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.io;
michael@0: 
michael@0: import java.io.IOException;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.util.CharArrayBuffer;
michael@0: 
michael@0: /**
michael@0:  * Session input buffer for blocking connections. This interface is similar to
michael@0:  * InputStream class, but it also provides methods for reading lines of text.
michael@0:  * <p>
michael@0:  * Implementing classes are also expected to manage intermediate data buffering
michael@0:  * for optimal input performance.
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public interface SessionInputBuffer {
michael@0: 
michael@0:     /**
michael@0:      * Reads up to <code>len</code> bytes of data from the session buffer into
michael@0:      * an array of bytes.  An attempt is made to read as many as
michael@0:      * <code>len</code> bytes, but a smaller number may be read, possibly
michael@0:      * zero. The number of bytes actually read is returned as an integer.
michael@0:      *
michael@0:      * <p> This method blocks until input data is available, end of file is
michael@0:      * detected, or an exception is thrown.
michael@0:      *
michael@0:      * <p> If <code>off</code> is negative, or <code>len</code> is negative, or
michael@0:      * <code>off+len</code> is greater than the length of the array
michael@0:      * <code>b</code>, then an <code>IndexOutOfBoundsException</code> is
michael@0:      * thrown.
michael@0:      *
michael@0:      * @param      b     the buffer into which the data is read.
michael@0:      * @param      off   the start offset in array <code>b</code>
michael@0:      *                   at which the data is written.
michael@0:      * @param      len   the maximum number of bytes to read.
michael@0:      * @return     the total number of bytes read into the buffer, or
michael@0:      *             <code>-1</code> if there is no more data because the end of
michael@0:      *             the stream has been reached.
michael@0:      * @exception  IOException  if an I/O error occurs.
michael@0:      */
michael@0:     int read(byte[] b, int off, int len) throws IOException;
michael@0: 
michael@0:     /**
michael@0:      * Reads some number of bytes from the session buffer and stores them into
michael@0:      * the buffer array <code>b</code>. The number of bytes actually read is
michael@0:      * returned as an integer.  This method blocks until input data is
michael@0:      * available, end of file is detected, or an exception is thrown.
michael@0:      *
michael@0:      * @param      b   the buffer into which the data is read.
michael@0:      * @return     the total number of bytes read into the buffer, or
michael@0:      *             <code>-1</code> is there is no more data because the end of
michael@0:      *             the stream has been reached.
michael@0:      * @exception  IOException  if an I/O error occurs.
michael@0:      */
michael@0:     int read(byte[] b) throws IOException;
michael@0: 
michael@0:     /**
michael@0:      * Reads the next byte of data from this session buffer. The value byte is
michael@0:      * returned as an <code>int</code> in the range <code>0</code> to
michael@0:      * <code>255</code>. If no byte is available because the end of the stream
michael@0:      * has been reached, the value <code>-1</code> is returned. This method
michael@0:      * blocks until input data is available, the end of the stream is detected,
michael@0:      * or an exception is thrown.
michael@0:      *
michael@0:      * @return     the next byte of data, or <code>-1</code> if the end of the
michael@0:      *             stream is reached.
michael@0:      * @exception  IOException  if an I/O error occurs.
michael@0:      */
michael@0:     int read() throws IOException;
michael@0: 
michael@0:     /**
michael@0:      * Reads a complete line of characters up to a line delimiter from this
michael@0:      * session buffer into the given line buffer. The number of chars actually
michael@0:      * read is returned as an integer. The line delimiter itself is discarded.
michael@0:      * If no char is available because the end of the stream has been reached,
michael@0:      * the value <code>-1</code> is returned. This method blocks until input
michael@0:      * data is available, end of file is detected, or an exception is thrown.
michael@0:      * <p>
michael@0:      * The choice of a char encoding and line delimiter sequence is up to the
michael@0:      * specific implementations of this interface.
michael@0:      *
michael@0:      * @param      buffer   the line buffer.
michael@0:      * @return     one line of characters
michael@0:      * @exception  IOException  if an I/O error occurs.
michael@0:      */
michael@0:     int readLine(CharArrayBuffer buffer) throws IOException;
michael@0: 
michael@0:     /**
michael@0:      * Reads a complete line of characters up to a line delimiter from this
michael@0:      * session buffer. The line delimiter itself is discarded. If no char is
michael@0:      * available because the end of the stream has been reached,
michael@0:      * <code>null</code> is returned. This method blocks until input data is
michael@0:      * available, end of file is detected, or an exception is thrown.
michael@0:      * <p>
michael@0:      * The choice of a char encoding and line delimiter sequence is up to the
michael@0:      * specific implementations of this interface.
michael@0:      *
michael@0:      * @return HTTP line as a string
michael@0:      * @exception  IOException  if an I/O error occurs.
michael@0:      */
michael@0:     String readLine() throws IOException;
michael@0: 
michael@0:     /** Blocks until some data becomes available in the session buffer or the
michael@0:      * given timeout period in milliseconds elapses. If the timeout value is
michael@0:      * <code>0</code> this method blocks indefinitely.
michael@0:      *
michael@0:      * @param timeout in milliseconds.
michael@0:      * @return <code>true</code> if some data is available in the session
michael@0:      *   buffer or <code>false</code> otherwise.
michael@0:      * @exception  IOException  if an I/O error occurs.
michael@0:      */
michael@0:     boolean isDataAvailable(int timeout) throws IOException;
michael@0: 
michael@0:     /**
michael@0:      * Returns {@link HttpTransportMetrics} for this session buffer.
michael@0:      *
michael@0:      * @return transport metrics.
michael@0:      */
michael@0:     HttpTransportMetrics getMetrics();
michael@0: 
michael@0: }