Adding upstream version 1:10.5.12.upstream/1%10.5.12upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 155 insertions, 0 deletions

diff --git a/wsrep-lib/wsrep-API/v26/examples/node/trx.c b/wsrep-lib/wsrep-API/v26/examples/node/trx.c
new file mode 100644
index 00000000..afdcada4
--- /dev/null
+++ b/wsrep-lib/wsrep-API/v26/examples/node/trx.c
@@ -0,0 +1,155 @@
+/* Copyright (c) 2019-2020, Codership Oy. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#include "trx.h"
+#include "log.h"
+
+#include <assert.h>
+#include <errno.h>  // ENOMEM, etc.
+#include <stdbool.h>
+
+wsrep_status_t
+node_trx_execute(node_store_t*   const store,
+                 wsrep_t*        const wsrep,
+                 wsrep_conn_id_t const conn_id,
+                 int                   ops_num)
+{
+    wsrep_status_t cert = WSREP_OK; // for cleanup
+
+    static unsigned int const ws_flags =
+        WSREP_FLAG_TRX_START | WSREP_FLAG_TRX_END; // atomic trx
+    wsrep_trx_meta_t ws_meta;
+    wsrep_status_t ret = WSREP_OK;
+
+    /* prepare simple transaction and obtain a writeset handle for it */
+    wsrep_ws_handle_t ws_handle = { 0, NULL };
+    while (ops_num--)
+    {
+        if (0 != (ret = node_store_execute(store, wsrep, &ws_handle)))
+        {
+#if 0
+            NODE_INFO("master [%d]: node_store_execute() returned %d",
+                      conn_id, ret);
+#endif
+            ret = WSREP_TRX_FAIL;
+            goto cleanup;
+        }
+    }
+
+    /* REPLICATION: (replicate and) certify the writeset (pointed to by
+     *              ws_handle) with the cluster */
+    cert = wsrep->certify(wsrep, conn_id, &ws_handle, ws_flags, &ws_meta);
+
+    if (WSREP_BF_ABORT == cert)
+    {
+        /* REPLICATION: transaction was signaled to abort due to multi-master
+         *              conflict. It must rollback immediately: it blocks
+         *              transaction that was ordered earlier and will never
+         *              be able to enter commit order. */
+        node_store_rollback(store, ws_handle.trx_id);
+    }
+
+    /* REPLICATION: writeset was totally ordered, need to enter commit order */
+    if (ws_meta.gtid.seqno > 0)
+    {
+        ret = wsrep->commit_order_enter(wsrep, &ws_handle, &ws_meta);
+        if (ret)
+        {
+            NODE_ERROR("master [%d]: wsrep::commit_order_enter(%lld) failed: "
+                       "%d", (long long)(ws_meta.gtid.seqno), ret);
+            goto cleanup;
+        }
+
+        /* REPLICATION: inside commit monitor
+         * Note: we commit transaction only if certification succeded */
+        if (WSREP_OK == cert)
+            node_store_commit(store, ws_handle.trx_id, &ws_meta.gtid);
+        else
+            node_store_update_gtid(store, &ws_meta.gtid);
+
+        ret = wsrep->commit_order_leave(wsrep, &ws_handle, &ws_meta, NULL);
+        if (ret)
+        {
+            NODE_ERROR("master [%d]: wsrep::commit_order_leave(%lld) failed: "
+                       "%d", (long long)(ws_meta.gtid.seqno), ret);
+            goto cleanup;
+        }
+    }
+    else
+    {
+        assert(cert);
+    }
+
+cleanup:
+    /* REPLICATION: if wsrep->certify() returned anything else but WSREP_OK
+     *              transaction must roll back. BF aborted trx already did it. */
+    if (cert && WSREP_BF_ABORT != cert)
+        node_store_rollback(store, ws_handle.trx_id);
+
+    /* NOTE: this application follows the approach that resources must be freed
+     *       at the same level where they were allocated, so it is assumed that
+     *       ws_key and ws were deallocated in either commit or rollback calls.*/
+
+    /* REPLICATION: release provider resources associated with the trx */
+    wsrep->release(wsrep, &ws_handle);
+
+    return ret ? ret : cert;
+}
+
+wsrep_status_t
+node_trx_apply(node_store_t*            const store,
+               wsrep_t*                 const wsrep,
+               const wsrep_ws_handle_t* const ws_handle,
+               const wsrep_trx_meta_t*  const ws_meta,
+               const wsrep_buf_t*       const ws)
+{
+    /* no business being here if event was not ordered */
+    assert(ws_meta->gtid.seqno > 0);
+
+    wsrep_trx_id_t trx_id;
+    wsrep_buf_t err_buf = { NULL, 0 };
+    int app_err;
+    if (ws)
+    {
+        app_err = node_store_apply(store, &trx_id, ws);
+        if (app_err)
+        {
+            /* REPLICATION: if applying failed, prepare an error buffer with
+             *              sufficient error specification */
+            err_buf.ptr = &app_err; // suppose error code is enough
+            err_buf.len = sizeof(app_err);
+        }
+    }
+    else /* ws failed certification and should be skipped */
+    {
+        /* just some non-0 code to choose node_store_update_gtid() below */
+        app_err = 1;
+    }
+
+    wsrep_status_t ret;
+    ret = wsrep->commit_order_enter(wsrep, ws_handle, ws_meta);
+    if (ret) {
+        node_store_rollback(store, trx_id);
+        return ret;
+    }
+
+    if (!app_err) node_store_commit(store, trx_id, &ws_meta->gtid);
+    else          node_store_update_gtid(store, &ws_meta->gtid);
+
+    ret = wsrep->commit_order_leave(wsrep, ws_handle, ws_meta, &err_buf);
+
+    return ret;
+}