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[xferbuf] Add generic data-transfer buffer
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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/* | ||
* Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>. | ||
* | ||
* 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 (at your option) 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., 51 Franklin Street, Fifth Floor, Boston, MA | ||
* 02110-1301, USA. | ||
*/ | ||
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FILE_LICENCE ( GPL2_OR_LATER ); | ||
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#include <stdlib.h> | ||
#include <string.h> | ||
#include <errno.h> | ||
#include <ipxe/xfer.h> | ||
#include <ipxe/iobuf.h> | ||
#include <ipxe/xferbuf.h> | ||
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/** @file | ||
* | ||
* Data transfer buffer | ||
* | ||
*/ | ||
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/** | ||
* Finish using data transfer buffer | ||
* | ||
* @v xferbuf Data transfer buffer | ||
*/ | ||
void xferbuf_done ( struct xfer_buffer *xferbuf ) { | ||
free ( xferbuf->data ); | ||
xferbuf->data = NULL; | ||
xferbuf->len = 0; | ||
xferbuf->pos = 0; | ||
} | ||
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/** | ||
* Ensure that data transfer buffer is large enough for the specified size | ||
* | ||
* @v xferbuf Data transfer buffer | ||
* @v len Required minimum size | ||
* @ret rc Return status code | ||
*/ | ||
static int xferbuf_ensure_size ( struct xfer_buffer *xferbuf, size_t len ) { | ||
void *new_data; | ||
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/* If buffer is already large enough, do nothing */ | ||
if ( len <= xferbuf->len ) | ||
return 0; | ||
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/* Extend buffer */ | ||
new_data = realloc ( xferbuf->data, len ); | ||
if ( ! new_data ) { | ||
DBGC ( xferbuf, "XFERBUF %p could not extend buffer to " | ||
"%zd bytes\n", xferbuf, len ); | ||
return -ENOSPC; | ||
} | ||
xferbuf->data = new_data; | ||
xferbuf->len = len; | ||
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return 0; | ||
} | ||
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/** | ||
* Add received data to data transfer buffer | ||
* | ||
* @v xferbuf Data transfer buffer | ||
* @v iobuf I/O buffer | ||
* @v meta Data transfer metadata | ||
* @ret rc Return status code | ||
*/ | ||
int xferbuf_deliver ( struct xfer_buffer *xferbuf, struct io_buffer *iobuf, | ||
struct xfer_metadata *meta ) { | ||
size_t len; | ||
size_t max; | ||
int rc; | ||
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/* Calculate new buffer position */ | ||
if ( meta->flags & XFER_FL_ABS_OFFSET ) | ||
xferbuf->pos = 0; | ||
xferbuf->pos += meta->offset; | ||
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/* Ensure that we have enough buffer space for this data */ | ||
len = iob_len ( iobuf ); | ||
max = ( xferbuf->pos + len ); | ||
if ( ( rc = xferbuf_ensure_size ( xferbuf, max ) ) != 0 ) | ||
goto done; | ||
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/* Copy data to buffer */ | ||
memcpy ( ( xferbuf->data + xferbuf->pos ), iobuf->data, len ); | ||
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/* Update current buffer position */ | ||
xferbuf->pos += len; | ||
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done: | ||
free_iob ( iobuf ); | ||
return rc; | ||
} |
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#ifndef _IPXE_XFERBUF_H | ||
#define _IPXE_XFERBUF_H | ||
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/** @file | ||
* | ||
* Data transfer buffer | ||
* | ||
*/ | ||
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FILE_LICENCE ( GPL2_OR_LATER ); | ||
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#include <stdint.h> | ||
#include <ipxe/iobuf.h> | ||
#include <ipxe/xfer.h> | ||
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/** A data transfer buffer */ | ||
struct xfer_buffer { | ||
/** Data */ | ||
void *data; | ||
/** Size of data */ | ||
size_t len; | ||
/** Current offset within data */ | ||
size_t pos; | ||
}; | ||
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extern void xferbuf_done ( struct xfer_buffer *xferbuf ); | ||
extern int xferbuf_deliver ( struct xfer_buffer *xferbuf, | ||
struct io_buffer *iobuf, | ||
struct xfer_metadata *meta ); | ||
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#endif /* _IPXE_XFERBUF_H */ |