nsIInputStream.idl
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- /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
- /* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (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.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is mozilla.org code.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1998
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- * Warren Harris <warren@netscape.com>
- * Darin Fisher <darin@netscape.com>
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either of the GNU General Public License Version 2 or later (the "GPL"),
- * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
- #include "nsISupports.idl"
- interface nsIInputStream;
- %{C++
- /**
- * The signature of the writer function passed to ReadSegments. This
- * is the "consumer" of data that gets read from the stream's buffer.
- *
- * @param aInStream stream being read
- * @param aClosure opaque parameter passed to ReadSegments
- * @param aFromSegment pointer to memory owned by the input stream
- * @param aToOffset amount already read (since ReadSegments was called)
- * @param aCount length of fromSegment
- * @param aWriteCount number of bytes read
- *
- * Implementers should return the following:
- *
- * @return NS_OK and (*aWriteCount > 0) if consumed some data
- * @return <any-error> if not interested in consuming any data
- *
- * Errors are never passed to the caller of ReadSegments.
- *
- * NOTE: returning NS_OK and (*aWriteCount = 0) has undefined behavior.
- *
- * @status FROZEN
- */
- typedef NS_CALLBACK(nsWriteSegmentFun)(nsIInputStream *aInStream,
- void *aClosure,
- const char *aFromSegment,
- PRUint32 aToOffset,
- PRUint32 aCount,
- PRUint32 *aWriteCount);
- %}
- native nsWriteSegmentFun(nsWriteSegmentFun);
- /**
- * nsIInputStream
- *
- * @status FROZEN
- */
- [scriptable, uuid(fa9c7f6c-61b3-11d4-9877-00c04fa0cf4a)]
- interface nsIInputStream : nsISupports
- {
- /**
- * Close the stream.
- */
- void close();
- /**
- * @return number of bytes currently available in the stream
- */
- unsigned long available();
- /**
- * Read data from the stream.
- *
- * @param aBuf the buffer into which the data is to be read
- * @param aCount the maximum number of bytes to be read
- *
- * @return number of bytes read (may be less than aCount).
- * @return 0 if reached end of file
- *
- * @throws NS_BASE_STREAM_WOULD_BLOCK if reading from the input stream would
- * block the calling thread (non-blocking mode only)
- * @throws <other-error> on failure
- */
- [noscript] unsigned long read(in charPtr aBuf, in unsigned long aCount);
- /**
- * Low-level read method that has access to the stream's underlying buffer.
- * The writer function may be called multiple times for segmented buffers.
- * ReadSegments is expected to keep calling the writer until either there is
- * nothing left to read or the writer returns an error. ReadSegments should
- * not call the writer with zero bytes to consume.
- *
- * @param aWriter the "consumer" of the data to be read
- * @param aClosure opaque parameter passed to writer
- * @param aCount the maximum number of bytes to be read
- *
- * @return number of bytes read (may be less than aCount)
- * @return 0 if reached end of file (or if aWriter refused to consume data)
- *
- * @throws NS_BASE_STREAM_WOULD_BLOCK if reading from the input stream would
- * block the calling thread (non-blocking mode only)
- * @throws <other-error> on failure
- *
- * NOTE: this function may be unimplemented if a stream has no underlying
- * buffer (e.g., socket input stream).
- */
- [noscript] unsigned long readSegments(in nsWriteSegmentFun aWriter,
- in voidPtr aClosure,
- in unsigned long aCount);
- /**
- * @return true if stream is non-blocking
- */
- boolean isNonBlocking();
- };