| /* AbstractDataInput.java -- |
| Copyright (C) 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.CORBA.CDR; |
| |
| import java.io.IOException; |
| |
| /** |
| * Some data input stream that can be either Big or |
| * Little Endian. |
| * |
| * This class reuses code from GNU Classpath DataInputStream. |
| * |
| * @author Audrius Meskauskas (AudriusA@Bioinformatics.org) |
| * @author Warren Levy (warrenl@cygnus.com) |
| * @author Aaron M. Renn (arenn@urbanophile.com) |
| */ |
| public interface AbstractDataInput |
| { |
| /** |
| * This method reads bytes from the underlying stream into the specified |
| * byte array buffer. It will attempt to fill the buffer completely, but |
| * may return a short count if there is insufficient data remaining to be |
| * read to fill the buffer. |
| * |
| * @param b The buffer into which bytes will be read. |
| * |
| * @return The actual number of bytes read, or -1 if end of stream reached |
| * before reading any bytes. |
| * |
| * @exception IOException If an error occurs. |
| */ |
| int read(byte[] b) |
| throws IOException; |
| |
| /** |
| * This method reads bytes from the underlying stream into the specified |
| * byte array buffer. It will attempt to read <code>len</code> bytes and |
| * will start storing them at position <code>off</code> into the buffer. |
| * This method can return a short count if there is insufficient data |
| * remaining to be read to complete the desired read length. |
| * |
| * @param b The buffer into which bytes will be read. |
| * @param off The offset into the buffer to start storing bytes. |
| * @param len The requested number of bytes to read. |
| * |
| * @return The actual number of bytes read, or -1 if end of stream reached |
| * before reading any bytes. |
| * |
| * @exception IOException If an error occurs. |
| */ |
| int read(byte[] b, int off, int len) |
| throws IOException; |
| |
| /** |
| * This method reads a Java boolean value from an input stream. It does |
| * so by reading a single byte of data. If that byte is zero, then the |
| * value returned is <code>false</code>. If the byte is non-zero, then |
| * the value returned is <code>true</code>. |
| * <p> |
| * This method can read a <code>boolean</code> written by an object |
| * implementing the <code>writeBoolean()</code> method in the |
| * <code>DataOutput</code> interface. |
| * |
| * @return The <code>boolean</code> value read |
| * |
| * @exception EOFException If end of file is reached before reading |
| * the boolean |
| * @exception IOException If any other error occurs |
| * |
| * @see DataOutput#writeBoolean |
| */ |
| boolean readBoolean() |
| throws IOException; |
| |
| /** |
| * This method reads a Java byte value from an input stream. The value |
| * is in the range of -128 to 127. |
| * <p> |
| * This method can read a <code>byte</code> written by an object |
| * implementing the <code>writeByte()</code> method in the |
| * <code>DataOutput</code> interface. |
| * |
| * @return The <code>byte</code> value read |
| * |
| * @exception EOFException If end of file is reached before reading the byte |
| * @exception IOException If any other error occurs |
| * |
| * @see DataOutput#writeByte |
| */ |
| byte readByte() |
| throws IOException; |
| |
| /** |
| * This method reads a Java <code>char</code> value from an input stream. |
| * It operates by reading two bytes from the stream and converting them to |
| * a single 16-bit Java <code>char</code>. The two bytes are stored most |
| * significant byte first (i.e., "big endian") regardless of the native |
| * host byte ordering. |
| * <p> |
| * As an example, if <code>byte1</code> and <code>byte2</code> |
| * represent the first and second byte read from the stream |
| * respectively, they will be transformed to a <code>char</code> in |
| * the following manner: |
| * <p> |
| * <code>(char)(((byte1 & 0xFF) << 8) | (byte2 & 0xFF)</code> |
| * <p> |
| * This method can read a <code>char</code> written by an object |
| * implementing the <code>writeChar()</code> method in the |
| * <code>DataOutput</code> interface. |
| * |
| * @return The <code>char</code> value read |
| * |
| * @exception EOFException If end of file is reached before reading the char |
| * @exception IOException If any other error occurs |
| * |
| * @see DataOutput#writeChar |
| */ |
| char readChar() |
| throws IOException; |
| |
| /** |
| * This method reads a Java double value from an input stream. It operates |
| * by first reading a <code>long</code> value from the stream by calling the |
| * <code>readLong()</code> method in this interface, then converts |
| * that <code>long</code> to a <code>double</code> using the |
| * <code>longBitsToDouble</code> method in the class |
| * <code>java.lang.Double</code> |
| * <p> |
| * This method can read a <code>double</code> written by an object |
| * implementing the <code>writeDouble()</code> method in the |
| * <code>DataOutput</code> interface. |
| * |
| * @return The <code>double</code> value read |
| * |
| * @exception EOFException If end of file is reached before reading |
| * the double |
| * @exception IOException If any other error occurs |
| * |
| * @see DataOutput#writeDouble |
| * @see java.lang.Double#longBitsToDouble |
| */ |
| double readDouble() |
| throws IOException; |
| |
| /** |
| * This method reads a Java float value from an input stream. It |
| * operates by first reading an <code>int</code> value from the |
| * stream by calling the <code>readInt()</code> method in this |
| * interface, then converts that <code>int</code> to a |
| * <code>float</code> using the <code>intBitsToFloat</code> method |
| * in the class <code>java.lang.Float</code> |
| * <p> |
| * This method can read a <code>float</code> written by an object |
| * implementing the <code>writeFloat()</code> method in the |
| * <code>DataOutput</code> interface. |
| * |
| * @return The <code>float</code> value read |
| * |
| * @exception EOFException If end of file is reached before reading the float |
| * @exception IOException If any other error occurs |
| * |
| * @see DataOutput#writeFloat |
| * @see java.lang.Float#intBitsToFloat |
| */ |
| float readFloat() |
| throws IOException; |
| |
| /** |
| * This method reads raw bytes into the passed array until the array is |
| * full. Note that this method blocks until the data is available and |
| * throws an exception if there is not enough data left in the stream to |
| * fill the buffer. Note also that zero length buffers are permitted. |
| * In this case, the method will return immediately without reading any |
| * bytes from the stream. |
| * |
| * @param b The buffer into which to read the data |
| * |
| * @exception EOFException If end of file is reached before filling the |
| * buffer |
| * @exception IOException If any other error occurs |
| */ |
| void readFully(byte[] b) |
| throws IOException; |
| |
| /** |
| * This method reads a Java <code>int</code> value from an input stream |
| * It operates by reading four bytes from the stream and converting them to |
| * a single Java <code>int</code>. The bytes are stored most |
| * significant byte first (i.e., "big endian") regardless of the native |
| * host byte ordering. |
| * <p> |
| * As an example, if <code>byte1</code> through <code>byte4</code> represent |
| * the first four bytes read from the stream, they will be |
| * transformed to an <code>int</code> in the following manner: |
| * <p> |
| * <code>(int)(((byte1 & 0xFF) << 24) + ((byte2 & 0xFF) << 16) + |
| * ((byte3 & 0xFF)<< 8) + (byte4 & 0xFF)))</code> |
| * <p> |
| * The value returned is in the range of -2147483648 to 2147483647. |
| * <p> |
| * This method can read an <code>int</code> written by an object |
| * implementing the <code>writeInt()</code> method in the |
| * <code>DataOutput</code> interface. |
| * |
| * @return The <code>int</code> value read |
| * |
| * @exception EOFException If end of file is reached before reading the int |
| * @exception IOException If any other error occurs |
| * |
| * @see DataOutput#writeInt |
| */ |
| int readInt() |
| throws IOException; |
| |
| /** |
| * This method reads a Java <code>long</code> value from an input stream |
| * It operates by reading eight bytes from the stream and converting them to |
| * a single Java <code>long</code>. The bytes are stored most |
| * significant byte first (i.e., "big endian") regardless of the native |
| * host byte ordering. |
| * <p> |
| * As an example, if <code>byte1</code> through <code>byte8</code> represent |
| * the first eight bytes read from the stream, they will be |
| * transformed to an <code>long</code> in the following manner: |
| * <p> |
| * <code>(long)(((byte1 & 0xFF) << 56) + ((byte2 & 0xFF) << 48) + |
| * ((byte3 & 0xFF) << 40) + ((byte4 & 0xFF) << 32) + |
| * ((byte5 & 0xFF) << 24) + ((byte6 & 0xFF) << 16) + |
| * ((byte7 & 0xFF) << 8) + (byte8 & 0xFF))) |
| * </code> |
| * <p> |
| * The value returned is in the range of -9223372036854775808 to |
| * 9223372036854775807. |
| * <p> |
| * This method can read an <code>long</code> written by an object |
| * implementing the <code>writeLong()</code> method in the |
| * <code>DataOutput</code> interface. |
| * |
| * @return The <code>long</code> value read |
| * |
| * @exception EOFException If end of file is reached before reading the long |
| * @exception IOException If any other error occurs |
| * |
| * @see DataOutput#writeLong |
| */ |
| long readLong() |
| throws IOException; |
| |
| /** |
| * This method reads a signed 16-bit value into a Java in from the |
| * stream. It operates by reading two bytes from the stream and |
| * converting them to a single 16-bit Java <code>short</code>. The |
| * two bytes are stored most significant byte first (i.e., "big |
| * endian") regardless of the native host byte ordering. |
| * <p> |
| * As an example, if <code>byte1</code> and <code>byte2</code> |
| * represent the first and second byte read from the stream |
| * respectively, they will be transformed to a <code>short</code>. in |
| * the following manner: |
| * <p> |
| * <code>(short)(((byte1 & 0xFF) << 8) | (byte2 & 0xFF))</code> |
| * <p> |
| * The value returned is in the range of -32768 to 32767. |
| * <p> |
| * This method can read a <code>short</code> written by an object |
| * implementing the <code>writeShort()</code> method in the |
| * <code>DataOutput</code> interface. |
| * |
| * @return The <code>short</code> value read |
| * |
| * @exception EOFException If end of file is reached before reading the value |
| * @exception IOException If any other error occurs |
| * |
| * @see DataOutput#writeShort |
| */ |
| short readShort() |
| throws IOException; |
| |
| /** |
| * This method reads 8 unsigned bits into a Java <code>int</code> |
| * value from the stream. The value returned is in the range of 0 to |
| * 255. |
| * <p> |
| * This method can read an unsigned byte written by an object |
| * implementing the <code>writeUnsignedByte()</code> method in the |
| * <code>DataOutput</code> interface. |
| * |
| * @return The unsigned bytes value read as a Java <code>int</code>. |
| * |
| * @exception EOFException If end of file is reached before reading the value |
| * @exception IOException If any other error occurs |
| * |
| * @see DataOutput#writeByte |
| */ |
| int readUnsignedByte() |
| throws IOException; |
| |
| /** |
| * This method reads 16 unsigned bits into a Java int value from the stream. |
| * It operates by reading two bytes from the stream and converting them to |
| * a single Java <code>int</code> The two bytes are stored most |
| * significant byte first (i.e., "big endian") regardless of the native |
| * host byte ordering. |
| * <p> |
| * As an example, if <code>byte1</code> and <code>byte2</code> |
| * represent the first and second byte read from the stream |
| * respectively, they will be transformed to an <code>int</code> in |
| * the following manner: |
| * <p> |
| * <code>(int)(((byte1 & 0xFF) << 8) + (byte2 & 0xFF))</code> |
| * <p> |
| * The value returned is in the range of 0 to 65535. |
| * <p> |
| * This method can read an unsigned short written by an object |
| * implementing the <code>writeUnsignedShort()</code> method in the |
| * <code>DataOutput</code> interface. |
| * |
| * @return The unsigned short value read as a Java <code>int</code> |
| * |
| * @exception EOFException If end of file is reached before reading the value |
| * @exception IOException If any other error occurs |
| * |
| * @see DataOutput#writeShort |
| */ |
| int readUnsignedShort() |
| throws IOException; |
| |
| /** |
| * Read a single byte. |
| * |
| * @return a byte, extracted from the stream or -1 if |
| * EOF has been reached. |
| * @throws IOException |
| */ |
| public int read() |
| throws IOException; |
| |
| /** |
| * This method attempts to skip and discard the specified number of bytes |
| * in the input stream. It may actually skip fewer bytes than requested. |
| * This method will not skip any bytes if passed a negative number of bytes |
| * to skip. |
| * |
| * @param n The requested number of bytes to skip. |
| * |
| * @return The requested number of bytes to skip. |
| * |
| * @exception IOException If an error occurs. |
| * @specnote The JDK docs claim that this returns the number of bytes |
| * actually skipped. The JCL claims that this method can throw an |
| * EOFException. Neither of these appear to be true in the JDK 1.3's |
| * implementation. This tries to implement the actual JDK behaviour. |
| */ |
| int skipBytes(int n) |
| throws IOException; |
| } |
