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- /****************************************************************************
- * mm/iob/iob_clone.c
- *
- * Copyright (C) 2014, 2017 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * 3. Neither the name NuttX nor the names of its contributors may be
- * used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <string.h>
- #include <assert.h>
- #include <errno.h>
- #include <debug.h>
- #include <nuttx/mm/iob.h>
- #include "iob.h"
- /****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
- #ifndef MIN
- # define MIN(a,b) ((a) < (b) ? (a) : (b))
- #endif
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: iob_clone
- *
- * Description:
- * Duplicate (and pack) the data in iob1 in iob2. iob2 must be empty.
- *
- ****************************************************************************/
- int iob_clone(FAR struct iob_s *iob1, FAR struct iob_s *iob2, bool throttled)
- {
- FAR uint8_t *src;
- FAR uint8_t *dest;
- unsigned int ncopy;
- unsigned int avail1;
- unsigned int avail2;
- unsigned int offset1;
- unsigned int offset2;
- DEBUGASSERT(iob2->io_len == 0 && iob2->io_offset == 0 &&
- iob2->io_pktlen == 0 && iob2->io_flink == NULL);
- /* Copy the total packet size from the I/O buffer at the head of the chain */
- iob2->io_pktlen = iob1->io_pktlen;
- /* Handle special case where there are empty buffers at the head
- * the list.
- */
- while (iob1->io_len <= 0)
- {
- iob1 = iob1->io_flink;
- }
- /* Pack each entry from iob1 to iob2 */
- offset1 = 0;
- offset2 = 0;
- while (iob1)
- {
- /* Get the source I/O buffer pointer and the number of bytes to copy
- * from this address.
- */
- src = &iob1->io_data[iob1->io_offset + offset1];
- avail1 = iob1->io_len - offset1;
- /* Get the destination I/O buffer pointer and the number of bytes to
- * copy to that address.
- */
- dest = &iob2->io_data[offset2];
- avail2 = CONFIG_IOB_BUFSIZE - offset2;
- /* Copy the smaller of the two and update the srce and destination
- * offsets.
- */
- ncopy = MIN(avail1, avail2);
- memcpy(dest, src, ncopy);
- offset1 += ncopy;
- offset2 += ncopy;
- /* Have we taken all of the data from the source I/O buffer? */
- if (offset1 >= iob1->io_len)
- {
- /* Skip over empty entries in the chain (there should not be any
- * but just to be safe).
- */
- do
- {
- /* Yes.. move to the next source I/O buffer */
- iob1 = iob1->io_flink;
- }
- while (iob1 && iob1->io_len <= 0);
- /* Reset the offset to the beginning of the I/O buffer */
- offset1 = 0;
- }
- /* Have we filled the destination I/O buffer? Is there more data to be
- * transferred?
- */
- if (offset2 >= CONFIG_IOB_BUFSIZE && iob1 != NULL)
- {
- FAR struct iob_s *next;
- /* Allocate new destination I/O buffer and hook it into the
- * destination I/O buffer chain.
- */
- next = iob_alloc(throttled);
- if (!next)
- {
- ioberr("ERROR: Failed to allocate an I/O buffer/n");
- return -ENOMEM;
- }
- iob2->io_flink = next;
- iob2 = next;
- offset2 = 0;
- }
- }
- return 0;
- }
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