Add getAllRows() to DataTableStore for cross-bucket aggregation

rewrite-core/src/main/java/org/openrewrite/DataTableStore.java

@@ -63,6 +63,17 @@ static DataTableStore noop() {
      */
     Stream<?> getRows(String dataTableName, @Nullable String group);
 
+    /**
+     * Stream all rows for a given data table name, merging across all
+     * groups and instance names.
+     *
+     * @param dataTableName the fully qualified class name of the data table
+     * @return a stream of all rows across all buckets with this name
+     */
+    default Stream<?> getAllRows(String dataTableName) {
+        return getRows(dataTableName, null);
+    }
+
     /**
      * Get the set of {@link DataTable} instances that have received rows.
      *

rewrite-core/src/main/java/org/openrewrite/InMemoryDataTableStore.java

@@ -78,6 +78,19 @@ private static Stream<Object> snapshotRows(Bucket bucket) {
         return snapshot.stream();
     }
 
+    @Override
+    public Stream<?> getAllRows(String dataTableName) {
+        List<Object> allRows = new ArrayList<>();
+        for (Bucket bucket : buckets.values()) {
+            if (bucket.dataTable.getName().equals(dataTableName)) {
+                synchronized (bucket.rows) {
+                    allRows.addAll(bucket.rows);
+                }
+            }
+        }
+        return allRows.stream();
+    }
+
     @Override
     public Collection<DataTable<?>> getDataTables() {
         List<DataTable<?>> result = new ArrayList<>(buckets.size());