diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
commit | 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch) | |
tree | a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /xpcom/io/nsIStreamBufferAccess.idl | |
parent | Initial commit. (diff) | |
download | firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.tar.xz firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.zip |
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'xpcom/io/nsIStreamBufferAccess.idl')
-rw-r--r-- | xpcom/io/nsIStreamBufferAccess.idl | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/xpcom/io/nsIStreamBufferAccess.idl b/xpcom/io/nsIStreamBufferAccess.idl new file mode 100644 index 0000000000..c0883a439b --- /dev/null +++ b/xpcom/io/nsIStreamBufferAccess.idl @@ -0,0 +1,88 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* 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" + +/** + * 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. + */ +[scriptable, builtinclass, 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(uint32_t)-1 for uint32_t 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,noscript] charPtr getBuffer(in uint32_t aLength, in uint32_t 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,noscript] void putBuffer(in charPtr aBuffer, in uint32_t 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++ + +/** + * 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)) + +%} |