config.c

#include "modules/log.h"
#include "modules/config.h"
#include "modules/filesystem.h"
#include "epicardium.h"

#include <assert.h>
#include <stdbool.h>
#include <ctype.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <stdio.h>

#define MAX_LINE_LENGTH 80
#define KEYS_PER_BLOCK 16
#define KEY_LENGTH 16
#define NOT_INT_MAGIC ((int)0x80000000)

// one key-value pair representing a line in the config
typedef struct {
	char key[KEY_LENGTH];

	// the value in the config file, if it's an integer.
	// for strings it's set to NOT_INT_MAGIC
	int value;

	// the byte offset in the config file to read the value string
	size_t value_offset;
} config_slot;

// a block of 16 config slots
// if more are needed, this becomes a linked list
typedef struct {
	config_slot slots[KEYS_PER_BLOCK];
	void *next;
} config_block;

static config_block *config_data = NULL;

// returns the config slot for a key name
static config_slot *find_config_slot(const char *key)
{
	config_block *current = config_data;

	while (current) {
		for (int i = 0; i < KEYS_PER_BLOCK; i++) {
			config_slot *k = &current->slots[i];

			if (strcmp(k->key, key) == 0) {
				// found what we're looking for
				return k;

			} else if (*k->key == '\0') {
				// found the first empty key
				return NULL;
			}
		}
		current = current->next;
	}

	return NULL;
}

// returns the next available config slot, or allocates a new block if needed
static config_slot *allocate_config_slot()
{
	config_block *current;