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