| Craig Tiller | 9d0e047 | 2015-06-23 09:12:48 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * |
| 3 | * Copyright 2015, Google Inc. |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions are |
| 8 | * met: |
| 9 | * |
| 10 | * * Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * * Redistributions in binary form must reproduce the above |
| 13 | * copyright notice, this list of conditions and the following disclaimer |
| 14 | * in the documentation and/or other materials provided with the |
| 15 | * distribution. |
| 16 | * * Neither the name of Google Inc. nor the names of its |
| 17 | * contributors may be used to endorse or promote products derived from |
| 18 | * this software without specific prior written permission. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 21 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 22 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 23 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 24 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 25 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 26 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 27 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 28 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 29 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 30 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 31 | * |
| 32 | */ |
| 33 | |
| 34 | #ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_H |
| 35 | #define GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_H |
| 36 | |
| 37 | #include "src/core/client_config/configured_channel.h" |
| 38 | |
| 39 | /** A load balancing policy: specified by a vtable and a struct (which |
| 40 | is expected to be extended to contain some parameters) */ |
| 41 | typedef struct grpc_lb_policy grpc_lb_policy; |
| 42 | typedef struct grpc_lb_policy_vtable grpc_lb_policy_vtable; |
| 43 | |
| 44 | typedef void (*grpc_lb_completion)(void *cb_arg, |
| 45 | grpc_configured_channel *configured_channel, |
| 46 | grpc_status_code status, const char *errmsg); |
| 47 | |
| 48 | struct grpc_lb_policy_vtable { |
| 49 | void (*ref)(grpc_lb_policy *policy); |
| 50 | void (*unref)(grpc_lb_policy *policy); |
| 51 | |
| 52 | void (*shutdown)(grpc_lb_policy *policy); |
| 53 | |
| 54 | /** implement grpc_lb_policy_pick */ |
| 55 | void (*pick)(grpc_lb_policy *policy, grpc_pollset *pollset, |
| 56 | grpc_metadata_batch *initial_metadata, |
| 57 | grpc_configured_channel **target, |
| 58 | grpc_iomgr_closure *on_complete); |
| 59 | }; |
| 60 | |
| 61 | /** Start shutting down (fail any pending picks) */ |
| 62 | void grpc_lb_policy_shutdown(grpc_lb_policy *policy); |
| 63 | |
| 64 | /** Given initial metadata in \a initial_metadata, find an appropriate |
| 65 | target for this rpc, and 'return' it by calling \a on_complete after setting |
| 66 | \a target. |
| 67 | Picking can be asynchronous. Any IO should be done under \a pollset. */ |
| 68 | void grpc_lb_policy_pick(grpc_lb_policy *policy, grpc_pollset *pollset, |
| 69 | grpc_metadata_batch *initial_metadata, |
| 70 | grpc_configured_channel **target, |
| 71 | grpc_iomgr_closure *on_complete); |
| 72 | |
| 73 | #endif /* GRPC_INTERNAL_CORE_CONFIG_LB_POLICY_H */ |