Implement global transaction starting in libdtm.

kvap · kvap · commit 864cf87a36c9 · 2015-09-09T14:01:25.000+03:00
diff --git a/contrib/pg_xtm/libdtm.c b/contrib/pg_xtm/libdtm.c
@@ -141,6 +141,26 @@ static bool dtm_query(DTMConn dtm, char cmd, int argc, ...) {
 	return true;
 }
 
+// Creates an entry for a new global transaction. Returns 'true' on success, or
+// 'false' otherwise.
+bool DtmGlobalStartTransaction(DTMConn dtm, GlobalTransactionId *gtid) {
+	bool ok;
+	int i;
+
+	// query
+	if (!dtm_write_char(dtm, 'b')) return false;
+	if (!dtm_write_hex16(dtm, 1 + 2 * gtid->nNodes)) return false;
+	if (!dtm_write_hex16(dtm, gtid->nNodes)) return false;
+	for (i = 0; i < gtid->nNodes; i++) {
+		if (!dtm_write_hex16(dtm, gtid->nodes[i])) return false;
+		if (!dtm_write_hex16(dtm, gtid->xids[i])) return false;
+	}
+
+	// response
+	if (!dtm_read_bool(dtm, &ok)) return false;
+	return ok;
+}
+
 // Asks DTM for a fresh snapshot. Returns 'true' on success, or 'false'
 // otherwise.
 bool DtmGlobalGetSnapshot(DTMConn dtm, NodeId nodeid, TransactionId xid, Snapshot s) {
diff --git a/contrib/pg_xtm/libdtm.h b/contrib/pg_xtm/libdtm.h
@@ -25,8 +25,9 @@ typedef struct {
     int nNodes;
 } GlobalTransactionId;
 
-// Creates an entry for a new global transaction.
-void DtmGlobalStartTransaction(DTMConn dtm, GlobalTransactionId* gtid);
+// Creates an entry for a new global transaction. Returns 'true' on success, or
+// 'false' otherwise.
+bool DtmGlobalStartTransaction(DTMConn dtm, GlobalTransactionId* gtid);
 
 // Asks DTM for a fresh snapshot. Returns 'true' on success, or 'false'
 // otherwise.
