more undo

1 files changed, 214 insertions, 0 deletions

diff --git a/arr.c b/arr.c
new file mode 100644
index 0000000..b9b3387
--- /dev/null
+++ b/arr.c
@@ -0,0 +1,214 @@
+#ifndef ARR_C_
+#define ARR_C_
+/*
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+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 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.
+For more information, please refer to <http://unlicense.org/>
+*/
+
+// functions in this file suffixed with _ are not meant to be used outside here, unless you
+// know what you're doing
+
+// IMPORTANT NOTE: If you are using this with structures containing `long double`s, do
+//  #define ARR_LONG_DOUBLE
+// before including this file
+
+#include <stddef.h>
+#if __STDC_VERSION__ >= 201112L
+typedef max_align_t ArrMaxAlign;
+#else
+typedef union {
+	long num;
+	void *ptr;
+	void (*fnptr)(void);
+#ifdef ARR_LONG_DOUBLE
+	long
+#endif
+	double flt;
+} ArrMaxAlign;
+#endif
+#if __STDC_VERSION__ < 199901L && !defined inline
+#define inline
+#endif
+
+
+typedef struct {
+	u32 len;
+	u32 cap;
+	ArrMaxAlign data[];
+} ArrHeader;
+
+// watch out! do not call this function if arr is NULL.
+static inline ArrHeader *arr_hdr_(void *arr) {
+	return (ArrHeader *)((char *)arr - offsetof(ArrHeader, data));
+}
+
+static inline u32 arr_len(void *arr) {
+	return arr ? arr_hdr_(arr)->len : 0;
+}
+
+static inline unsigned arr_lenu(void *arr) {
+	return (unsigned)arr_len(arr);
+}
+
+// grow array to fit one more member
+static void *arr_grow1_(void *arr, size_t member_size) {
+	if (arr) {
+		ArrHeader *hdr = arr_hdr_(arr);
+		if (hdr->len >= hdr->cap) {
+			u32 new_capacity = hdr->cap * 2;
+			ArrHeader *old_hdr = hdr;
+			hdr = (ArrHeader *)realloc(old_hdr, sizeof(ArrHeader) + new_capacity * member_size);
+			if (hdr) {
+				hdr->cap = new_capacity;
+			} else {
+				free(old_hdr);
+				return NULL;
+			}
+		}
+		return hdr->data;
+	} else {
+		// create a new array
+		u32 initial_capacity = 2; // allocate enough space for two members
+		ArrHeader *ret = (ArrHeader *)calloc(1, sizeof(ArrHeader) + initial_capacity * member_size);
+		if (ret) {
+			ret->cap = initial_capacity;
+			return ret->data;
+		} else {
+			return NULL;
+		}
+	}
+}
+
+static inline void *arr_add_ptr_(void **arr, size_t member_size) {
+	u8 *ret;
+	*arr = arr_grow1_(*arr, member_size);
+	if (*arr) {
+		ret = (u8 *)*arr + member_size * (arr_hdr_(*arr)->len++);
+		memset(ret, 0, member_size);
+	} else {
+		ret = NULL;
+	}
+	return ret;
+}
+
+#if 0
+// NOT TESTED
+static inline void arr_set_len_(void **arr, size_t member_size, size_t n) {
+	if (n >= U32_MAX-1) { 
+		// too big; free arr.
+		if (*arr) free(arr_hdr_(*arr));
+		*arr = NULL;
+	}
+
+	if (!*arr) {
+		// create a new array with capacity n+1
+		ArrHeader *hdr = calloc(1, sizeof(ArrHeader) + (n+1) * member_size);
+		if (hdr) {
+			hdr->cap = (u32)n+1;
+			hdr->len = (u32)n;
+			*arr = hdr->data;
+		}
+	} else {
+		// increase capacity of array
+		ArrHeader *hdr = arr_hdr_(*arr);
+		u32 curr_cap = hdr->cap;
+		if (n > curr_cap) {
+			ArrHeader *old_hdr = hdr;
+			while (n > curr_cap) {
+				if (curr_cap < U32_MAX/2)
+					curr_cap *= 2;
+				else
+					curr_cap = U32_MAX;
+			}
+			hdr = realloc(hdr, sizeof(ArrHeader) + curr_cap * member_size);
+			if (hdr) {
+				hdr->cap = curr_cap;
+			} else {
+				// growing failed
+				free(old_hdr);
+				*arr = NULL;
+				return;
+			}
+		}
+		if (n > hdr->len) {
+			// zero new elements
+			memset((char *)hdr->data + hdr->len, 0, (n - hdr->len) * member_size);
+		}
+		hdr->len = (u32)n;
+	}
+}
+#define arr_set_len(a, n) arr_set_len_((void **)&a, sizeof *(a), n)
+#endif
+
+#ifdef __cplusplus
+#define arr_cast_typeof(a) (decltype(a))
+#elif defined __GNUC__
+#define arr_cast_typeof(a) (__typeof__(a))
+#else
+#define arr_cast_typeof(a)
+#endif
+
+// if the array is not NULL, free it and set it to NULL
+#define arr_free(a) do { if (a) { free(arr_hdr_(a)); (a) = NULL; } } while (0)
+// add an item to the array - if allocation fails, the array will be freed and set to NULL.
+// (how this works: if we can successfully grow the array, increase the length and add the item.)
+#define arr_add(a, x) do { if (((a) = arr_cast_typeof(a) arr_grow1_((a), sizeof *(a)))) ((a)[arr_hdr_(a)->len++] = (x)); } while (0)
+// like arr_add, but instead of passing it the value, it returns a pointer to the value. returns NULL if allocation failed.
+// the added item will be zero-initialized.
+#define arr_addp(a) arr_cast_typeof(a) arr_add_ptr_((void **)&(a), sizeof *(a))
+// set the length of `a` to `n`, increasing the capacity if necessary.
+// the newly-added elements are zero-initialized.
+#define arr_qsort(a, cmp) qsort((a), arr_len(a), sizeof *(a), (cmp))
+#define arr_remove_last(a) do { assert(a); if (--arr_hdr_(a)->len == 0) arr_free(a); } while (0)
+#define arr_pop_last(a) ((a)[--arr_hdr_(a)->len])
+#define arr_size_in_bytes(a) (arr_len(a) * sizeof *(a))
+#define arr_lastp(a) ((a) ? &(a)[arr_len(a)-1] : NULL)
+#define arr_shrink(a, n) ((void)((a) && (arr_hdr_(a)->len -= (n))))
+#define arr_foreach_backwards(a, var) for (var = arr_lastp(a); var; var = var == (a) ? NULL : var-1)
+#define arr_reverse(a, type) do { \
+	u64 _i, _len = arr_len(a); \
+	for (_i = 0; 2*_i < _len; ++_i) { \
+		type *_x = &(a)[_i]; \
+		type *_y = &(a)[_len-1-_i]; \
+		type _tmp; \
+		_tmp = *_x; \
+		*_x = *_y; \
+		*_y = _tmp; \
+	} \
+	} while (0)
+
+static void arr_test(void) {
+	u32 *arr = NULL;
+	u32 i;
+	assert(arr_len(arr) == 0);
+	for (i = 0; i < 10000; ++i) {
+		arr_add(arr, i*i);
+	}
+	assert(arr_len(arr) == 10000);
+	arr_remove_last(arr);
+	assert(arr_len(arr) == 9999);
+	for (i = 0; i < arr_len(arr); ++i)
+		assert(arr[i] == i*i);
+	while (arr_len(arr))
+		arr_remove_last(arr);
+	assert(arr_len(arr) == 0);
+}
+#endif // ARR_C_