taisei/src/ringbuf.h
2024-05-17 14:11:48 +02:00

128 lines
3.8 KiB
C

/*
* This software is licensed under the terms of the MIT License.
* See COPYING for further information.
* ---
* Copyright (c) 2011-2024, Lukas Weber <laochailan@web.de>.
* Copyright (c) 2012-2024, Andrei Alexeyev <akari@taisei-project.org>.
*/
#pragma once
#include "taisei.h"
#include "util/compat.h"
typedef int32_t ringbuf_size_t;
#define RING_BUFFER_BASE(elem_type) struct { \
elem_type *data; \
ringbuf_size_t head; \
ringbuf_size_t tail; \
ringbuf_size_t capacity; \
ringbuf_size_t num_elements; \
}
typedef RING_BUFFER_BASE(void) RingBuffer;
#define RING_BUFFER(elem_type) union { \
RING_BUFFER_BASE(elem_type); \
RingBuffer ring_buffer; \
}
#define RINGBUF_ASSERT_VALID(rbuf) do { \
static_assert( \
__builtin_types_compatible_p(RingBuffer, __typeof__((rbuf)->ring_buffer)), \
"x->ring_buffer must be of RingBuffer type"); \
static_assert( \
__builtin_offsetof(__typeof__(*(rbuf)), ring_buffer) == 0, \
"x->ring_buffer must be the first member in struct"); \
} while(0)
#define RBUF_ASSERT_CONSISTENT(rbuf) ({ \
RINGBUF_ASSERT_VALID(rbuf); \
auto _rbuf = rbuf; \
assert(_rbuf->data != NULL); \
assert(_rbuf->num_elements >= 0); \
assert(_rbuf->num_elements <= _rbuf->capacity); \
_rbuf; \
})
#define RINGBUF_CHECK_ELEMENT_TYPE(rbuf, elem) do { \
static_assert( \
__builtin_types_compatible_p(__typeof__(elem), __typeof__(*(rbuf)->data)), \
"Ring buffer element type mismatch" \
); \
} while(0)
#define RINGBUF_CAST_TO_BASE(rbuf) \
&RBUF_ASSERT_CONSISTENT(rbuf)->ring_buffer
#define RING_BUFFER_INIT(backbuffer, num_elements) \
{ .data = (backbuffer), .capacity = (num_elements), }
ringbuf_size_t _ringbuf_prepare_push(RingBuffer *rbuf) attr_nonnull_all attr_nodiscard;
ringbuf_size_t _ringbuf_prepare_pop(RingBuffer *rbuf) attr_nonnull_all attr_nodiscard;
ringbuf_size_t _ringbuf_prepare_peek(RingBuffer *rbuf, ringbuf_size_t ofs) attr_nonnull_all attr_nodiscard;
attr_nonnull_all
INLINE bool _ringbuf_is_full(RingBuffer *rbuf) {
return rbuf->num_elements == rbuf->capacity;
}
attr_nonnull_all
INLINE bool _ringbuf_is_empty(RingBuffer *rbuf) {
return rbuf->num_elements == 0;
}
#define ringbuf_is_full(rbuf) _ringbuf_is_full(RINGBUF_CAST_TO_BASE(rbuf))
#define ringbuf_is_empty(rbuf) _ringbuf_is_empty(RINGBUF_CAST_TO_BASE(rbuf))
#define ringbuf_push(rbuf, value) ({ \
auto _rbuf = RBUF_ASSERT_CONSISTENT(rbuf); \
RINGBUF_CHECK_ELEMENT_TYPE(_rbuf, value); \
auto _idx = _ringbuf_prepare_push(&_rbuf->ring_buffer); \
_rbuf->data[_idx] = value; \
})
#define ringbuf_pop(rbuf, default_value) ({ \
auto _rbuf = RBUF_ASSERT_CONSISTENT(rbuf); \
RINGBUF_CHECK_ELEMENT_TYPE(_rbuf, default_value); \
auto _return_value = default_value; \
auto _idx = _ringbuf_prepare_pop(&_rbuf->ring_buffer); \
if(_idx >= 0) _return_value = _rbuf->data[_idx]; \
_return_value; \
})
#define _ringbuf_peek_ptr(_rbuf, ofs) ({ \
typeof(_rbuf->data) _ptr = NULL; \
auto _idx = _ringbuf_prepare_peek(&_rbuf->ring_buffer, ofs); \
if(_idx >= 0) _ptr = _rbuf->data + _idx; \
_ptr; \
})
#define ringbuf_peek_ptr(rbuf, ofs) ({ \
auto _rbuf = RBUF_ASSERT_CONSISTENT(rbuf); \
_ringbuf_peek_ptr(_rbuf, ofs); \
})
#define _ringbuf_peek(_rbuf, ofs, default_value) ({ \
RINGBUF_CHECK_ELEMENT_TYPE(_rbuf, default_value); \
auto _ptr = _ringbuf_peek_ptr(_rbuf, ofs); \
auto _return_value = default_value; \
if(_ptr != NULL) _return_value = *_ptr; \
_return_value; \
})
#define ringbuf_peek(rbuf, ofs, default_value) ({ \
auto _rbuf = RBUF_ASSERT_CONSISTENT(rbuf); \
_ringbuf_peek(_rbuf, ofs, default_value); \
})
#define ringbuf_rpeek_ptr(rbuf, ofs) ({ \
auto _rbuf = RBUF_ASSERT_CONSISTENT(rbuf); \
_ringbuf_peek_ptr(_rbuf, _rbuf->num_elements - ((ofs) + 1)); \
})
#define ringbuf_rpeek(rbuf, ofs, default_value) ({ \
auto _rbuf = RBUF_ASSERT_CONSISTENT(rbuf); \
_ringbuf_peek(_rbuf, _rbuf->num_elements - ((ofs) + 1), default_value); \
})