more reorganizing

1 files changed, 458 insertions, 0 deletions

diff --git a/ds.h b/ds.h
new file mode 100644
index 0000000..a447e4c
--- /dev/null
+++ b/ds.h
@@ -0,0 +1,458 @@
+#ifndef DS_H_
+#define DS_H_
+
+/*
+VARIOUS DATA STRUCTURES
+- dynamic array
+- string builder
+- string hash table
+
+This file is self-contained and should not use anything from any project it's contained in.
+You can just #include it -- it's not huge, the functions are all static, and
+any reasonable compiler will ignore the unused code.
+
+functions in this file suffixed with _ are not meant to be used outside here, unless you
+know what you're doing
+
+NOTE: even on 64-bit platforms, dynamic arrays can only hold ~2^32 elements.
+
+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;
+
+typedef struct {
+	char *str;
+	size_t len;
+	uint64_t data[];
+} StrHashTableSlot;
+
+typedef StrHashTableSlot *StrHashTableSlotPtr;
+
+typedef struct {
+	StrHashTableSlot **slots;
+	size_t data_size;
+	size_t nentries; /* # of filled slots */
+} StrHashTable;
+
+typedef struct {
+	// dynamic array, including a null byte.
+	char *str;
+} StrBuilder;
+
+
+// watch out! do not call this function if arr is NULL.
+static ArrHeader *arr_hdr_(void *arr) {
+	return (ArrHeader *)((char *)arr - offsetof(ArrHeader, data));
+}
+
+static u32 arr_len(const void *arr) {
+	return arr ? arr_hdr_((void*)arr)->len : 0;
+}
+
+static u32 arr_cap(void *arr) {
+	return arr ? arr_hdr_(arr)->cap : 0;
+}
+
+static 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 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;
+		return;
+	}
+	
+	if (n == 0) return;
+
+	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))
+
+#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
+
+static void str_builder_create(StrBuilder *builder) {
+	memset(builder, 0, sizeof *builder);
+	arr_add(builder->str, 0);
+}
+
+static StrBuilder str_builder_new(void) {
+	StrBuilder ret = {0};
+	str_builder_create(&ret);
+	return ret;
+}
+
+static void str_builder_free(StrBuilder *builder) {
+	arr_free(builder->str);
+}
+
+static void str_builder_clear(StrBuilder *builder) {
+	str_builder_free(builder);
+	str_builder_create(builder);
+}
+
+static 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);
+	memcpy(builder->str + prev_len, s, s_len);
+}
+
+static void str_builder_appendf(StrBuilder *builder, PRINTF_FORMAT_STRING const char *fmt, ...) ATTRIBUTE_PRINTF(2, 3);
+static 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.
+static void str_builder_append_null(StrBuilder *builder, size_t n) {
+	arr_set_len(builder->str, arr_len(builder->str) + n);
+}
+
+static u32 str_builder_len(StrBuilder *builder) {
+	assert(builder->str);
+	return arr_len(builder->str) - 1;
+}
+
+static char *str_builder_get_ptr(StrBuilder *builder, size_t index) {
+	assert(index <= str_builder_len(builder));
+	return &builder->str[index];
+}
+
+static void str_builder_shrink(StrBuilder *builder, size_t new_len) {
+	if (new_len > str_builder_len(builder)) {
+		assert(0);
+		return;
+	}
+	arr_set_len(builder->str, new_len + 1);
+}
+
+
+static uint64_t str_hash(const char *str, size_t len) {
+	uint64_t hash = 0;
+	const char *p = str, *end = str + len;
+	for (; p < end; ++p) {
+		hash = ((hash * 1664737020647550361 + 123843) << 8) + 2918635993572506131*(uint64_t)*p;
+	}
+	return hash;
+}
+
+static void str_hash_table_create(StrHashTable *t, size_t data_size) {
+	t->slots = NULL;
+	t->data_size = data_size;
+	t->nentries = 0;
+}
+
+static StrHashTableSlot **str_hash_table_slot_get(StrHashTableSlot **slots, const char *s, size_t s_len, size_t i) {
+	StrHashTableSlot **slot;
+	size_t slots_cap = arr_len(slots);
+	while (1) {
+		assert(i < slots_cap);
+		slot = &slots[i];
+		if (!*slot) break;
+		if (s && (*slot)->str &&
+			s_len == (*slot)->len && memcmp(s, (*slot)->str, s_len) == 0)
+			break;
+		i = (i+1) % slots_cap;
+	}
+	return slot;
+}
+
+static void str_hash_table_grow(StrHashTable *t) {
+	size_t slots_cap = arr_len(t->slots);
+	if (slots_cap <= 2 * t->nentries) {
+		StrHashTableSlot **new_slots = NULL;
+		size_t new_slots_cap = slots_cap * 2 + 10;
+		arr_set_len(new_slots, new_slots_cap);
+		memset(new_slots, 0, new_slots_cap * sizeof *new_slots);
+		arr_foreach_ptr(t->slots, StrHashTableSlotPtr, slotp) {
+			StrHashTableSlot *slot = *slotp;
+			if (slot) {
+				uint64_t new_hash = str_hash(slot->str, slot->len);
+				StrHashTableSlot **new_slot = str_hash_table_slot_get(new_slots, slot->str, slot->len, new_hash % new_slots_cap);
+				*new_slot = slot;
+			}
+		}
+		arr_clear(t->slots);
+		t->slots = new_slots;
+	}
+}
+
+static size_t str_hash_table_slot_size(StrHashTable *t) {
+	return sizeof(StrHashTableSlot) + ((t->data_size + sizeof(uint64_t) - 1) / sizeof(uint64_t)) * sizeof(uint64_t);
+}
+
+static StrHashTableSlot *str_hash_table_insert_(StrHashTable *t, const char *str, size_t len) {
+	size_t slots_cap;
+	uint64_t hash;
+	StrHashTableSlot **slot;
+	str_hash_table_grow(t);
+	slots_cap = arr_len(t->slots);
+	hash = str_hash(str, len);
+	slot = str_hash_table_slot_get(t->slots, str, len, hash % slots_cap);
+	if (!*slot) {
+		*slot = calloc(1, str_hash_table_slot_size(t));
+		char *s = (*slot)->str = calloc(1, len + 1);
+		memcpy(s, str, len);
+		(*slot)->len = len;
+		++t->nentries;
+	}
+	return *slot;
+}
+
+// does NOT check for a null byte.
+static void *str_hash_table_insert_with_len(StrHashTable *t, const char *str, size_t len) {
+	return str_hash_table_insert_(t, str, len)->data;
+}
+
+static void *str_hash_table_insert(StrHashTable *t, const char *str) {
+	return str_hash_table_insert_(t, str, strlen(str))->data;
+}
+
+static void str_hash_table_clear(StrHashTable *t) {
+	arr_foreach_ptr(t->slots, StrHashTableSlotPtr, slotp) {
+		if (*slotp) {
+			free((*slotp)->str);
+		}
+		free(*slotp);
+	}
+	arr_clear(t->slots);
+	t->nentries = 0;
+}
+
+static StrHashTableSlot *str_hash_table_get_(StrHashTable *t, const char *str, size_t len) {
+	size_t nslots = arr_len(t->slots), slot_index;
+	if (!nslots) return NULL;
+	slot_index = str_hash(str, len) % arr_len(t->slots);
+	return *str_hash_table_slot_get(t->slots, str, len, slot_index);
+}
+
+static void *str_hash_table_get_with_len(StrHashTable *t, const char *str, size_t len) {
+	StrHashTableSlot *slot = str_hash_table_get_(t, str, len);
+	if (!slot) return NULL;
+	return slot->data;
+}
+
+static void *str_hash_table_get(StrHashTable *t, const char *str) {
+	return str_hash_table_get_with_len(t, str, strlen(str));
+}
+
+#endif