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#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_FACTORY_H
#define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_FACTORY_H

#include "src/core/ext/client_config/client_channel_factory.h"
#include "src/core/ext/client_config/lb_policy.h"
#include "src/core/lib/iomgr/resolve_address.h"

#include "src/core/lib/iomgr/exec_ctx.h"

typedef struct grpc_lb_policy_factory grpc_lb_policy_factory;
typedef struct grpc_lb_policy_factory_vtable grpc_lb_policy_factory_vtable;

struct grpc_lb_policy_factory {
  const grpc_lb_policy_factory_vtable *vtable;
};

/** A resolved address alongside any LB related information associated with it.
 * \a user_data, if not NULL, contains opaque data meant to be consumed by the
 * gRPC LB policy. Note that no all LB policies support \a user_data as input.
 * Those who don't will simply ignore it and will correspondingly return NULL in
 * their namesake pick() output argument. */
typedef struct grpc_lb_address {
  grpc_resolved_address *resolved_address;
  void *user_data;
} grpc_lb_address;

typedef struct grpc_lb_policy_args {
  grpc_lb_address *addresses;
  size_t num_addresses;
  grpc_client_channel_factory *client_channel_factory;
} grpc_lb_policy_args;

struct grpc_lb_policy_factory_vtable {
  void (*ref)(grpc_lb_policy_factory *factory);
  void (*unref)(grpc_lb_policy_factory *factory);

  /** Implementation of grpc_lb_policy_factory_create_lb_policy */
  grpc_lb_policy *(*create_lb_policy)(grpc_exec_ctx *exec_ctx,
                                      grpc_lb_policy_factory *factory,
                                      grpc_lb_policy_args *args);

  /** Name for the LB policy this factory implements */
  const char *name;
};

void grpc_lb_policy_factory_ref(grpc_lb_policy_factory *factory);
void grpc_lb_policy_factory_unref(grpc_lb_policy_factory *factory);

/** Create a lb_policy instance. */
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);

#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_FACTORY_H */