+size_t lbx_extract(struct lbx_state *lbx, size_t index, FILE *of)
+{
+ size_t base, len;
+
+ if (index >= lbx->nfiles) {
+ lbx_errno = LBX_ERANGE;
+ return 0;
+ }
+
+ base = lbx->offsets[index];
+ len = lbx->offsets[index+1] - lbx->offsets[index];
+
+ if (lbx->mem)
+ return _lbx_mextract(lbx, base, len, of);
+ return _lbx_fextract(lbx, base, len, of);
+}
+
+void *lbx_mmap(struct lbx_state *lbx, size_t index, size_t *len)
+{
+ unsigned char *mapping;
+ struct stat statbuf;
+ size_t base;
+
+ if (index >= lbx->nfiles) {
+ lbx_errno = LBX_ERANGE;
+ return NULL;
+ }
+
+ base = lbx->offsets[index];
+ *len = lbx->offsets[index+1] - lbx->offsets[index];
+
+ if (lbx->mem)
+ return lbx->mem + base;
+
+ if (fstat(fileno(lbx->f), &statbuf) == -1) {
+ lbx_errno = -errno;
+ return NULL;
+ }
+
+ mapping = mmap(NULL, statbuf.st_size, PROT_READ, 0, fileno(lbx->f), 0);
+ if (mapping == MAP_FAILED) {
+ lbx_errno = -errno;
+ return NULL;
+ }
+
+ lbx->mem = mapping;
+ lbx->memsize = statbuf.st_size;
+ return mapping + base;
+}
+