fix: drop partially created tables when workspace upload fails

Author: mkemeter

src/main/java/org/sap/cytoscape/internal/hdb/HanaConnectionManager.java

@@ -506,6 +506,16 @@ public void createSchema(String schema) throws SQLException {
         execute(String.format(sqlStrings.getProperty("CREATE_SCHEMA"), schema));
     }
 
+    /**
+     * Drops a table if it exists. Used to clean up after a partially failed workspace upload.
+     *
+     * @param table     Schema and name of the table to drop
+     * @throws SQLException     sql error
+     */
+    public void dropTableIfExists(HanaDbObject table) throws SQLException {
+        execute(String.format(sqlStrings.getProperty("DROP_TABLE_IF_EXISTS"), table));
+    }
+
     /**
      * Creates a new table on the database instance
      *

src/main/java/org/sap/cytoscape/internal/tasks/CyCreateWorkspaceTask.java

@@ -69,45 +69,53 @@ public void run(TaskMonitor taskMonitor) throws Exception {
         }
 
         taskMonitor.setStatusMessage("Creating node table");
-        // create nodes table
-        this.connectionManager.createTable(
-                newWorkspace.getNodeTableDbObject(),
-                newWorkspace.getNodeFieldList()
-        );
-
-        taskMonitor.setStatusMessage("Uploading node records");
-        //insert values
-        this.connectionManager.bulkInsertData(
-                newWorkspace.getNodeTableDbObject(),
-                newWorkspace.getNodeFieldList(),
-                newWorkspace.getNodeTableData()
-        );
-
-        taskMonitor.setStatusMessage("Creating edge table");
-        // create edges table
-        this.connectionManager.createTable(
-                newWorkspace.getEdgeTableDbObject(),
-                newWorkspace.getEdgeFieldList()
-        );
-
-        taskMonitor.setStatusMessage("Uploading edge records");
-        //insert values
-        this.connectionManager.bulkInsertData(
-                newWorkspace.getEdgeTableDbObject(),
-                newWorkspace.getEdgeFieldList(),
-                newWorkspace.getEdgeTableData()
-        );
-
-        taskMonitor.setStatusMessage("Linking Cytoscape Network to SAP HANA Graph Workspace");
-        CyUtils.enhanceCyNetworkWithDatabaseLinkInformation(
-                selectedNetwork.getDefaultNetworkTable(),
-                selectedNetwork.getSUID(),
-                connectionManager.getInstanceIdentifier(),
-                newWorkspace.getWorkspaceDbObject()
-        );
-
-        taskMonitor.setStatusMessage("Creating Graph Workspace");
-        // create graph workspace
-        this.connectionManager.createGraphWorkspace(newWorkspace);
+        boolean nodeTableCreated = false;
+        boolean edgeTableCreated = false;
+        try {
+            // create nodes table
+            this.connectionManager.createTable(
+                    newWorkspace.getNodeTableDbObject(),
+                    newWorkspace.getNodeFieldList()
+            );
+            nodeTableCreated = true;
+
+            taskMonitor.setStatusMessage("Uploading node records");
+            this.connectionManager.bulkInsertData(
+                    newWorkspace.getNodeTableDbObject(),
+                    newWorkspace.getNodeFieldList(),
+                    newWorkspace.getNodeTableData()
+            );
+
+            taskMonitor.setStatusMessage("Creating edge table");
+            this.connectionManager.createTable(
+                    newWorkspace.getEdgeTableDbObject(),
+                    newWorkspace.getEdgeFieldList()
+            );
+            edgeTableCreated = true;
+
+            taskMonitor.setStatusMessage("Uploading edge records");
+            this.connectionManager.bulkInsertData(
+                    newWorkspace.getEdgeTableDbObject(),
+                    newWorkspace.getEdgeFieldList(),
+                    newWorkspace.getEdgeTableData()
+            );
+
+            taskMonitor.setStatusMessage("Linking Cytoscape Network to SAP HANA Graph Workspace");
+            CyUtils.enhanceCyNetworkWithDatabaseLinkInformation(
+                    selectedNetwork.getDefaultNetworkTable(),
+                    selectedNetwork.getSUID(),
+                    connectionManager.getInstanceIdentifier(),
+                    newWorkspace.getWorkspaceDbObject()
+            );
+
+            taskMonitor.setStatusMessage("Creating Graph Workspace");
+            this.connectionManager.createGraphWorkspace(newWorkspace);
+
+        } catch (Exception e) {
+            // Drop any tables already created so the user can retry cleanly.
+            if (edgeTableCreated) try { this.connectionManager.dropTableIfExists(newWorkspace.getEdgeTableDbObject()); } catch (Exception ignore) {}
+            if (nodeTableCreated) try { this.connectionManager.dropTableIfExists(newWorkspace.getNodeTableDbObject()); } catch (Exception ignore) {}
+            throw e;
+        }
     }
 }

src/main/resources/SqlStrings.sql

@@ -57,4 +57,7 @@ CREATE_GRAPH_WORKSPACE=\
             TARGET COLUMN "%s" \
             KEY COLUMN "%s" \
         VERTEX TABLE "%s"."%s" \
-            KEY COLUMN "%s"
+            KEY COLUMN "%s"
+
+DROP_TABLE_IF_EXISTS=\
+    DROP TABLE IF EXISTS %s