/**
* Licensed under the Common Development and Distribution License,
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.sun.com/cddl/
*
* 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.
*/
package com.sun.facelets;
import java.io.IOException;
import java.io.Writer;
import com.sun.facelets.util.FastWriter;
/**
* A class for handling state insertion. Content is written
* directly to "out" until an attempt to write state; at that
* point, it's redirected into a buffer that can be picked through
* in theory, this buffer should be very small, since it only
* needs to be enough to contain all the content after the close
* of the first (and, hopefully, only) form.
* <p>
* Potential optimizations:
* <ul>
* <li>If we created a new FastWriter at each call to writingState(),
* and stored a List of them, then we'd know that state tokens could
* only possibly be near the start of each buffer (and might not be there
* at all). (There might be a close-element before the state token). Then,
* we'd only need to check the start of the buffer for the state token;
* if it's there, write out the real state, then blast the rest of the
* buffer out. This wouldn't even require toString(), which for
* large buffers is expensive. However, this optimization is only
* going to be especially meaningful for the multi-form case.
* </li>
* <li>More of a FastWriter optimization than a StateWriter, but:
* it is far faster to create a set of small 1K buffers than constantly
* reallocating one big buffer.</li>
* </ul>
*
* @author Adam Winer
* @version $Id: StateWriter.java,v 1.1 2006/04/12 05:50:45 adamwiner Exp $
*/
final class StateWriter extends Writer {
private int initialSize;
private Writer out;
private FastWriter fast;
private boolean writtenState;
static public StateWriter getCurrentInstance() {
return (StateWriter) CURRENT_WRITER.get();
}
public StateWriter(Writer initialOut, int initialSize) {
if (initialSize < 0) {
throw new IllegalArgumentException("Initial Size cannot be less than 0");
}
this.initialSize = initialSize;
this.out = initialOut;
CURRENT_WRITER.set(this);
}
/**
* Mark that state is about to be written. Contrary to what you'd expect,
* we cannot and should not assume that this location is really going
* to have state; it is perfectly legit to have a ResponseWriter that
* filters out content, and ignores an attempt to write out state
* at this point. So, we have to check after the fact to see
* if there really are state markers.
*/
public void writingState() {
if (!this.writtenState) {
this.writtenState = true;
this.out = this.fast = new FastWriter(this.initialSize);
}
}
public boolean isStateWritten() {
return this.writtenState;
}
public void close() throws IOException {
// do nothing
}
public void flush() throws IOException {
// do nothing
}
public void write(char[] cbuf, int off, int len) throws IOException {
this.out.write(cbuf, off, len);
}
public void write(char[] cbuf) throws IOException {
this.out.write(cbuf);
}
public void write(int c) throws IOException {
this.out.write(c);
}
public void write(String str, int off, int len) throws IOException {
this.out.write(str, off, len);
}
public void write(String str) throws IOException {
this.out.write(str);
}
public String getAndResetBuffer() {
if (!this.writtenState) {
throw new IllegalStateException(
"Did not write state; no buffer is available");
}
String result = this.fast.toString();
this.fast.reset();
return result;
}
public void release() {
CURRENT_WRITER.set(null);
}
static private final ThreadLocal CURRENT_WRITER = new ThreadLocal();
}