Move DataSource reading methods into Util

This will be used to read ads responses out of data: URLs in a subsequent
change.

PiperOrigin-RevId: 334778780

library/common/src/main/java/com/google/android/exoplayer2/util/Util.java

@@ -534,6 +534,54 @@ public final class Util {
     return Executors.newSingleThreadExecutor(runnable -> new Thread(runnable, threadName));
   }
 
+  /**
+   * Reads data from the specified opened {@link DataSource} until it ends, and returns a byte array
+   * containing the read data.
+   *
+   * @param dataSource The source from which to read.
+   * @return The concatenation of all read data.
+   * @throws IOException If an error occurs reading from the source.
+   */
+  public static byte[] readToEnd(DataSource dataSource) throws IOException {
+    byte[] data = new byte[1024];
+    int position = 0;
+    int bytesRead = 0;
+    while (bytesRead != C.RESULT_END_OF_INPUT) {
+      if (position == data.length) {
+        data = Arrays.copyOf(data, data.length * 2);
+      }
+      bytesRead = dataSource.read(data, position, data.length - position);
+      if (bytesRead != C.RESULT_END_OF_INPUT) {
+        position += bytesRead;
+      }
+    }
+    return Arrays.copyOf(data, position);
+  }
+
+  /**
+   * Reads {@code length} bytes from the specified opened {@link DataSource}, and returns a byte
+   * array containing the read data.
+   *
+   * @param dataSource The source from which to read.
+   * @return The read data.
+   * @throws IOException If an error occurs reading from the source.
+   * @throws IllegalStateException If the end of the source was reached before {@code length} bytes
+   *     could be read.
+   */
+  public static byte[] readExactly(DataSource dataSource, int length) throws IOException {
+    byte[] data = new byte[length];
+    int position = 0;
+    while (position < length) {
+      int bytesRead = dataSource.read(data, position, data.length - position);
+      if (bytesRead == C.RESULT_END_OF_INPUT) {
+        throw new IllegalStateException(
+            "Not enough data could be read: " + position + " < " + length);
+      }
+      position += bytesRead;
+    }
+    return data;
+  }
+
   /**
    * Closes a {@link DataSource}, suppressing any {@link IOException} that may occur.
    *

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

@@ -22,7 +22,6 @@ import static org.junit.Assert.fail;
 import android.net.Uri;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.testutil.TestUtil;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
 import org.junit.Before;
@@ -167,7 +166,7 @@ public final class DataSchemeDataSourceTest {
     try {
       long length = dataSource.open(dataSpec);
       assertThat(length).isEqualTo(expectedData.length);
-      byte[] readData = TestUtil.readToEnd(dataSource);
+      byte[] readData = Util.readToEnd(dataSource);
       assertThat(readData).isEqualTo(expectedData);
     } finally {
       dataSource.close();

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

@@ -302,7 +302,7 @@ public final class CacheDataSourceTest {
     CacheDataSource cacheDataSource = new CacheDataSource(cache, upstream, 0);
 
     cacheDataSource.open(unboundedDataSpec);
-    TestUtil.readToEnd(cacheDataSource);
+    Util.readToEnd(cacheDataSource);
     cacheDataSource.close();
 
     assertThat(upstream.getAndClearOpenedDataSpecs()).hasLength(1);
@@ -319,7 +319,7 @@ public final class CacheDataSourceTest {
             cache, upstream, CacheDataSource.FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS);
 
     cacheDataSource.open(unboundedDataSpec);
-    TestUtil.readToEnd(cacheDataSource);
+    Util.readToEnd(cacheDataSource);
     cacheDataSource.close();
 
     assertThat(cache.getKeys()).isEmpty();
@@ -369,7 +369,7 @@ public final class CacheDataSourceTest {
     cacheWriter.cache();
 
     // Read the rest of the data.
-    TestUtil.readToEnd(cacheDataSource);
+    Util.readToEnd(cacheDataSource);
     cacheDataSource.close();
   }
 
@@ -419,7 +419,7 @@ public final class CacheDataSourceTest {
     cacheWriter.cache();
 
     // Read the rest of the data.
-    TestUtil.readToEnd(cacheDataSource);
+    Util.readToEnd(cacheDataSource);
     cacheDataSource.close();
   }
 
@@ -449,14 +449,14 @@ public final class CacheDataSourceTest {
 
     // Open source and read some data from upstream as the data hasn't cached yet.
     cacheDataSource.open(unboundedDataSpec);
-    TestUtil.readExactly(cacheDataSource, 100);
+    Util.readExactly(cacheDataSource, 100);
 
     // Delete cached data.
     cache.removeResource(cacheDataSource.getCacheKeyFactory().buildCacheKey(unboundedDataSpec));
     assertCacheEmpty(cache);
 
     // Read the rest of the data.
-    TestUtil.readToEnd(cacheDataSource);
+    Util.readToEnd(cacheDataSource);
     cacheDataSource.close();
   }
 
@@ -487,7 +487,7 @@ public final class CacheDataSourceTest {
     cacheDataSource.open(unboundedDataSpec);
 
     // Read the first half from upstream as it hasn't cached yet.
-    TestUtil.readExactly(cacheDataSource, halfDataLength);
+    Util.readExactly(cacheDataSource, halfDataLength);
 
     // Delete the cached latter half.
     NavigableSet<CacheSpan> cachedSpans = cache.getCachedSpans(defaultCacheKey);
@@ -498,7 +498,7 @@ public final class CacheDataSourceTest {
     }
 
     // Read the rest of the data.
-    TestUtil.readToEnd(cacheDataSource);
+    Util.readToEnd(cacheDataSource);
     cacheDataSource.close();
   }
 

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

@@ -130,7 +130,7 @@ public final class CacheAsserts {
     byte[] bytes;
     try {
       dataSource.open(dataSpec);
-      bytes = TestUtil.readToEnd(dataSource);
+      bytes = Util.readToEnd(dataSource);
     } catch (IOException e) {
       throw new IOException("Opening/reading cache failed: " + dataSpec, e);
     } finally {

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

@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.testutil;
 
 import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.fail;
 
 import android.content.Context;
 import android.database.sqlite.SQLiteDatabase;
@@ -53,7 +52,6 @@ import java.io.InputStream;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.nio.ByteBuffer;
-import java.util.Arrays;
 import java.util.Random;
 import java.util.concurrent.TimeoutException;
 import org.checkerframework.checker.nullness.qual.EnsuresNonNull;
@@ -77,52 +75,6 @@ public class TestUtil {
 
   private TestUtil() {}
 
-  /**
-   * Given an open {@link DataSource}, repeatedly calls {@link DataSource#read(byte[], int, int)}
-   * until {@link C#RESULT_END_OF_INPUT} is returned.
-   *
-   * @param dataSource The source from which to read.
-   * @return The concatenation of all read data.
-   * @throws IOException If an error occurs reading from the source.
-   */
-  public static byte[] readToEnd(DataSource dataSource) throws IOException {
-    byte[] data = new byte[1024];
-    int position = 0;
-    int bytesRead = 0;
-    while (bytesRead != C.RESULT_END_OF_INPUT) {
-      if (position == data.length) {
-        data = Arrays.copyOf(data, data.length * 2);
-      }
-      bytesRead = dataSource.read(data, position, data.length - position);
-      if (bytesRead != C.RESULT_END_OF_INPUT) {
-        position += bytesRead;
-      }
-    }
-    return Arrays.copyOf(data, position);
-  }
-
-  /**
-   * Given an open {@link DataSource}, repeatedly calls {@link DataSource#read(byte[], int, int)}
-   * until exactly {@code length} bytes have been read.
-   *
-   * @param dataSource The source from which to read.
-   * @return The read data.
-   * @throws IOException If an error occurs reading from the source.
-   */
-  public static byte[] readExactly(DataSource dataSource, int length) throws IOException {
-    byte[] data = new byte[length];
-    int position = 0;
-    while (position < length) {
-      int bytesRead = dataSource.read(data, position, data.length - position);
-      if (bytesRead == C.RESULT_END_OF_INPUT) {
-        fail("Not enough data could be read: " + position + " < " + length);
-      } else {
-        position += bytesRead;
-      }
-    }
-    return data;
-  }
-
   /**
    * Equivalent to {@code buildTestData(length, length)}.
    *
@@ -271,7 +223,7 @@ public class TestUtil {
     try {
       long length = dataSource.open(dataSpec);
       assertThat(length).isEqualTo(expectKnownLength ? expectedData.length : C.LENGTH_UNSET);
-      byte[] readData = readToEnd(dataSource);
+      byte[] readData = Util.readToEnd(dataSource);
       assertThat(readData).isEqualTo(expectedData);
     } finally {
       dataSource.close();