ovsdb: Add/use partial set updates.

This patchset mimics the changes introduced in

  f199df26 (ovsdb-idl: Add partial map updates functionality.)
  010fe7ae (ovsdb-idlc.in: Autogenerate partial map updates functions.)
  7251075c (tests: Add test for partial map updates.)
  b1048e6a (ovsdb-idl: Fix issues detected in Partial Map Update feature)

but for columns that store sets of values rather than key-value
pairs.  These columns will now be able to use the OVSDB mutate
operation to transmit deltas on the wire rather than use
verify/update and transmit wait/update operations on the wire.

Side effect of modifying the comments in the partial map update
tests.

Signed-off-by: Ryan Moats <rmoats@us.ibm.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

1 files changed, 170 insertions, 0 deletions

diff --git a/lib/ovsdb-set-op.c b/lib/ovsdb-set-op.c
new file mode 100644
index 000000000..f41034cd8
--- /dev/null
+++ b/lib/ovsdb-set-op.c
@@ -0,0 +1,170 @@
+/* Copyright (C) 2016, IBM
+ * All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License. You may obtain
+ * a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <config.h>
+#include "ovsdb-set-op.h"
+#include "util.h"
+
+/* Set Operation: a Partial Set Update */
+struct set_op {
+    struct hmap_node node;
+    struct ovsdb_datum *datum;
+    enum set_op_type type;
+};
+
+/* List of Set Operations */
+struct set_op_list {
+    struct hmap hmap;
+};
+
+static void set_op_destroy_datum(struct set_op *, const struct ovsdb_type *);
+static struct set_op *set_op_list_find(struct set_op_list *, struct set_op *,
+                                       const struct ovsdb_type *, size_t);
+
+struct set_op*
+set_op_create(struct ovsdb_datum *datum, enum set_op_type type)
+{
+    struct set_op *set_op = xmalloc(sizeof *set_op);
+    set_op->node.hash = 0;
+    set_op->node.next = HMAP_NODE_NULL;
+    set_op->datum = datum;
+    set_op->type = type;
+    return set_op;
+}
+
+static void
+set_op_destroy_datum(struct set_op *set_op, const struct ovsdb_type *type)
+{
+    if (set_op->type == SET_OP_DELETE){
+        struct ovsdb_type type_ = *type;
+        type_.value.type = OVSDB_TYPE_VOID;
+        ovsdb_datum_destroy(set_op->datum, &type_);
+    } else {
+        ovsdb_datum_destroy(set_op->datum, type);
+    }
+    free(set_op->datum);
+    set_op->datum = NULL;
+}
+
+void
+set_op_destroy(struct set_op *set_op, const struct ovsdb_type *type)
+{
+    set_op_destroy_datum(set_op, type);
+    free(set_op);
+}
+
+struct ovsdb_datum*
+set_op_datum(const struct set_op *set_op)
+{
+    return set_op->datum;
+}
+
+enum set_op_type
+set_op_type(const struct set_op *set_op)
+{
+    return set_op->type;
+}
+
+struct set_op_list*
+set_op_list_create(void)
+{
+    struct set_op_list *list = xmalloc(sizeof *list);
+    hmap_init(&list->hmap);
+    return list;
+}
+
+void
+set_op_list_destroy(struct set_op_list *list, const struct ovsdb_type *type)
+{
+    struct set_op *set_op, *next;
+    HMAP_FOR_EACH_SAFE (set_op, next, node, &list->hmap) {
+        set_op_destroy(set_op, type);
+    }
+    hmap_destroy(&list->hmap);
+    free(list);
+}
+
+static struct set_op*
+set_op_list_find(struct set_op_list *list, struct set_op *set_op,
+                 const struct ovsdb_type *type, size_t hash)
+{
+    struct set_op *found = NULL;
+    struct set_op *old;
+    HMAP_FOR_EACH_WITH_HASH(old, node, hash, &list->hmap) {
+        if (ovsdb_atom_equals(&old->datum->keys[0], &set_op->datum->keys[0],
+                              type->key.type)) {
+            found = old;
+            break;
+        }
+    }
+    return found;
+}
+
+/* Inserts 'set_op' into 'list'. Makes sure that any conflict with a previous
+ * set operation is resolved, so only one set operation is possible on each key
+ * per transactions. 'type' must be the type of the column over which the set
+ * operation will be applied. */
+void
+set_op_list_add(struct set_op_list *list, struct set_op *set_op,
+                const struct ovsdb_type *type)
+{
+    /* Check if there is a previous update with the same key. */
+    size_t hash;
+    struct set_op *prev_set_op;
+
+    hash = ovsdb_atom_hash(&set_op->datum->keys[0], type->key.type, 0);
+    prev_set_op = set_op_list_find(list, set_op, type, hash);
+    if (prev_set_op == NULL){
+        hmap_insert(&list->hmap, &set_op->node, hash);
+    } else {
+        if (prev_set_op->type == SET_OP_INSERT &&
+            set_op->type == SET_OP_DELETE) {
+            /* These operations cancel each other out. */
+            hmap_remove(&list->hmap, &prev_set_op->node);
+            set_op_destroy(prev_set_op, type);
+            set_op_destroy(set_op, type);
+        } else {
+            /* For any other case, the new update operation replaces
+             * the previous update operation. */
+            set_op_destroy_datum(prev_set_op, type);
+            prev_set_op->type = set_op->type;
+            prev_set_op->datum = set_op->datum;
+            free(set_op);
+        }
+    }
+}
+
+struct set_op*
+set_op_list_first(struct set_op_list *list)
+{
+    struct hmap_node *node = hmap_first(&list->hmap);
+    if (node == NULL) {
+        return NULL;
+    }
+    struct set_op *set_op = CONTAINER_OF(node, struct set_op, node);
+    return set_op;
+}
+
+struct set_op*
+set_op_list_next(struct set_op_list *list, struct set_op *set_op)
+{
+    struct hmap_node *node = hmap_next(&list->hmap, &set_op->node);
+    if (node == NULL) {
+        return NULL;
+    }
+    struct set_op *next = CONTAINER_OF(node, struct set_op, node);
+    return next;
+}