1 /* Copyright (C) 2010-2020 The RetroArch team
3 * ---------------------------------------------------------------------------------------
4 * The following license statement only applies to this file (rbuf.h).
5 * ---------------------------------------------------------------------------------------
7 * Permission is hereby granted, free of charge,
8 * to any person obtaining a copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation the rights to
10 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
11 * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
16 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
19 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 #ifndef __LIBRETRO_SDK_ARRAY_RBUF_H__
24 #define __LIBRETRO_SDK_ARRAY_RBUF_H__
27 * This file implements stretchy buffers as invented (?) by Sean Barrett.
28 * Based on the implementation from the public domain Bitwise project
29 * by Per Vognsen - https://github.com/pervognsen/bitwise
31 * It's a super simple type safe dynamic array for C with no need
32 * to predeclare any type or anything.
33 * The first time an element is added, memory for 16 elements are allocated.
34 * Then every time length is about to exceed capacity, capacity is doubled.
36 * Be careful not to supply modifying statements to the macro arguments.
37 * Something like RBUF_REMOVE(buf, i--); would have unintended results.
41 * mytype_t* buf = NULL;
42 * RBUF_PUSH(buf, some_element);
43 * RBUF_PUSH(buf, other_element);
44 * -- now RBUF_LEN(buf) == 2, buf[0] == some_element, buf[1] == other_element
46 * -- Free allocated memory:
48 * -- now buf == NULL, RBUF_LEN(buf) == 0, RBUF_CAP(buf) == 0
50 * -- Explicitly increase allocated memory and set capacity:
52 * -- now RBUF_LEN(buf) == 0, RBUF_CAP(buf) == 100
54 * -- Resize buffer (does not initialize or zero memory!)
55 * RBUF_RESIZE(buf, 200);
56 * -- now RBUF_LEN(buf) == 200, RBUF_CAP(buf) == 200
58 * -- To handle running out of memory:
59 * bool ran_out_of_memory = !RBUF_TRYFIT(buf, 1000);
60 * -- before RESIZE or PUSH. When out of memory, buf will stay unmodified.
63 #include <retro_math.h> /* for MAX */
64 #include <stdlib.h> /* for malloc, realloc */
66 #define RBUF__HDR(b) (((struct rbuf__hdr *)(b))-1)
68 #define RBUF_LEN(b) ((b) ? RBUF__HDR(b)->len : 0)
69 #define RBUF_CAP(b) ((b) ? RBUF__HDR(b)->cap : 0)
70 #define RBUF_END(b) ((b) + RBUF_LEN(b))
71 #define RBUF_SIZEOF(b) ((b) ? RBUF_LEN(b)*sizeof(*b) : 0)
73 #define RBUF_FREE(b) ((b) ? (free(RBUF__HDR(b)), (b) = NULL) : 0)
74 #define RBUF_FIT(b, n) ((size_t)(n) <= RBUF_CAP(b) ? 0 : (*(void**)(&(b)) = rbuf__grow((b), (n), sizeof(*(b)))))
75 #define RBUF_PUSH(b, val) (RBUF_FIT((b), 1 + RBUF_LEN(b)), (b)[RBUF__HDR(b)->len++] = (val))
76 #define RBUF_POP(b) (b)[--RBUF__HDR(b)->len]
77 #define RBUF_RESIZE(b, sz) (RBUF_FIT((b), (sz)), ((b) ? RBUF__HDR(b)->len = (sz) : 0))
78 #define RBUF_CLEAR(b) ((b) ? RBUF__HDR(b)->len = 0 : 0)
79 #define RBUF_TRYFIT(b, n) (RBUF_FIT((b), (n)), (((b) && RBUF_CAP(b) >= (size_t)(n)) || !(n)))
80 #define RBUF_REMOVE(b, idx) memmove((b) + (idx), (b) + (idx) + 1, (--RBUF__HDR(b)->len - (idx)) * sizeof(*(b)))
89 __attribute__((__unused__))
90 #elif defined(_MSC_VER)
92 #pragma warning(disable:4505) //unreferenced local function has been removed
94 static void *rbuf__grow(void *buf,
95 size_t new_len, size_t elem_size)
97 struct rbuf__hdr *new_hdr;
98 size_t new_cap = MAX(2 * RBUF_CAP(buf), MAX(new_len, 16));
99 size_t new_size = sizeof(struct rbuf__hdr) + new_cap*elem_size;
102 new_hdr = (struct rbuf__hdr *)realloc(RBUF__HDR(buf), new_size);
104 return buf; /* out of memory, return unchanged */
108 new_hdr = (struct rbuf__hdr *)malloc(new_size);
110 return NULL; /* out of memory */
113 new_hdr->cap = new_cap;
116 #if defined(_MSC_VER)