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Diffstat (limited to 'src/core/lib/transport/service_config.c')
| -rw-r--r-- | src/core/lib/transport/service_config.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/src/core/lib/transport/service_config.c b/src/core/lib/transport/service_config.c new file mode 100644 index 0000000000..552d3ec856 --- /dev/null +++ b/src/core/lib/transport/service_config.c @@ -0,0 +1,251 @@ +// +// 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 "src/core/lib/transport/service_config.h" + +#include <string.h> + +#include <grpc/impl/codegen/grpc_types.h> +#include <grpc/support/alloc.h> +#include <grpc/support/log.h> +#include <grpc/support/string_util.h> + +#include "src/core/lib/json/json.h" +#include "src/core/lib/support/string.h" +#include "src/core/lib/transport/mdstr_hash_table.h" + +// The main purpose of the code here is to parse the service config in +// JSON form, which will look like this: +// +// { +// "loadBalancingPolicy": "string", // optional +// "methodConfig": [ // array of one or more method_config objects +// { +// "name": [ // array of one or more name objects +// { +// "service": "string", // required +// "method": "string", // optional +// } +// ], +// // remaining fields are optional. +// // see https://developers.google.com/protocol-buffers/docs/proto3#json +// // for format details. +// "waitForReady": bool, +// "timeout": "duration_string", +// "maxRequestMessageBytes": "int64_string", +// "maxResponseMessageBytes": "int64_string", +// } +// ] +// } + +struct grpc_service_config { + char* json_string; // Underlying storage for json_tree. + grpc_json* json_tree; +}; + +grpc_service_config* grpc_service_config_create(const char* json_string) { + grpc_service_config* service_config = gpr_malloc(sizeof(*service_config)); + service_config->json_string = gpr_strdup(json_string); + service_config->json_tree = + grpc_json_parse_string(service_config->json_string); + if (service_config->json_tree == NULL) { + gpr_log(GPR_INFO, "failed to parse JSON for service config"); + gpr_free(service_config->json_string); + gpr_free(service_config); + return NULL; + } + return service_config; +} + +void grpc_service_config_destroy(grpc_service_config* service_config) { + grpc_json_destroy(service_config->json_tree); + gpr_free(service_config->json_string); + gpr_free(service_config); +} + +const char* grpc_service_config_get_lb_policy_name( + const grpc_service_config* service_config) { + const grpc_json* json = service_config->json_tree; + if (json->type != GRPC_JSON_OBJECT || json->key != NULL) return NULL; + const char* lb_policy_name = NULL; + for (grpc_json* field = json->child; field != NULL; field = field->next) { + if (field->key == NULL) return NULL; + if (strcmp(field->key, "loadBalancingPolicy") == 0) { + if (lb_policy_name != NULL) return NULL; // Duplicate. + if (field->type != GRPC_JSON_STRING) return NULL; + lb_policy_name = field->value; + } + } + return lb_policy_name; +} + +// Returns the number of names specified in the method config \a json. +static size_t count_names_in_method_config_json(grpc_json* json) { + size_t num_names = 0; + for (grpc_json* field = json->child; field != NULL; field = field->next) { + if (field->key != NULL && strcmp(field->key, "name") == 0) ++num_names; + } + return num_names; +} + +// Returns a path string for the JSON name object specified by \a json. +// Returns NULL on error. Caller takes ownership of result. +static char* parse_json_method_name(grpc_json* json) { + if (json->type != GRPC_JSON_OBJECT) return NULL; + const char* service_name = NULL; + const char* method_name = NULL; + for (grpc_json* child = json->child; child != NULL; child = child->next) { + if (child->key == NULL) return NULL; + if (child->type != GRPC_JSON_STRING) return NULL; + if (strcmp(child->key, "service") == 0) { + if (service_name != NULL) return NULL; // Duplicate. + if (child->value == NULL) return NULL; + service_name = child->value; + } else if (strcmp(child->key, "method") == 0) { + if (method_name != NULL) return NULL; // Duplicate. + if (child->value == NULL) return NULL; + method_name = child->value; + } + } + if (service_name == NULL) return NULL; // Required field. + char* path; + gpr_asprintf(&path, "/%s/%s", service_name, + method_name == NULL ? "*" : method_name); + return path; +} + +// Parses the method config from \a json. Adds an entry to \a entries for +// each name found, incrementing \a idx for each entry added. +// Returns false on error. +static bool parse_json_method_config( + grpc_exec_ctx* exec_ctx, grpc_json* json, + void* (*create_value)(const grpc_json* method_config_json), + const grpc_mdstr_hash_table_vtable* vtable, + grpc_mdstr_hash_table_entry* entries, size_t* idx) { + // Construct value. + void* method_config = create_value(json); + if (method_config == NULL) return false; + // Construct list of paths. + bool success = false; + gpr_strvec paths; + gpr_strvec_init(&paths); + for (grpc_json* child = json->child; child != NULL; child = child->next) { + if (child->key == NULL) continue; + if (strcmp(child->key, "name") == 0) { + if (child->type != GRPC_JSON_ARRAY) goto done; + for (grpc_json* name = child->child; name != NULL; name = name->next) { + char* path = parse_json_method_name(name); + gpr_strvec_add(&paths, path); + } + } + } + if (paths.count == 0) goto done; // No names specified. + // Add entry for each path. + for (size_t i = 0; i < paths.count; ++i) { + entries[*idx].key = grpc_mdstr_from_string(paths.strs[i]); + entries[*idx].value = vtable->copy_value(method_config); + entries[*idx].vtable = vtable; + ++*idx; + } + success = true; +done: + vtable->destroy_value(exec_ctx, method_config); + gpr_strvec_destroy(&paths); + return success; +} + +grpc_mdstr_hash_table* grpc_service_config_create_method_config_table( + grpc_exec_ctx* exec_ctx, const grpc_service_config* service_config, + void* (*create_value)(const grpc_json* method_config_json), + const grpc_mdstr_hash_table_vtable* vtable) { + const grpc_json* json = service_config->json_tree; + // Traverse parsed JSON tree. + if (json->type != GRPC_JSON_OBJECT || json->key != NULL) return NULL; + size_t num_entries = 0; + grpc_mdstr_hash_table_entry* entries = NULL; + for (grpc_json* field = json->child; field != NULL; field = field->next) { + if (field->key == NULL) return NULL; + if (strcmp(field->key, "methodConfig") == 0) { + if (entries != NULL) return NULL; // Duplicate. + if (field->type != GRPC_JSON_ARRAY) return NULL; + // Find number of entries. + for (grpc_json* method = field->child; method != NULL; + method = method->next) { + num_entries += count_names_in_method_config_json(method); + } + // Populate method config table entries. + entries = gpr_malloc(num_entries * sizeof(grpc_mdstr_hash_table_entry)); + size_t idx = 0; + for (grpc_json* method = field->child; method != NULL; + method = method->next) { + if (!parse_json_method_config(exec_ctx, method, create_value, vtable, + entries, &idx)) { + return NULL; + } + } + GPR_ASSERT(idx == num_entries); + } + } + // Instantiate method config table. + grpc_mdstr_hash_table* method_config_table = NULL; + if (entries != NULL) { + method_config_table = grpc_mdstr_hash_table_create(num_entries, entries); + // Clean up. + for (size_t i = 0; i < num_entries; ++i) { + GRPC_MDSTR_UNREF(exec_ctx, entries[i].key); + vtable->destroy_value(exec_ctx, entries[i].value); + } + gpr_free(entries); + } + return method_config_table; +} + +void* grpc_method_config_table_get(grpc_exec_ctx* exec_ctx, + const grpc_mdstr_hash_table* table, + const grpc_mdstr* path) { + void* value = grpc_mdstr_hash_table_get(table, path); + // If we didn't find a match for the path, try looking for a wildcard + // entry (i.e., change "/service/method" to "/service/*"). + if (value == NULL) { + const char* path_str = grpc_mdstr_as_c_string(path); + const char* sep = strrchr(path_str, '/') + 1; + const size_t len = (size_t)(sep - path_str); + char* buf = gpr_malloc(len + 2); // '*' and NUL + memcpy(buf, path_str, len); + buf[len] = '*'; + buf[len + 1] = '\0'; + grpc_mdstr* wildcard_path = grpc_mdstr_from_string(buf); + gpr_free(buf); + value = grpc_mdstr_hash_table_get(table, wildcard_path); + GRPC_MDSTR_UNREF(exec_ctx, wildcard_path); + } + return value; +} |