object.c

#include <stdio.h>
#include <string.h>

#include "memory.h"
#include "object.h"
#include "table.h"
#include "value.h"
#include "vm.h"

#define ALLOCATE_OBJ(type, objectType) \
		(type*)allocateObject(sizeof(type), objectType)

static Obj* allocateObject(size_t size, ObjType type) {
	Obj* object = (Obj*)reallocate(NULL, 0, size);
	object->type = type;

	object->next = vm.objects;
	vm.objects = object;

	return object;
}

static ObjString* allocateString(char* chars, int length, uint32_t hash) {
	ObjString* string = ALLOCATE_OBJ(ObjString, OBJ_STRING);
	string->length = length;
	string->chars = chars;
	string->hash = hash;

	tableSet(&vm.strings, string, NIL_VAL);

	return string;
}

static uint32_t hashString(const char* key, int length) {
	uint32_t hash = 2166136261u;

	for (int i = 0; i < length; i++) {
		hash ^=  key[i];
		hash *= 16777619;
	}

	return hash;
}

ObjString* takeString(char* chars, int length) {
	uint32_t hash = hashString(chars, length);
	ObjString* interned = tableFindString(&vm.strings, chars, length, hash);

	if (interned != NULL) {
		FREE_ARRAY(char, chars, length + 1);
		return interned;
	}

	return allocateString(chars, length, hash);
}

ObjString* copyString(const char* chars, int length) {
	uint32_t hash = hashString(chars, length);
	ObjString* interned = tableFindString(&vm.strings, chars, length, hash);
	if (interned != NULL) return interned;

	char* heapChars = ALLOCATE(char, length + 1);
	memcpy(heapChars, chars, length);
	heapChars[length] = '\0';

	return allocateString(heapChars, length, hash);
}

void printObject(Value value) {
	switch (OBJ_TYPE(value)) {
		case OBJ_STRING:
			printf("%s", AS_CSTRING(value));
			break;
	}
}