legacy-libs/grpc/deps/grpc/src/core/lib/surface/lame_client.cc

   1 /*
   2  *
   3  * Copyright 2015 gRPC authors.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  *
  17  */
  18
  19 #include <grpc/support/port_platform.h>
  20
  21 #include <grpc/grpc.h>
  22
  23 #include <string.h>
  24
  25 #include <grpc/support/alloc.h>
  26 #include <grpc/support/log.h>
  27
  28 #include "src/core/lib/channel/channel_stack.h"
  29 #include "src/core/lib/gpr/string.h"
  30 #include "src/core/lib/gprpp/atomic.h"
  31 #include "src/core/lib/surface/api_trace.h"
  32 #include "src/core/lib/surface/call.h"
  33 #include "src/core/lib/surface/channel.h"
  34 #include "src/core/lib/surface/lame_client.h"
  35 #include "src/core/lib/transport/static_metadata.h"
  36
  37 namespace grpc_core {
  38
  39 namespace {
  40
  41 struct CallData {
  42   grpc_core::CallCombiner* call_combiner;
  43   grpc_linked_mdelem status;
  44   grpc_linked_mdelem details;
  45   grpc_core::Atomic<bool> filled_metadata;
  46 };
  47
  48 struct ChannelData {
  49   grpc_status_code error_code;
  50   const char* error_message;
  51 };
  52
  53 static void fill_metadata(grpc_call_element* elem, grpc_metadata_batch* mdb) {
  54   CallData* calld = static_cast<CallData*>(elem->call_data);
  55   bool expected = false;
  56   if (!calld->filled_metadata.CompareExchangeStrong(
  57           &expected, true, MemoryOrder::RELAXED, MemoryOrder::RELAXED)) {
  58     return;
  59   }
  60   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
  61   char tmp[GPR_LTOA_MIN_BUFSIZE];
  62   gpr_ltoa(chand->error_code, tmp);
  63   calld->status.md = grpc_mdelem_from_slices(
  64       GRPC_MDSTR_GRPC_STATUS, grpc_core::UnmanagedMemorySlice(tmp));
  65   calld->details.md = grpc_mdelem_from_slices(
  66       GRPC_MDSTR_GRPC_MESSAGE,
  67       grpc_core::UnmanagedMemorySlice(chand->error_message));
  68   calld->status.prev = calld->details.next = nullptr;
  69   calld->status.next = &calld->details;
  70   calld->details.prev = &calld->status;
  71   mdb->list.head = &calld->status;
  72   mdb->list.tail = &calld->details;
  73   mdb->list.count = 2;
  74   mdb->deadline = GRPC_MILLIS_INF_FUTURE;
  75 }
  76
  77 static void lame_start_transport_stream_op_batch(
  78     grpc_call_element* elem, grpc_transport_stream_op_batch* op) {
  79   CallData* calld = static_cast<CallData*>(elem->call_data);
  80   if (op->recv_initial_metadata) {
  81     fill_metadata(elem,
  82                   op->payload->recv_initial_metadata.recv_initial_metadata);
  83   } else if (op->recv_trailing_metadata) {
  84     fill_metadata(elem,
  85                   op->payload->recv_trailing_metadata.recv_trailing_metadata);
  86   }
  87   grpc_transport_stream_op_batch_finish_with_failure(
  88       op, GRPC_ERROR_CREATE_FROM_STATIC_STRING("lame client channel"),
  89       calld->call_combiner);
  90 }
  91
  92 static void lame_get_channel_info(grpc_channel_element* elem,
  93                                   const grpc_channel_info* channel_info) {}
  94
  95 static void lame_start_transport_op(grpc_channel_element* elem,
  96                                     grpc_transport_op* op) {
  97   if (op->on_connectivity_state_change) {
  98     GPR_ASSERT(*op->connectivity_state != GRPC_CHANNEL_SHUTDOWN);
  99     *op->connectivity_state = GRPC_CHANNEL_SHUTDOWN;
 100     GRPC_CLOSURE_SCHED(op->on_connectivity_state_change, GRPC_ERROR_NONE);
 101   }
 102   if (op->send_ping.on_initiate != nullptr) {
 103     GRPC_CLOSURE_SCHED(
 104         op->send_ping.on_initiate,
 105         GRPC_ERROR_CREATE_FROM_STATIC_STRING("lame client channel"));
 106   }
 107   if (op->send_ping.on_ack != nullptr) {
 108     GRPC_CLOSURE_SCHED(
 109         op->send_ping.on_ack,
 110         GRPC_ERROR_CREATE_FROM_STATIC_STRING("lame client channel"));
 111   }
 112   GRPC_ERROR_UNREF(op->disconnect_with_error);
 113   if (op->on_consumed != nullptr) {
 114     GRPC_CLOSURE_SCHED(op->on_consumed, GRPC_ERROR_NONE);
 115   }
 116 }
 117
 118 static grpc_error* init_call_elem(grpc_call_element* elem,
 119                                   const grpc_call_element_args* args) {
 120   CallData* calld = static_cast<CallData*>(elem->call_data);
 121   calld->call_combiner = args->call_combiner;
 122   return GRPC_ERROR_NONE;
 123 }
 124
 125 static void destroy_call_elem(grpc_call_element* elem,
 126                               const grpc_call_final_info* final_info,
 127                               grpc_closure* then_schedule_closure) {
 128   GRPC_CLOSURE_SCHED(then_schedule_closure, GRPC_ERROR_NONE);
 129 }
 130
 131 static grpc_error* init_channel_elem(grpc_channel_element* elem,
 132                                      grpc_channel_element_args* args) {
 133   GPR_ASSERT(args->is_first);
 134   GPR_ASSERT(args->is_last);
 135   return GRPC_ERROR_NONE;
 136 }
 137
 138 static void destroy_channel_elem(grpc_channel_element* elem) {}
 139
 140 }  // namespace
 141
 142 }  // namespace grpc_core
 143
 144 const grpc_channel_filter grpc_lame_filter = {
 145     grpc_core::lame_start_transport_stream_op_batch,
 146     grpc_core::lame_start_transport_op,
 147     sizeof(grpc_core::CallData),
 148     grpc_core::init_call_elem,
 149     grpc_call_stack_ignore_set_pollset_or_pollset_set,
 150     grpc_core::destroy_call_elem,
 151     sizeof(grpc_core::ChannelData),
 152     grpc_core::init_channel_elem,
 153     grpc_core::destroy_channel_elem,
 154     grpc_core::lame_get_channel_info,
 155     "lame-client",
 156 };
 157
 158 #define CHANNEL_STACK_FROM_CHANNEL(c) ((grpc_channel_stack*)((c) + 1))
 159
 160 grpc_channel* grpc_lame_client_channel_create(const char* target,
 161                                               grpc_status_code error_code,
 162                                               const char* error_message) {
 163   grpc_core::ExecCtx exec_ctx;
 164   grpc_channel_element* elem;
 165   grpc_channel* channel =
 166       grpc_channel_create(target, nullptr, GRPC_CLIENT_LAME_CHANNEL, nullptr);
 167   elem = grpc_channel_stack_element(grpc_channel_get_channel_stack(channel), 0);
 168   GRPC_API_TRACE(
 169       "grpc_lame_client_channel_create(target=%s, error_code=%d, "
 170       "error_message=%s)",
 171       3, (target, (int)error_code, error_message));
 172   GPR_ASSERT(elem->filter == &grpc_lame_filter);
 173   auto chand = static_cast<grpc_core::ChannelData*>(elem->channel_data);
 174   chand->error_code = error_code;
 175   chand->error_message = error_message;
 176
 177   return channel;
 178 }