text: /*
   *
   * Copyright 2015 gRPC authors.
   *
   * Licensed 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 <string.h>
  
  #include <grpc/support/alloc.h>
  #include <grpc/support/string_util.h>
  
  #include "src/core/lib/channel/channel_args.h"
  
  #include "src/core/ext/filters/client_channel/lb_policy_factory.h"
  #include "src/core/ext/filters/client_channel/parse_address.h"
  
  grpc_lb_addresses* grpc_lb_addresses_create(
      size_t num_addresses, const grpc_lb_user_data_vtable* user_data_vtable) {
    grpc_lb_addresses* addresses =
        (grpc_lb_addresses*)gpr_zalloc(sizeof(grpc_lb_addresses));
    addresses->num_addresses = num_addresses;
    addresses->user_data_vtable = user_data_vtable;
    const size_t addresses_size = sizeof(grpc_lb_address) * num_addresses;
    addresses->addresses = (grpc_lb_address*)gpr_zalloc(addresses_size);
    return addresses;
  }
  
  grpc_lb_addresses* grpc_lb_addresses_copy(const grpc_lb_addresses* addresses) {
    grpc_lb_addresses* new_addresses = grpc_lb_addresses_create(
        addresses->num_addresses, addresses->user_data_vtable);
    memcpy(new_addresses->addresses, addresses->addresses,
           sizeof(grpc_lb_address) * addresses->num_addresses);
    for (size_t i = 0; i < addresses->num_addresses; ++i) {
      if (new_addresses->addresses[i].balancer_name != nullptr) {
        new_addresses->addresses[i].balancer_name =
            gpr_strdup(new_addresses->addresses[i].balancer_name);
      }
      if (new_addresses->addresses[i].user_data != nullptr) {
        new_addresses->addresses[i].user_data = addresses->user_data_vtable->copy(
            new_addresses->addresses[i].user_data);
      }
    }
    return new_addresses;
  }
  
  void grpc_lb_addresses_set_address(grpc_lb_addresses* addresses, size_t index,
                                     const void* address, size_t address_len,
                                     bool is_balancer, const char* balancer_name,
                                     void* user_data) {
    GPR_ASSERT(index < addresses->num_addresses);
    if (user_data != nullptr) GPR_ASSERT(addresses->user_data_vtable != nullptr);
    grpc_lb_address* target = &addresses->addresses[index];
    memcpy(target->address.addr, address, address_len);
    target->address.len = address_len;
    target->is_balancer = is_balancer;
    target->balancer_name = gpr_strdup(balancer_name);
    target->user_data = user_data;
  }
  
  bool grpc_lb_addresses_set_address_from_uri(grpc_lb_addresses* addresses,
                                              size_t index, const grpc_uri* uri,
                                              bool is_balancer,
                                              const char* balancer_name,
                                              void* user_data) {
    grpc_resolved_address address;
    if (!grpc_parse_uri(uri, &address)) return false;
    grpc_lb_addresses_set_address(addresses, index, address.addr, address.len,
                                  is_balancer, balancer_name, user_data);
    return true;
  }
  
  int grpc_lb_addresses_cmp(const grpc_lb_addresses* addresses1,
                            const grpc_lb_addresses* addresses2) {
    if (addresses1->num_addresses > addresses2->num_addresses) return 1;
    if (addresses1->num_addresses < addresses2->num_addresses) return -1;
    if (addresses1->user_data_vtable > addresses2->user_data_vtable) return 1;
    if (addresses1->user_data_vtable < addresses2->user_data_vtable) return -1;
    for (size_t i = 0; i < addresses1->num_addresses; ++i) {
      const grpc_lb_address* target1 = &addresses1->addresses[i];
      const grpc_lb_address* target2 = &addresses2->addresses[i];
      if (target1->address.len > target2->address.len) return 1;
      if (target1->address.len < target2->address.len) return -1;
      int retval = memcmp(target1->address.addr, target2->address.addr,
                          target1->address.len);
      if (retval != 0) return retval;
      if (target1->is_balancer > target2->is_balancer) return 1;
      if (target1->is_balancer < target2->is_balancer) return -1;
      const char* balancer_name1 =
          target1->balancer_name != nullptr ? target1->balancer_name : "";
      const char* balancer_name2 =
          target2->balancer_name != nullptr ? target2->balancer_name : "";
      retval = strcmp(balancer_name1, balancer_name2);
      if (retval != 0) return retval;
      if (addresses1->user_data_vtable != nullptr) {
        retval = addresses1->user_data_vtable->cmp(target1->user_data,
                                                   target2->user_data);
        if (retval != 0) return retval;
      }
    }
    return 0;
  }
  
  void grpc_lb_addresses_destroy(grpc_exec_ctx* exec_ctx,
                                 grpc_lb_addresses* addresses) {
    for (size_t i = 0; i < addresses->num_addresses; ++i) {
      gpr_free(addresses->addresses[i].balancer_name);
      if (addresses->addresses[i].user_data != nullptr) {
        addresses->user_data_vtable->destroy(exec_ctx,
                                             addresses->addresses[i].user_data);
      }
    }
    gpr_free(addresses->addresses);
    gpr_free(addresses);
  }
  
  static void* lb_addresses_copy(void* addresses) {
    return grpc_lb_addresses_copy((grpc_lb_addresses*)addresses);
  }
  static void lb_addresses_destroy(grpc_exec_ctx* exec_ctx, void* addresses) {
    grpc_lb_addresses_destroy(exec_ctx, (grpc_lb_addresses*)addresses);
  }
  static int lb_addresses_cmp(void* addresses1, void* addresses2) {
    return grpc_lb_addresses_cmp((grpc_lb_addresses*)addresses1,
                                 (grpc_lb_addresses*)addresses2);
  }
  static const grpc_arg_pointer_vtable lb_addresses_arg_vtable = {
      lb_addresses_copy, lb_addresses_destroy, lb_addresses_cmp};
  
  grpc_arg grpc_lb_addresses_create_channel_arg(
      const grpc_lb_addresses* addresses) {
    return grpc_channel_arg_pointer_create(
        (char*)GRPC_ARG_LB_ADDRESSES, (void*)addresses, &lb_addresses_arg_vtable);
  }
  
  grpc_lb_addresses* grpc_lb_addresses_find_channel_arg(
      const grpc_channel_args* channel_args) {
    const grpc_arg* lb_addresses_arg =
        grpc_channel_args_find(channel_args, GRPC_ARG_LB_ADDRESSES);
    if (lb_addresses_arg == nullptr || lb_addresses_arg->type != GRPC_ARG_POINTER)
      return nullptr;
    return (grpc_lb_addresses*)lb_addresses_arg->value.pointer.p;
  }
  
  void grpc_lb_policy_factory_ref(grpc_lb_policy_factory* factory) {
    factory->vtable->ref(factory);
  }
  
  void grpc_lb_policy_factory_unref(grpc_lb_policy_factory* factory) {
    factory->vtable->unref(factory);
  }
  
  grpc_lb_policy* grpc_lb_policy_factory_create_lb_policy(
      grpc_exec_ctx* exec_ctx, grpc_lb_policy_factory* factory,
      grpc_lb_policy_args* args) {
    if (factory == nullptr) return nullptr;
    return factory->vtable->create_lb_policy(exec_ctx, factory, args);
  }
  