Add a new flag to DataSpec which permits content to be cached even if its length…

Add a new flag to DataSpec which permits content to be cached even if its length can not be resolved

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=143560360

extensions/okhttp/src/main/java/com/google/android/exoplayer2/ext/okhttp/OkHttpDataSource.java

@@ -261,7 +261,7 @@ public class OkHttpDataSource implements HttpDataSource {
   private Request makeRequest(DataSpec dataSpec) {
     long position = dataSpec.position;
     long length = dataSpec.length;
-    boolean allowGzip = (dataSpec.flags & DataSpec.FLAG_ALLOW_GZIP) != 0;
+    boolean allowGzip = dataSpec.isFlagSet(DataSpec.FLAG_ALLOW_GZIP);
 
     HttpUrl url = HttpUrl.parse(dataSpec.uri.toString());
     Request.Builder builder = new Request.Builder().url(url);

library/src/main/java/com/google/android/exoplayer2/upstream/DataSpec.java

@@ -32,7 +32,7 @@ public final class DataSpec {
    * The flags that apply to any request for data.
    */
   @Retention(RetentionPolicy.SOURCE)
-  @IntDef(flag = true, value = {FLAG_ALLOW_GZIP})
+  @IntDef(flag = true, value = {FLAG_ALLOW_GZIP, FLAG_ALLOW_CACHING_UNKNOWN_LENGTH})
   public @interface Flags {}
   /**
    * Permits an underlying network stack to request that the server use gzip compression.
@@ -45,7 +45,10 @@ public final class DataSpec {
    * {@link DataSource#open(DataSpec)} will typically be {@link C#LENGTH_UNSET}. The data read from
    * {@link DataSource#read(byte[], int, int)} will be the decompressed data.
    */
-  public static final int FLAG_ALLOW_GZIP = 1;
+  public static final int FLAG_ALLOW_GZIP = 1 << 0;
+
+  /** Permits content to be cached even if its length can not be resolved. */
+  public static final int FLAG_ALLOW_CACHING_UNKNOWN_LENGTH = 1 << 1;
 
   /**
    * The source from which data should be read.
@@ -76,7 +79,8 @@ public final class DataSpec {
    */
   public final String key;
   /**
-   * Request flags. Currently {@link #FLAG_ALLOW_GZIP} is the only supported flag.
+   * Request flags. Currently {@link #FLAG_ALLOW_GZIP} and
+   * {@link #FLAG_ALLOW_CACHING_UNKNOWN_LENGTH} are the only supported flags.
    */
   @Flags
   public final int flags;
@@ -167,6 +171,15 @@ public final class DataSpec {
     this.flags = flags;
   }
 
+  /**
+   * Returns whether the given flag is set.
+   *
+   * @param flag Flag to be checked if it is set.
+   */
+  public boolean isFlagSet(@Flags int flag) {
+    return (this.flags & flag) == flag;
+  }
+
   @Override
   public String toString() {
     return "DataSpec[" + uri + ", " + Arrays.toString(postBody) + ", " + absoluteStreamPosition

library/src/main/java/com/google/android/exoplayer2/upstream/DefaultHttpDataSource.java

@@ -230,7 +230,7 @@ public class DefaultHttpDataSource implements HttpDataSource {
     bytesToSkip = responseCode == 200 && dataSpec.position != 0 ? dataSpec.position : 0;
 
     // Determine the length of the data to be read, after skipping.
-    if ((dataSpec.flags & DataSpec.FLAG_ALLOW_GZIP) == 0) {
+    if (!dataSpec.isFlagSet(DataSpec.FLAG_ALLOW_GZIP)) {
       if (dataSpec.length != C.LENGTH_UNSET) {
         bytesToRead = dataSpec.length;
       } else {
@@ -343,7 +343,7 @@ public class DefaultHttpDataSource implements HttpDataSource {
     byte[] postBody = dataSpec.postBody;
     long position = dataSpec.position;
     long length = dataSpec.length;
-    boolean allowGzip = (dataSpec.flags & DataSpec.FLAG_ALLOW_GZIP) != 0;
+    boolean allowGzip = dataSpec.isFlagSet(DataSpec.FLAG_ALLOW_GZIP);
 
     if (!allowCrossProtocolRedirects) {
       // HttpURLConnection disallows cross-protocol redirects, but otherwise performs redirection

library/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheDataSink.java

@@ -81,10 +81,12 @@ public final class CacheDataSink implements DataSink {
 
   @Override
   public void open(DataSpec dataSpec) throws CacheDataSinkException {
-    this.dataSpec = dataSpec;
-    if (dataSpec.length == C.LENGTH_UNSET) {
+    if (dataSpec.length == C.LENGTH_UNSET
+        && !dataSpec.isFlagSet(DataSpec.FLAG_ALLOW_CACHING_UNKNOWN_LENGTH)) {
+      this.dataSpec = null;
       return;
     }
+    this.dataSpec = dataSpec;
     dataSpecBytesWritten = 0;
     try {
       openNextOutputStream();
@@ -95,7 +97,7 @@ public final class CacheDataSink implements DataSink {
 
   @Override
   public void write(byte[] buffer, int offset, int length) throws CacheDataSinkException {
-    if (dataSpec.length == C.LENGTH_UNSET) {
+    if (dataSpec == null) {
       return;
     }
     try {
@@ -119,7 +121,7 @@ public final class CacheDataSink implements DataSink {
 
   @Override
   public void close() throws CacheDataSinkException {
-    if (dataSpec == null || dataSpec.length == C.LENGTH_UNSET) {
+    if (dataSpec == null) {
       return;
     }
     try {
@@ -130,8 +132,10 @@ public final class CacheDataSink implements DataSink {
   }
 
   private void openNextOutputStream() throws IOException {
+    long maxLength = dataSpec.length == C.LENGTH_UNSET ? maxCacheFileSize
+        : Math.min(dataSpec.length - dataSpecBytesWritten, maxCacheFileSize);
     file = cache.startFile(dataSpec.key, dataSpec.absoluteStreamPosition + dataSpecBytesWritten,
-        Math.min(dataSpec.length - dataSpecBytesWritten, maxCacheFileSize));
+        maxLength);
     underlyingFileOutputStream = new FileOutputStream(file);
     if (bufferSize > 0) {
       if (bufferedOutputStream == null) {