michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.impl.io;
michael@0: 
michael@0: import java.io.IOException;
michael@0: import java.io.OutputStream;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.io.BufferInfo;
michael@0: import ch.boye.httpclientandroidlib.io.SessionOutputBuffer;
michael@0: import ch.boye.httpclientandroidlib.io.HttpTransportMetrics;
michael@0: import ch.boye.httpclientandroidlib.params.CoreConnectionPNames;
michael@0: import ch.boye.httpclientandroidlib.params.HttpParams;
michael@0: import ch.boye.httpclientandroidlib.params.HttpProtocolParams;
michael@0: import ch.boye.httpclientandroidlib.protocol.HTTP;
michael@0: import ch.boye.httpclientandroidlib.util.ByteArrayBuffer;
michael@0: import ch.boye.httpclientandroidlib.util.CharArrayBuffer;
michael@0: 
michael@0: /**
michael@0:  * Abstract base class for session output buffers that stream data to
michael@0:  * an arbitrary {@link OutputStream}. This class buffers small chunks of
michael@0:  * output data in an internal byte array for optimal output performance.
michael@0:  * <p>
michael@0:  * {@link #writeLine(CharArrayBuffer)} and {@link #writeLine(String)} methods
michael@0:  * of this class use CR-LF as a line delimiter.
michael@0:  * <p>
michael@0:  * The following parameters can be used to customize the behavior of this
michael@0:  * class:
michael@0:  * <ul>
michael@0:  *  <li>{@link ch.boye.httpclientandroidlib.params.CoreProtocolPNames#HTTP_ELEMENT_CHARSET}</li>
michael@0:  *  <li>{@link ch.boye.httpclientandroidlib.params.CoreConnectionPNames#MIN_CHUNK_LIMIT}</li>
michael@0:  * </ul>
michael@0:  * <p>
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public abstract class AbstractSessionOutputBuffer implements SessionOutputBuffer, BufferInfo {
michael@0: 
michael@0:     private static final byte[] CRLF = new byte[] {HTTP.CR, HTTP.LF};
michael@0: 
michael@0:     private OutputStream outstream;
michael@0:     private ByteArrayBuffer buffer;
michael@0: 
michael@0:     private String charset = HTTP.US_ASCII;
michael@0:     private boolean ascii = true;
michael@0:     private int minChunkLimit = 512;
michael@0: 
michael@0:     private HttpTransportMetricsImpl metrics;
michael@0: 
michael@0:     /**
michael@0:      * Initializes this session output buffer.
michael@0:      *
michael@0:      * @param outstream the destination output stream.
michael@0:      * @param buffersize the size of the internal buffer.
michael@0:      * @param params HTTP parameters.
michael@0:      */
michael@0:     protected void init(final OutputStream outstream, int buffersize, final HttpParams params) {
michael@0:         if (outstream == null) {
michael@0:             throw new IllegalArgumentException("Input stream may not be null");
michael@0:         }
michael@0:         if (buffersize <= 0) {
michael@0:             throw new IllegalArgumentException("Buffer size may not be negative or zero");
michael@0:         }
michael@0:         if (params == null) {
michael@0:             throw new IllegalArgumentException("HTTP parameters may not be null");
michael@0:         }
michael@0:         this.outstream = outstream;
michael@0:         this.buffer = new ByteArrayBuffer(buffersize);
michael@0:         this.charset = HttpProtocolParams.getHttpElementCharset(params);
michael@0:         this.ascii = this.charset.equalsIgnoreCase(HTTP.US_ASCII)
michael@0:                      || this.charset.equalsIgnoreCase(HTTP.ASCII);
michael@0:         this.minChunkLimit = params.getIntParameter(CoreConnectionPNames.MIN_CHUNK_LIMIT, 512);
michael@0:         this.metrics = createTransportMetrics();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @since 4.1
michael@0:      */
michael@0:     protected HttpTransportMetricsImpl createTransportMetrics() {
michael@0:         return new HttpTransportMetricsImpl();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @since 4.`1
michael@0:      */
michael@0:     public int capacity() {
michael@0:         return this.buffer.capacity();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @since 4.1
michael@0:      */
michael@0:     public int length() {
michael@0:         return this.buffer.length();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @since 4.1
michael@0:      */
michael@0:     public int available() {
michael@0:         return capacity() - length();
michael@0:     }
michael@0: 
michael@0:     protected void flushBuffer() throws IOException {
michael@0:         int len = this.buffer.length();
michael@0:         if (len > 0) {
michael@0:             this.outstream.write(this.buffer.buffer(), 0, len);
michael@0:             this.buffer.clear();
michael@0:             this.metrics.incrementBytesTransferred(len);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     public void flush() throws IOException {
michael@0:         flushBuffer();
michael@0:         this.outstream.flush();
michael@0:     }
michael@0: 
michael@0:     public void write(final byte[] b, int off, int len) throws IOException {
michael@0:         if (b == null) {
michael@0:             return;
michael@0:         }
michael@0:         // Do not want to buffer large-ish chunks
michael@0:         // if the byte array is larger then MIN_CHUNK_LIMIT
michael@0:         // write it directly to the output stream
michael@0:         if (len > this.minChunkLimit || len > this.buffer.capacity()) {
michael@0:             // flush the buffer
michael@0:             flushBuffer();
michael@0:             // write directly to the out stream
michael@0:             this.outstream.write(b, off, len);
michael@0:             this.metrics.incrementBytesTransferred(len);
michael@0:         } else {
michael@0:             // Do not let the buffer grow unnecessarily
michael@0:             int freecapacity = this.buffer.capacity() - this.buffer.length();
michael@0:             if (len > freecapacity) {
michael@0:                 // flush the buffer
michael@0:                 flushBuffer();
michael@0:             }
michael@0:             // buffer
michael@0:             this.buffer.append(b, off, len);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     public void write(final byte[] b) throws IOException {
michael@0:         if (b == null) {
michael@0:             return;
michael@0:         }
michael@0:         write(b, 0, b.length);
michael@0:     }
michael@0: 
michael@0:     public void write(int b) throws IOException {
michael@0:         if (this.buffer.isFull()) {
michael@0:             flushBuffer();
michael@0:         }
michael@0:         this.buffer.append(b);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Writes characters from the specified string followed by a line delimiter
michael@0:      * to this session buffer.
michael@0:      * <p>
michael@0:      * This method uses CR-LF as a line delimiter.
michael@0:      *
michael@0:      * @param      s   the line.
michael@0:      * @exception  IOException  if an I/O error occurs.
michael@0:      */
michael@0:     public void writeLine(final String s) throws IOException {
michael@0:         if (s == null) {
michael@0:             return;
michael@0:         }
michael@0:         if (s.length() > 0) {
michael@0:             write(s.getBytes(this.charset));
michael@0:         }
michael@0:         write(CRLF);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Writes characters from the specified char array followed by a line
michael@0:      * delimiter to this session buffer.
michael@0:      * <p>
michael@0:      * This method uses CR-LF as a line delimiter.
michael@0:      *
michael@0:      * @param      s the buffer containing chars of the line.
michael@0:      * @exception  IOException  if an I/O error occurs.
michael@0:      */
michael@0:     public void writeLine(final CharArrayBuffer s) throws IOException {
michael@0:         if (s == null) {
michael@0:             return;
michael@0:         }
michael@0:         if (this.ascii) {
michael@0:             int off = 0;
michael@0:             int remaining = s.length();
michael@0:             while (remaining > 0) {
michael@0:                 int chunk = this.buffer.capacity() - this.buffer.length();
michael@0:                 chunk = Math.min(chunk, remaining);
michael@0:                 if (chunk > 0) {
michael@0:                     this.buffer.append(s, off, chunk);
michael@0:                 }
michael@0:                 if (this.buffer.isFull()) {
michael@0:                     flushBuffer();
michael@0:                 }
michael@0:                 off += chunk;
michael@0:                 remaining -= chunk;
michael@0:             }
michael@0:         } else {
michael@0:             // This is VERY memory inefficient, BUT since non-ASCII charsets are
michael@0:             // NOT meant to be used anyway, there's no point optimizing it
michael@0:             byte[] tmp = s.toString().getBytes(this.charset);
michael@0:             write(tmp);
michael@0:         }
michael@0:         write(CRLF);
michael@0:     }
michael@0: 
michael@0:     public HttpTransportMetrics getMetrics() {
michael@0:         return this.metrics;
michael@0:     }
michael@0: 
michael@0: }