Author: kkolinko
Date: Fri Nov 4 14:06:24 2011
New Revision: 1197578
URL: http://svn.apache.org/viewvc?rev=1197578&view=rev
Log:
FlushableGZIPOutputStream:
Reserve one byte of real data and perform standard write() call.
This uses more standard code: deflate() is never called directly and empty byte
array trick is not used.
TestFlushableGZIPOutputStream:
Add a check that the decompressed stream equals to the original one.
Modified:
tomcat/trunk/java/org/apache/coyote/http11/filters/FlushableGZIPOutputStream.java
tomcat/trunk/test/org/apache/coyote/http11/filters/TestFlushableGZIPOutputStream.java
Modified:
tomcat/trunk/java/org/apache/coyote/http11/filters/FlushableGZIPOutputStream.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/coyote/http11/filters/FlushableGZIPOutputStream.java?rev=1197578&r1=1197577&r2=1197578&view=diff
==============================================================================
---
tomcat/trunk/java/org/apache/coyote/http11/filters/FlushableGZIPOutputStream.java
(original)
+++
tomcat/trunk/java/org/apache/coyote/http11/filters/FlushableGZIPOutputStream.java
Fri Nov 4 14:06:24 2011
@@ -35,69 +35,74 @@ public class FlushableGZIPOutputStream e
super(os);
}
- private static final byte[] EMPTYBYTEARRAY = new byte[0];
- private boolean hasData = false;
- private boolean needReenableCompression = false;
-
/**
- * Here we make sure we have received data, so that the header has been for
- * sure written to the output stream already.
+ * It is used to reserve one byte of real data so that it can be used when
+ * flushing the stream.
*/
+ private byte[] lastByte = new byte[1];
+ private boolean hasLastByte = false;
+
+ @Override
+ public synchronized void write(byte[] bytes) throws IOException {
+ write(bytes, 0, bytes.length);
+ }
+
@Override
public synchronized void write(byte[] bytes, int offset, int length)
throws IOException {
if (length > 0) {
- prepareForOutput();
- super.write(bytes, offset, length);
+ flushLastByte();
+ if (length > 1) {
+ super.write(bytes, offset, length - 1);
+ }
+ rememberLastByte(bytes[offset + length - 1]);
}
}
@Override
public synchronized void write(int i) throws IOException {
- prepareForOutput();
- super.write(i);
+ flushLastByte();
+ rememberLastByte((byte) (i & 0xFF));
}
@Override
- public synchronized void write(byte[] bytes) throws IOException {
- write(bytes, 0, bytes.length);
+ public void close() throws IOException {
+ flushLastByte();
+ super.close();
}
- private void prepareForOutput() throws IOException {
- hasData = true;
- if (needReenableCompression) {
- def.setLevel(Deflater.DEFAULT_COMPRESSION);
- deflate();
- needReenableCompression = false;
+ private void rememberLastByte(byte b) {
+ lastByte[0] = b;
+ hasLastByte = true;
+ }
+
+ private void flushLastByte() throws IOException {
+ if (hasLastByte) {
+ super.write(lastByte, 0, 1);
+ hasLastByte = false;
}
}
@Override
public synchronized void flush() throws IOException {
- if (!hasData) {
- return; // do not allow the gzip header to be flushed on its own
- }
-
- // trick the deflater to flush
- /**
- * Now this is tricky: We force the Deflater to flush its data by
- * switching compression level. As yet, a perplexingly simple
workaround
- * for
- * http://developer.java.sun.com/developer/bugParade/bugs/4255743.html
- */
- if (!def.finished()) {
- def.setInput(EMPTYBYTEARRAY, 0, 0);
-
- def.setLevel(Deflater.NO_COMPRESSION);
- deflate();
-
- // Cannot reenable compression now. Must wait for data.
- needReenableCompression = true;
-
- out.flush();
+ if (hasLastByte) {
+ // - do not allow the gzip header to be flushed on its own
+ // - do not do anything if there is no data to send
+
+ // trick the deflater to flush
+ /**
+ * Now this is tricky: We force the Deflater to flush its data by
+ * switching compression level. As yet, a perplexingly simple
workaround
+ * for
+ *
http://developer.java.sun.com/developer/bugParade/bugs/4255743.html
+ */
+ if (!def.finished()) {
+ def.setLevel(Deflater.NO_COMPRESSION);
+ flushLastByte();
+ def.setLevel(Deflater.DEFAULT_COMPRESSION);
+ }
}
-
- hasData = false; // no more data to flush
+ out.flush();
}
/*
Modified:
tomcat/trunk/test/org/apache/coyote/http11/filters/TestFlushableGZIPOutputStream.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/test/org/apache/coyote/http11/filters/TestFlushableGZIPOutputStream.java?rev=1197578&r1=1197577&r2=1197578&view=diff
==============================================================================
---
tomcat/trunk/test/org/apache/coyote/http11/filters/TestFlushableGZIPOutputStream.java
(original)
+++
tomcat/trunk/test/org/apache/coyote/http11/filters/TestFlushableGZIPOutputStream.java
Fri Nov 4 14:06:24 2011
@@ -20,10 +20,16 @@ import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
-import java.io.InputStream;
+import java.io.IOException;
import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
import java.util.zip.GZIPInputStream;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+
import org.junit.Test;
import org.apache.catalina.util.IOTools;
@@ -38,32 +44,25 @@ public class TestFlushableGZIPOutputStre
public void testBug52121() throws Exception {
ByteArrayOutputStream byteOutStream = new ByteArrayOutputStream();
- ByteArrayOutputStream sink = new ByteArrayOutputStream();
-
OutputStream output = new FlushableGZIPOutputStream(byteOutStream);
File sourcesDir = new File("test/org/apache/coyote/http11/filters/");
- InputStream input;
+ List<byte[]> parts = new ArrayList<byte[]>();
+ byte[] part;
- input = new FileInputStream(new File(sourcesDir, "bug52121-part1"));
- try {
- IOTools.flow(input, output);
- } finally {
- input.close();
- }
+ part = loadFile(new File(sourcesDir, "bug52121-part1"));
+ parts.add(part);
+ flowBytes(part, output);
output.flush();
- input = new FileInputStream(new File(sourcesDir, "bug52121-part2"));
- try {
- IOTools.flow(input, output);
- } finally {
- input.close();
- }
+ part = loadFile(new File(sourcesDir, "bug52121-part2"));
+ parts.add(part);
+ flowBytes(part, output);
output.flush();
- // Using "data" may trigger a JVM crash
- // output.write("data".getBytes());
- output.write("data2".getBytes());
+ part = "data2".getBytes("ASCII");
+ parts.add(part);
+ output.write(part);
output.flush();
output.close();
@@ -72,6 +71,49 @@ public class TestFlushableGZIPOutputStre
new ByteArrayInputStream(byteOutStream.toByteArray());
GZIPInputStream inflaterStream = new GZIPInputStream(byteInStream);
- IOTools.flow(inflaterStream, sink);
+ ByteArrayOutputStream sink = new ByteArrayOutputStream();
+ try {
+ IOTools.flow(inflaterStream, sink);
+ } finally {
+ sink.close();
+ }
+
+ byte[] decompressedBytes = sink.toByteArray();
+ int originalLength = 0;
+ for (byte[] bytes : parts) {
+ assertArrayEquals(bytes, Arrays.copyOfRange(decompressedBytes,
+ originalLength, originalLength + bytes.length));
+ originalLength += bytes.length;
+ }
+ assertEquals(originalLength, decompressedBytes.length);
+ }
+
+ /**
+ * Loads file into memory.
+ */
+ private byte[] loadFile(File file) throws IOException {
+ ByteArrayOutputStream byteOutStream = new ByteArrayOutputStream();
+ FileInputStream input = new FileInputStream(file);
+ try {
+ IOTools.flow(input, byteOutStream);
+ } finally {
+ input.close();
+ }
+ return byteOutStream.toByteArray();
+ }
+
+ /**
+ * Writes data to the stream and returns the size of the file.
+ */
+ private void flowBytes(byte[] bytes, OutputStream output)
+ throws IOException {
+ // Could use output.write(), but IOTools writes in small portions, and
+ // that is more natural
+ ByteArrayInputStream byteInStream = new ByteArrayInputStream(bytes);
+ try {
+ IOTools.flow(byteInStream, output);
+ } finally {
+ byteInStream.close();
+ }
}
}
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