xemu/util/buffer.c
Gerd Hoffmann 4d1eb5fdb1 buffer: add buffer_move_empty
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-4-git-send-email-kraxel@redhat.com
2015-11-05 09:08:36 +01:00

94 lines
2.2 KiB
C

/*
* QEMU generic buffers
*
* Copyright (c) 2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/buffer.h"
#define BUFFER_MIN_INIT_SIZE 4096
void buffer_init(Buffer *buffer, const char *name, ...)
{
va_list ap;
va_start(ap, name);
buffer->name = g_strdup_vprintf(name, ap);
va_end(ap);
}
void buffer_reserve(Buffer *buffer, size_t len)
{
if ((buffer->capacity - buffer->offset) < len) {
buffer->capacity = pow2ceil(buffer->offset + len);
buffer->capacity = MAX(buffer->capacity, BUFFER_MIN_INIT_SIZE);
buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
}
}
gboolean buffer_empty(Buffer *buffer)
{
return buffer->offset == 0;
}
uint8_t *buffer_end(Buffer *buffer)
{
return buffer->buffer + buffer->offset;
}
void buffer_reset(Buffer *buffer)
{
buffer->offset = 0;
}
void buffer_free(Buffer *buffer)
{
g_free(buffer->buffer);
g_free(buffer->name);
buffer->offset = 0;
buffer->capacity = 0;
buffer->buffer = NULL;
buffer->name = NULL;
}
void buffer_append(Buffer *buffer, const void *data, size_t len)
{
memcpy(buffer->buffer + buffer->offset, data, len);
buffer->offset += len;
}
void buffer_advance(Buffer *buffer, size_t len)
{
memmove(buffer->buffer, buffer->buffer + len,
(buffer->offset - len));
buffer->offset -= len;
}
void buffer_move_empty(Buffer *to, Buffer *from)
{
assert(to->offset == 0);
g_free(to->buffer);
to->offset = from->offset;
to->capacity = from->capacity;
to->buffer = from->buffer;
from->offset = 0;
from->capacity = 0;
from->buffer = NULL;
}