| /* |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * |
| */ |
| |
| #include <proton/link.h> |
| #include <proton/handlers.h> |
| #include <assert.h> |
| |
| typedef struct { |
| int window; |
| int drained; |
| } pni_flowcontroller_t; |
| |
| pni_flowcontroller_t *pni_flowcontroller(pn_handler_t *handler) { |
| return (pni_flowcontroller_t *) pn_handler_mem(handler); |
| } |
| |
| static void pni_topup(pn_link_t *link, int window) { |
| int delta = window - pn_link_credit(link); |
| pn_link_flow(link, delta); |
| } |
| |
| static void pn_flowcontroller_dispatch(pn_handler_t *handler, pn_event_t *event, pn_event_type_t type) { |
| pni_flowcontroller_t *fc = pni_flowcontroller(handler); |
| int window = fc->window; |
| pn_link_t *link = pn_event_link(event); |
| |
| switch (pn_event_type(event)) { |
| case PN_LINK_LOCAL_OPEN: |
| case PN_LINK_REMOTE_OPEN: |
| case PN_LINK_FLOW: |
| case PN_DELIVERY: |
| if (pn_link_is_receiver(link)) { |
| fc->drained += pn_link_drained(link); |
| if (!fc->drained) { |
| pni_topup(link, window); |
| } |
| } |
| break; |
| default: |
| break; |
| } |
| } |
| |
| pn_flowcontroller_t *pn_flowcontroller(int window) { |
| // XXX: a window of 1 doesn't work because we won't necessarily get |
| // notified when the one allowed delivery is settled |
| assert(window > 1); |
| pn_flowcontroller_t *handler = pn_handler_new(pn_flowcontroller_dispatch, sizeof(pni_flowcontroller_t), NULL); |
| pni_flowcontroller_t *fc = pni_flowcontroller(handler); |
| fc->window = window; |
| fc->drained = 0; |
| return handler; |
| } |