[Tarantool-patches] [PATCH 1/2] box: introduce constraint names hash table

[Roman Khabibov <roman.habibov@tarantool.org>]

Add hash table and API for interaction with it to struct space. This
hash table is needed to keep constraint names of a table together and check
their duplicates.

Needed for #3503
---
 src/box/space.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 src/box/space.h | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+)

diff --git a/src/box/space.c b/src/box/space.c
index 94716a414..c15b9f5b4 100644
--- a/src/box/space.c
+++ b/src/box/space.c
@@ -45,6 +45,7 @@
 #include "iproto_constants.h"
 #include "schema.h"
 #include "ck_constraint.h"
+#include "assoc.h"
 
 int
 access_check_space(struct space *space, user_access_t access)
@@ -202,6 +203,13 @@ space_create(struct space *space, struct engine *engine,
 			}
 		}
 	}
+
+	space->constraint_names = mh_strnptr_new();
+	if (space->constraint_names == NULL) {
+		diag_set(OutOfMemory, sizeof(*space->constraint_names), "malloc",
+			 "constraint_names");
+		goto fail;
+	}
 	return 0;
 
 fail_free_indexes:
@@ -257,6 +265,7 @@ space_delete(struct space *space)
 	trigger_destroy(&space->before_replace);
 	trigger_destroy(&space->on_replace);
 	space_def_delete(space->def);
+	mh_strnptr_delete(space->constraint_names);
 	/*
 	 * SQL Triggers should be deleted with
 	 * on_replace_dd_trigger on deletion from _trigger.
@@ -617,6 +626,43 @@ space_remove_ck_constraint(struct space *space, struct ck_constraint *ck)
 	}
 }
 
+bool
+space_has_constraint(struct space *space, const char *name)
+{
+	uint32_t len = strlen(name);
+	mh_int_t pos = mh_strnptr_find_inp(space->constraint_names, name, len);
+	if (pos != mh_end(space->constraint_names))
+		return true;
+	return false;
+}
+
+int
+space_put_constraint_name(struct space *space, const char *name)
+{
+	uint32_t len = strlen(name);
+	uint32_t hash = mh_strn_hash(name, len);
+	char *name_copy = malloc(len);
+	memcpy(name_copy, name, len);
+	const struct mh_strnptr_node_t name_node = { name_copy, len, hash,
+						     NULL };
+	if (mh_strnptr_put(space->constraint_names, &name_node, NULL,
+			   NULL) == mh_end(space->constraint_names)) {
+		diag_set(OutOfMemory, sizeof(name_node), "malloc",
+			 "constraint_names");
+		return -1;
+	}
+
+	return 0;
+}
+
+void
+space_drop_constraint_name(struct space *space, const char *name)
+{
+	mh_int_t pos = mh_strnptr_find_inp(space->constraint_names, name,
+					   strlen(name));
+	mh_strnptr_del(space->constraint_names, pos, NULL);
+}
+
 /* {{{ Virtual method stubs */
 
 size_t
diff --git a/src/box/space.h b/src/box/space.h
index 7926aa65e..36a767421 100644
--- a/src/box/space.h
+++ b/src/box/space.h
@@ -234,6 +234,11 @@ struct space {
 	 * of parent constraints as well as child ones.
 	 */
 	uint64_t fk_constraint_mask;
+	/**
+	  * Hash table with constraint names. Used for non-system
+	  * spaces only.
+	  */
+	struct mh_strnptr_t *constraint_names;
 };
 
 /** Initialize a base space instance. */
@@ -516,6 +521,41 @@ space_add_ck_constraint(struct space *space, struct ck_constraint *ck);
 void
 space_remove_ck_constraint(struct space *space, struct ck_constraint *ck);
 
+/**
+ * Check if a constraint with @a name exists within @a space.
+ *
+ * @param space Space.
+ * @param name  Constraint name.
+ *
+ * @retval true  The constraint with @a name exists.
+ * @retval false Doesn't exist respectively.
+ */
+bool
+space_has_constraint(struct space *space, const char *name);
+
+/**
+ * Put node with @a name of a constraint the the hash table of @a
+ * space.
+ *
+ * @param space Space.
+ * @param name  Constraint name.
+ *
+ * @retval  0 Success.
+ * @retval -1 Memory allocation error.
+ */
+int
+space_put_constraint_name(struct space *space, const char *name);
+
+/**
+ * Remove node with @a name of a constraint from the hash table of
+ * @a space.
+ *
+ * @param space Space.
+ * @param name  Constraint name.
+ */
+void
+space_drop_constraint_name(struct space *space, const char *name);
+
 /*
  * Virtual method stubs.
  */
-- 
2.21.0 (Apple Git-122)