tmux/buffer.c

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2009-06-25 16:21:32 +00:00
/* $Id: buffer.c,v 1.7 2009-06-25 16:21:32 nicm Exp $ */
/*
* Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <string.h>
#include "tmux.h"
/* Create a buffer. */
struct buffer *
buffer_create(size_t size)
{
struct buffer *b;
if (size == 0)
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fatalx("zero size");
b = xcalloc(1, sizeof *b);
b->base = xmalloc(size);
b->space = size;
return (b);
}
/* Destroy a buffer. */
void
buffer_destroy(struct buffer *b)
{
xfree(b->base);
xfree(b);
}
/* Ensure free space for size in buffer. */
void
buffer_ensure(struct buffer *b, size_t size)
{
if (size == 0)
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fatalx("zero size");
if (BUFFER_FREE(b) >= size)
return;
if (b->off > 0) {
if (b->size > 0)
memmove(b->base, b->base + b->off, b->size);
b->off = 0;
}
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if (SIZE_MAX - b->size < size)
fatalx("size too big");
while (b->space < b->size + size) {
b->base = xrealloc(b->base, 2, b->space);
b->space *= 2;
}
}
/* Adjust buffer after data appended. */
void
buffer_add(struct buffer *b, size_t size)
{
if (size == 0)
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fatalx("zero size");
if (size > b->space - b->size)
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fatalx("overflow");
b->size += size;
}
/* Adjust buffer after data removed. */
void
buffer_remove(struct buffer *b, size_t size)
{
if (size == 0)
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fatalx("zero size");
if (size > b->size)
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fatalx("underflow");
b->size -= size;
b->off += size;
}
/* Copy data into a buffer. */
void
buffer_write(struct buffer *b, const void *data, size_t size)
{
if (size == 0)
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fatalx("zero size");
buffer_ensure(b, size);
memcpy(BUFFER_IN(b), data, size);
buffer_add(b, size);
}
/* Copy data out of a buffer. */
void
buffer_read(struct buffer *b, void *data, size_t size)
{
if (size == 0)
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fatalx("zero size");
if (size > b->size)
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fatalx("underflow");
memcpy(data, BUFFER_OUT(b), size);
buffer_remove(b, size);
}
/* Store an 8-bit value. */
void
buffer_write8(struct buffer *b, uint8_t n)
{
buffer_ensure(b, 1);
BUFFER_IN(b)[0] = n;
buffer_add(b, 1);
}
/* Extract an 8-bit value. */
uint8_t
buffer_read8(struct buffer *b)
{
uint8_t n;
n = BUFFER_OUT(b)[0];
buffer_remove(b, 1);
return (n);
}