From a6467c99a021d2740b195dd29fbe920ea7338967 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Sun, 29 Jul 2007 16:05:14 +0100 Subject: [PATCH] Added a simple pass-through filter layer for data transfer interfaces. --- src/core/filter.c | 78 +++++++++++++++++++++++++++++++++++++++ src/include/gpxe/filter.h | 75 +++++++++++++++++++++++++++++++++++++ 2 files changed, 153 insertions(+) create mode 100644 src/core/filter.c create mode 100644 src/include/gpxe/filter.h diff --git a/src/core/filter.c b/src/core/filter.c new file mode 100644 index 00000000..51ec5c4b --- /dev/null +++ b/src/core/filter.c @@ -0,0 +1,78 @@ +/* + * Copyright (C) 2007 Michael Brown . + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include + +/** @file + * + * Data transfer filters + * + */ + +/* + * Pass-through methods to be used by filters which don't want to + * intercept all events. + * + */ + +void filter_close ( struct xfer_interface *xfer, int rc ) { + struct xfer_interface *other = filter_other_half ( xfer ); + + xfer_close ( other, rc ); +} + +int filter_vredirect ( struct xfer_interface *xfer, int type, + va_list args ) { + struct xfer_interface *other = filter_other_half ( xfer ); + + return xfer_vredirect ( other, type, args ); +} + +int filter_seek ( struct xfer_interface *xfer, off_t offset, int whence ) { + struct xfer_interface *other = filter_other_half ( xfer ); + + return xfer_seek ( other, offset, whence ); +} + +size_t filter_window ( struct xfer_interface *xfer ) { + struct xfer_interface *other = filter_other_half ( xfer ); + + return xfer_window ( other ); +} + +struct io_buffer * filter_alloc_iob ( struct xfer_interface *xfer, + size_t len ) { + struct xfer_interface *other = filter_other_half ( xfer ); + + return xfer_alloc_iob ( other, len ); +} + +int filter_deliver_iob ( struct xfer_interface *xfer, struct io_buffer *iobuf, + struct xfer_metadata *meta ) { + struct xfer_interface *other = filter_other_half ( xfer ); + + return xfer_deliver_iob_meta ( other, iobuf, meta ); +} + +int filter_deliver_raw ( struct xfer_interface *xfer, const void *data, + size_t len ) { + struct xfer_interface *other = filter_other_half ( xfer ); + + return xfer_deliver_raw ( other, data, len ); +} diff --git a/src/include/gpxe/filter.h b/src/include/gpxe/filter.h new file mode 100644 index 00000000..3943a9e1 --- /dev/null +++ b/src/include/gpxe/filter.h @@ -0,0 +1,75 @@ +#ifndef _GPXE_FILTER_H +#define _GPXE_FILTER_H + +/** @file + * + * Data transfer filters + * + */ + +#include +#include + +/** + * Half of a data transfer filter + * + * Embed two of these structures within a structure implementing a + * data transfer filter, and intialise with filter_init(). You can + * then use the filter_xxx() methods as the data transfer interface + * methods as required. + */ +struct xfer_filter_half { + /** Data transfer interface */ + struct xfer_interface xfer; + /** Other half of the data transfer filter */ + struct xfer_filter_half *other; +}; + +/** + * Get data transfer interface for the other half of a data transfer filter + * + * @v xfer Data transfer interface + * @ret other Other half's data transfer interface + */ +static inline __attribute__ (( always_inline )) struct xfer_interface * +filter_other_half ( struct xfer_interface *xfer ) { + struct xfer_filter_half *half = + container_of ( xfer, struct xfer_filter_half, xfer ); + return &half->other->xfer; +} + +extern void filter_close ( struct xfer_interface *xfer, int rc ); +extern int filter_vredirect ( struct xfer_interface *xfer, int type, + va_list args ); +extern int filter_seek ( struct xfer_interface *xfer, off_t offset, + int whence ); +extern size_t filter_window ( struct xfer_interface *xfer ); +extern struct io_buffer * filter_alloc_iob ( struct xfer_interface *xfer, + size_t len ); +extern int filter_deliver_iob ( struct xfer_interface *xfer, + struct io_buffer *iobuf, + struct xfer_metadata *meta ); +extern int filter_deliver_raw ( struct xfer_interface *xfer, const void *data, + size_t len ); + +/** + * Initialise a data transfer filter + * + * @v left "Left" half of the filter + * @v left_op Data transfer interface operations for "left" half + * @v right "Right" half of the filter + * @v right_op Data transfer interface operations for "right" half + * @v refcnt Containing object reference counter, or NULL + */ +static inline void filter_init ( struct xfer_filter_half *left, + struct xfer_interface_operations *left_op, + struct xfer_filter_half *right, + struct xfer_interface_operations *right_op, + struct refcnt *refcnt ) { + xfer_init ( &left->xfer, left_op, refcnt ); + xfer_init ( &right->xfer, right_op, refcnt ); + left->other = right; + right->other = left; +} + +#endif /* _GPXE_FILTER_H */