Function expand_index

sparse-index.c:323–460

}

void expand_index(struct index_state *istate, struct pattern_list *pl)
{
	int i;
	struct index_state *full;
	struct strbuf base = STRBUF_INIT;
	const char *tr_region;
	struct modify_index_context ctx;

	/*
	 * If the index is already full, then keep it full. We will convert
	 * it to a sparse index on write, if possible.
	 */
	if (istate->sparse_index == INDEX_EXPANDED)
		return;

	/*
	 * If our index is sparse, but our new pattern set does not use
	 * cone mode patterns, then we need to expand the index before we
	 * continue. A NULL pattern set indicates a full expansion to a
	 * full index.
	 */
	if (pl && !pl->use_cone_patterns) {
		pl = NULL;
	} else {
		/*
		 * We might contract file entries into sparse-directory
		 * entries, and for that we will need the cache tree to
		 * be recomputed.
		 */
		cache_tree_free(&istate->cache_tree);

		/*
		 * If there is a problem creating the cache tree, then we
		 * need to expand to a full index since we cannot satisfy
		 * the current request as a sparse index.
		 */
		if (cache_tree_update(istate, 0))
			pl = NULL;
	}

	if (!pl && give_advice_on_expansion) {
		give_advice_on_expansion = 0;
		advise_if_enabled(ADVICE_SPARSE_INDEX_EXPANDED,
				  _(ADVICE_MSG));
	}

	/*
	 * A NULL pattern set indicates we are expanding a full index, so
	 * we use a special region name that indicates the full expansion.
	 * This is used by test cases, but also helps to differentiate the
	 * two cases.
	 */
	tr_region = pl ? "expand_index" : "ensure_full_index";
	trace2_region_enter("index", tr_region, istate->repo);

	/* initialize basics of new index */
	full = xcalloc(1, sizeof(struct index_state));
	memcpy(full, istate, sizeof(struct index_state));