Mercurial > libjeffpc
diff buffer_static.c @ 562:584def85123e
buffer: introduce a static read-write buffer type
This is very similar to the const buffer type, but it allows writing to the
buffer.
Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
author | Josef 'Jeff' Sipek <jeffpc@josefsipek.net> |
---|---|
date | Thu, 11 Oct 2018 12:23:11 -0400 |
parents | buffer_const.c@6795f8427fed |
children | bc0841b964fb |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/buffer_static.c Thu Oct 11 12:23:11 2018 -0400 @@ -0,0 +1,54 @@ +/* + * Copyright (c) 2017-2018 Josef 'Jeff' Sipek <jeffpc@josefsipek.net> + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "buffer_impl.h" + +static int static_buffer_check_append(struct buffer *buffer, const void *data, + size_t size) +{ + if ((buffer->used + size) <= buffer->allocsize) + return 0; + + return -ENOSPC; +} + +static int static_buffer_check_truncate(struct buffer *buffer, size_t size) +{ + if (size <= buffer->allocsize) + return 0; + + return -ENOSPC; +} + +const struct buffer_ops static_buffer = { + .check_append = static_buffer_check_append, + .check_truncate = static_buffer_check_truncate, + + /* + * no need for: + * - realloc since we have a borrowed static buffer + * - free since we have a borrowed static buffer + */ + + .clear = generic_buffer_clear_memset, + .copyin = generic_buffer_copyin_memcpy, +};