radare2/libr/util/cache.c

/* radare - LGPL - Copyright 2013 - pancake */

#include <r_util.h>
// TODO: optimize reallocs.. store RBuffer info.. wait. extend r_buf_ for that?

R_API RCache *r_cache_new() {
	RCache *c = R_NEW (RCache);
	c->buf = NULL;
	c->base = 0;
	c->len = 0;
	return c;
}

R_API void r_cache_free(RCache *c) {
	free (c->buf);
	free (c);
}

R_API const ut8* r_cache_get(RCache *c, ut64 addr, int *len) {
	if (!c->buf)
		return NULL;
	if (len) *len = c->base - addr;
	if (addr<c->base)
		return NULL;
	if (addr>(c->base+c->len))
		return NULL;
	if (len) *len = c->len - (addr-c->base);
//eprintf ("4 - %d\n", (addr-c->base));
	return c->buf + (addr-c->base);
}

R_API int r_cache_set(RCache *c, ut64 addr, const ut8 *buf, int len) {
	if (c->buf == NULL) {
		c->buf = malloc (len);
		if (!c->buf) return 0;
		memcpy (c->buf, buf, len);
		c->base = addr;
		c->len = len;
	} else
	if (addr < c->base) {
		ut8 *b;
		int baselen = (c->base - addr);
		int newlen = baselen + ((len > c->len)? len: c->base);
		// XXX expensive heap usage. must simplify
		b = malloc (newlen);
		if (!b) return 0;
		memset (b, 0xff, newlen);
		memcpy (b+baselen, c->buf, c->len);
		memcpy (b, buf, len);
		free (c->buf);
		c->buf = b;
		c->base = addr;
		c->len = newlen;
	} else if ((addr+len)>(c->base+c->len)) {
		ut8 *b;
		int baselen = (addr - c->base);
		int newlen = baselen + len;
		b = realloc (c->buf, newlen);
		if (!b) return 0;
		memcpy (b+baselen, buf, len);
		c->buf = b;
		c->len = newlen;
	} else {
		memcpy (c->buf, buf, len);
	}
	return c->len;
}

R_API void r_cache_flush (RCache *c) {
	c->base = 0;
	c->len = 0;
	free (c->buf);
	c->buf = NULL;
}