cluster/ec: Fix dictionary compare function

If both dicts are NULL then equal. If one of the dicts is NULL but the other
has only ignorable keys then also they are equal. If both dicts are non-null
then check if for each non-ignorable key, values are same or not.  value_ignore
function is used to skip comparing values for the keys which must be present in
both the dictionaries but the value could be different.

geo-rep's stime xattr doesn't need to be present in list xattr but when
getxattr comes on stime xattr even if there aren't enough responses with the
xattr we should still give out an answer which is maximum of the stimes
available.

Change-Id: I8de2ceaa2db785b797f302f585d88e73b154167d
BUG: 1207712
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/10078
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Xavier Hernandez <xhernandez@datalab.es>

2 files changed, 91 insertions, 1 deletions

diff --git a/libglusterfs/src/dict.c b/libglusterfs/src/dict.c
index b8b6aeab248..ffc92e72724 100644
--- a/libglusterfs/src/dict.c
+++ b/libglusterfs/src/dict.c
@@ -31,6 +31,11 @@
 #include "globals.h"
 #include "statedump.h"
 
+struct dict_cmp {
+        dict_t *dict;
+        gf_boolean_t (*value_ignore) (char *k);
+};
+
 data_t *
 get_new_data ()
 {
@@ -107,7 +112,6 @@ dict_new (void)
         return dict;
 }
 
-
 int32_t
 is_data_equal (data_t *one,
                data_t *two)
@@ -134,6 +138,87 @@ is_data_equal (data_t *one,
         return 0;
 }
 
+static int
+key_value_cmp (dict_t *one, char *key1, data_t *value1, void *data)
+{
+        struct dict_cmp *cmp = data;
+        dict_t *two = NULL;
+        data_t *value2 = NULL;
+
+        two = cmp->dict;
+        value2 = dict_get (two, key1);
+
+        if (value2) {
+                if (cmp->value_ignore && cmp->value_ignore (key1))
+                        return 0;
+
+                if (is_data_equal (value1, value2) == 1)
+                        return 0;
+        }
+
+        if (value2 == NULL) {
+                gf_log (THIS->name, GF_LOG_DEBUG,
+                        "'%s' found only on one dict", key1);
+        } else {
+                gf_log (THIS->name, GF_LOG_DEBUG, "'%s' is different in two "
+                        "dicts (%u, %u)", key1, value1->len, value2->len);
+        }
+
+        return -1;
+}
+
+/* If both dicts are NULL then equal. If one of the dicts is NULL but the
+ * other has only ignorable keys then also they are equal. If both dicts are
+ * non-null then check if for each non-ignorable key, values are same or
+ * not.  value_ignore function is used to skip comparing values for the keys
+ * which must be present in both the dictionaries but the value could be
+ * different.
+ */
+gf_boolean_t
+are_dicts_equal (dict_t *one, dict_t *two,
+                 gf_boolean_t (*match) (dict_t *d, char *k, data_t *v,
+                                        void *data),
+                 gf_boolean_t (*value_ignore) (char *k))
+{
+        int     num_matches1 = 0;
+        int     num_matches2 = 0;
+        struct  dict_cmp cmp = {0};
+
+        if (one == two)
+                return _gf_true;
+
+        if (!match)
+                match = dict_match_everything;
+
+        cmp.dict = two;
+        cmp.value_ignore = value_ignore;
+        if (!two) {
+                num_matches1 = dict_foreach_match (one, match, NULL,
+                                                   dict_null_foreach_fn, NULL);
+                goto done;
+        } else {
+                num_matches1 = dict_foreach_match (one, match, NULL,
+                                                   key_value_cmp, &cmp);
+        }
+
+        if (num_matches1 == -1)
+                return _gf_false;
+
+        if ((num_matches1 == one->count) && (one->count == two->count))
+                return _gf_true;
+
+        num_matches2 = dict_foreach_match (two, match, NULL,
+                                           dict_null_foreach_fn, NULL);
+done:
+        /* If the number of matches is same in 'two' then for all the
+         * valid-keys that exist in 'one' the value matched and no extra valid
+         * keys exist in 'two' alone. Otherwise there exists at least one extra
+         * valid-key in 'two' which doesn't exist in 'one' */
+        if (num_matches1 == num_matches2)
+                return _gf_true;
+        return _gf_false;
+}
+
 void
 data_destroy (data_t *data)
 {
diff --git a/libglusterfs/src/dict.h b/libglusterfs/src/dict.h
index 3708eede06d..a9004e96a50 100644
--- a/libglusterfs/src/dict.h
+++ b/libglusterfs/src/dict.h
@@ -264,4 +264,9 @@ dict_match_everything (dict_t *d, char *k, data_t *v, void *data);
 dict_t *
 dict_for_key_value (const char *name, const char *value, size_t size);
 
+gf_boolean_t
+are_dicts_equal (dict_t *one, dict_t *two,
+                 gf_boolean_t (*match) (dict_t *d, char *k, data_t *v,
+                                        void *data),
+                 gf_boolean_t (*value_ignore) (char *k));
 #endif