xattrs: introduce a rsync_xa_list struct as layer between two nested item_lists

We have the global 'item_list rsync_xal_l', this maintains an array
of rsync_xa_list structure, one per file.

Each rsync_xa_list structure maintains an array of rsync_xa structure,
while each represent a single xattr with name and value.

Part of a patchset for bug 5324.

diff --git a/xattrs.c b/xattrs.c
index 88da5ee0c68b0f6aa19b45a6f4799cbad8a195fe..7c52e7bfe86a956d1b1e0ce4f35b42760be54dc2 100644 (file)
--- a/xattrs.c
+++ b/xattrs.c
@@ -79,9 +79,16 @@ typedef struct {
        int num;
 } rsync_xa;
 
+typedef struct {
+       item_list xa_items;
+} rsync_xa_list;
+
 static size_t namebuf_len = 0;
 static char *namebuf = NULL;
 
+static const rsync_xa_list empty_xa_list = {
+       .xa_items = EMPTY_ITEM_LIST,
+};
 static const item_list empty_xattr = EMPTY_ITEM_LIST;
 static item_list rsync_xal_l = EMPTY_ITEM_LIST;
 
@@ -360,17 +367,19 @@ int copy_xattrs(const char *source, const char *dest)
        return 0;
 }
 
-static int find_matching_xattr(item_list *xalp)
+static int find_matching_xattr(const item_list *xalp)
 {
-       size_t i, j;
-       item_list *lst = rsync_xal_l.items;
+       const rsync_xa_list *glst = rsync_xal_l.items;
+       size_t i;
 
        for (i = 0; i < rsync_xal_l.count; i++) {
-               rsync_xa *rxas1 = lst[i].items;
-               rsync_xa *rxas2 = xalp->items;
+               const item_list *lst = &glst[i].xa_items;
+               const rsync_xa *rxas1 = lst->items;
+               const rsync_xa *rxas2 = xalp->items;
+               size_t j;
 
                /* Wrong number of elements? */
-               if (lst[i].count != xalp->count)
+               if (lst->count != xalp->count)
                        continue;
                /* any elements different? */
                for (j = 0; j < xalp->count; j++) {
@@ -401,13 +410,13 @@ static int find_matching_xattr(item_list *xalp)
 static int rsync_xal_store(item_list *xalp)
 {
        int ndx = rsync_xal_l.count; /* pre-incremented count */
-       item_list *new_lst = EXPAND_ITEM_LIST(&rsync_xal_l, item_list, RSYNC_XAL_LIST_INITIAL);
+       rsync_xa_list *new_list = EXPAND_ITEM_LIST(&rsync_xal_l, rsync_xa_list, RSYNC_XAL_LIST_INITIAL);
        /* Since the following call starts a new list, we know it will hold the
         * entire initial-count, not just enough space for one new item. */
-       *new_lst = empty_xattr;
-       (void)EXPAND_ITEM_LIST(new_lst, rsync_xa, xalp->count);
-       memcpy(new_lst->items, xalp->items, xalp->count * sizeof (rsync_xa));
-       new_lst->count = xalp->count;
+       *new_list = empty_xa_list;
+       (void)EXPAND_ITEM_LIST(&new_list->xa_items, rsync_xa, xalp->count);
+       memcpy(new_list->xa_items.items, xalp->items, xalp->count * sizeof (rsync_xa));
+       new_list->xa_items.count = xalp->count;
        xalp->count = 0;
        return ndx;
 }
@@ -467,7 +476,8 @@ int send_xattr(int f, stat_x *sxp)
  * need so that send_xattr_request() can tell the sender about them. */
 int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all)
 {
-       const item_list *lst = rsync_xal_l.items;
+       const rsync_xa_list *glst = rsync_xal_l.items;
+       const item_list *lst;
        rsync_xa *snd_rxa, *rec_rxa;
        int snd_cnt, rec_cnt;
        int cmp, same, xattrs_equal = 1;
@@ -480,9 +490,10 @@ int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all)
                rec_cnt = 0;
        }
 
-       if (F_XATTR(file) >= 0)
-               lst += F_XATTR(file);
-       else
+       if (F_XATTR(file) >= 0) {
+               glst += F_XATTR(file);
+               lst = &glst->xa_items;
+       } else
                lst = &empty_xattr;
 
        snd_rxa = lst->items;
@@ -541,11 +552,14 @@ int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all)
  * XSTATE_ABBREV states into XSTATE_DONE. */
 void send_xattr_request(const char *fname, struct file_struct *file, int f_out)
 {
-       item_list *lst = rsync_xal_l.items;
+       const rsync_xa_list *glst = rsync_xal_l.items;
+       const item_list *lst;
        int cnt, prior_req = 0;
        rsync_xa *rxa;
 
-       lst += F_XATTR(file);
+       glst += F_XATTR(file);
+       lst = &glst->xa_items;
+
        for (rxa = lst->items, cnt = lst->count; cnt--; rxa++) {
                if (rxa->datum_len <= MAX_FULL_DATUM)
                        continue;
@@ -596,7 +610,8 @@ void send_xattr_request(const char *fname, struct file_struct *file, int f_out)
  * stores it in place of its checksum. */
 int recv_xattr_request(struct file_struct *file, int f_in)
 {
-       item_list *lst = rsync_xal_l.items;
+       const rsync_xa_list *glst = rsync_xal_l.items;
+       const item_list *lst;
        char *old_datum, *name;
        rsync_xa *rxa;
        int rel_pos, cnt, num, got_xattr_data = 0;
@@ -605,7 +620,8 @@ int recv_xattr_request(struct file_struct *file, int f_in)
                rprintf(FERROR, "recv_xattr_request: internal data error!\n");
                exit_cleanup(RERR_PROTOCOL);
        }
-       lst += F_XATTR(file);
+       glst += F_XATTR(file);
+       lst = &glst->xa_items;
 
        cnt = lst->count;
        rxa = lst->items;
@@ -796,12 +812,13 @@ void cache_tmp_xattr(struct file_struct *file, stat_x *sxp)
 void uncache_tmp_xattrs(void)
 {
        if (prior_xattr_count != (size_t)-1) {
-               item_list *xattr_item = rsync_xal_l.items;
-               item_list *xattr_start = xattr_item + prior_xattr_count;
-               xattr_item += rsync_xal_l.count;
+               rsync_xa_list *xa_list_item = rsync_xal_l.items;
+               rsync_xa_list *xa_list_start = xa_list_item + prior_xattr_count;
+               xa_list_item += rsync_xal_l.count;
                rsync_xal_l.count = prior_xattr_count;
-               while (xattr_item-- > xattr_start)
-                       rsync_xal_free(xattr_item);
+               while (xa_list_item-- > xa_list_start) {
+                       rsync_xal_free(&xa_list_item->xa_items);
+               }
                prior_xattr_count = (size_t)-1;
        }
 }
@@ -921,8 +938,9 @@ static int rsync_xal_set(const char *fname, item_list *xalp,
 int set_xattr(const char *fname, const struct file_struct *file,
              const char *fnamecmp, stat_x *sxp)
 {
+       rsync_xa_list *glst = rsync_xal_l.items;
+       item_list *lst;
        int ndx;
-       item_list *lst = rsync_xal_l.items;
 
        if (dry_run)
                return 1; /* FIXME: --dry-run needs to compute this value */
@@ -952,7 +970,9 @@ int set_xattr(const char *fname, const struct file_struct *file,
 #endif
 
        ndx = F_XATTR(file);
-       return rsync_xal_set(fname, lst + ndx, fnamecmp, sxp);
+       glst += ndx;
+       lst = &glst->xa_items;
+       return rsync_xal_set(fname, lst, fnamecmp, sxp);
 }
 
 #ifdef SUPPORT_ACLS