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/* -*- Mode: C++; tab-width: 4; 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):
*
* 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 "nsIAsyncInputStream.idl"
#include "nsIAsyncOutputStream.idl"
interface nsIMemory;
/**
* nsIPipe represents an in-process buffer that can be read using nsIInputStream
* and written using nsIOutputStream. The reader and writer of a pipe do not
* have to be on the same thread. As a result, the pipe is an ideal mechanism
* to bridge data exchange between two threads. For example, a worker thread
* might write data to a pipe from which the main thread will read.
*
* Each end of the pipe can be either blocking or non-blocking. Recall that a
* non-blocking stream will return NS_BASE_STREAM_WOULD_BLOCK if it cannot be
* read or written to without blocking the calling thread. For example, if you
* try to read from an empty pipe that has not yet been closed, then if that
* pipe's input end is non-blocking, then the read call will fail immediately
* with NS_BASE_STREAM_WOULD_BLOCK as the error condition. However, if that
* pipe's input end is blocking, then the read call will not return until the
* pipe has data or until the pipe is closed. This example presumes that the
* pipe is being filled asynchronously on some background thread.
*
* The pipe supports nsIAsyncInputStream and nsIAsyncOutputStream, which give
* the user of a non-blocking pipe the ability to wait for the pipe to become
* ready again. For example, in the case of an empty non-blocking pipe, the
* user can call AsyncWait on the input end of the pipe to be notified when
* the pipe has data to read (or when the pipe becomes closed).
*
* NS_NewPipe2 and NS_NewPipe provide convenient pipe constructors. In most
* cases nsIPipe is not actually used. It is usually enough to just get
* references to the pipe's input and output end. In which case, the pipe is
* automatically closed when the respective pipe ends are released.
*/
[scriptable, uuid(f4211abc-61b3-11d4-9877-00c04fa0cf4a)]
interface nsIPipe : nsISupports
{
/**
* initialize this pipe
*/
void init(in boolean nonBlockingInput,
in boolean nonBlockingOutput,
in unsigned long segmentSize,
in unsigned long segmentCount,
in nsIMemory segmentAllocator);
/**
* The pipe's input end, which also implements nsISearchableInputStream.
*/
readonly attribute nsIAsyncInputStream inputStream;
/**
* The pipe's output end.
*/
readonly attribute nsIAsyncOutputStream outputStream;
};
/**
* XXX this interface doesn't really belong in here. It is here because
* currently nsPipeInputStream is the only implementation of this interface.
*/
[scriptable, uuid(8C39EF62-F7C9-11d4-98F5-001083010E9B)]
interface nsISearchableInputStream : nsISupports
{
/**
* Searches for a string in the input stream. Since the stream has a notion
* of EOF, it is possible that the string may at some time be in the
* buffer, but is is not currently found up to some offset. Consequently,
* both the found and not found cases return an offset:
* if found, return offset where it was found
* if not found, return offset of the first byte not searched
* In the case the stream is at EOF and the string is not found, the first
* byte not searched will correspond to the length of the buffer.
*/
void search(in string forString,
in boolean ignoreCase,
out boolean found,
out unsigned long offsetSearchedTo);
};
%{C++
/**
* NS_NewPipe2
*
* This function supercedes NS_NewPipe. It differs from NS_NewPipe in two
* major ways:
* (1) returns nsIAsyncInputStream and nsIAsyncOutputStream, so it is
* not necessary to QI in order to access these interfaces.
* (2) the size of the pipe is determined by the number of segments
* times the size of each segment.
*
* @param pipeIn
* resulting input end of the pipe
* @param pipeOut
* resulting output end of the pipe
* @param nonBlockingInput
* true specifies non-blocking input stream behavior
* @param nonBlockingOutput
* true specifies non-blocking output stream behavior
* @param segmentSize
* specifies the segment size in bytes (pass 0 to use default value)
* @param segmentCount
* specifies the max number of segments (pass 0 to use default value)
* passing PR_UINT32_MAX here causes the pipe to have "infinite" space.
* this mode can be useful in some cases, but should always be used with
* caution. the default value for this parameter is a finite value.
* @param segmentAlloc
* pass reference to nsIMemory to have all pipe allocations use this
* allocator (pass null to use the default allocator)
*/
extern NS_COM nsresult
NS_NewPipe2(nsIAsyncInputStream **pipeIn,
nsIAsyncOutputStream **pipeOut,
PRBool nonBlockingInput = PR_FALSE,
PRBool nonBlockingOutput = PR_FALSE,
PRUint32 segmentSize = 0,
PRUint32 segmentCount = 0,
nsIMemory *segmentAlloc = nsnull);
/**
* NS_NewPipe
*
* Preserved for backwards compatibility. Plus, this interface is more
* amiable in certain contexts (e.g., when you don't need the pipe's async
* capabilities).
*
* @param pipeIn
* resulting input end of the pipe
* @param pipeOut
* resulting output end of the pipe
* @param segmentSize
* specifies the segment size in bytes (pass 0 to use default value)
* @param maxSize
* specifies the max size of the pipe (pass 0 to use default value)
* number of segments is maxSize / segmentSize, and maxSize must be a
* multiple of segmentSize. passing PR_UINT32_MAX here causes the
* pipe to have "infinite" space. this mode can be useful in some
* cases, but should always be used with caution. the default value
* for this parameter is a finite value.
* @param nonBlockingInput
* true specifies non-blocking input stream behavior
* @param nonBlockingOutput
* true specifies non-blocking output stream behavior
* @param segmentAlloc
* pass reference to nsIMemory to have all pipe allocations use this
* allocator (pass null to use the default allocator)
*/
inline nsresult
NS_NewPipe(nsIInputStream **pipeIn,
nsIOutputStream **pipeOut,
PRUint32 segmentSize = 0,
PRUint32 maxSize = 0,
PRBool nonBlockingInput = PR_FALSE,
PRBool nonBlockingOutput = PR_FALSE,
nsIMemory *segmentAlloc = nsnull)
{
PRUint32 segmentCount;
if (segmentSize == 0)
segmentCount = 0; // use default
else
segmentCount = maxSize / segmentSize;
nsIAsyncInputStream *in;
nsIAsyncOutputStream *out;
nsresult rv = NS_NewPipe2(&in, &out, nonBlockingInput, nonBlockingOutput,
segmentSize, segmentCount, segmentAlloc);
if (NS_FAILED(rv)) return rv;
*pipeIn = in;
*pipeOut = out;
return NS_OK;
}
%}
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