/*
* Copyright 1999,2004 The Apache Software Foundation.
*
* Licensed 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.
*/
package org.apache.coyote.tomcat5;
import java.io.IOException;
import java.io.Writer;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.HashMap;
import org.apache.catalina.connector.ClientAbortException;
import org.apache.coyote.ActionCode;
import org.apache.coyote.Response;
import org.apache.tomcat.util.buf.ByteChunk;
import org.apache.tomcat.util.buf.C2BConverter;
import org.apache.tomcat.util.buf.CharChunk;
/**
* The buffer used by Tomcat response. This is a derivative of the Tomcat 3.3
* OutputBuffer, with the removal of some of the state handling (which in
* Coyote is mostly the Processor's responsability).
*
* @author Costin Manolache
* @author Remy Maucherat
*/
public class OutputBuffer extends Writer
implements ByteChunk.ByteOutputChannel, CharChunk.CharOutputChannel {
// -------------------------------------------------------------- Constants
public static final String DEFAULT_ENCODING =
org.apache.coyote.Constants.DEFAULT_CHARACTER_ENCODING;
public static final int DEFAULT_BUFFER_SIZE = 8*1024;
static final int debug = 0;
// The buffer can be used for byte[] and char[] writing
// ( this is needed to support ServletOutputStream and for
// efficient implementations of templating systems )
public final int INITIAL_STATE = 0;
public final int CHAR_STATE = 1;
public final int BYTE_STATE = 2;
// ----------------------------------------------------- Instance Variables
/**
* The byte buffer.
*/
private ByteChunk bb;
/**
* The chunk buffer.
*/
private CharChunk cb;
/**
* State of the output buffer.
*/
private int state = 0;
/**
* Number of bytes written.
*/
private int bytesWritten = 0;
/**
* Number of chars written.
*/
private int charsWritten = 0;
/**
* Flag which indicates if the output buffer is closed.
*/
private boolean closed = false;
/**
* Do a flush on the next operation.
*/
private boolean doFlush = false;
/**
* Byte chunk used to output bytes.
*/
private ByteChunk outputChunk = new ByteChunk();
/**
* Encoding to use.
*/
private String enc;
/**
* Encoder is set.
*/
private boolean gotEnc = false;
/**
* List of encoders.
*/
protected HashMap encoders = new HashMap();
/**
* Current char to byte converter.
*/
protected C2BConverter conv;
/**
* Associated Coyote response.
*/
private Response coyoteResponse;
/**
* Suspended flag. All output bytes will be swallowed if this is true.
*/
private boolean suspended = false;
// ----------------------------------------------------------- Constructors
/**
* Default constructor. Allocate the buffer with the default buffer size.
*/
public OutputBuffer() {
this(DEFAULT_BUFFER_SIZE);
}
/**
* Alternate constructor which allows specifying the initial buffer size.
*
* @param size Buffer size to use
*/
public OutputBuffer(int size) {
bb = new ByteChunk(size);
bb.setLimit(size);
bb.setByteOutputChannel(this);
cb = new CharChunk(size);
cb.setCharOutputChannel(this);
cb.setLimit(size);
}
// ------------------------------------------------------------- Properties
/**
* Associated Coyote response.
*
* @param coyoteResponse Associated Coyote response
*/
public void setResponse(Response coyoteResponse) {
this.coyoteResponse = coyoteResponse;
}
/**
* Get associated Coyote response.
*
* @return the associated Coyote response
*/
public Response getResponse() {
return this.coyoteResponse;
}
/**
* Is the response output suspended ?
*
* @return suspended flag value
*/
public boolean isSuspended() {
return this.suspended;
}
/**
* Set the suspended flag.
*
* @param suspended New suspended flag value
*/
public void setSuspended(boolean suspended) {
this.suspended = suspended;
}
// --------------------------------------------------------- Public Methods
/**
* Recycle the output buffer.
*/
public void recycle() {
if (debug > 0)
log("recycle()");
state = INITIAL_STATE;
bytesWritten = 0;
charsWritten = 0;
cb.recycle();
bb.recycle();
closed = false;
suspended = false;
if (conv!= null) {
conv.recycle();
}
gotEnc = false;
enc = null;
}
/**
* Close the output buffer. This tries to calculate the response size if
* the response has not been committed yet.
*
* @throws IOException An underlying IOException occurred
*/
public void close()
throws IOException {
if (closed)
return;
if (suspended)
return;
if ((!coyoteResponse.isCommitted())
&& (coyoteResponse.getContentLength() == -1)) {
// Flushing the char buffer
if (state == CHAR_STATE) {
cb.flushBuffer();
state = BYTE_STATE;
}
// If this didn't cause a commit of the response, the final content
// length can be calculated
if (!coyoteResponse.isCommitted()) {
coyoteResponse.setContentLength(bb.getLength());
}
}
doFlush(false);
closed = true;
coyoteResponse.finish();
}
/**
* Flush bytes or chars contained in the buffer.
*
* @throws IOException An underlying IOException occurred
*/
public void flush()
throws IOException {
doFlush(true);
}
/**
* Flush bytes or chars contained in the buffer.
*
* @throws IOException An underlying IOException occurred
*/
protected void doFlush(boolean realFlush)
throws IOException {
if (suspended)
return;
doFlush = true;
if (state == CHAR_STATE) {
cb.flushBuffer();
bb.flushBuffer();
state = BYTE_STATE;
} else if (state == BYTE_STATE) {
bb.flushBuffer();
} else if (state == INITIAL_STATE) {
// If the buffers are empty, commit the response header
coyoteResponse.sendHeaders();
}
doFlush = false;
if (realFlush) {
coyoteResponse.action(ActionCode.ACTION_CLIENT_FLUSH,
coyoteResponse);
// If some exception occurred earlier, or if some IOE occurred
// here, notify the servlet with an IOE
if (coyoteResponse.isExceptionPresent()) {
throw new ClientAbortException
(coyoteResponse.getErrorException());
}
}
}
// ------------------------------------------------- Bytes Handling Methods
/**
* Sends the buffer data to the client output, checking the
* state of Response and calling the right interceptors.
*
* @param buf Byte buffer to be written to the response
* @param off Offset
* @param cnt Length
*
* @throws IOException An underlying IOException occurred
*/
public void realWriteBytes(byte buf[], int off, int cnt)
throws IOException {
if (debug > 2)
log("realWrite(b, " + off + ", " + cnt + ") " + coyoteResponse);
if (closed)
return;
if (coyoteResponse == null)
return;
// If we really have something to write
if (cnt > 0) {
// real write to the adapter
outputChunk.setBytes(buf, off, cnt);
try {
coyoteResponse.doWrite(outputChunk);
} catch (IOException e) {
// An IOException on a write is almost always due to
// the remote client aborting the request. Wrap this
// so that it can be handled better by the error dispatcher.
throw new ClientAbortException(e);
}
}
}
public void write(byte b[], int off, int len) throws IOException {
if (suspended)
return;
if (state == CHAR_STATE)
cb.flushBuffer();
state = BYTE_STATE;
writeBytes(b, off, len);
}
private void writeBytes(byte b[], int off, int len)
throws IOException {
if (closed)
return;
if (debug > 0)
log("write(b,off,len)");
bb.append(b, off, len);
bytesWritten += len;
// if called from within flush(), then immediately flush
// remaining bytes
if (doFlush) {
bb.flushBuffer();
}
}
// XXX Char or byte ?
public void writeByte(int b)
throws IOException {
if (suspended)
return;
if (state == CHAR_STATE)
cb.flushBuffer();
state = BYTE_STATE;
if (debug > 0)
log("write(b)");
bb.append( (byte)b );
bytesWritten++;
}
// ------------------------------------------------- Chars Handling Methods
public void write(int c)
throws IOException {
if (suspended)
return;
state = CHAR_STATE;
if (debug > 0)
log("writeChar(b)");
cb.append((char) c);
charsWritten++;
}
public void write(char c[])
throws IOException {
if (suspended)
return;
write(c, 0, c.length);
}
public void write(char c[], int off, int len)
throws IOException {
if (suspended)
return;
state = CHAR_STATE;
if (debug > 0)
log("write(c,off,len)" + cb.getLength() + " " + cb.getLimit());
cb.append(c, off, len);
charsWritten += len;
}
public void write(StringBuffer sb)
throws IOException {
if (suspended)
return;
state = CHAR_STATE;
if (debug > 1)
log("write(s,off,len)");
int len = sb.length();
charsWritten += len;
cb.append(sb);
}
/**
* Append a string to the buffer
*/
public void write(String s, int off, int len)
throws IOException {
if (suspended)
return;
state=CHAR_STATE;
if (debug > 1)
log("write(s,off,len)");
charsWritten += len;
if (s==null)
s="null";
cb.append( s, off, len );
}
public void write(String s)
throws IOException {
if (suspended)
return;
state = CHAR_STATE;
if (s==null)
s="null";
write(s, 0, s.length());
}
public void flushChars()
throws IOException {
if (debug > 0)
log("flushChars() " + cb.getLength());
cb.flushBuffer();
state = BYTE_STATE;
}
public boolean flushCharsNeeded() {
return state == CHAR_STATE;
}
public void setEncoding(String s) {
enc = s;
}
public void realWriteChars(char c[], int off, int len)
throws IOException {
if (debug > 0)
log("realWrite(c,o,l) " + cb.getOffset() + " " + len);
if (!gotEnc)
setConverter();
if (debug > 0)
log("encoder: " + conv + " " + gotEnc);
conv.convert(c, off, len);
conv.flushBuffer(); // ???
}
public void checkConverter()
throws IOException {
if (!gotEnc)
setConverter();
}
protected void setConverter()
throws IOException {
if (coyoteResponse != null)
enc = coyoteResponse.getCharacterEncoding();
if (debug > 0)
log("Got encoding: " + enc);
gotEnc = true;
if (enc == null)
enc = DEFAULT_ENCODING;
conv = (C2BConverter) encoders.get(enc);
if (conv == null) {
if (System.getSecurityManager() != null){
try{
conv = (C2BConverter)AccessController.doPrivileged(
new PrivilegedExceptionAction(){
public Object run() throws IOException{
return new C2BConverter(bb, enc);
}
}
);
}catch(PrivilegedActionException ex){
Exception e = ex.getException();
if (e instanceof IOException)
throw (IOException)e;
if (debug > 0)
log("setConverter: " + ex.getMessage());
}
} else {
conv = new C2BConverter(bb, enc);
}
encoders.put(enc, conv);
}
}
// -------------------- BufferedOutputStream compatibility
/**
* Real write - this buffer will be sent to the client
*/
public void flushBytes()
throws IOException {
if (debug > 0)
log("flushBytes() " + bb.getLength());
bb.flushBuffer();
}
public int getBytesWritten() {
return bytesWritten;
}
public int getCharsWritten() {
return charsWritten;
}
public int getContentWritten() {
return bytesWritten + charsWritten;
}
/**
* True if this buffer hasn't been used ( since recycle() ) -
* i.e. no chars or bytes have been added to the buffer.
*/
public boolean isNew() {
return (bytesWritten == 0) && (charsWritten == 0);
}
public void setBufferSize(int size) {
if (size > bb.getLimit()) {// ??????
bb.setLimit(size);
}
}
public void reset() {
//count=0;
bb.recycle();
bytesWritten = 0;
cb.recycle();
charsWritten = 0;
gotEnc = false;
enc = null;
}
public int getBufferSize() {
return bb.getLimit();
}
protected void log( String s ) {
System.out.println("OutputBuffer: " + s);
}
}