1 files changed, 33 insertions, 11 deletions

diff --git a/src/cache.c b/src/cache.c
index 0c99322..f8a2026 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -47,8 +47,10 @@ int cache_populate(struct stream * const in)
 				break;
 			}
 		}
+	} else if (in->type == stream_in) {
+		try(1, err, ENOSYS, "populating cache from file is a TODO");
 	} else {
-		/* TODO */
+		try(1, err, EINVAL, "cannot populate a non-reading stream cache");
 	}
 
 err:
@@ -92,7 +94,7 @@ int cache_block_copy(struct stream const * const src, struct stream * const dest
 
 	try(src->settings->access != cached || dest->settings->access != cached, err, EINVAL, "cannot cache-copy between uncached streams");
 	try(!src->cache, err, EINVAL, "no cache to transfer");
-	try(!(src->n < dest->settings->to), err, EINVAL, "invalid copy size");
+	try(src->n > dest->settings->to, err, EINVAL, "invalid copy size");
 	try(!dest->cache, err, EINVAL, "no cache to transfer to");
 
 	memcpy(dest->cache, src->cache_a + dest->settings->ss, (dest->settings->to - dest->settings->ss) * dest->settings->stride);
@@ -109,7 +111,7 @@ int cache_list_copy(struct stream * const src, struct stream * const dest)
 
 	try(src->settings->access != cached || dest->settings->access != cached, err, EINVAL, "cannot cache-copy between uncached streams");
 	try(!src->cache, err, EINVAL, "no cache to transfer");
-	try(!(src->n < dest->settings->to), err, EINVAL, "invalid copy size");
+	try(!(src->n > dest->settings->to), err, EINVAL, "invalid copy size");
 	try(!dest->cache, err, EINVAL, "no cache to transfer to");
 
 	while ((tmp = get(src))) {
@@ -125,18 +127,38 @@ err:
 int cache_block_split(struct stream * const src, struct stream * const A, struct stream * const B)
 {
 	int ret = 0;
+	struct settings tmp_settings;
 
 	try(src->n < 2, err, EINVAL, "cannot split single element stream.");
 
-	/* copy everything, then change whatever's neccesary */
-	*A = *B = *src;
-
-	A->n = A->n / 2 + A->n % 2;
-	B->n = B->n / 2;
+	/* setting up minimal stream basics */
+	A->n = src->n / 2;
+	B->n = src->n / 2 + (src->n & 1ul);
 	A->index = B->index = 0;
-	B->cache_a = B->cache_a + A->n;
-	B->cache_l = (struct entry_l *) B->cache_a;
-	B->cache = (char *) B->cache_a;
+	A->parentid = B->parentid = random(); /* generate random parent ID that needs to match between children */
+	A->type = B->type = stream_invalid; /* disallow any stream operations other than split/merge on children */
+	A->fd = B->fd = -1; /* if we're splitting, these are for holding cache only */
+	/* we only care about these three functions for these temporary streams */
+	A->get_next_element_cache = B->get_next_element_cache = src->get_next_element_cache;
+	A->place_next_element_cache = B->place_next_element_cache = src->place_next_element_cache;
+	A->split = B->split = src->split;
+
+	tmp_settings = *src->settings;
+	A->settings = B->settings = &tmp_settings;
+
+	/* setting up A */
+	tmp_settings.ss = 0;
+	tmp_settings.to = A->n;
+	try_s((ret = cache_create(A)), err);
+	try_s((ret = cache_block_copy(src, A)), err);
+
+	/* setting up B */
+	tmp_settings.ss = A->n;
+	tmp_settings.to = src->n;
+	try_s((ret = cache_create(B)), err);
+	try_s((ret = cache_block_copy(src, B)), err);
+
+	A->settings = B->settings = &tmp_settings;
 
 err:
 	return ret;