On Thursday 02 August 2007 06:55:20 Robin Garner wrote:
> GCC Bugzilla Bug 32541
>
> On JikesRVM (and possibly other VMs), dacapo xalan performs lots of
> small IO using the default character encoding. OutputStreamWriter
> currently buffers characters when converting between character sets, but
> bypasses this when not converting. Applying the buffering uniformly
> speeds up dacapo xalan by 2x on JikesRVM.
>
> Also, for single character IO, a new char array is allocated per IO
> operation. Avoiding this allocation gives a ~5% speedup.
Committed.
2007-10-12 Robin Garner <[EMAIL PROTECTED]>
PR classpath/32541:
* java/io/OutputStreamWriter.java:
Provide buffering when not converting to improve
performance.
--
Andrew :)
Index: java/io/OutputStreamWriter.java
===================================================================
RCS file: /sources/classpath/classpath/java/io/OutputStreamWriter.java,v
retrieving revision 1.24
diff -u -r1.24 OutputStreamWriter.java
--- java/io/OutputStreamWriter.java 28 Mar 2007 20:28:40 -0000 1.24
+++ java/io/OutputStreamWriter.java 12 Oct 2007 11:59:21 -0000
@@ -121,6 +121,8 @@
throws UnsupportedEncodingException
{
this.out = out;
+ outputBuffer = CharBuffer.allocate(BUFFER_SIZE);
+
try
{
// Don't use NIO if avoidable
@@ -132,7 +134,7 @@
}
/*
- * Workraround for encodings with a byte-order-mark.
+ * Workaround for encodings with a byte-order-mark.
* We only want to write it once per stream.
*/
try
@@ -155,8 +157,6 @@
{
}
- outputBuffer = CharBuffer.allocate(BUFFER_SIZE);
-
Charset cs = EncodingHelper.getCharset(encoding_scheme);
if(cs == null)
throw new UnsupportedEncodingException("Encoding "+encoding_scheme+
@@ -185,7 +185,7 @@
public OutputStreamWriter (OutputStream out)
{
this.out = out;
- outputBuffer = null;
+ outputBuffer = CharBuffer.allocate(BUFFER_SIZE);
try
{
String encoding = System.getProperty("file.encoding");
@@ -203,7 +203,6 @@
{
encoder.onMalformedInput(CodingErrorAction.REPLACE);
encoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
- outputBuffer = CharBuffer.allocate(BUFFER_SIZE);
}
}
@@ -345,7 +344,7 @@
{
byte[] b = new byte[count];
for(int i=0;i<count;i++)
- b[i] = (byte)((buf[offset+i] <= 0xFF)?buf[offset+i]:'?');
+ b[i] = nullConversion(buf[offset+i]);
out.write(b);
} else {
try {
@@ -369,6 +368,10 @@
}
}
+ private byte nullConversion(char c) {
+ return (byte)((c <= 0xFF)?c:'?');
+ }
+
/**
* This method writes <code>count</code> bytes from the specified
* <code>String</code> starting at position <code>offset</code> into the
@@ -398,7 +401,20 @@
*/
public void write (int ch) throws IOException
{
- write(new char[]{ (char)ch }, 0, 1);
+ // No buffering, no encoding ... just pass through
+ if (encoder == null && outputBuffer == null) {
+ out.write(nullConversion((char)ch));
+ } else {
+ if (outputBuffer != null) {
+ if (outputBuffer.remaining() == 0) {
+ writeConvert(outputBuffer.array(), 0, BUFFER_SIZE);
+ outputBuffer.clear();
+ }
+ outputBuffer.put((char)ch);
+ } else {
+ writeConvert(new char[]{ (char)ch }, 0, 1);
+ }
+ }
}
} // class OutputStreamWriter
