[IO-515] Allow Specifying Initial Buffer Size of

DeferredFileOutputStream. Redo submitted patch.

Author: garydgregory

src/changes/changes.xml

@@ -52,6 +52,9 @@ The <action> type attribute can be add,update,fix,remove.
       </action>
     </release>
     <release version="2.6" date="2016-MM-DD" description="New features and bug fixes.">
+      <action issue="IO-515" dev="ggregory" type="fix" due-to="Brett Lounsbury, Gary Gregory">
+        Allow Specifying Initial Buffer Size of DeferredFileOutputStream.
+      </action>
       <action issue="IO-512" dev="ggregory" type="fix" due-to="Ralf Hauser">
         ThresholdingOutputStream.thresholdReached() results in FileNotFoundException.
       </action>

src/main/java/org/apache/commons/io/output/ByteArrayOutputStream.java

@@ -56,6 +56,8 @@
  */
 public class ByteArrayOutputStream extends OutputStream {
 
+    static final int DEFAULT_SIZE = 1024;
+
     /** A singleton empty byte array. */
     private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
 
@@ -77,7 +79,7 @@ public class ByteArrayOutputStream extends OutputStream {
      * initially 1024 bytes, though its size increases if necessary.
      */
     public ByteArrayOutputStream() {
-        this(1024);
+        this(DEFAULT_SIZE);
     }
 
     /**

src/main/java/org/apache/commons/io/output/DeferredFileOutputStream.java

@@ -42,7 +42,6 @@
 public class DeferredFileOutputStream
     extends ThresholdingOutputStream
 {
-
     // ----------------------------------------------------------- Data members
 
 
@@ -93,19 +92,38 @@ public class DeferredFileOutputStream
     /**
      * Constructs an instance of this class which will trigger an event at the
      * specified threshold, and save data to a file beyond that point.
+     * The initial buffer size will default to 1024 bytes which is ByteArrayOutputStream's default buffer size.
      *
      * @param threshold  The number of bytes at which to trigger an event.
      * @param outputFile The file to which data is saved beyond the threshold.
      */
     public DeferredFileOutputStream(final int threshold, final File outputFile)
     {
-        this(threshold,  outputFile, null, null, null);
+        this(threshold,  outputFile, null, null, null, ByteArrayOutputStream.DEFAULT_SIZE);
     }
 
+    /**
+     * Constructs an instance of this class which will trigger an event at the
+     * specified threshold, and save data to a file beyond that point.
+     *
+     * @param threshold  The number of bytes at which to trigger an event.
+     * @param initialBufferSize The initial size of the in memory buffer.
+     * @param outputFile The file to which data is saved beyond the threshold.
+     *
+     * @since 2.5
+     */
+    public DeferredFileOutputStream(final int threshold, final int initialBufferSize, final File outputFile)
+    {
+        this(threshold, outputFile, null, null, null, initialBufferSize);
+        if (initialBufferSize < 0) {
+            throw new IllegalArgumentException("Initial buffer size must be atleast 0.");
+        }
+    }
 
     /**
      * Constructs an instance of this class which will trigger an event at the
      * specified threshold, and save data to a temporary file beyond that point.
+     * The initial buffer size will default to 32 bytes which is ByteArrayOutputStream's default buffer size.
      *
      * @param threshold  The number of bytes at which to trigger an event.
      * @param prefix Prefix to use for the temporary file.
@@ -116,12 +134,36 @@ public DeferredFileOutputStream(final int threshold, final File outputFile)
      */
     public DeferredFileOutputStream(final int threshold, final String prefix, final String suffix, final File directory)
     {
-        this(threshold, null, prefix, suffix, directory);
+        this(threshold, null, prefix, suffix, directory, ByteArrayOutputStream.DEFAULT_SIZE);
         if (prefix == null) {
             throw new IllegalArgumentException("Temporary file prefix is missing");
         }
     }
 
+    /**
+     * Constructs an instance of this class which will trigger an event at the
+     * specified threshold, and save data to a temporary file beyond that point.
+     *
+     * @param threshold  The number of bytes at which to trigger an event.
+     * @param initialBufferSize The initial size of the in memory buffer.
+     * @param prefix Prefix to use for the temporary file.
+     * @param suffix Suffix to use for the temporary file.
+     * @param directory Temporary file directory.
+     *
+     * @since 2.5
+     */
+    public DeferredFileOutputStream(final int threshold, final int initialBufferSize, final String prefix,
+                                    final String suffix, final File directory)
+    {
+        this(threshold, null, prefix, suffix, directory, initialBufferSize);
+        if (prefix == null) {
+            throw new IllegalArgumentException("Temporary file prefix is missing");
+        }
+        if (initialBufferSize < 0) {
+            throw new IllegalArgumentException("Initial buffer size must be atleast 0.");
+        }
+    }
+
     /**
      * Constructs an instance of this class which will trigger an event at the
      * specified threshold, and save data either to a file beyond that point.
@@ -131,17 +173,18 @@ public DeferredFileOutputStream(final int threshold, final String prefix, final
      * @param prefix Prefix to use for the temporary file.
      * @param suffix Suffix to use for the temporary file.
      * @param directory Temporary file directory.
+     * @param initialBufferSize The initial size of the in memory buffer.
      */
     private DeferredFileOutputStream(final int threshold, final File outputFile, final String prefix,
-                                     final String suffix, final File directory) {
+                                     final String suffix, final File directory, final int initialBufferSize) {
         super(threshold);
         this.outputFile = outputFile;
-
-        memoryOutputStream = new ByteArrayOutputStream();
-        currentOutputStream = memoryOutputStream;
         this.prefix = prefix;
         this.suffix = suffix;
         this.directory = directory;
+
+        memoryOutputStream = new ByteArrayOutputStream(initialBufferSize);
+        currentOutputStream = memoryOutputStream;
     }
 
 

src/test/java/org/apache/commons/io/output/DeferredFileOutputStreamTest.java

@@ -16,29 +16,42 @@
  */
 package org.apache.commons.io.output;
 
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.Arrays;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
 
 /**
  * Unit tests for the <code>DeferredFileOutputStream</code> class.
  *
  * @version $Id$
  */
+@RunWith(value=Parameterized.class)
 public class DeferredFileOutputStreamTest
  {
 
+    @Parameters(name = "initialBufferSize = {0}")
+    public static Iterable<Object[]> data() {
+        return Arrays.asList(new Object[][] { { 1 }, { 2 }, { 4 }, { 8 }, { 16 }, { 32 }, { 64 }, { 128 }, { 256 },
+                { 512 }, { 1024 }, { 2048 }, { 4096 } });
+    }
+
+    public DeferredFileOutputStreamTest(final int initialBufferSize) {
+        this.initialBufferSize = initialBufferSize;
+    }
     /**
      * The test data as a string (which is the simplest form).
      */
@@ -48,6 +61,8 @@ public class DeferredFileOutputStreamTest
      * The test data as a byte array, derived from the string.
      */
     private final byte[] testBytes = testString.getBytes();
+    
+    private final int initialBufferSize;
 
     /**
      * Tests the case where the amount of data falls below the threshold, and
@@ -57,7 +72,7 @@ public class DeferredFileOutputStreamTest
     public void testBelowThreshold()
     {
         final DeferredFileOutputStream dfos =
-                new DeferredFileOutputStream(testBytes.length + 42, null);
+                new DeferredFileOutputStream(testBytes.length + 42, initialBufferSize, null);
         try
         {
             dfos.write(testBytes, 0, testBytes.length);
@@ -81,7 +96,7 @@ public void testBelowThreshold()
     @Test
     public void testAtThreshold() {
         final DeferredFileOutputStream dfos =
-                new DeferredFileOutputStream(testBytes.length, null);
+                new DeferredFileOutputStream(testBytes.length, initialBufferSize, null);
         try
         {
             dfos.write(testBytes, 0, testBytes.length);
@@ -110,7 +125,7 @@ public void testAboveThreshold() {
         testFile.delete();
 
         final DeferredFileOutputStream dfos =
-                new DeferredFileOutputStream(testBytes.length - 5, testFile);
+                new DeferredFileOutputStream(testBytes.length - 5, initialBufferSize, testFile);
         try
         {
             dfos.write(testBytes, 0, testBytes.length);
@@ -141,7 +156,7 @@ public void testThresholdReached() {
         testFile.delete();
 
         final DeferredFileOutputStream dfos =
-                new DeferredFileOutputStream(testBytes.length / 2, testFile);
+                new DeferredFileOutputStream(testBytes.length / 2, initialBufferSize, testFile);
         final int chunkSize = testBytes.length / 3;
 
         try
@@ -171,12 +186,12 @@ public void testThresholdReached() {
     @Test
     public void testWriteToSmall(){
         final File testFile = new File("testWriteToMem.dat");
-        final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        final ByteArrayOutputStream baos = new ByteArrayOutputStream(initialBufferSize);
         // Ensure that the test starts from a clean base.
         testFile.delete();
 
         final DeferredFileOutputStream dfos =
-                new DeferredFileOutputStream(testBytes.length *2, testFile);
+                new DeferredFileOutputStream(testBytes.length *2, initialBufferSize, testFile);
         try{
             dfos.write(testBytes);
 
@@ -207,7 +222,7 @@ public void testWriteToSmall(){
     @Test
     public void testWriteToLarge(){
         final File testFile = new File("testWriteToFile.dat");
-        final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        final ByteArrayOutputStream baos = new ByteArrayOutputStream(initialBufferSize);
         // Ensure that the test starts from a clean base.
         testFile.delete();
 
@@ -247,7 +262,7 @@ public void testTempFileBelowThreshold() {
         final String suffix = ".out";
         final File tempDir  = new File(".");
         final DeferredFileOutputStream dfos =
-                new DeferredFileOutputStream(testBytes.length + 42, prefix, suffix, tempDir);
+                new DeferredFileOutputStream(testBytes.length + 42, initialBufferSize, prefix, suffix, tempDir);
         assertNull("Check file is null-A", dfos.getFile());
         try
         {
@@ -271,7 +286,7 @@ public void testTempFileAboveThreshold() {
         final String suffix = ".out";
         final File tempDir  = new File(".");
         final DeferredFileOutputStream dfos =
-                new DeferredFileOutputStream(testBytes.length - 5, prefix, suffix, tempDir);
+                new DeferredFileOutputStream(testBytes.length - 5, initialBufferSize, prefix, suffix, tempDir);
         assertNull("Check file is null-A", dfos.getFile());
         try
         {
@@ -305,7 +320,7 @@ public void testTempFileAboveThresholdPrefixOnly() {
         final String suffix = null;
         final File tempDir  = null;
         final DeferredFileOutputStream dfos =
-                new DeferredFileOutputStream(testBytes.length - 5, prefix, suffix, tempDir);
+                new DeferredFileOutputStream(testBytes.length - 5, initialBufferSize, prefix, suffix, tempDir);
         assertNull("Check file is null-A", dfos.getFile());
         try
         {