parray.c

#pragma warning(disable: 4996)
#include <stdlib.h>
#include <string.h>
#include "parray.h"

PArray *parray_create(size_t length, size_t sz, char *filename)
{
	PArray *pa = (PArray *)malloc(sizeof(PArray));

	if (!pa)
		return 0;

	pa->filename = _strdup(filename);

	if (!pa->filename) {
		free(pa);
		return 0;
	}

	pa->fp = fopen(filename, "wb");

	if (!pa->fp) {
		free(pa);
		return 0;
	}

	pa->length = length;
	pa->sz = sz;
	pa->base = malloc(sz * length);

	if (!pa->base) {
		fclose(pa->fp);
		free(pa);
		return 0;
	}

	return pa;
}

PArray *parray_open(char *filename)
{
	FILE *fp = fopen(filename, "r+b");
	PArray *pa;

	if (!fp)
		return 0;

	pa = (PArray *)malloc(sizeof(PArray));

	if (!pa) {
		fclose(fp);
		return 0;
	}

	pa->fp = fp;

	if (fread(&pa->length, sizeof (pa->length), 1, pa->fp) < 1) {
		fclose(fp);
		free(pa);
		return 0;
	}

	if (fread(&pa->sz, sizeof (pa->sz), 1, pa->fp) < 1) {
		fclose(fp);
		free(pa);
		return 0;
	}

	pa->base = malloc(pa->sz * pa->length);

	if (!pa->base) {
		fclose(fp);
		free(pa);
		return 0;
	}

	pa->filename = _strdup(filename);

	if (!pa->filename) {
		fclose(fp);
		free(pa->base);
		free(pa);
		return 0;
	}

	if (fread(pa->base, pa->sz, pa->length, fp) < pa->length) {
		fclose(fp);
		free(pa->base);
		free(pa->filename);
		free(pa);
				
		return 0;
	}

	return pa;
}

void parray_free(PArray *pa)
{
	parray_flush(pa);
	fclose(pa->fp);
	free(pa->base);
	free(pa->filename);
	free(pa);
}

void parray_destroy(PArray *pa)
{
	fclose(pa->fp);
	free(pa->base);
	
	_unlink(pa->filename);

	free(pa->filename);
	free(pa);
}

int parray_flush(PArray *pa)
{
	if (fseek(pa->fp, 0, SEEK_SET))
		return 4;

	if (fwrite(&pa->length, sizeof (pa->length), 1, pa->fp) < 1)
		return 1;

	if (fwrite(&pa->sz, sizeof (pa->sz), 1, pa->fp) < 1)
		return 2;

	if (fwrite(pa->base, pa->sz, pa->length, pa->fp) < pa->length)
		return 3;

	return 0;
}

parray.h

#ifndef __parray_h
#define __parray_h

#include <stdio.h>

typedef struct _PArray {
	void *base;
	size_t length, sz;
	FILE *fp;
	char *filename;
} PArray;

PArray *parray_create(size_t length, size_t sz, char *filename);
PArray *parray_open(char *filename);
void parray_free(PArray *pa);
void parray_destroy(PArray *pa);
int parray_flush(PArray *pa);		// 0 if ok

#endif