+       * Sets the path this data should be served at. This is required.
+       *
+       * @return this builder, for convenience.
+       */
+      public Builder setPath(String path) {
+        this.path = path.startsWith("/") ? path : "/" + path;
+        return this;
+      }
+
+      /**
+       * Sets the data served by this resource. This is required.
+       *
+       * @return this builder, for convenience.
+       */
+      public Builder setData(byte[] data) {
+        this.data = data;
+        return this;
+      }
+
+      /**
+       * Sets if RFC 7233 range requests should be supported for this resource. Defaults to false.
+       *
+       * @return this builder, for convenience.
+       */
+      public Builder supportsRangeRequests(boolean supportsRangeRequests) {
+        this.supportsRangeRequests = supportsRangeRequests;
+        return this;
+      }
+
+      /**
+       * Sets if the resource should resolve to an unknown length. Defaults to false.
+       *
+       * @return this builder, for convenience.
+       */
+      public Builder resolvesToUnknownLength(boolean resolvesToUnknownLength) {
+        this.resolvesToUnknownLength = resolvesToUnknownLength;
+        return this;
+      }
+
+      /** Builds the {@link Resource}. */
+      public Resource build() {
+        return new Resource(
+            checkNotNull(path), checkNotNull(data), supportsRangeRequests, resolvesToUnknownLength);
+      }
+    }
+
+    private final String path;
+    private final byte[] data;
+    private final boolean supportsRangeRequests;
+    private final boolean resolvesToUnknownLength;
+
+    private Resource(
+        String path, byte[] data, boolean supportsRangeRequests, boolean resolvesToUnknownLength) {
+      this.path = path;
+      this.data = data;
+      this.supportsRangeRequests = supportsRangeRequests;
+      this.resolvesToUnknownLength = resolvesToUnknownLength;
+    }
+
+    /** Returns the path this resource is available at. */
+    public String getPath() {
+      return path;
+    }
+
+    /** Returns the data served by this resource. */
+    public byte[] getData() {
+      return data.clone();
+    }
+
+    /** Returns true if RFC 7233 range requests should be supported for this resource. */
+    public boolean supportsRangeRequests() {
+      return supportsRangeRequests;
+    }
+
+    /**
+     * Returns true if the server shouldn't include the resource length in header responses.
+     *
+     * <p>Responses to unbound requests won't include a Content-Length header, and Content-Range
+     * headers won't include the total resource length.
+     */
+    public boolean resolvesToUnknownLength() {
+      return resolvesToUnknownLength;
+    }
+  }
+
+  private final ImmutableMap<String, Resource> resourcesByPath;
+
+  /**
+   * Constructs a dispatcher that handles requests based the provided {@link Resource} instances.
+   */
+  public static WebServerDispatcher forResources(Iterable<Resource> resources) {
+    return new WebServerDispatcher(Maps.uniqueIndex(resources, Resource::getPath));
+  }
+
+  private WebServerDispatcher(ImmutableMap<String, Resource> resourcesByPath) {
+    this.resourcesByPath = resourcesByPath;
+  }
+
+  @Override
+  public MockResponse dispatch(RecordedRequest request) {
+    MockResponse response = new MockResponse();
+    if (!resourcesByPath.containsKey(request.getPath())) {
+      return response.setResponseCode(404);
+    }
+    Resource resource = checkNotNull(resourcesByPath.get(request.getPath()));
+    byte[] resourceData = resource.getData();
+    if (resource.supportsRangeRequests()) {
+      response.setHeader("Accept-ranges", "bytes");
+    }
+    String rangeHeader = request.getHeader("Range");
+    if (!resource.supportsRangeRequests() || rangeHeader == null) {
+      response.setBody(new Buffer().write(resourceData));
+      if (resource.resolvesToUnknownLength()) {
+        response.setHeader("Content-Length", "");
+      }
+      return response;
+    }
+
+    @Nullable
+    Pair<@NullableType Integer, @NullableType Integer> range = parseRangeHeader(rangeHeader);
+
+    if (range == null || (range.first != null && range.first >= resourceData.length)) {
+      return response
+          .setResponseCode(416)
+          .setHeader("Content-Range", "bytes */" + resourceData.length);
+    }
+
+    if (range.first == null || range.second == null) {
+      int start;
+      if (range.first == null) {
+        // We're handling a suffix range
+        if (resource.resolvesToUnknownLength()) {
+          // Can't return the suffix of an unknown-length resource.
+          return response
+              .setResponseCode(416)
+              .setHeader("Content-Range", "bytes */" + resourceData.length);
+        }
+        start = max(0, resourceData.length - checkNotNull(range.second));
+      } else {
+        // We're handling an unbounded range
+        start = checkNotNull(range.first);
+      }
+      response
+          .setResponseCode(206)
+          .setHeader(
+              "Content-Range",
+              "bytes "
+                  + start
+                  + "-"
+                  + (resourceData.length - 1)
+                  + "/"
+                  + (resource.resolvesToUnknownLength() ? "*" : resourceData.length))
+          .setBody(new Buffer().write(resourceData, start, resourceData.length - start));
+      if (resource.resolvesToUnknownLength()) {
+        response.setHeader("Content-Length", "");
+      }
+      return response;
+    }
+
+    // range.first and range.second are both non-null, so the range is bounded.
+
+    if (range.second < range.first) {
+      return response
+          .setResponseCode(416)
+          .setHeader("Content-Range", "bytes */" + resourceData.length);
+    }
+
+    int end = min(range.second + 1, resourceData.length);
+    return response
+        .setResponseCode(206)
+        .setHeader(
+            "Content-Range",
+            "bytes "
+                + range.first
+                + "-"
+                + (end - 1)
+                + "/"
+                + (resource.resolvesToUnknownLength() ? "*" : resourceData.length))
+        .setBody(new Buffer().write(resourceData, range.first, end - range.first));
+  }
+
+  /**
+   * Parses an RFC 7233 Range header to its component parts. Returns null if the Range is invalid.
+   */
+  @Nullable
+  private static Pair<@NullableType Integer, @NullableType Integer> parseRangeHeader(
+      String rangeHeader) {
+    Pattern rangePattern = Pattern.compile("bytes=(\\d*)-(\\d*)");
+    Matcher rangeMatcher = rangePattern.matcher(rangeHeader);
+    if (!rangeMatcher.matches() || rangeHeader.contains(",")) {
+      // This implementation only supports byte ranges and doesn't support multiple ranges.
+      return null;
+    }
+    String first = checkNotNull(rangeMatcher.group(1));
+    String second = checkNotNull(rangeMatcher.group(2));
+
+    Pair<@NullableType Integer, @NullableType Integer> result =
+        Pair.create(
+            first.isEmpty() ? null : Integer.parseInt(first),
+            second.isEmpty() ? null : Integer.parseInt(second));
+    if (result.first != null && result.second != null && result.second < result.first) {
+      return null;
+    }
+    return result;
+  }
+}