src/core/iomgr/endpoint.h

/*
 *
 * Copyright 2015, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */

#ifndef GRPC_INTERNAL_CORE_IOMGR_ENDPOINT_H
#define GRPC_INTERNAL_CORE_IOMGR_ENDPOINT_H

#include "src/core/iomgr/pollset.h"
#include <grpc/support/slice.h>
#include <grpc/support/time.h>

/* An endpoint caps a streaming channel between two communicating processes.
   Examples may be: a tcp socket, <stdin+stdout>, or some shared memory. */

typedef struct grpc_endpoint grpc_endpoint;
typedef struct grpc_endpoint_vtable grpc_endpoint_vtable;

typedef enum grpc_endpoint_cb_status {
  GRPC_ENDPOINT_CB_OK = 0, /* Call completed successfully */
  GRPC_ENDPOINT_CB_EOF, /* Call completed successfully, end of file reached */
  GRPC_ENDPOINT_CB_SHUTDOWN, /* Call interrupted by shutdown */
  GRPC_ENDPOINT_CB_ERROR     /* Call interrupted by socket error */
} grpc_endpoint_cb_status;

typedef enum grpc_endpoint_write_status {
  GRPC_ENDPOINT_WRITE_DONE,    /* completed immediately, cb won't be called */
  GRPC_ENDPOINT_WRITE_PENDING, /* cb will be called when completed */
  GRPC_ENDPOINT_WRITE_ERROR    /* write errored out, cb won't be called */
} grpc_endpoint_write_status;

typedef void (*grpc_endpoint_read_cb)(void *user_data, gpr_slice *slices,
                                      size_t nslices,
                                      grpc_endpoint_cb_status error);
typedef void (*grpc_endpoint_write_cb)(void *user_data,
                                       grpc_endpoint_cb_status error);

struct grpc_endpoint_vtable {
  void (*notify_on_read)(grpc_endpoint *ep, grpc_endpoint_read_cb cb,
                         void *user_data);
  grpc_endpoint_write_status (*write)(grpc_endpoint *ep, gpr_slice *slices,
                                      size_t nslices, grpc_endpoint_write_cb cb,
                                      void *user_data);
  void (*add_to_pollset)(grpc_endpoint *ep, grpc_pollset *pollset);
  void (*shutdown)(grpc_endpoint *ep);
  void (*destroy)(grpc_endpoint *ep);
  char *(*get_peer)(grpc_endpoint *ep);
};

/* When data is available on the connection, calls the callback with slices. */
void grpc_endpoint_notify_on_read(grpc_endpoint *ep, grpc_endpoint_read_cb cb,
                                  void *user_data);

char *grpc_endpoint_get_peer(grpc_endpoint *ep);

/* Write slices out to the socket.

   If the connection is ready for more data after the end of the call, it
   returns GRPC_ENDPOINT_WRITE_DONE.
   Otherwise it returns GRPC_ENDPOINT_WRITE_PENDING and calls cb when the
   connection is ready for more data. */
grpc_endpoint_write_status grpc_endpoint_write(grpc_endpoint *ep,
                                               gpr_slice *slices,
                                               size_t nslices,
                                               grpc_endpoint_write_cb cb,
                                               void *user_data);

/* Causes any pending read/write callbacks to run immediately with
   GRPC_ENDPOINT_CB_SHUTDOWN status */
void grpc_endpoint_shutdown(grpc_endpoint *ep);
void grpc_endpoint_destroy(grpc_endpoint *ep);

/* Add an endpoint to a pollset, so that when the pollset is polled, events from
   this endpoint are considered */
void grpc_endpoint_add_to_pollset(grpc_endpoint *ep, grpc_pollset *pollset);

struct grpc_endpoint {
  const grpc_endpoint_vtable *vtable;
};

#endif  /* GRPC_INTERNAL_CORE_IOMGR_ENDPOINT_H */