/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /* ***** BEGIN LICENSE BLOCK ***** * Version: NPL 1.1/GPL 2.0/LGPL 2.1 * * 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 FastLoad code. * * The Initial Developer of the Original Code is * Netscape Communications Corporation. * Portions created by the Initial Developer are Copyright (C) 2001 * the Initial Developer. All Rights Reserved. * * Contributor(s): * Brendan Eich (original author) * * Alternatively, the contents of this file may be used under the terms of * either 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 NPL, 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 NPL, the GPL or the LGPL. * * ***** END LICENSE BLOCK ***** */ #include "nsISupports.idl" #include "nsrootidl.idl" /** * An interface for access to a buffering stream implementation's underlying * memory buffer. * * Stream implementations that QueryInterface to nsIStreamBufferAccess must * ensure that all buffers are aligned on the most restrictive type size for * the current architecture (e.g., sizeof(double) for RISCy CPUs). malloc(3) * satisfies this requirement. */ [uuid(ac923b72-ac87-4892-ac7a-ca385d429435)] interface nsIStreamBufferAccess : nsISupports { /** * Get access to a contiguous, aligned run of bytes in the stream's buffer. * Exactly one successful getBuffer call must occur before a putBuffer call * taking the non-null pointer returned by the successful getBuffer. * * The run of bytes are the next bytes (modulo alignment padding) to read * for an input stream, and the next bytes (modulo alignment padding) to * store before (eventually) writing buffered data to an output stream. * There can be space beyond this run of bytes in the buffer for further * accesses before the fill or flush point is reached. * * @param aLength * Count of contiguous bytes requested at the address A that satisfies * (A & aAlignMask) == 0 in the buffer, starting from the current stream * position, mapped to a buffer address B. The stream implementation * must pad from B to A by skipping bytes (if input stream) or storing * zero bytes (if output stream). * * @param aAlignMask * Bit-mask computed by subtracting 1 from the power-of-two alignment * modulus (e.g., 3 or sizeof(PRUint32)-1 for PRUint32 alignment). * * @return * The aligned pointer to aLength bytes in the buffer, or null if the * buffer has no room for aLength bytes starting at the next address A * after the current position that satisfies (A & aAlignMask) == 0. */ [notxpcom] charPtr getBuffer(in PRUint32 aLength, in PRUint32 aAlignMask); /** * Relinquish access to the stream's buffer, filling if at end of an input * buffer, flushing if completing an output buffer. After a getBuffer call * that returns non-null, putBuffer must be called. * * @param aBuffer * A non-null pointer returned by getBuffer on the same stream buffer * access object. * * @param aLength * The same count of contiguous bytes passed to the getBuffer call that * returned aBuffer. */ [notxpcom] void putBuffer(in charPtr aBuffer, in PRUint32 aLength); /** * Disable and enable buffering on the stream implementing this interface. * DisableBuffering flushes an output stream's buffer, and invalidates an * input stream's buffer. */ void disableBuffering(); void enableBuffering(); /** * The underlying, unbuffered input or output stream. */ readonly attribute nsISupports unbufferedStream; }; %{C++ // Swap macros, used to convert to/from canonical (big-endian) format #if defined IS_LITTLE_ENDIAN # define NS_SWAP16(x) ((((x) & 0xff) << 8) | (((x) >> 8) & 0xff)) # define NS_SWAP32(x) ((NS_SWAP16((x) & 0xffff) << 16) | (NS_SWAP16((x) >> 16))) // We want to avoid casting to 32-bit types if possible, since that violates // aliasing rules (a standard compiler may assume that pointers of two types // do not address overlapping storage). // // XXX What if we have a compiler that follows aliasing rules strictly but // doesn't have a 64-bit int type? // // XXXbe shouldn't NSPR's LL_INIT work for non-constant arguments in all cases? # if defined HAVE_LONG_LONG # if PR_BYTES_PER_LONG == 8 # define ULL_(x) x ## UL # elif (defined WIN32 || defined WIN16) && !defined __GNUC__ # define ULL_(x) ((uint64) x ## i64) # else # define ULL_(x) x ## ULL # endif # define NS_SWAP64(x) ((((x) & ULL_(0xff00000000000000)) >> 56) | \ (((x) & ULL_(0x00ff000000000000)) >> 40) | \ (((x) & ULL_(0x0000ff0000000000)) >> 24) | \ (((x) & ULL_(0x000000ff00000000)) >> 8) | \ (((x) & ULL_(0x00000000ff000000)) << 8) | \ (((x) & ULL_(0x0000000000ff0000)) << 24) | \ (((x) & ULL_(0x000000000000ff00)) << 40) | \ (((x) /* & ULL_(0x00000000000000ff) */) << 56)) # else # define NS_SWAP64(x) LL_INIT((((x).lo /* & 0xff000000ul */) >> 24) | \ (((x).lo & 0x00ff0000ul) >> 8) | \ (((x).lo & 0x0000ff00ul) << 8) | \ (((x).lo /* & 0x000000fful */) << 24), \ (((x).hi /* & 0xff000000ul */) >> 24) | \ (((x).hi & 0x00ff0000ul) >> 8) | \ (((x).hi & 0x0000ff00ul) << 8) | \ (((x).hi /* & 0x000000fful */) << 24)) # endif #elif defined IS_BIG_ENDIAN # define NS_SWAP16(x) (x) # define NS_SWAP32(x) (x) # define NS_SWAP64(x) (x) #else # error "Unknown byte order" #endif /** * These macros get and put a buffer given either an sba parameter that may * point to an object implementing nsIStreamBufferAccess, nsIObjectInputStream, * or nsIObjectOutputStream. */ #define NS_GET_BUFFER(sba,n,a) ((sba)->GetBuffer(n, a)) #define NS_PUT_BUFFER(sba,p,n) ((sba)->PutBuffer(p, n)) #define NS_GET8(p) (*(PRUint8*)(p)) #define NS_GET16(p) NS_SWAP16(*(PRUint16*)(p)) #define NS_GET32(p) NS_SWAP32(*(PRUint32*)(p)) #define NS_GET64(p) NS_SWAP64(*(PRUint64*)(p)) #define NS_GET_FLOAT(p) ((float)NS_SWAP32(*(PRUint32*)(p))) #define NS_GET_DOUBLE(p) ((double)NS_SWAP64(*(PRUint64*)(p))) #define NS_PUT8(p,x) (*(PRUint8*)(p) = (x)) #define NS_PUT16(p,x) (*(PRUint16*)(p) = NS_SWAP16(x)) #define NS_PUT32(p,x) (*(PRUint32*)(p) = NS_SWAP32(x)) #define NS_PUT64(p,x) (*(PRUint64*)(p) = NS_SWAP64(x)) #define NS_PUT_FLOAT(p,x) (*(PRUint32*)(p) = NS_SWAP32(*(PRUint32*)&(x))) #define NS_PUT_DOUBLE(p,x) (*(PRUint64*)(p) = NS_SWAP64(*(PRUint64*)&(x))) %}