| /* |
| * |
| * Copyright 2016, 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 "src/core/lib/channel/channel_stack_builder.h" |
| |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/string_util.h> |
| |
| grpc_tracer_flag grpc_trace_channel_stack_builder; |
| |
| typedef struct filter_node { |
| struct filter_node *next; |
| struct filter_node *prev; |
| const grpc_channel_filter *filter; |
| grpc_post_filter_create_init_func init; |
| void *init_arg; |
| } filter_node; |
| |
| struct grpc_channel_stack_builder { |
| // sentinel nodes for filters that have been added |
| filter_node begin; |
| filter_node end; |
| // various set/get-able parameters |
| grpc_channel_args *args; |
| grpc_transport *transport; |
| char *target; |
| const char *name; |
| }; |
| |
| struct grpc_channel_stack_builder_iterator { |
| grpc_channel_stack_builder *builder; |
| filter_node *node; |
| }; |
| |
| grpc_channel_stack_builder *grpc_channel_stack_builder_create(void) { |
| grpc_channel_stack_builder *b = gpr_zalloc(sizeof(*b)); |
| |
| b->begin.filter = NULL; |
| b->end.filter = NULL; |
| b->begin.next = &b->end; |
| b->begin.prev = &b->end; |
| b->end.next = &b->begin; |
| b->end.prev = &b->begin; |
| |
| return b; |
| } |
| |
| void grpc_channel_stack_builder_set_target(grpc_channel_stack_builder *b, |
| const char *target) { |
| gpr_free(b->target); |
| b->target = gpr_strdup(target); |
| } |
| |
| const char *grpc_channel_stack_builder_get_target( |
| grpc_channel_stack_builder *b) { |
| return b->target; |
| } |
| |
| static grpc_channel_stack_builder_iterator *create_iterator_at_filter_node( |
| grpc_channel_stack_builder *builder, filter_node *node) { |
| grpc_channel_stack_builder_iterator *it = gpr_malloc(sizeof(*it)); |
| it->builder = builder; |
| it->node = node; |
| return it; |
| } |
| |
| void grpc_channel_stack_builder_iterator_destroy( |
| grpc_channel_stack_builder_iterator *it) { |
| gpr_free(it); |
| } |
| |
| grpc_channel_stack_builder_iterator * |
| grpc_channel_stack_builder_create_iterator_at_first( |
| grpc_channel_stack_builder *builder) { |
| return create_iterator_at_filter_node(builder, &builder->begin); |
| } |
| |
| grpc_channel_stack_builder_iterator * |
| grpc_channel_stack_builder_create_iterator_at_last( |
| grpc_channel_stack_builder *builder) { |
| return create_iterator_at_filter_node(builder, &builder->end); |
| } |
| |
| bool grpc_channel_stack_builder_iterator_is_end( |
| grpc_channel_stack_builder_iterator *iterator) { |
| return iterator->node == &iterator->builder->end; |
| } |
| |
| const char *grpc_channel_stack_builder_iterator_filter_name( |
| grpc_channel_stack_builder_iterator *iterator) { |
| if (iterator->node->filter == NULL) return NULL; |
| return iterator->node->filter->name; |
| } |
| |
| bool grpc_channel_stack_builder_move_next( |
| grpc_channel_stack_builder_iterator *iterator) { |
| if (iterator->node == &iterator->builder->end) return false; |
| iterator->node = iterator->node->next; |
| return true; |
| } |
| |
| bool grpc_channel_stack_builder_move_prev( |
| grpc_channel_stack_builder_iterator *iterator) { |
| if (iterator->node == &iterator->builder->begin) return false; |
| iterator->node = iterator->node->prev; |
| return true; |
| } |
| |
| bool grpc_channel_stack_builder_move_prev( |
| grpc_channel_stack_builder_iterator *iterator); |
| |
| void grpc_channel_stack_builder_set_name(grpc_channel_stack_builder *builder, |
| const char *name) { |
| GPR_ASSERT(builder->name == NULL); |
| builder->name = name; |
| } |
| |
| void grpc_channel_stack_builder_set_channel_arguments( |
| grpc_exec_ctx *exec_ctx, grpc_channel_stack_builder *builder, |
| const grpc_channel_args *args) { |
| if (builder->args != NULL) { |
| grpc_channel_args_destroy(exec_ctx, builder->args); |
| } |
| builder->args = grpc_channel_args_copy(args); |
| } |
| |
| void grpc_channel_stack_builder_set_transport( |
| grpc_channel_stack_builder *builder, grpc_transport *transport) { |
| GPR_ASSERT(builder->transport == NULL); |
| builder->transport = transport; |
| } |
| |
| grpc_transport *grpc_channel_stack_builder_get_transport( |
| grpc_channel_stack_builder *builder) { |
| return builder->transport; |
| } |
| |
| const grpc_channel_args *grpc_channel_stack_builder_get_channel_arguments( |
| grpc_channel_stack_builder *builder) { |
| return builder->args; |
| } |
| |
| bool grpc_channel_stack_builder_append_filter( |
| grpc_channel_stack_builder *builder, const grpc_channel_filter *filter, |
| grpc_post_filter_create_init_func post_init_func, void *user_data) { |
| grpc_channel_stack_builder_iterator *it = |
| grpc_channel_stack_builder_create_iterator_at_last(builder); |
| bool ok = grpc_channel_stack_builder_add_filter_before( |
| it, filter, post_init_func, user_data); |
| grpc_channel_stack_builder_iterator_destroy(it); |
| return ok; |
| } |
| |
| bool grpc_channel_stack_builder_prepend_filter( |
| grpc_channel_stack_builder *builder, const grpc_channel_filter *filter, |
| grpc_post_filter_create_init_func post_init_func, void *user_data) { |
| grpc_channel_stack_builder_iterator *it = |
| grpc_channel_stack_builder_create_iterator_at_first(builder); |
| bool ok = grpc_channel_stack_builder_add_filter_after( |
| it, filter, post_init_func, user_data); |
| grpc_channel_stack_builder_iterator_destroy(it); |
| return ok; |
| } |
| |
| static void add_after(filter_node *before, const grpc_channel_filter *filter, |
| grpc_post_filter_create_init_func post_init_func, |
| void *user_data) { |
| filter_node *new = gpr_malloc(sizeof(*new)); |
| new->next = before->next; |
| new->prev = before; |
| new->next->prev = new->prev->next = new; |
| new->filter = filter; |
| new->init = post_init_func; |
| new->init_arg = user_data; |
| } |
| |
| bool grpc_channel_stack_builder_add_filter_before( |
| grpc_channel_stack_builder_iterator *iterator, |
| const grpc_channel_filter *filter, |
| grpc_post_filter_create_init_func post_init_func, void *user_data) { |
| if (iterator->node == &iterator->builder->begin) return false; |
| add_after(iterator->node->prev, filter, post_init_func, user_data); |
| return true; |
| } |
| |
| bool grpc_channel_stack_builder_add_filter_after( |
| grpc_channel_stack_builder_iterator *iterator, |
| const grpc_channel_filter *filter, |
| grpc_post_filter_create_init_func post_init_func, void *user_data) { |
| if (iterator->node == &iterator->builder->end) return false; |
| add_after(iterator->node, filter, post_init_func, user_data); |
| return true; |
| } |
| |
| void grpc_channel_stack_builder_destroy(grpc_exec_ctx *exec_ctx, |
| grpc_channel_stack_builder *builder) { |
| filter_node *p = builder->begin.next; |
| while (p != &builder->end) { |
| filter_node *next = p->next; |
| gpr_free(p); |
| p = next; |
| } |
| if (builder->args != NULL) { |
| grpc_channel_args_destroy(exec_ctx, builder->args); |
| } |
| gpr_free(builder->target); |
| gpr_free(builder); |
| } |
| |
| grpc_error *grpc_channel_stack_builder_finish( |
| grpc_exec_ctx *exec_ctx, grpc_channel_stack_builder *builder, |
| size_t prefix_bytes, int initial_refs, grpc_iomgr_cb_func destroy, |
| void *destroy_arg, void **result) { |
| // count the number of filters |
| size_t num_filters = 0; |
| for (filter_node *p = builder->begin.next; p != &builder->end; p = p->next) { |
| num_filters++; |
| } |
| |
| // create an array of filters |
| const grpc_channel_filter **filters = |
| gpr_malloc(sizeof(*filters) * num_filters); |
| size_t i = 0; |
| for (filter_node *p = builder->begin.next; p != &builder->end; p = p->next) { |
| filters[i++] = p->filter; |
| } |
| |
| // calculate the size of the channel stack |
| size_t channel_stack_size = grpc_channel_stack_size(filters, num_filters); |
| |
| // allocate memory, with prefix_bytes followed by channel_stack_size |
| *result = gpr_zalloc(prefix_bytes + channel_stack_size); |
| // fetch a pointer to the channel stack |
| grpc_channel_stack *channel_stack = |
| (grpc_channel_stack *)((char *)(*result) + prefix_bytes); |
| // and initialize it |
| grpc_error *error = grpc_channel_stack_init( |
| exec_ctx, initial_refs, destroy, |
| destroy_arg == NULL ? *result : destroy_arg, filters, num_filters, |
| builder->args, builder->transport, builder->name, channel_stack); |
| |
| if (error != GRPC_ERROR_NONE) { |
| grpc_channel_stack_destroy(exec_ctx, channel_stack); |
| gpr_free(*result); |
| *result = NULL; |
| } else { |
| // run post-initialization functions |
| i = 0; |
| for (filter_node *p = builder->begin.next; p != &builder->end; |
| p = p->next) { |
| if (p->init != NULL) { |
| p->init(channel_stack, grpc_channel_stack_element(channel_stack, i), |
| p->init_arg); |
| } |
| i++; |
| } |
| } |
| |
| grpc_channel_stack_builder_destroy(exec_ctx, builder); |
| gpr_free((grpc_channel_filter **)filters); |
| |
| return error; |
| } |