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Diffstat (limited to 'src/libs/xpcom18a4/xpcom/io/nsIStreamBufferAccess.idl')
| -rw-r--r-- | src/libs/xpcom18a4/xpcom/io/nsIStreamBufferAccess.idl | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/src/libs/xpcom18a4/xpcom/io/nsIStreamBufferAccess.idl b/src/libs/xpcom18a4/xpcom/io/nsIStreamBufferAccess.idl new file mode 100644 index 00000000..dc41585f --- /dev/null +++ b/src/libs/xpcom18a4/xpcom/io/nsIStreamBufferAccess.idl @@ -0,0 +1,191 @@ +/* -*- 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 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 <brendan@mozilla.org> (original author) + * + * 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" +#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))) + +%} |