diff options
Diffstat (limited to 'ds.c')
| -rw-r--r-- | ds.c | 333 |
1 files changed, 333 insertions, 0 deletions
@@ -0,0 +1,333 @@ +/* VARIOUS DATA STRUCTURES +- dynamic array +- string builder +- string hash table +*/ + + +// 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 +// ( otherwise the long doubles will not be aligned. +// this does mean that arrays waste 8 bytes of memory. +// which isnt important unless you're making a lot of arrays.) + +#include <stddef.h> +typedef union { + long num; + void *ptr; + void (*fnptr)(void); +#ifdef ARR_LONG_DOUBLE + long +#endif + double flt; +} ArrMaxAlign; +#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(const void *arr) { + return arr ? arr_hdr_((void*)arr)->len : 0; +} + +static inline u32 arr_cap(void *arr) { + return arr ? arr_hdr_(arr)->cap : 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; +} + +static void arr_reserve_(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 + // why n+1? i dont know i wrote this a while ago + ArrHeader *hdr = calloc(1, sizeof(ArrHeader) + (n+1) * member_size); + if (hdr) { + hdr->cap = (u32)n+1; + *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; + } + } + *arr = hdr->data; + } +} + +static void arr_set_len_(void **arr, size_t member_size, size_t n) { + arr_reserve_(arr, member_size, n); + if (*arr) { + ArrHeader *hdr = arr_hdr_(*arr); + if (n > hdr->len) { + // zero new elements + memset((char *)hdr->data + hdr->len * member_size, 0, (n - hdr->len) * member_size); + } + hdr->len = (u32)n; + } +} + +static void *arr_remove_(void *arr, size_t member_size, size_t index) { + ArrHeader *hdr = arr_hdr_(arr); + assert(index < hdr->len); + memmove((char *)arr + index * member_size, (char *)arr + (index+1) * member_size, (hdr->len - (index+1)) * member_size); + if (--hdr->len == 0) { + free(hdr); + return NULL; + } else { + return arr; + } +} + +#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 + +#define arr__join2(a,b) a##b +#define arr__join(a,b) arr__join2(a,b) // macro used internally + +// 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) +// a nice alias +#define arr_clear(a) arr_free(a) +// 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_remove(a, i) (void)((a) = arr_remove_((a), sizeof *(a), (i))) +#define arr_insert(a, i, x) do { u32 _index = (i); (a) = arr_cast_typeof(a) arr_grow1_((a), sizeof *(a)); \ + if (a) { memmove((a) + _index + 1, (a) + _index, (arr_len(a) - _index) * sizeof *(a));\ + (a)[_index] = x; \ + ++arr_hdr_(a)->len; } } 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_foreach_ptr_end(a, type, var, end) type *end = (a) + arr_len(a); \ + for (type *var = (a); var != end; ++var) +// Iterate through each element of the array, setting var to a pointer to the element. +// You can't use this like, e.g.: +// if (something) +// arr_foreach_ptr(a, int, i); +// You'll get an error. You will need to use braces because it expands to multiple statements. +// (we need to name the end pointer something unique, which is why there's that arr__join thing +// we can't just declare it inside the for loop, because type could be something like char *.) +#define arr_foreach_ptr(a, type, var) arr_foreach_ptr_end(a, type, var, arr__join(_foreach_end,__LINE__)) + +#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) + +// Ensure that enough space is allocated for n elements. +#define arr_reserve(a, n) arr_reserve_((void **)&(a), sizeof *(a), (n)) +// Similar to arr_reserve, but also sets the length of the array to n. +#define arr_set_len(a, n) arr_set_len_((void **)&(a), sizeof *(a), (n)) + +#if 0 +static void arrcstr_append_strn_(char **a, char const *s, size_t s_len) { + size_t curr_len = arr_len(*a); + size_t new_len = curr_len + s_len; + arr_reserve(*a, new_len + 1); + arr_set_len(*a, new_len); + memcpy(*a + curr_len, s, s_len); + (*a)[curr_len + s_len] = '\0'; +} + +static void arrcstr_shrink_(char **a, u32 new_len) { + ArrHeader *hdr = arr_hdr_(*a); + assert(hdr->cap > new_len); + hdr->len = new_len; + (*a)[new_len] = '\0'; +} + +// append to a C-string array +#define arrcstr_append_str(a, s) arrcstr_append_strn_(&(a), (s), strlen(s)) +// take at most n bytes from s +#define arrcstr_append_strn(a, s, n) arrcstr_append_strn_(&(a), (s), (n)) +// make the string smaller +#define arrcstr_shrink(a, n) arrcstr_shrink_(&(a), (n)) +#endif + +#ifndef NDEBUG +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 + +typedef struct { + // dynamic array, including a null byte. + char *str; +} StrBuilder; + +void str_builder_create(StrBuilder *builder) { + memset(builder, 0, sizeof *builder); + arr_add(builder->str, 0); +} + +StrBuilder str_builder_new(void) { + StrBuilder ret = {0}; + str_builder_create(&ret); + return ret; +} + +void str_builder_free(StrBuilder *builder) { + arr_free(builder->str); +} + +void str_builder_clear(StrBuilder *builder) { + str_builder_free(builder); + str_builder_create(builder); +} + +void str_builder_append(StrBuilder *builder, const char *s) { + assert(builder->str); + + size_t s_len = strlen(s); + size_t prev_size = arr_len(builder->str); + size_t prev_len = prev_size - 1; // null terminator + // note: this zeroes the newly created elements, so we have a new null terminator + arr_set_len(builder->str, prev_size + s_len); + // -1 for null terminator + memcpy(builder->str + prev_len, s, s_len); +} + +void str_builder_appendf(StrBuilder *builder, PRINTF_FORMAT_STRING const char *fmt, ...) ATTRIBUTE_PRINTF(2, 3); +void str_builder_appendf(StrBuilder *builder, const char *fmt, ...) { + // idk if you can always just pass NULL to vsnprintf + va_list args; + char fakebuf[2] = {0}; + va_start(args, fmt); + int ret = vsnprintf(fakebuf, 1, fmt, args); + va_end(args); + + if (ret < 0) return; // bad format or something + u32 n = (u32)ret; + + size_t prev_size = arr_len(builder->str); + size_t prev_len = prev_size - 1; // null terminator + arr_set_len(builder->str, prev_size + n); + va_start(args, fmt); + vsnprintf(builder->str + prev_len, n + 1, fmt, args); + va_end(args); +} + +// append n null bytes. +void str_builder_append_null(StrBuilder *builder, size_t n) { + arr_set_len(builder->str, arr_len(builder->str) + n); +} + +u32 str_builder_len(StrBuilder *builder) { + assert(builder->str); + return arr_len(builder->str) - 1; +} + |