src/core/ext/filters/client_channel/client_channel_factory.h

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#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H
#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H

#include <grpc/impl/codegen/grpc_types.h>

#include "src/core/ext/filters/client_channel/subchannel.h"
#include "src/core/lib/channel/channel_stack.h"

// Channel arg key for client channel factory.
#define GRPC_ARG_CLIENT_CHANNEL_FACTORY "grpc.client_channel_factory"

typedef struct grpc_client_channel_factory grpc_client_channel_factory;
typedef struct grpc_client_channel_factory_vtable
    grpc_client_channel_factory_vtable;

typedef enum {
  GRPC_CLIENT_CHANNEL_TYPE_REGULAR, /** for the user-level regular calls */
  GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, /** for communication with a load
                                              balancing service */
} grpc_client_channel_type;

/** Constructor for new configured channels.
    Creating decorators around this type is encouraged to adapt behavior. */
struct grpc_client_channel_factory {
  const grpc_client_channel_factory_vtable *vtable;
};

struct grpc_client_channel_factory_vtable {
  void (*ref)(grpc_client_channel_factory *factory);
  void (*unref)(grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *factory);
  grpc_subchannel *(*create_subchannel)(grpc_exec_ctx *exec_ctx,
                                        grpc_client_channel_factory *factory,
                                        const grpc_subchannel_args *args);
  grpc_channel *(*create_client_channel)(grpc_exec_ctx *exec_ctx,
                                         grpc_client_channel_factory *factory,
                                         const char *target,
                                         grpc_client_channel_type type,
                                         const grpc_channel_args *args);
};

void grpc_client_channel_factory_ref(grpc_client_channel_factory *factory);
void grpc_client_channel_factory_unref(grpc_exec_ctx *exec_ctx,
                                       grpc_client_channel_factory *factory);

/** Create a new grpc_subchannel */
grpc_subchannel *grpc_client_channel_factory_create_subchannel(
    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *factory,
    const grpc_subchannel_args *args);

/** Create a new grpc_channel */
grpc_channel *grpc_client_channel_factory_create_channel(
    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *factory,
    const char *target, grpc_client_channel_type type,
    const grpc_channel_args *args);

grpc_arg grpc_client_channel_factory_create_channel_arg(
    grpc_client_channel_factory *factory);

#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H */