mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-14 15:37:55 +00:00
187 lines
8.0 KiB
Plaintext
187 lines
8.0 KiB
Plaintext
/* -*- 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. This is
|
|
* where the writer function should start consuming data.
|
|
* @param aToOffset amount of data already consumed by this writer during this
|
|
* ReadSegments call. This is also the sum of the aWriteCount
|
|
* returns from this writer over the previous invocations of
|
|
* the writer by this ReadSegments call.
|
|
* @param aCount Number of bytes available to be read starting at aFromSegment
|
|
* @param [out] aWriteCount number of bytes read by this writer function call
|
|
*
|
|
* 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
|
|
*
|
|
* An interface describing a readable stream of data. An input stream may be
|
|
* "blocking" or "non-blocking" (see the IsNonBlocking method). A blocking
|
|
* input stream may suspend the calling thread in order to satisfy a call to
|
|
* Close, Available, Read, or ReadSegments. A non-blocking input stream, on
|
|
* the other hand, must not block the calling thread of execution.
|
|
*
|
|
* NOTE: blocking input streams are often read on a background thread to avoid
|
|
* locking up the main application thread. For this reason, it is generally
|
|
* the case that a blocking input stream should be implemented using thread-
|
|
* safe AddRef and Release.
|
|
*
|
|
* @status FROZEN
|
|
*/
|
|
[scriptable, uuid(fa9c7f6c-61b3-11d4-9877-00c04fa0cf4a)]
|
|
interface nsIInputStream : nsISupports
|
|
{
|
|
/**
|
|
* Close the stream. This method causes subsequent calls to Read and
|
|
* ReadSegments to return 0 bytes read to indicate end-of-file. Any
|
|
* subsequent calls to Available should throw NS_BASE_STREAM_CLOSED.
|
|
*/
|
|
void close();
|
|
|
|
/**
|
|
* Determine number of bytes available in the stream. A non-blocking
|
|
* stream that does not yet have any data to read should return 0 bytes
|
|
* from this method (i.e., it must not throw the NS_BASE_STREAM_WOULD_BLOCK
|
|
* exception).
|
|
*
|
|
* In addition to the number of bytes available in the stream, this method
|
|
* also informs the caller of the current status of the stream. A stream
|
|
* that is closed will throw an exception when this method is called. That
|
|
* enables the caller to know the condition of the stream before attempting
|
|
* to read from it. If a stream is at end-of-file, but not closed, then
|
|
* this method should return 0 bytes available.
|
|
*
|
|
* @return number of bytes currently available in the stream, or
|
|
* PR_UINT32_MAX if the size of the stream exceeds PR_UINT32_MAX.
|
|
*
|
|
* @throws NS_BASE_STREAM_CLOSED if the stream is closed normally or at
|
|
* end-of-file
|
|
* @throws <other-error> if the stream is closed due to some error
|
|
* condition
|
|
*/
|
|
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
|
|
*
|
|
* NOTE: this method should not throw NS_BASE_STREAM_CLOSED.
|
|
*/
|
|
[noscript] unsigned long read(in charPtr aBuf, in unsigned long aCount);
|
|
|
|
/**
|
|
* Low-level read method that provides 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 NS_ERROR_NOT_IMPLEMENTED if the stream has no underlying buffer
|
|
* @throws <other-error> on failure
|
|
*
|
|
* NOTE: this function may be unimplemented if a stream has no underlying
|
|
* buffer (e.g., socket input stream).
|
|
*
|
|
* NOTE: this method should not throw NS_BASE_STREAM_CLOSED.
|
|
*/
|
|
[noscript] unsigned long readSegments(in nsWriteSegmentFun aWriter,
|
|
in voidPtr aClosure,
|
|
in unsigned long aCount);
|
|
|
|
/**
|
|
* @return true if stream is non-blocking
|
|
*
|
|
* NOTE: reading from a blocking input stream will block the calling thread
|
|
* until at least one byte of data can be extracted from the stream.
|
|
*
|
|
* NOTE: a non-blocking input stream may implement nsIAsyncInputStream to
|
|
* provide consumers with a way to wait for the stream to have more data
|
|
* once its read method is unable to return any data without blocking.
|
|
*/
|
|
boolean isNonBlocking();
|
|
};
|