1 files changed, 141 insertions, 0 deletions
diff --git a/lib/fstree/xattr.c b/lib/fstree/xattr.c
new file mode 100644
index 0000000..916ab6e
--- /dev/null
+++ b/lib/fstree/xattr.c
@@ -0,0 +1,141 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "fstree.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+int fstree_add_xattr(fstree_t *fs, tree_node_t *node,
+		     const char *key, const char *value)
+{
+	tree_xattr_t *xattr, *prev, *it;
+	size_t key_idx, value_idx;
+
+	if (str_table_get_index(&fs->xattr_keys, key, &key_idx))
+		return -1;
+
+	if (str_table_get_index(&fs->xattr_values, value, &value_idx))
+		return -1;
+
+	if (sizeof(size_t) > sizeof(uint32_t)) {
+		if (key_idx > 0xFFFFFFFFUL) {
+			fputs("Too many unique xattr keys\n", stderr);
+			return -1;
+		}
+
+		if (value_idx > 0xFFFFFFFFUL) {
+			fputs("Too many unique xattr values\n", stderr);
+			return -1;
+		}
+	}
+
+	if (node->xattr == NULL) {
+		xattr = calloc(1, sizeof(*xattr) + sizeof(uint64_t) * 4);
+		if (xattr == NULL) {
+			perror("adding extended attributes");
+			return -1;
+		}
+
+		xattr->max_attr = 4;
+		xattr->owner = node;
+
+		xattr->next = fs->xattr;
+		fs->xattr = xattr;
+
+		node->xattr = xattr;
+	} else {
+		xattr = node->xattr;
+
+		if (xattr->max_attr == xattr->num_attr) {
+			prev = NULL;
+			it = fs->xattr;
+
+			while (it != xattr) {
+				prev = it;
+				it = it->next;
+			}
+
+			if (prev == NULL) {
+				fs->xattr = xattr->next;
+			} else {
+				prev->next = xattr->next;
+			}
+
+			node->xattr = NULL;
+
+			it = realloc(xattr, sizeof(*xattr) +
+				     sizeof(uint64_t) * xattr->max_attr * 2);
+
+			if (it == NULL) {
+				perror("adding extended attributes");
+				free(xattr);
+				return -1;
+			}
+
+			xattr = it;
+			xattr->max_attr *= 2;
+
+			node->xattr = xattr;
+			xattr->next = fs->xattr;
+			fs->xattr = xattr;
+		}
+	}
+
+	xattr->ref[xattr->num_attr]  = (uint64_t)key_idx << 32;
+	xattr->ref[xattr->num_attr] |= (uint64_t)value_idx;
+	xattr->num_attr += 1;
+	return 0;
+}
+
+static int cmp_u64(const void *lhs, const void *rhs)
+{
+	uint64_t l = *((uint64_t *)lhs), r = *((uint64_t *)rhs);
+
+	return l < r ? -1 : (l > r ? 1 : 0);
+}
+
+void fstree_xattr_reindex(fstree_t *fs)
+{
+	tree_xattr_t *it;
+	size_t index = 0;
+
+	for (it = fs->xattr; it != NULL; it = it->next)
+		it->index = index++;
+}
+
+void fstree_xattr_deduplicate(fstree_t *fs)
+{
+	tree_xattr_t *it, *it1, *prev;
+	int diff;
+
+	for (it = fs->xattr; it != NULL; it = it->next)
+		qsort(it->ref, it->num_attr, sizeof(it->ref[0]), cmp_u64);
+
+	prev = NULL;
+	it = fs->xattr;
+
+	while (it != NULL) {
+		for (it1 = fs->xattr; it1 != it; it1 = it1->next) {
+			if (it1->num_attr != it->num_attr)
+				continue;
+
+			diff = memcmp(it1->ref, it->ref,
+				      it->num_attr * sizeof(it->ref[0]));
+			if (diff == 0)
+				break;
+		}
+
+		if (it1 != it) {
+			prev->next = it->next;
+			it->owner->xattr = it1;
+
+			free(it);
+			it = prev->next;
+		} else {
+			prev = it;
+			it = it->next;
+		}
+	}
+
+	fstree_xattr_reindex(fs);
+}