8205361: Better RIFF reading support

Reviewed-by: prr, rhalade, mschoene

src/share/classes/com/sun/media/sound/DLSSoundbank.java

@@ -548,7 +548,7 @@ public final class DLSSoundbank implements Soundbank {
         long count = riff.readUnsignedInt();
 
         if (size - 8 != 0)
-            riff.skipBytes(size - 8);
+            riff.skip(size - 8);
 
         for (int i = 0; i < count; i++) {
             DLSModulator modulator = new DLSModulator();
@@ -568,7 +568,7 @@ public final class DLSSoundbank implements Soundbank {
         long count = riff.readUnsignedInt();
 
         if (size - 8 != 0)
-            riff.skipBytes(size - 8);
+            riff.skip(size - 8);
 
         for (int i = 0; i < count; i++) {
             DLSModulator modulator = new DLSModulator();
@@ -661,7 +661,7 @@ public final class DLSSoundbank implements Soundbank {
         long loops = riff.readInt();
 
         if (size > 20)
-            riff.skipBytes(size - 20);
+            riff.skip(size - 20);
 
         for (int i = 0; i < loops; i++) {
             DLSSampleLoop loop = new DLSSampleLoop();
@@ -671,7 +671,7 @@ public final class DLSSoundbank implements Soundbank {
             loop.length = riff.readUnsignedInt();
             sampleOptions.loops.add(loop);
             if (size2 > 16)
-                riff.skipBytes(size2 - 16);
+                riff.skip(size2 - 16);
         }
     }
 

src/share/classes/com/sun/media/sound/RIFFReader.java

@@ -172,49 +172,41 @@ public final class RIFFReader extends InputStream {
         }
     }
 
-    public final long skipBytes(long n) throws IOException {
-        if (n < 0)
+    @Override
+    public long skip(final long n) throws IOException {
+        if (n <= 0 || avail == 0) {
             return 0;
-        long skipped = 0;
-        while (skipped != n) {
-            long s = skip(n - skipped);
-            if (s < 0)
-                break;
-            if (s == 0)
-                Thread.yield();
-            skipped += s;
         }
-        return skipped;
-    }
-
-    public long skip(long n) throws IOException {
-        if (avail == 0)
-            return -1;
-        if (n > avail) {
-            long len = stream.skip(avail);
-            if (len != -1)
-                filepointer += len;
-            avail = 0;
-            return len;
-        } else {
-            long ret = stream.skip(n);
-            if (ret == -1) {
-                avail = 0;
-                return -1;
+        // will not skip more than
+        long remaining = Math.min(n, avail);
+        while (remaining > 0) {
+            // Some input streams like FileInputStream can return more bytes,
+            // when EOF is reached.
+            long ret = Math.min(stream.skip(remaining), remaining);
+            if (ret == 0) {
+                // EOF or not? we need to check.
+                Thread.yield();
+                if (stream.read() == -1) {
+                    avail = 0;
+                    break;
+                }
+                ret = 1;
             }
+            remaining -= ret;
             avail -= ret;
             filepointer += ret;
-            return ret;
         }
+        return n - remaining;
     }
 
+    @Override
     public int available() {
         return (int)avail;
     }
 
     public void finish() throws IOException {
         if (avail != 0) {
-            skipBytes(avail);
+            skip(avail);
         }
     }
 
@@ -337,6 +329,7 @@ public final class RIFFReader extends InputStream {
         return ch1 + (ch2 << 8) | (ch3 << 16) | (ch4 << 24);
     }
 
+    @Override
     public void close() throws IOException {
         finish();
         if (this == root)

test/javax/sound/midi/Gervill/RiffReaderWriter/Skip.java

@@ -27,9 +27,8 @@
 import java.io.File;
 import java.io.FileInputStream;
 
-import javax.sound.sampled.*;
-
-import com.sun.media.sound.*;
+import com.sun.media.sound.RIFFReader;
+import com.sun.media.sound.RIFFWriter;
 
 public class Skip {
 
@@ -40,6 +39,11 @@ public class Skip {
     }
 
     public static void main(String[] args) throws Exception {
+        test(false);
+        test(true);
+    }
+
+    private static void test(boolean customStream) throws Exception {
         RIFFWriter writer = null;
         RIFFReader reader = null;
         File tempfile = File.createTempFile("test",".riff");
@@ -51,7 +55,17 @@ public class Skip {
             chunk.write((byte)44);
             writer.close();
             writer = null;
-            FileInputStream fis = new FileInputStream(tempfile);
+            final FileInputStream fis;
+            if (customStream) {
+                fis = new FileInputStream(tempfile);
+            } else {
+                fis = new FileInputStream(tempfile) {
+                    @Override
+                    public long skip(long n) {
+                        return 0;
+                    }
+                };
+            }
             reader = new RIFFReader(fis);
             RIFFReader readchunk = reader.nextChunk();
             reader.skip(1);