Decouple filter selection from channel construction
Allow plugins to extend the set of filters used by gRPC core:
- plugins at construction time can register against the 'channel_init' system to be allowed to mutate a new channel_stack_builder type
- channel_stack_builder provides a central and rather dynamic place to construct the list of filters required by a channel stack
- ultimately we construct the channel stack in the fashion we always have
This is also a prerequisite step to allowing filters to be implemented from wrapped languages.
diff --git a/src/core/surface/server.c b/src/core/surface/server.c
index fb5e0d4..c88f769 100644
--- a/src/core/surface/server.c
+++ b/src/core/surface/server.c
@@ -42,7 +42,6 @@
#include <grpc/support/string_util.h>
#include <grpc/support/useful.h>
-#include "src/core/census/grpc_filter.h"
#include "src/core/channel/channel_args.h"
#include "src/core/channel/connected_channel.h"
#include "src/core/iomgr/iomgr.h"
@@ -182,8 +181,6 @@
} channel_broadcaster;
struct grpc_server {
- size_t channel_filter_count;
- grpc_channel_filter const **channel_filters;
grpc_channel_args *channel_args;
grpc_completion_queue **cqs;
@@ -355,7 +352,6 @@
grpc_channel_args_destroy(server->channel_args);
gpr_mu_destroy(&server->mu_global);
gpr_mu_destroy(&server->mu_call);
- gpr_free((void *)server->channel_filters);
while ((rm = server->registered_methods) != NULL) {
server->registered_methods = rm->next;
request_matcher_destroy(&rm->request_matcher);
@@ -750,7 +746,7 @@
}
}
-static const grpc_channel_filter server_surface_filter = {
+const grpc_channel_filter grpc_server_top_filter = {
server_start_transport_stream_op, grpc_channel_next_op, sizeof(call_data),
init_call_elem, grpc_call_stack_ignore_set_pollset, destroy_call_elem,
sizeof(channel_data), init_channel_elem, destroy_channel_elem,
@@ -776,11 +772,10 @@
server->cqs[n] = cq;
}
-grpc_server *grpc_server_create_from_filters(
- const grpc_channel_filter **filters, size_t filter_count,
- const grpc_channel_args *args) {
+grpc_server *grpc_server_create(const grpc_channel_args *args, void *reserved) {
size_t i;
- int census_enabled = grpc_channel_args_is_census_enabled(args);
+
+ GRPC_API_TRACE("grpc_server_create(%p, %p)", 2, (args, reserved));
grpc_server *server = gpr_malloc(sizeof(grpc_server));
@@ -808,23 +803,6 @@
server->requested_calls = gpr_malloc(server->max_requested_calls *
sizeof(*server->requested_calls));
- /* Server filter stack is:
-
- server_surface_filter - for making surface API calls
- grpc_server_census_filter (optional) - for stats collection and tracing
- {passed in filter stack}
- grpc_connected_channel_filter - for interfacing with transports */
- server->channel_filter_count = filter_count + 1u + (census_enabled ? 1u : 0u);
- server->channel_filters =
- gpr_malloc(server->channel_filter_count * sizeof(grpc_channel_filter *));
- server->channel_filters[0] = &server_surface_filter;
- if (census_enabled) {
- server->channel_filters[1] = &grpc_server_census_filter;
- }
- for (i = 0; i < filter_count; i++) {
- server->channel_filters[i + 1u + (census_enabled ? 1u : 0u)] = filters[i];
- }
-
server->channel_args = grpc_channel_args_copy(args);
return server;
@@ -885,12 +863,7 @@
void grpc_server_setup_transport(grpc_exec_ctx *exec_ctx, grpc_server *s,
grpc_transport *transport,
- grpc_channel_filter const **extra_filters,
- size_t num_extra_filters,
const grpc_channel_args *args) {
- size_t num_filters = s->channel_filter_count + num_extra_filters + 1;
- grpc_channel_filter const **filters =
- gpr_malloc(sizeof(grpc_channel_filter *) * num_filters);
size_t i;
size_t num_registered_methods;
size_t alloc;
@@ -906,22 +879,14 @@
uint32_t max_probes = 0;
grpc_transport_op op;
- for (i = 0; i < s->channel_filter_count; i++) {
- filters[i] = s->channel_filters[i];
- }
- for (; i < s->channel_filter_count + num_extra_filters; i++) {
- filters[i] = extra_filters[i - s->channel_filter_count];
- }
- filters[i] = &grpc_connected_channel_filter;
-
for (i = 0; i < s->cq_count; i++) {
memset(&op, 0, sizeof(op));
op.bind_pollset = grpc_cq_pollset(s->cqs[i]);
grpc_transport_perform_op(exec_ctx, transport, &op);
}
- channel = grpc_channel_create_from_filters(exec_ctx, NULL, filters,
- num_filters, args, 0);
+ channel =
+ grpc_channel_create(exec_ctx, NULL, args, GRPC_SERVER_CHANNEL, transport);
chand = (channel_data *)grpc_channel_stack_element(
grpc_channel_get_channel_stack(channel), 0)->channel_data;
chand->server = s;
@@ -958,17 +923,12 @@
chand->registered_method_max_probes = max_probes;
}
- grpc_connected_channel_bind_transport(grpc_channel_get_channel_stack(channel),
- transport);
-
gpr_mu_lock(&s->mu_global);
chand->next = &s->root_channel_data;
chand->prev = chand->next->prev;
chand->next->prev = chand->prev->next = chand;
gpr_mu_unlock(&s->mu_global);
- gpr_free((void *)filters);
-
GRPC_CHANNEL_INTERNAL_REF(channel, "connectivity");
memset(&op, 0, sizeof(op));
op.set_accept_stream = accept_stream;