[Tarantool-patches] [PATCH v4 03/12] txm: save does_require_old_tuple flag in txn_stmt
Aleksandr Lyapunov
alyapunov at tarantool.org
Tue Sep 8 13:22:03 MSK 2020
That flag is needed for transactional conflict manager - if any
other transaction commits a replacement of old_tuple before
current one and the flag is set - the current transaction will
be aborted.
For example REPLACE just replaces a key, no matter what tuple
lays in the index and thus does_require_old_tuple = false.
In contrast, UPDATE makes new tuple using old_tuple and thus
the statement will require old_tuple (does_require_old_tuple = true).
INSERT also does_require_old_tuple = true because it requires
old_tuple to be NULL.
Part of #4897
---
src/box/memtx_space.c | 17 +++++++++++++++++
src/box/txn.c | 53 ++++++++++++++++++++++++++++++++++-----------------
src/box/txn.h | 13 +++++++++++++
3 files changed, 65 insertions(+), 18 deletions(-)
diff --git a/src/box/memtx_space.c b/src/box/memtx_space.c
index d30ce44..7624130 100644
--- a/src/box/memtx_space.c
+++ b/src/box/memtx_space.c
@@ -316,6 +316,10 @@ memtx_space_execute_replace(struct space *space, struct txn *txn,
if (stmt->new_tuple == NULL)
return -1;
tuple_ref(stmt->new_tuple);
+
+ if (mode == DUP_INSERT)
+ stmt->does_require_old_tuple = true;
+
if (memtx_space->replace(space, NULL, stmt->new_tuple,
mode, &stmt->old_tuple) != 0)
return -1;
@@ -342,6 +346,13 @@ memtx_space_execute_delete(struct space *space, struct txn *txn,
struct tuple *old_tuple;
if (index_get(pk, key, part_count, &old_tuple) != 0)
return -1;
+
+ /*
+ * We have to delete exactly old_tuple just because we return it as
+ * a result.
+ */
+ stmt->does_require_old_tuple = true;
+
if (old_tuple != NULL &&
memtx_space->replace(space, old_tuple, NULL,
DUP_REPLACE_OR_INSERT, &stmt->old_tuple) != 0)
@@ -390,6 +401,9 @@ memtx_space_execute_update(struct space *space, struct txn *txn,
if (stmt->new_tuple == NULL)
return -1;
tuple_ref(stmt->new_tuple);
+
+ stmt->does_require_old_tuple = true;
+
if (memtx_space->replace(space, old_tuple, stmt->new_tuple,
DUP_REPLACE, &stmt->old_tuple) != 0)
return -1;
@@ -496,6 +510,9 @@ memtx_space_execute_upsert(struct space *space, struct txn *txn,
stmt->new_tuple = NULL;
}
}
+
+ stmt->does_require_old_tuple = true;
+
/*
* It's OK to use DUP_REPLACE_OR_INSERT: we don't risk
* inserting a new tuple if the old one exists, since
diff --git a/src/box/txn.c b/src/box/txn.c
index 093808a..d9fbb51 100644
--- a/src/box/txn.c
+++ b/src/box/txn.c
@@ -109,6 +109,7 @@ txn_stmt_new(struct region *region)
stmt->engine_savepoint = NULL;
stmt->row = NULL;
stmt->has_triggers = false;
+ stmt->does_require_old_tuple = false;
return stmt;
}
@@ -351,27 +352,43 @@ txn_commit_stmt(struct txn *txn, struct request *request)
* - perhaps we should run triggers even for deletes which
* doesn't find any rows
*/
- if (stmt->space != NULL && !rlist_empty(&stmt->space->on_replace) &&
- stmt->space->run_triggers && (stmt->old_tuple || stmt->new_tuple)) {
- int rc = 0;
- if(!space_is_temporary(stmt->space)) {
- rc = trigger_run(&stmt->space->on_replace, txn);
- } else {
+ if (stmt->space != NULL && stmt->space->run_triggers &&
+ (stmt->old_tuple || stmt->new_tuple)) {
+ if (!rlist_empty(&stmt->space->before_replace)) {
/*
- * There is no row attached to txn_stmt for
- * temporary spaces, since DML operations on them
- * are not written to WAL. Fake a row to pass operation
- * type to lua on_replace triggers.
+ * Triggers see old_tuple and that tuple
+ * must remain the same
*/
- assert(stmt->row == NULL);
- struct xrow_header temp_header;
- temp_header.type = request->type;
- stmt->row = &temp_header;
- rc = trigger_run(&stmt->space->on_replace, txn);
- stmt->row = NULL;
+ stmt->does_require_old_tuple = true;
+ }
+ if (!rlist_empty(&stmt->space->on_replace)) {
+ /*
+ * Triggers see old_tuple and that tuple
+ * must remain the same
+ */
+ stmt->does_require_old_tuple = true;
+
+ int rc = 0;
+ if(!space_is_temporary(stmt->space)) {
+ rc = trigger_run(&stmt->space->on_replace, txn);
+ } else {
+ /*
+ * There is no row attached to txn_stmt for
+ * temporary spaces, since DML operations on
+ * them are not written to WAL.
+ * Fake a row to pass operation type to lua
+ * on_replace triggers.
+ */
+ assert(stmt->row == NULL);
+ struct xrow_header temp_header;
+ temp_header.type = request->type;
+ stmt->row = &temp_header;
+ rc = trigger_run(&stmt->space->on_replace, txn);
+ stmt->row = NULL;
+ }
+ if (rc != 0)
+ goto fail;
}
- if (rc != 0)
- goto fail;
}
--txn->in_sub_stmt;
return 0;
diff --git a/src/box/txn.h b/src/box/txn.h
index 35e1ab9..007284f 100644
--- a/src/box/txn.h
+++ b/src/box/txn.h
@@ -175,6 +175,19 @@ struct txn_stmt {
struct xrow_header *row;
/** on_commit and/or on_rollback list is not empty. */
bool has_triggers;
+ /**
+ * Whether the stmt requires to replace exactly old_tuple (member).
+ * That flag is needed for transactional conflict manager - if any
+ * other transaction commits a replacement of old_tuple before current
+ * one and the flag is set - the current transaction will be aborted.
+ * For example REPLACE just replaces a key, no matter what tuple
+ * lays in the index and thus does_require_old_tuple = false.
+ * In contrast, UPDATE makes new tuple using old_tuple and thus
+ * the statement will require old_tuple (does_require_old_tuple = true).
+ * INSERT also does_require_old_tuple = true because it requires
+ * old_tuple to be NULL.
+ */
+ bool does_require_old_tuple;
/** Commit/rollback triggers associated with this statement. */
struct rlist on_commit;
struct rlist on_rollback;
--
2.7.4
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