/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* 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/. */ #include "nsISupports.idl" interface nsIUnicharInputStream; 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: * * @throws <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. */ typedef nsresult (*nsWriteUnicharSegmentFun)(nsIUnicharInputStream *aInStream, void *aClosure, const char16_t *aFromSegment, uint32_t aToOffset, uint32_t aCount, uint32_t *aWriteCount); %} native nsWriteUnicharSegmentFun(nsWriteUnicharSegmentFun); /** * Abstract unicode character input stream * @see nsIInputStream */ [scriptable, uuid(d5e3bd80-6723-4b92-b0c9-22f6162fd94f)] interface nsIUnicharInputStream : nsISupports { /** * Reads into a caller-provided character array. * * @return The number of characters that were successfully read. May be less * than aCount, even if there is more data in the input stream. * A return value of 0 means EOF. * * @note To read more than 2^32 characters, call this method multiple times. */ [noscript] unsigned long read([array, size_is(aCount)] in char16_t 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 characters 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 characters to be read * * @return number of characters 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 */ [noscript] unsigned long readSegments(in nsWriteUnicharSegmentFun aWriter, in voidPtr aClosure, in unsigned long aCount); /** * Read into a string object. * @param aCount The number of characters that should be read * @return The number of characters that were read. */ unsigned long readString(in unsigned long aCount, out AString aString); /** * Close the stream and free associated resources. This also closes the * underlying stream, if any. */ void close(); };