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/*
*
* Copyright 2014, 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 "src/core/channel/census_filter.h"
#include "src/core/channel/channel_args.h"
#include "src/core/channel/client_channel.h"
#include "src/core/channel/client_setup.h"
#include "src/core/channel/connected_channel.h"
#include "src/core/channel/http_client_filter.h"
#include "src/core/channel/http_filter.h"
#include "src/core/endpoint/resolve_address.h"
#include "src/core/endpoint/tcp.h"
#include "src/core/endpoint/tcp_client.h"
#include "src/core/surface/channel.h"
#include "src/core/surface/client.h"
#include "src/core/surface/surface_em.h"
#include "src/core/transport/chttp2_transport.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string.h>
#include <grpc/support/sync.h>
#include <grpc/support/useful.h>
typedef struct setup setup;
/* A single setup request (started via initiate) */
typedef struct {
grpc_client_setup_request *cs_request;
setup *setup;
/* Resolved addresses, or null if resolution not yet completed */
grpc_resolved_addresses *resolved;
/* which address in resolved should we pick for the next connection attempt */
size_t resolved_index;
} request;
/* Global setup logic (may be running many simultaneous setup requests, but
with only one 'active' */
struct setup {
const char *target;
grpc_transport_setup_callback setup_callback;
void *setup_user_data;
grpc_em *em;
};
static int maybe_try_next_resolved(request *r);
static void done(request *r, int was_successful) {
grpc_client_setup_request_finish(r->cs_request, was_successful);
if (r->resolved) {
grpc_resolved_addresses_destroy(r->resolved);
}
gpr_free(r);
}
/* connection callback: tcp is either valid, or null on error */
static void on_connect(void *rp, grpc_endpoint *tcp) {
request *r = rp;
if (!grpc_client_setup_request_should_continue(r->cs_request)) {
if (tcp) {
grpc_endpoint_shutdown(tcp);
grpc_endpoint_destroy(tcp);
}
done(r, 0);
return;
}
if (!tcp) {
if (!maybe_try_next_resolved(r)) {
done(r, 0);
return;
} else {
return;
}
} else {
grpc_create_chttp2_transport(
r->setup->setup_callback, r->setup->setup_user_data,
grpc_client_setup_get_channel_args(r->cs_request), tcp, NULL, 0,
grpc_client_setup_get_mdctx(r->cs_request), 1);
done(r, 1);
return;
}
}
/* attempt to connect to the next available resolved address */
static int maybe_try_next_resolved(request *r) {
grpc_resolved_address *addr;
if (!r->resolved) return 0;
if (r->resolved_index == r->resolved->naddrs) return 0;
addr = &r->resolved->addrs[r->resolved_index++];
grpc_tcp_client_connect(on_connect, r, r->setup->em,
(struct sockaddr *)&addr->addr, addr->len,
grpc_client_setup_request_deadline(r->cs_request));
return 1;
}
/* callback for when our target address has been resolved */
static void on_resolved(void *rp, grpc_resolved_addresses *resolved) {
request *r = rp;
/* if we're not still the active request, abort */
if (!grpc_client_setup_request_should_continue(r->cs_request)) {
if (resolved) {
grpc_resolved_addresses_destroy(resolved);
}
done(r, 0);
return;
}
if (!resolved) {
done(r, 0);
return;
} else {
r->resolved = resolved;
r->resolved_index = 0;
if (!maybe_try_next_resolved(r)) {
done(r, 0);
}
}
}
static void initiate_setup(void *sp, grpc_client_setup_request *cs_request) {
request *r = gpr_malloc(sizeof(request));
r->setup = sp;
r->cs_request = cs_request;
r->resolved = NULL;
r->resolved_index = 0;
/* TODO(klempner): Make grpc_resolve_address respect deadline */
grpc_resolve_address(r->setup->target, "http", on_resolved, r);
}
static void done_setup(void *sp) {
setup *s = sp;
gpr_free((void *)s->target);
gpr_free(s);
}
static grpc_transport_setup_result complete_setup(void *channel_stack,
grpc_transport *transport,
grpc_mdctx *mdctx) {
static grpc_channel_filter const *extra_filters[] = {&grpc_http_client_filter,
&grpc_http_filter};
return grpc_client_channel_transport_setup_complete(
channel_stack, transport, extra_filters, GPR_ARRAY_SIZE(extra_filters),
mdctx);
}
/* Create a client channel:
Asynchronously: - resolve target
- connect to it (trying alternatives as presented)
- perform handshakes */
grpc_channel *grpc_channel_create(const char *target,
const grpc_channel_args *args) {
setup *s = gpr_malloc(sizeof(setup));
grpc_mdctx *mdctx = grpc_mdctx_create();
grpc_channel *channel = NULL;
#define MAX_FILTERS 3
const grpc_channel_filter *filters[MAX_FILTERS];
int n = 0;
filters[n++] = &grpc_client_surface_filter;
if (grpc_channel_args_is_census_enabled(args)) {
filters[n++] = &grpc_client_census_filter;
}
filters[n++] = &grpc_client_channel_filter;
GPR_ASSERT(n <= MAX_FILTERS);
channel = grpc_channel_create_from_filters(filters, n, args, mdctx, 1);
s->target = gpr_strdup(target);
s->em = grpc_surface_em();
s->setup_callback = complete_setup;
s->setup_user_data = grpc_channel_get_channel_stack(channel);
grpc_client_setup_create_and_attach(grpc_channel_get_channel_stack(channel),
args, mdctx, initiate_setup, done_setup,
s, s->em);
return channel;
}
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