src/core/surface/channel_create.c

/*
 *
 * 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.
 *     * Neither the name of Google Inc. nor the names of its
 * 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
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <grpc/grpc.h>

#include <stdlib.h>
#include <string.h>

#include <grpc/support/alloc.h>

#include "src/core/census/grpc_filter.h"
#include "src/core/channel/channel_args.h"
#include "src/core/channel/client_channel.h"
#include "src/core/channel/compress_filter.h"
#include "src/core/channel/http_client_filter.h"
#include "src/core/client_config/resolver_registry.h"
#include "src/core/iomgr/tcp_client.h"
#include "src/core/surface/channel.h"
#include "src/core/transport/chttp2_transport.h"

typedef struct
{
  grpc_connector base;
  gpr_refcount refs;

  grpc_closure *notify;
  grpc_connect_in_args args;
  grpc_connect_out_args *result;

  grpc_endpoint *tcp;

  grpc_mdctx *mdctx;

  grpc_closure connected;
} connector;

static void
connector_ref (grpc_connector * con)
{
  connector *c = (connector *) con;
  gpr_ref (&c->refs);
}

static void
connector_unref (grpc_exec_ctx * exec_ctx, grpc_connector * con)
{
  connector *c = (connector *) con;
  if (gpr_unref (&c->refs))
    {
      grpc_mdctx_unref (c->mdctx);
      gpr_free (c);
    }
}

static void
connected (grpc_exec_ctx * exec_ctx, void *arg, int success)
{
  connector *c = arg;
  grpc_closure *notify;
  grpc_endpoint *tcp = c->tcp;
  if (tcp != NULL)
    {
      c->result->transport = grpc_create_chttp2_transport (exec_ctx, c->args.channel_args, tcp, c->mdctx, 1);
      grpc_chttp2_transport_start_reading (exec_ctx, c->result->transport, NULL, 0);
      GPR_ASSERT (c->result->transport);
      c->result->filters = gpr_malloc (sizeof (grpc_channel_filter *));
      c->result->filters[0] = &grpc_http_client_filter;
      c->result->num_filters = 1;
    }
  else
    {
      memset (c->result, 0, sizeof (*c->result));
    }
  notify = c->notify;
  c->notify = NULL;
  notify->cb (exec_ctx, notify->cb_arg, 1);
}

static void
connector_shutdown (grpc_exec_ctx * exec_ctx, grpc_connector * con)
{
}

static void
connector_connect (grpc_exec_ctx * exec_ctx, grpc_connector * con, const grpc_connect_in_args * args, grpc_connect_out_args * result, grpc_closure * notify)
{
  connector *c = (connector *) con;
  GPR_ASSERT (c->notify == NULL);
  GPR_ASSERT (notify->cb);
  c->notify = notify;
  c->args = *args;
  c->result = result;
  c->tcp = NULL;
  grpc_closure_init (&c->connected, connected, c);
  grpc_tcp_client_connect (exec_ctx, &c->connected, &c->tcp, args->interested_parties, args->addr, args->addr_len, args->deadline);
}

static const grpc_connector_vtable connector_vtable = {
  connector_ref, connector_unref, connector_shutdown, connector_connect
};

typedef struct
{
  grpc_subchannel_factory base;
  gpr_refcount refs;
  grpc_mdctx *mdctx;
  grpc_channel_args *merge_args;
  grpc_channel *master;
} subchannel_factory;

static void
subchannel_factory_ref (grpc_subchannel_factory * scf)
{
  subchannel_factory *f = (subchannel_factory *) scf;
  gpr_ref (&f->refs);
}

static void
subchannel_factory_unref (grpc_exec_ctx * exec_ctx, grpc_subchannel_factory * scf)
{
  subchannel_factory *f = (subchannel_factory *) scf;
  if (gpr_unref (&f->refs))
    {
      GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, f->master, "subchannel_factory");
      grpc_channel_args_destroy (f->merge_args);
      grpc_mdctx_unref (f->mdctx);
      gpr_free (f);
    }
}

static grpc_subchannel *
subchannel_factory_create_subchannel (grpc_exec_ctx * exec_ctx, grpc_subchannel_factory * scf, grpc_subchannel_args * args)
{
  subchannel_factory *f = (subchannel_factory *) scf;
  connector *c = gpr_malloc (sizeof (*c));
  grpc_channel_args *final_args = grpc_channel_args_merge (args->args, f->merge_args);
  grpc_subchannel *s;
  memset (c, 0, sizeof (*c));
  c->base.vtable = &connector_vtable;
  c->mdctx = f->mdctx;
  grpc_mdctx_ref (c->mdctx);
  gpr_ref_init (&c->refs, 1);
  args->mdctx = f->mdctx;
  args->args = final_args;
  args->master = f->master;
  s = grpc_subchannel_create (&c->base, args);
  grpc_connector_unref (exec_ctx, &c->base);
  grpc_channel_args_destroy (final_args);
  return s;
}

static const grpc_subchannel_factory_vtable subchannel_factory_vtable = {
  subchannel_factory_ref, subchannel_factory_unref,
  subchannel_factory_create_subchannel
};

/* Create a client channel:
   Asynchronously: - resolve target
                   - connect to it (trying alternatives as presented)
                   - perform handshakes */
grpc_channel *
grpc_insecure_channel_create (const char *target, const grpc_channel_args * args, void *reserved)
{
  grpc_channel *channel = NULL;
#define MAX_FILTERS 3
  const grpc_channel_filter *filters[MAX_FILTERS];
  grpc_resolver *resolver;
  subchannel_factory *f;
  grpc_mdctx *mdctx = grpc_mdctx_create ();
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  size_t n = 0;
  GPR_ASSERT (!reserved);
  if (grpc_channel_args_is_census_enabled (args))
    {
      filters[n++] = &grpc_client_census_filter;
    }
  filters[n++] = &grpc_compress_filter;
  filters[n++] = &grpc_client_channel_filter;
  GPR_ASSERT (n <= MAX_FILTERS);

  channel = grpc_channel_create_from_filters (target, filters, n, args, mdctx, 1, &closure_list);

  f = gpr_malloc (sizeof (*f));
  f->base.vtable = &subchannel_factory_vtable;
  gpr_ref_init (&f->refs, 1);
  grpc_mdctx_ref (mdctx);
  f->mdctx = mdctx;
  f->merge_args = grpc_channel_args_copy (args);
  f->master = channel;
  GRPC_CHANNEL_INTERNAL_REF (f->master, "subchannel_factory");
  resolver = grpc_resolver_create (target, &f->base);
  if (!resolver)
    {
      return NULL;
    }

  grpc_client_channel_set_resolver (grpc_channel_get_channel_stack (channel), resolver, &closure_list);
  GRPC_RESOLVER_UNREF (resolver, "create", &closure_list);
  grpc_subchannel_factory_unref (&f->base, &closure_list);

  grpc_closure_list_run (&closure_list);

  return channel;
}