Cleanup xattr handling

 - Store them in a struct instead of a hacky uint64_t with magic shifts
 - Split up key/value pair write function to write_key and write_value
 - Move the size accounting into those functions respectively

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

3 files changed, 31 insertions, 21 deletions

diff --git a/include/fstree.h b/include/fstree.h
index ea7cf88..4efa9d5 100644
--- a/include/fstree.h
+++ b/include/fstree.h
@@ -46,9 +46,11 @@ struct tree_xattr_t {
 	/* linked list pointer of list of attributes in @ref fstree_t */
 	tree_xattr_t *next;
 
-	/* Array with pairs of key-value tupples.
-	   Each key-value tupple is encoded as (key << 32) | value. */
-	uint64_t ref[];
+	/* Array with pairs of key-value tupples */
+	struct {
+		uint32_t key_index;
+		uint32_t value_index;
+	} attr[];
 };
 
 /* Additional meta data stored in a tree_node_t for regular files. */
diff --git a/lib/fstree/xattr.c b/lib/fstree/xattr.c
index 4597d9d..2ce39f4 100644
--- a/lib/fstree/xattr.c
+++ b/lib/fstree/xattr.c
@@ -87,17 +87,15 @@ int fstree_add_xattr(fstree_t *fs, tree_node_t *node,
 		fs->xattr = xattr;
 	}
 
-	xattr->ref[xattr->num_attr]  = (uint64_t)key_idx << 32;
-	xattr->ref[xattr->num_attr] |= (uint64_t)value_idx;
+	xattr->attr[xattr->num_attr].key_index = key_idx;
+	xattr->attr[xattr->num_attr].value_index = value_idx;
 	xattr->num_attr += 1;
 	return 0;
 }
 
-static int cmp_u64(const void *lhs, const void *rhs)
+static int cmp_attr(const void *lhs, const void *rhs)
 {
-	uint64_t l = *((uint64_t *)lhs), r = *((uint64_t *)rhs);
-
-	return l < r ? -1 : (l > r ? 1 : 0);
+	return memcmp(lhs, rhs, sizeof(((tree_xattr_t *)0)->attr[0]));
 }
 
 void fstree_xattr_reindex(fstree_t *fs)
@@ -113,8 +111,8 @@ void fstree_xattr_reindex(fstree_t *fs)
 		it->index = index++;
 
 		for (i = 0; i < it->num_attr; ++i) {
-			key_idx = (it->ref[i] >> 32) & 0x00000000FFFFFFFF;
-			value_idx = it->ref[i] & 0x00000000FFFFFFFF;
+			key_idx = it->attr[i].key_index;
+			value_idx = it->attr[i].value_index;
 
 			str_table_add_ref(&fs->xattr_keys, key_idx);
 			str_table_add_ref(&fs->xattr_values, value_idx);
@@ -128,7 +126,7 @@ void fstree_xattr_deduplicate(fstree_t *fs)
 	int diff;
 
 	for (it = fs->xattr; it != NULL; it = it->next)
-		qsort(it->ref, it->num_attr, sizeof(it->ref[0]), cmp_u64);
+		qsort(it->attr, it->num_attr, sizeof(it->attr[0]), cmp_attr);
 
 	prev = NULL;
 	it = fs->xattr;
@@ -138,8 +136,8 @@ void fstree_xattr_deduplicate(fstree_t *fs)
 			if (it1->num_attr != it->num_attr)
 				continue;
 
-			diff = memcmp(it1->ref, it->ref,
-				      it->num_attr * sizeof(it->ref[0]));
+			diff = memcmp(it1->attr, it->attr,
+				      it->num_attr * sizeof(it->attr[0]));
 			if (diff == 0)
 				break;
 		}
diff --git a/lib/sqfs/write_xattr.c b/lib/sqfs/write_xattr.c
index 31fdf50..89c65db 100644
--- a/lib/sqfs/write_xattr.c
+++ b/lib/sqfs/write_xattr.c
@@ -38,10 +38,10 @@ bool sqfs_has_xattr(const char *key)
 	return get_prefix(key) >= 0;
 }
 
-static int write_pair(meta_writer_t *mw, const char *key, const char *value)
+static int write_key(meta_writer_t *mw, const char *key, tree_xattr_t *xattr)
 {
+	const char *orig_key = key;
 	sqfs_xattr_entry_t kent;
-	sqfs_xattr_value_t vent;
 	int type;
 
 	type = get_prefix(key);
@@ -62,6 +62,15 @@ static int write_pair(meta_writer_t *mw, const char *key, const char *value)
 	if (meta_writer_append(mw, key, strlen(key)))
 		return -1;
 
+	xattr->size += sizeof(sqfs_xattr_entry_t) + strlen(orig_key);
+	return 0;
+}
+
+static int write_value(meta_writer_t *mw, const char *value,
+		       tree_xattr_t *xattr)
+{
+	sqfs_xattr_value_t vent;
+
 	vent.size = htole32(strlen(value));
 
 	if (meta_writer_append(mw, &vent, sizeof(vent)))
@@ -69,6 +78,7 @@ static int write_pair(meta_writer_t *mw, const char *key, const char *value)
 	if (meta_writer_append(mw, value, strlen(value)))
 		return -1;
 
+	xattr->size += sizeof(vent) + strlen(value);
 	return 0;
 }
 
@@ -79,17 +89,17 @@ static int write_kv_pairs(fstree_t *fs, meta_writer_t *mw, tree_xattr_t *xattr)
 	size_t i;
 
 	for (i = 0; i < xattr->num_attr; ++i) {
-		key_idx = (xattr->ref[i] >> 32) & 0xFFFFFFFF;
-		val_idx = xattr->ref[i] & 0xFFFFFFFF;
+		key_idx = xattr->attr[i].key_index;
+		val_idx = xattr->attr[i].value_index;
 
 		key = str_table_get_string(&fs->xattr_keys, key_idx);
 		value = str_table_get_string(&fs->xattr_values, val_idx);
 
-		if (write_pair(mw, key, value))
+		if (write_key(mw, key, xattr))
 			return -1;
 
-		xattr->size += sizeof(sqfs_xattr_entry_t) + strlen(key);
-		xattr->size += sizeof(sqfs_xattr_value_t) + strlen(value);
+		if (write_value(mw, value, xattr))
+			return -1;
 	}
 
 	return 0;