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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you 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 .
*/
module com { module sun { module star { module io {
/** This is the basic interface to read data from a stream.
<p>
See the <a href="http://udk.openoffice.org/common/man/concept/streams.html">
streaming document</a> for further information on chaining and piping streams.
*/
published interface XInputStream: com::sun::star::uno::XInterface
{
/** reads the specified number of bytes in the given sequence.
<p>The return value specifies the number of bytes which have been
put into the sequence. A difference between <var>nBytesToRead</var>
and the return value indicates that EOF has been reached. This means
that the method blocks until the specified number of bytes are
available or the EOF is reached. </p>
@param aData
after the call, the byte sequence contains the requested number
of bytes (or less as a sign of EOF).
<br>
C++ only : Note that for unbridged (e.g., in-process)
calls, using the same sequence for repetitive readBytes()-calls
can bear a performance advantage. The callee can put the data
directly into the sequence so that no buffer reallocation is
necessary.
But this holds only when
<ol>
<li> neither caller nor callee keep a second reference to the same
sequence.
<li> the sequence is pre-allocated with the requested number of bytes.
<li> the same sequence is reused (simply preallocating a new
sequence for every call bears no advantage).
<li> the call is not bridged (e.g., between different compilers
or different processes).
</ol>
<br>
If the same 'optimized' code runs against an interface in a different process,
there is an unnecessary memory allocation/deallocation (the out parameter
is of course NOT transported over the connection), but this should
be negligible compared to a synchron call.
@param nBytesToRead
the total number of bytes to read
*/
long readBytes( [out] sequence<byte> aData,
[in] long nBytesToRead )
raises( com::sun::star::io::NotConnectedException,
com::sun::star::io::BufferSizeExceededException,
com::sun::star::io::IOException);
/** reads the available number of bytes, at maximum
<var>nMaxBytesToRead</var>.
<p>This method is very similar to the readBytes method, except that
it has different blocking behaviour.
The method blocks as long as at least 1 byte is available or
EOF has been reached. EOF has only been reached, when the method
returns 0 and the corresponding byte sequence is empty.
Otherwise, after the call, aData contains the available,
but no more than nMaxBytesToRead, bytes.
@param aData contains the data read from the stream.
@param nMaxBytesToRead The maximum number of bytes to be read from this
stream during the call.
@see com::sun::star::io::XInputStream::readBytes
*/
long readSomeBytes( [out] sequence<byte> aData,
[in] long nMaxBytesToRead )
raises( com::sun::star::io::NotConnectedException,
com::sun::star::io::BufferSizeExceededException,
com::sun::star::io::IOException );
/** skips the next <var>nBytesToSkip</var> bytes (must be positive).
<p>It is up to the implementation whether this method is
blocking the thread or not. </p>
@param nBytesToSkip
number of bytes to skip
*/
void skipBytes( [in] long nBytesToSkip )
raises( com::sun::star::io::NotConnectedException,
com::sun::star::io::BufferSizeExceededException,
com::sun::star::io::IOException );
/** states how many bytes can be read or skipped without blocking.
<p>Note: This method offers no information on whether the EOF
has been reached. </p>
*/
long available()
raises( com::sun::star::io::NotConnectedException,
com::sun::star::io::IOException
);
/** closes the stream.
<p>Users must close the stream explicitly when no further
reading should be done. (There may exist ring references to
chained objects that can only be released during this call.
Thus not calling this method would result in a leak of memory or
external resources.) </p>
*/
void closeInput()
raises( com::sun::star::io::NotConnectedException,
com::sun::star::io::IOException);
};
}; }; }; };
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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