mirror of
https://github.com/brain-hackers/u-boot-brain
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![Tom Rini](/assets/img/avatar_default.png)
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
390 lines
8.2 KiB
C
390 lines
8.2 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (c) 2015 Google, Inc
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* Written by Simon Glass <sjg@chromium.org>
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*
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* Copyright (c) 1992 Simon Glass
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*/
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#include <common.h>
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#include <errno.h>
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#include <malloc.h>
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#include "membuff.h"
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void membuff_purge(struct membuff *mb)
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{
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/* set mb->head and mb->tail so the buffers look empty */
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mb->head = mb->start;
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mb->tail = mb->start;
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}
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static int membuff_putrawflex(struct membuff *mb, int maxlen, bool update,
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char ***data, int *offsetp)
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{
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int len;
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/* always write to 'mb->head' */
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assert(data && offsetp);
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*data = &mb->start;
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*offsetp = mb->head - mb->start;
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/* if there is no buffer, we can do nothing */
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if (!mb->start)
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return 0;
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/*
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* if head is ahead of tail, we can write from head until the end of
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* the buffer
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*/
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if (mb->head >= mb->tail) {
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/* work out how many bytes can fit here */
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len = mb->end - mb->head - 1;
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if (maxlen >= 0 && len > maxlen)
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len = maxlen;
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/* update the head pointer to mark these bytes as written */
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if (update)
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mb->head += len;
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/*
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* if the tail isn't at start of the buffer, then we can
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* write one more byte right at the end
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*/
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if ((maxlen < 0 || len < maxlen) && mb->tail != mb->start) {
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len++;
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if (update)
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mb->head = mb->start;
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}
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/* otherwise now we can write until head almost reaches tail */
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} else {
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/* work out how many bytes can fit here */
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len = mb->tail - mb->head - 1;
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if (maxlen >= 0 && len > maxlen)
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len = maxlen;
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/* update the head pointer to mark these bytes as written */
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if (update)
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mb->head += len;
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}
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/* return the number of bytes which can be/must be written */
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return len;
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}
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int membuff_putraw(struct membuff *mb, int maxlen, bool update, char **data)
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{
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char **datap;
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int offset;
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int size;
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size = membuff_putrawflex(mb, maxlen, update, &datap, &offset);
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*data = *datap + offset;
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return size;
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}
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bool membuff_putbyte(struct membuff *mb, int ch)
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{
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char *data;
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if (membuff_putraw(mb, 1, true, &data) != 1)
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return false;
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*data = ch;
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return true;
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}
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int membuff_getraw(struct membuff *mb, int maxlen, bool update, char **data)
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{
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int len;
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/* assume for now there is no data to get */
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len = 0;
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/*
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* in this case head is ahead of tail, so we must return data between
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*'tail' and 'head'
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*/
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if (mb->head > mb->tail) {
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/* work out the amount of data */
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*data = mb->tail;
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len = mb->head - mb->tail;
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/* check it isn't too much */
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if (maxlen >= 0 && len > maxlen)
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len = maxlen;
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/* & mark it as read from the buffer */
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if (update)
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mb->tail += len;
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}
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/*
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* if head is before tail, then we have data between 'tail' and 'end'
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* and some more data between 'start' and 'head'(which we can't
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* return this time
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*/
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else if (mb->head < mb->tail) {
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/* work out the amount of data */
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*data = mb->tail;
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len = mb->end - mb->tail;
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if (maxlen >= 0 && len > maxlen)
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len = maxlen;
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if (update) {
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mb->tail += len;
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if (mb->tail == mb->end)
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mb->tail = mb->start;
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}
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}
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debug("getraw: maxlen=%d, update=%d, head=%d, tail=%d, data=%d, len=%d",
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maxlen, update, (int)(mb->head - mb->start),
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(int)(mb->tail - mb->start), (int)(*data - mb->start), len);
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/* return the number of bytes we found */
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return len;
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}
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int membuff_getbyte(struct membuff *mb)
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{
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char *data = 0;
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return membuff_getraw(mb, 1, true, &data) != 1 ? -1 : *(uint8_t *)data;
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}
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int membuff_peekbyte(struct membuff *mb)
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{
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char *data = 0;
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return membuff_getraw(mb, 1, false, &data) != 1 ? -1 : *(uint8_t *)data;
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}
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int membuff_get(struct membuff *mb, char *buff, int maxlen)
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{
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char *data = 0, *buffptr = buff;
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int len = 1, i;
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/*
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* do this in up to two lots(see GetRaw for why) stopping when there
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* is no more data
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*/
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for (i = 0; len && i < 2; i++) {
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/* get a pointer to the data available */
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len = membuff_getraw(mb, maxlen, true, &data);
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/* copy it into the buffer */
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memcpy(buffptr, data, len);
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buffptr += len;
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maxlen -= len;
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}
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/* return the number of bytes read */
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return buffptr - buff;
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}
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int membuff_put(struct membuff *mb, const char *buff, int length)
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{
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char *data;
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int towrite, i, written;
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for (i = written = 0; i < 2; i++) {
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/* ask where some data can be written */
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towrite = membuff_putraw(mb, length, true, &data);
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/* and write it, updating the bytes length */
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memcpy(data, buff, towrite);
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written += towrite;
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buff += towrite;
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length -= towrite;
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}
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/* return the number of bytes written */
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return written;
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}
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bool membuff_isempty(struct membuff *mb)
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{
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return mb->head == mb->tail;
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}
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int membuff_avail(struct membuff *mb)
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{
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struct membuff copy;
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int i, avail;
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char *data = 0;
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/* make a copy of this buffer's control data */
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copy = *mb;
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/* now read everything out of the copied buffer */
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for (i = avail = 0; i < 2; i++)
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avail += membuff_getraw(©, -1, true, &data);
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/* and return how much we read */
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return avail;
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}
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int membuff_size(struct membuff *mb)
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{
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return mb->end - mb->start;
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}
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bool membuff_makecontig(struct membuff *mb)
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{
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int topsize, botsize;
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debug("makecontig: head=%d, tail=%d, size=%d",
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(int)(mb->head - mb->start), (int)(mb->tail - mb->start),
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(int)(mb->end - mb->start));
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/*
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* first we move anything at the start of the buffer into the correct
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* place some way along
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*/
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if (mb->tail > mb->head) {
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/*
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* the data is split into two parts, from 0 to ->head and
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* from ->tail to ->end. We move the stuff from 0 to ->head
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* up to make space for the other data before it
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*/
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topsize = mb->end - mb->tail;
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botsize = mb->head - mb->start;
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/*
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* must move data at bottom up by 'topsize' bytes - check if
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* there's room
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*/
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if (mb->head + topsize >= mb->tail)
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return false;
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memmove(mb->start + topsize, mb->start, botsize);
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debug(" - memmove(%d, %d, %d)", topsize, 0, botsize);
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/* nothing at the start, so skip that step */
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} else {
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topsize = mb->head - mb->tail;
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botsize = 0;
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}
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/* now move data at top down to the bottom */
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memcpy(mb->start, mb->tail, topsize);
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debug(" - memcpy(%d, %d, %d)", 0, (int)(mb->tail - mb->start), topsize);
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/* adjust pointers */
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mb->tail = mb->start;
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mb->head = mb->start + topsize + botsize;
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debug(" - head=%d, tail=%d", (int)(mb->head - mb->start),
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(int)(mb->tail - mb->start));
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/* all ok */
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return true;
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}
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int membuff_free(struct membuff *mb)
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{
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return mb->end == mb->start ? 0 :
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(mb->end - mb->start) - 1 - membuff_avail(mb);
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}
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int membuff_readline(struct membuff *mb, char *str, int maxlen, int minch)
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{
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int len; /* number of bytes read (!= string length) */
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char *s, *end;
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bool ok = false;
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char *orig = str;
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end = mb->head >= mb->tail ? mb->head : mb->end;
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for (len = 0, s = mb->tail; s < end && len < maxlen - 1; str++) {
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*str = *s++;
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len++;
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if (*str == '\n' || *str < minch) {
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ok = true;
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break;
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}
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if (s == end && mb->tail > mb->head) {
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s = mb->start;
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end = mb->head;
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}
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}
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/* couldn't get the whole string */
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if (!ok) {
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if (maxlen)
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*orig = '\0';
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return 0;
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}
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/* terminate the string, update the membuff and return success */
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*str = '\0';
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mb->tail = s == mb->end ? mb->start : s;
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return len;
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}
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int membuff_extend_by(struct membuff *mb, int by, int max)
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{
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int oldhead, oldtail;
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int size, orig;
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char *ptr;
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/* double the buffer size until it is big enough */
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assert(by >= 0);
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for (orig = mb->end - mb->start, size = orig; size < orig + by;)
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size *= 2;
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if (max != -1)
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size = min(size, max);
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by = size - orig;
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/* if we're already at maximum, give up */
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if (by <= 0)
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return -E2BIG;
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oldhead = mb->head - mb->start;
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oldtail = mb->tail - mb->start;
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ptr = realloc(mb->start, size);
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if (!ptr)
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return -ENOMEM;
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mb->start = ptr;
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mb->head = mb->start + oldhead;
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mb->tail = mb->start + oldtail;
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if (mb->head < mb->tail) {
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memmove(mb->tail + by, mb->tail, orig - oldtail);
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mb->tail += by;
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}
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mb->end = mb->start + size;
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return 0;
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}
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void membuff_init(struct membuff *mb, char *buff, int size)
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{
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mb->start = buff;
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mb->end = mb->start + size;
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membuff_purge(mb);
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}
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int membuff_new(struct membuff *mb, int size)
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{
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mb->start = malloc(size);
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if (!mb->start)
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return -ENOMEM;
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membuff_init(mb, mb->start, size);
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return 0;
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}
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void membuff_uninit(struct membuff *mb)
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{
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mb->end = NULL;
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mb->start = NULL;
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membuff_purge(mb);
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}
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void membuff_dispose(struct membuff *mb)
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{
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free(&mb->start);
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membuff_uninit(mb);
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}
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