pjs/xpcom/io/nsIBufferOutputStream.idl

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape 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/NPL/
 *
 * 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 Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s): 
 */

#include "nsIOutputStream.idl"

interface nsIBuffer;

%{C++
/**
 * The signature for the reader function passed to WriteSegment. This 
 * specifies where the data should come from that gets written into the buffer.
 * Implementers should return the following:
 * @return NS_OK and readCount > 0 - if successfully read something
 * @return NS_OK and readCount == 0 - if no more to read (EOF)
 * @return NS_BASE_STREAM_WOULD_BLOCK - if there is currently no data (in
 *   a non-blocking mode)
 * @return <other-error> - on failure
 */
typedef NS_CALLBACK(nsReadSegmentFun)(void* closure,
                                      char* toRawSegment,
                                      PRUint32 fromOffset,
                                      PRUint32 count,
                                      PRUint32 *readCount);
%}

native nsReadSegmentFun(nsReadSegmentFun);

[scriptable, uuid(d2aaae66-1ab0-11d3-8ccd-0060b0fc14a3)]
interface nsIBufferOutputStream : nsIOutputStream
{
    /**
     * Returns the buffer underlying this output stream.
     */
    readonly attribute nsIBuffer Buffer;

    [noscript] unsigned long WriteSegments(in nsReadSegmentFun reader,
                                           in voidPtr closure,
                                           in unsigned long count);

    /**
     * Writes data into the stream from an input stream.
     * Implementer's note: This method is defined by this interface in order
     * to allow the output stream to efficiently copy the data from the input
     * stream into its internal buffer (if any). If this method was provide
     * as an external facility, a separate char* buffer would need to be used
     * in order to call the output stream's other Write method.
     * @param fromStream the stream from which the data is read
     * @param count the maximun number of bytes to write
     * @return aWriteCount out parameter to hold the number of
     *         bytes written. if an error occurs, the writecount
     *         is undefined
     */
    unsigned long WriteFrom(in nsIInputStream inStr,
                            in unsigned long count);

    /**
     * Set this attribute to put the stream in non-blocking mode.
     */
    attribute boolean NonBlocking;
};