httpcore5/src/test/java/org/apache/hc/core5/http/impl/nio/TestIdentityDecoder.java - httpcomponents-core - Git at Google

 /*
  * ====================================================================
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you 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
  *
  *   http://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.
  * ====================================================================
  *
  * This software consists of voluntary contributions made by many
  * individuals on behalf of the Apache Software Foundation.  For more
  * information on the Apache Software Foundation, please see
  * <http://www.apache.org/>.
  *
  */

 package org.apache.hc.core5.http.impl.nio;

 import java.io.File;
 import java.io.IOException;
 import java.io.RandomAccessFile;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.charset.StandardCharsets;

 import org.apache.hc.core5.http.ReadableByteChannelMock;
 import org.apache.hc.core5.http.impl.BasicHttpTransportMetrics;
 import org.apache.hc.core5.http.nio.SessionInputBuffer;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;

 /**
  * Simple tests for {@link LengthDelimitedDecoder}.
  */
 public class TestIdentityDecoder {

     private File tmpfile;

     protected File createTempFile() throws IOException {
         this.tmpfile = File.createTempFile("testFile", ".txt");
         return this.tmpfile;
     }

     @AfterEach
     public void deleteTempFile() {
         if (this.tmpfile != null && this.tmpfile.exists()) {
             this.tmpfile.delete();
         }
     }

     @Test
     public void testBasicDecoding() throws Exception {
         final ReadableByteChannel channel = new ReadableByteChannelMock(
                 new String[] {"stuff;", "more stuff"}, StandardCharsets.US_ASCII);

         final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
         final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
         final IdentityDecoder decoder = new IdentityDecoder(channel, inbuf, metrics);

         final ByteBuffer dst = ByteBuffer.allocate(1024);

         int bytesRead = decoder.read(dst);
         Assertions.assertEquals(6, bytesRead);
         Assertions.assertEquals("stuff;", CodecTestUtils.convert(dst));
         Assertions.assertFalse(decoder.isCompleted());
         Assertions.assertEquals(6, metrics.getBytesTransferred());

         dst.clear();
         bytesRead = decoder.read(dst);
         Assertions.assertEquals(10, bytesRead);
         Assertions.assertEquals("more stuff", CodecTestUtils.convert(dst));
         Assertions.assertFalse(decoder.isCompleted());
         Assertions.assertEquals(16, metrics.getBytesTransferred());

         dst.clear();
         bytesRead = decoder.read(dst);
         Assertions.assertEquals(-1, bytesRead);
         Assertions.assertTrue(decoder.isCompleted());
         Assertions.assertEquals(16, metrics.getBytesTransferred());

         dst.clear();
         bytesRead = decoder.read(dst);
         Assertions.assertEquals(-1, bytesRead);
         Assertions.assertTrue(decoder.isCompleted());
         Assertions.assertEquals(16, metrics.getBytesTransferred());

         Assertions.assertEquals("[identity; completed: true]", decoder.toString());
     }

     @Test
     public void testDecodingFromSessionBuffer() throws Exception {
         final ReadableByteChannel channel = new ReadableByteChannelMock(
                 new String[] {"stuff;", "more stuff"}, StandardCharsets.US_ASCII);

         final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
         final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();

         inbuf.fill(channel);

         Assertions.assertEquals(6, inbuf.length());

         final IdentityDecoder decoder = new IdentityDecoder(channel, inbuf, metrics);

         final ByteBuffer dst = ByteBuffer.allocate(1024);

         int bytesRead = decoder.read(dst);
         Assertions.assertEquals(6, bytesRead);
         Assertions.assertEquals("stuff;", CodecTestUtils.convert(dst));
         Assertions.assertFalse(decoder.isCompleted());
         Assertions.assertEquals(0, metrics.getBytesTransferred()); // doesn't count if from session buffer

         dst.clear();
         bytesRead = decoder.read(dst);
         Assertions.assertEquals(10, bytesRead);
         Assertions.assertEquals("more stuff", CodecTestUtils.convert(dst));
         Assertions.assertFalse(decoder.isCompleted());
         Assertions.assertEquals(10, metrics.getBytesTransferred());

         dst.clear();
         bytesRead = decoder.read(dst);
         Assertions.assertEquals(-1, bytesRead);
         Assertions.assertTrue(decoder.isCompleted());
         Assertions.assertEquals(10, metrics.getBytesTransferred());

         dst.clear();
         bytesRead = decoder.read(dst);
         Assertions.assertEquals(-1, bytesRead);
         Assertions.assertTrue(decoder.isCompleted());
         Assertions.assertEquals(10, metrics.getBytesTransferred());

     }

     @Test
     public void testBasicDecodingFile() throws Exception {
         final ReadableByteChannel channel = new ReadableByteChannelMock(
                 new String[] {"stuff; ", "more stuff; ", "a lot more stuff!"}, StandardCharsets.US_ASCII);

         final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
         final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
         final IdentityDecoder decoder = new IdentityDecoder(
                 channel, inbuf, metrics);

         createTempFile();
         try (RandomAccessFile testfile = new RandomAccessFile(this.tmpfile, "rw")) {
             final FileChannel fchannel = testfile.getChannel();
             long pos = 0;
             while (!decoder.isCompleted()) {
                 final long bytesRead = decoder.transfer(fchannel, pos, 10);
                 if (bytesRead > 0) {
                     pos += bytesRead;
                 }
             }

             Assertions.assertEquals(testfile.length(), metrics.getBytesTransferred());
         }
         Assertions.assertEquals("stuff; more stuff; a lot more stuff!",
             CodecTestUtils.readFromFile(this.tmpfile));
     }

     @Test
     public void testDecodingFileWithBufferedSessionData() throws Exception {
         final ReadableByteChannel channel = new ReadableByteChannelMock(
                 new String[] {"stuff; ", "more stuff; ", "a lot more stuff!"}, StandardCharsets.US_ASCII);

         final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
         final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
         final IdentityDecoder decoder = new IdentityDecoder(
                 channel, inbuf, metrics);

         final int i = inbuf.fill(channel);
         Assertions.assertEquals(7, i);

         createTempFile();
         try (RandomAccessFile testfile = new RandomAccessFile(this.tmpfile, "rw")) {
             final FileChannel fchannel = testfile.getChannel();
             long pos = 0;
             while (!decoder.isCompleted()) {
                 final long bytesRead = decoder.transfer(fchannel, pos, 10);
                 if (bytesRead > 0) {
                     pos += bytesRead;
                 }
             }

             // count everything except the initial 7 bytes that went to the session buffer
             Assertions.assertEquals(testfile.length() - 7, metrics.getBytesTransferred());
         }
         Assertions.assertEquals("stuff; more stuff; a lot more stuff!",
             CodecTestUtils.readFromFile(this.tmpfile));
     }

     @Test
     public void testDecodingFileWithOffsetAndBufferedSessionData() throws Exception {
         final ReadableByteChannel channel = new ReadableByteChannelMock(
                 new String[] {"stuff; ", "more stuff; ", "a lot more stuff!"}, StandardCharsets.US_ASCII);

         final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
         final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
         final IdentityDecoder decoder = new IdentityDecoder(
                 channel, inbuf, metrics);

         final int i = inbuf.fill(channel);
         Assertions.assertEquals(7, i);

         final byte[] beginning = "beginning; ".getBytes(StandardCharsets.US_ASCII);

         createTempFile();
         RandomAccessFile testfile = new RandomAccessFile(this.tmpfile, "rw");
         try {
             testfile.write(beginning);
         } finally {
             testfile.close();
         }

         testfile = new RandomAccessFile(this.tmpfile, "rw");
         try {
             final FileChannel fchannel = testfile.getChannel();
             long pos = beginning.length;
             while (!decoder.isCompleted()) {
                 if(testfile.length() < pos) {
                     testfile.setLength(pos);
                 }
                 final long bytesRead = decoder.transfer(fchannel, pos, 10);
                 if (bytesRead > 0) {
                     pos += bytesRead;
                 }
             }

             // count everything except the initial 7 bytes that went to the session buffer
             Assertions.assertEquals(testfile.length() - 7 - beginning.length, metrics.getBytesTransferred());
         } finally {
             testfile.close();
         }

         Assertions.assertEquals("beginning; stuff; more stuff; a lot more stuff!",
             CodecTestUtils.readFromFile(this.tmpfile));
     }

     @Test
     public void testDecodingFileWithLimit() throws Exception {
         final ReadableByteChannel channel = new ReadableByteChannelMock(
                 new String[] {"stuff; more stuff; ", "a lot more stuff!"}, StandardCharsets.US_ASCII);

         final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
         final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
         final IdentityDecoder decoder = new IdentityDecoder(channel, inbuf, metrics);

         final int i = inbuf.fill(channel);
         Assertions.assertEquals(19, i);

         createTempFile();
         try (RandomAccessFile testfile = new RandomAccessFile(this.tmpfile, "rw")) {
             final FileChannel fchannel = testfile.getChannel();
             long pos = 0;

             // transferred from buffer
             long bytesRead = decoder.transfer(fchannel, pos, 1);
             Assertions.assertEquals(1, bytesRead);
             Assertions.assertFalse(decoder.isCompleted());
             Assertions.assertEquals(0, metrics.getBytesTransferred());
             pos += bytesRead;

             bytesRead = decoder.transfer(fchannel, pos, 2);
             Assertions.assertEquals(2, bytesRead);
             Assertions.assertFalse(decoder.isCompleted());
             Assertions.assertEquals(0, metrics.getBytesTransferred());
             pos += bytesRead;

             bytesRead = decoder.transfer(fchannel, pos, 17);
             Assertions.assertEquals(16, bytesRead);
             Assertions.assertFalse(decoder.isCompleted());
             Assertions.assertEquals(0, metrics.getBytesTransferred());
             pos += bytesRead;

             // transferred from channel
             bytesRead = decoder.transfer(fchannel, pos, 1);
             Assertions.assertEquals(1, bytesRead);
             Assertions.assertFalse(decoder.isCompleted());
             Assertions.assertEquals(1, metrics.getBytesTransferred());
             pos += bytesRead;

             bytesRead = decoder.transfer(fchannel, pos, 2);
             Assertions.assertEquals(2, bytesRead);
             Assertions.assertFalse(decoder.isCompleted());
             Assertions.assertEquals(3, metrics.getBytesTransferred());
             pos += bytesRead;

             bytesRead = decoder.transfer(fchannel, pos, 15);
             Assertions.assertEquals(14, bytesRead);
             Assertions.assertFalse(decoder.isCompleted());
             Assertions.assertEquals(17, metrics.getBytesTransferred());
             pos += bytesRead;

             bytesRead = decoder.transfer(fchannel, pos, 1);
             Assertions.assertEquals(-1, bytesRead);
             Assertions.assertTrue(decoder.isCompleted());
             Assertions.assertEquals(17, metrics.getBytesTransferred());
         }
         Assertions.assertEquals("stuff; more stuff; a lot more stuff!",
                 CodecTestUtils.readFromFile(this.tmpfile));
     }

     @Test
     public void testWriteBeyondFileSize() throws Exception {
         final ReadableByteChannel channel = new ReadableByteChannelMock(
                 new String[] {"a"}, StandardCharsets.US_ASCII);

         final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
         final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
         final IdentityDecoder decoder = new IdentityDecoder(
                 channel, inbuf, metrics);

         createTempFile();
         try (RandomAccessFile testfile = new RandomAccessFile(this.tmpfile, "rw")) {
             Assertions.assertEquals(0, testfile.length());
             final FileChannel fchannel = testfile.getChannel();
             Assertions.assertThrows(IOException.class, () -> decoder.transfer(fchannel, 5, 10));
         }
     }

     @Test
     public void testInvalidConstructor() {
         final ReadableByteChannel channel = new ReadableByteChannelMock(
                 new String[] {"stuff;", "more stuff"}, StandardCharsets.US_ASCII);

         final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
         Assertions.assertThrows(NullPointerException.class, () -> new IdentityDecoder(null, null, null));
         Assertions.assertThrows(NullPointerException.class, () -> new IdentityDecoder(channel, null, null));
         Assertions.assertThrows(NullPointerException.class, () -> new IdentityDecoder(channel, inbuf, null));
     }

     @Test
     public void testInvalidInput() throws Exception {
         final String s = "stuff";
         final ReadableByteChannel channel = new ReadableByteChannelMock(
                 new String[] {s}, StandardCharsets.US_ASCII);

         final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
         final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
         final IdentityDecoder decoder = new IdentityDecoder(channel, inbuf, metrics);

         Assertions.assertThrows(NullPointerException.class, () -> decoder.read(null));
     }

 }
	/*
	* ====================================================================
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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
	*
	* http://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.
	* ====================================================================
	*
	* This software consists of voluntary contributions made by many
	* individuals on behalf of the Apache Software Foundation. For more
	* information on the Apache Software Foundation, please see
	* <http://www.apache.org/>.
	*
	*/

	package org.apache.hc.core5.http.impl.nio;

	import java.io.File;
	import java.io.IOException;
	import java.io.RandomAccessFile;
	import java.nio.ByteBuffer;
	import java.nio.channels.FileChannel;
	import java.nio.channels.ReadableByteChannel;
	import java.nio.charset.StandardCharsets;

	import org.apache.hc.core5.http.ReadableByteChannelMock;
	import org.apache.hc.core5.http.impl.BasicHttpTransportMetrics;
	import org.apache.hc.core5.http.nio.SessionInputBuffer;
	import org.junit.jupiter.api.AfterEach;
	import org.junit.jupiter.api.Assertions;
	import org.junit.jupiter.api.Test;

	/**
	* Simple tests for {@link LengthDelimitedDecoder}.
	*/
	public class TestIdentityDecoder {

	private File tmpfile;

	protected File createTempFile() throws IOException {
	this.tmpfile = File.createTempFile("testFile", ".txt");
	return this.tmpfile;
	}

	@AfterEach
	public void deleteTempFile() {
	if (this.tmpfile != null && this.tmpfile.exists()) {
	this.tmpfile.delete();
	}
	}

	@Test
	public void testBasicDecoding() throws Exception {
	final ReadableByteChannel channel = new ReadableByteChannelMock(
	new String[] {"stuff;", "more stuff"}, StandardCharsets.US_ASCII);

	final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
	final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
	final IdentityDecoder decoder = new IdentityDecoder(channel, inbuf, metrics);

	final ByteBuffer dst = ByteBuffer.allocate(1024);

	int bytesRead = decoder.read(dst);
	Assertions.assertEquals(6, bytesRead);
	Assertions.assertEquals("stuff;", CodecTestUtils.convert(dst));
	Assertions.assertFalse(decoder.isCompleted());
	Assertions.assertEquals(6, metrics.getBytesTransferred());

	dst.clear();
	bytesRead = decoder.read(dst);
	Assertions.assertEquals(10, bytesRead);
	Assertions.assertEquals("more stuff", CodecTestUtils.convert(dst));
	Assertions.assertFalse(decoder.isCompleted());
	Assertions.assertEquals(16, metrics.getBytesTransferred());

	dst.clear();
	bytesRead = decoder.read(dst);
	Assertions.assertEquals(-1, bytesRead);
	Assertions.assertTrue(decoder.isCompleted());
	Assertions.assertEquals(16, metrics.getBytesTransferred());

	dst.clear();
	bytesRead = decoder.read(dst);
	Assertions.assertEquals(-1, bytesRead);
	Assertions.assertTrue(decoder.isCompleted());
	Assertions.assertEquals(16, metrics.getBytesTransferred());

	Assertions.assertEquals("[identity; completed: true]", decoder.toString());
	}

	@Test
	public void testDecodingFromSessionBuffer() throws Exception {
	final ReadableByteChannel channel = new ReadableByteChannelMock(
	new String[] {"stuff;", "more stuff"}, StandardCharsets.US_ASCII);

	final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
	final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();

	inbuf.fill(channel);

	Assertions.assertEquals(6, inbuf.length());

	final IdentityDecoder decoder = new IdentityDecoder(channel, inbuf, metrics);

	final ByteBuffer dst = ByteBuffer.allocate(1024);

	int bytesRead = decoder.read(dst);
	Assertions.assertEquals(6, bytesRead);
	Assertions.assertEquals("stuff;", CodecTestUtils.convert(dst));
	Assertions.assertFalse(decoder.isCompleted());
	Assertions.assertEquals(0, metrics.getBytesTransferred()); // doesn't count if from session buffer

	dst.clear();
	bytesRead = decoder.read(dst);
	Assertions.assertEquals(10, bytesRead);
	Assertions.assertEquals("more stuff", CodecTestUtils.convert(dst));
	Assertions.assertFalse(decoder.isCompleted());
	Assertions.assertEquals(10, metrics.getBytesTransferred());

	dst.clear();
	bytesRead = decoder.read(dst);
	Assertions.assertEquals(-1, bytesRead);
	Assertions.assertTrue(decoder.isCompleted());
	Assertions.assertEquals(10, metrics.getBytesTransferred());

	dst.clear();
	bytesRead = decoder.read(dst);
	Assertions.assertEquals(-1, bytesRead);
	Assertions.assertTrue(decoder.isCompleted());
	Assertions.assertEquals(10, metrics.getBytesTransferred());

	}

	@Test
	public void testBasicDecodingFile() throws Exception {
	final ReadableByteChannel channel = new ReadableByteChannelMock(
	new String[] {"stuff; ", "more stuff; ", "a lot more stuff!"}, StandardCharsets.US_ASCII);

	final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
	final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
	final IdentityDecoder decoder = new IdentityDecoder(
	channel, inbuf, metrics);

	createTempFile();
	try (RandomAccessFile testfile = new RandomAccessFile(this.tmpfile, "rw")) {
	final FileChannel fchannel = testfile.getChannel();
	long pos = 0;
	while (!decoder.isCompleted()) {
	final long bytesRead = decoder.transfer(fchannel, pos, 10);
	if (bytesRead > 0) {
	pos += bytesRead;
	}
	}

	Assertions.assertEquals(testfile.length(), metrics.getBytesTransferred());
	}
	Assertions.assertEquals("stuff; more stuff; a lot more stuff!",
	CodecTestUtils.readFromFile(this.tmpfile));
	}

	@Test
	public void testDecodingFileWithBufferedSessionData() throws Exception {
	final ReadableByteChannel channel = new ReadableByteChannelMock(
	new String[] {"stuff; ", "more stuff; ", "a lot more stuff!"}, StandardCharsets.US_ASCII);

	final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
	final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
	final IdentityDecoder decoder = new IdentityDecoder(
	channel, inbuf, metrics);

	final int i = inbuf.fill(channel);
	Assertions.assertEquals(7, i);

	createTempFile();
	try (RandomAccessFile testfile = new RandomAccessFile(this.tmpfile, "rw")) {
	final FileChannel fchannel = testfile.getChannel();
	long pos = 0;
	while (!decoder.isCompleted()) {
	final long bytesRead = decoder.transfer(fchannel, pos, 10);
	if (bytesRead > 0) {
	pos += bytesRead;
	}
	}

	// count everything except the initial 7 bytes that went to the session buffer
	Assertions.assertEquals(testfile.length() - 7, metrics.getBytesTransferred());
	}
	Assertions.assertEquals("stuff; more stuff; a lot more stuff!",
	CodecTestUtils.readFromFile(this.tmpfile));
	}

	@Test
	public void testDecodingFileWithOffsetAndBufferedSessionData() throws Exception {
	final ReadableByteChannel channel = new ReadableByteChannelMock(
	new String[] {"stuff; ", "more stuff; ", "a lot more stuff!"}, StandardCharsets.US_ASCII);

	final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
	final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
	final IdentityDecoder decoder = new IdentityDecoder(
	channel, inbuf, metrics);

	final int i = inbuf.fill(channel);
	Assertions.assertEquals(7, i);

	final byte[] beginning = "beginning; ".getBytes(StandardCharsets.US_ASCII);

	createTempFile();
	RandomAccessFile testfile = new RandomAccessFile(this.tmpfile, "rw");
	try {
	testfile.write(beginning);
	} finally {
	testfile.close();
	}

	testfile = new RandomAccessFile(this.tmpfile, "rw");
	try {
	final FileChannel fchannel = testfile.getChannel();
	long pos = beginning.length;
	while (!decoder.isCompleted()) {
	if(testfile.length() < pos) {
	testfile.setLength(pos);
	}
	final long bytesRead = decoder.transfer(fchannel, pos, 10);
	if (bytesRead > 0) {
	pos += bytesRead;
	}
	}

	// count everything except the initial 7 bytes that went to the session buffer
	Assertions.assertEquals(testfile.length() - 7 - beginning.length, metrics.getBytesTransferred());
	} finally {
	testfile.close();
	}

	Assertions.assertEquals("beginning; stuff; more stuff; a lot more stuff!",
	CodecTestUtils.readFromFile(this.tmpfile));
	}

	@Test
	public void testDecodingFileWithLimit() throws Exception {
	final ReadableByteChannel channel = new ReadableByteChannelMock(
	new String[] {"stuff; more stuff; ", "a lot more stuff!"}, StandardCharsets.US_ASCII);

	final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
	final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
	final IdentityDecoder decoder = new IdentityDecoder(channel, inbuf, metrics);

	final int i = inbuf.fill(channel);
	Assertions.assertEquals(19, i);

	createTempFile();
	try (RandomAccessFile testfile = new RandomAccessFile(this.tmpfile, "rw")) {
	final FileChannel fchannel = testfile.getChannel();
	long pos = 0;

	// transferred from buffer
	long bytesRead = decoder.transfer(fchannel, pos, 1);
	Assertions.assertEquals(1, bytesRead);
	Assertions.assertFalse(decoder.isCompleted());
	Assertions.assertEquals(0, metrics.getBytesTransferred());
	pos += bytesRead;

	bytesRead = decoder.transfer(fchannel, pos, 2);
	Assertions.assertEquals(2, bytesRead);
	Assertions.assertFalse(decoder.isCompleted());
	Assertions.assertEquals(0, metrics.getBytesTransferred());
	pos += bytesRead;

	bytesRead = decoder.transfer(fchannel, pos, 17);
	Assertions.assertEquals(16, bytesRead);
	Assertions.assertFalse(decoder.isCompleted());
	Assertions.assertEquals(0, metrics.getBytesTransferred());
	pos += bytesRead;

	// transferred from channel
	bytesRead = decoder.transfer(fchannel, pos, 1);
	Assertions.assertEquals(1, bytesRead);
	Assertions.assertFalse(decoder.isCompleted());
	Assertions.assertEquals(1, metrics.getBytesTransferred());
	pos += bytesRead;

	bytesRead = decoder.transfer(fchannel, pos, 2);
	Assertions.assertEquals(2, bytesRead);
	Assertions.assertFalse(decoder.isCompleted());
	Assertions.assertEquals(3, metrics.getBytesTransferred());
	pos += bytesRead;

	bytesRead = decoder.transfer(fchannel, pos, 15);
	Assertions.assertEquals(14, bytesRead);
	Assertions.assertFalse(decoder.isCompleted());
	Assertions.assertEquals(17, metrics.getBytesTransferred());
	pos += bytesRead;

	bytesRead = decoder.transfer(fchannel, pos, 1);
	Assertions.assertEquals(-1, bytesRead);
	Assertions.assertTrue(decoder.isCompleted());
	Assertions.assertEquals(17, metrics.getBytesTransferred());
	}
	Assertions.assertEquals("stuff; more stuff; a lot more stuff!",
	CodecTestUtils.readFromFile(this.tmpfile));
	}

	@Test
	public void testWriteBeyondFileSize() throws Exception {
	final ReadableByteChannel channel = new ReadableByteChannelMock(
	new String[] {"a"}, StandardCharsets.US_ASCII);

	final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
	final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
	final IdentityDecoder decoder = new IdentityDecoder(
	channel, inbuf, metrics);

	createTempFile();
	try (RandomAccessFile testfile = new RandomAccessFile(this.tmpfile, "rw")) {
	Assertions.assertEquals(0, testfile.length());
	final FileChannel fchannel = testfile.getChannel();
	Assertions.assertThrows(IOException.class, () -> decoder.transfer(fchannel, 5, 10));
	}
	}

	@Test
	public void testInvalidConstructor() {
	final ReadableByteChannel channel = new ReadableByteChannelMock(
	new String[] {"stuff;", "more stuff"}, StandardCharsets.US_ASCII);

	final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
	Assertions.assertThrows(NullPointerException.class, () -> new IdentityDecoder(null, null, null));
	Assertions.assertThrows(NullPointerException.class, () -> new IdentityDecoder(channel, null, null));
	Assertions.assertThrows(NullPointerException.class, () -> new IdentityDecoder(channel, inbuf, null));
	}

	@Test
	public void testInvalidInput() throws Exception {
	final String s = "stuff";
	final ReadableByteChannel channel = new ReadableByteChannelMock(
	new String[] {s}, StandardCharsets.US_ASCII);

	final SessionInputBuffer inbuf = new SessionInputBufferImpl(1024, 256, 0, StandardCharsets.US_ASCII);
	final BasicHttpTransportMetrics metrics = new BasicHttpTransportMetrics();
	final IdentityDecoder decoder = new IdentityDecoder(channel, inbuf, metrics);

	Assertions.assertThrows(NullPointerException.class, () -> decoder.read(null));
	}

	}