now with generating lists!

Signed-off-by: Gediminas Jakutis <gediminas@varciai.lt>

1 files changed, 52 insertions, 11 deletions

diff --git a/src/cache.c b/src/cache.c
index bb41689..fe97fef 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -9,6 +9,8 @@
 #include <rin/diagnostic.h>
 #include "defs.h"
 
+static int cache_rewind(struct stream * const in);
+
 int cache_create(struct stream * const in)
 {
 	int ret = 0;
@@ -100,15 +102,23 @@ err:
 	return ret;
 }
 
-int cache_list_copy(struct stream const * const src, struct stream * const dest)
+int cache_list_copy(struct stream * const src, struct stream * const dest)
 {
-	int ret = ENOSYS;
+	int ret = 0;
+	struct entry_l *tmp;
 
-	(void) src;
-	(void) 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(!dest->cache, err, EINVAL, "no cache to transfer to");
 
-	rin_warn("stub!");
+	while ((tmp = get(src))) {
+		put(dest, tmp);
+	}
+
+	cache_rewind(src);
 
+err:
 	return ret;
 }
 
@@ -163,7 +173,7 @@ struct entry_l *cached_get_list(struct stream * const in)
 
 	if (in->index < in->n) {
 		ret = in->cnode;
-		in->cnode = (struct entry_l *) ret->next;
+		in->cnode = ret->next;
 		++in->index;
 	}
 
@@ -172,7 +182,7 @@ struct entry_l *cached_get_list(struct stream * const in)
 
 int cached_put_array(struct stream * const in, const struct entry_l * const data)
 {
-	int ret = EINVAL;
+	int ret = 0;
 
 	if (in->index < in->n) {
 		in->cache_a[in->index].val = data->val;
@@ -182,14 +192,45 @@ int cached_put_array(struct stream * const in, const struct entry_l * const data
 	return ret;
 }
 
+/* This is were fun with the fact mergesort is NOT an in-place algorightm begins.
+ * Since we only ever need to "put" on a) generating data and b) merging lists,
+ * we basically have to generate the list anew each and every time. For generating,
+ * it's a no-brainer, but for lists, while reusing existing nodes COULD be done in
+ * a chached variant, file variant cannot do this, as cross-file links are not
+ * something that could be handled without going into pretty insane (and laughably
+ * inefficient) lenghts either way.
+ *
+ * And thus alas, we have no option but to just make a list anew
+ */
 int cached_put_list(struct stream * const restrict in, const struct entry_l * const node)
 {
-	int ret = ENOSYS;
+	int ret = 0;
 
-	(void) in;
-	(void) node;
+	if (!in->cnode) { /* if this is the very first one */
+		in->pnode = NULL;
+		in->cnode = in->cache_l;
+		in->cnode->val = node->val;
+		in->cnode->next = NULL;
+		in->index = 0;
+	} else {
+		in->pnode = in->cnode;
+		in->cnode = in->cnode + 1; /* lol says librin, lmao */
+		in->pnode->next = in->cnode;
+		in->cnode->val = node->val;
+		in->cnode->next = NULL;
+		++in->index;
+	}
 
-	rin_warn("stub!");
+	return ret;
+}
+
+int cache_rewind(struct stream * const in)
+{
+	int ret = 0;
+
+	in->pnode = NULL;
+	in->cnode = in->cnode ? in->cache_l : NULL;
+	in->index = 0;
 
 	return ret;
 }