Separate out message size parsing into a different file to avoid build issues

BUILD

@@ -1099,6 +1099,7 @@ grpc_cc_library(
         "src/core/ext/filters/client_channel/service_config.cc",
         "src/core/ext/filters/client_channel/subchannel.cc",
         "src/core/ext/filters/client_channel/subchannel_pool_interface.cc",
+        "src/core/ext/filters/message_size/message_size_parser.cc",
     ],
     hdrs = [
         "src/core/ext/filters/client_channel/backup_poller.h",
@@ -1128,6 +1129,7 @@ grpc_cc_library(
         "src/core/ext/filters/client_channel/service_config.h",
         "src/core/ext/filters/client_channel/subchannel.h",
         "src/core/ext/filters/client_channel/subchannel_pool_interface.h",
+        "src/core/ext/filters/message_size/message_size_parser.h",
     ],
     language = "c++",
     deps = [

BUILD.gn

@@ -354,6 +354,8 @@ config("grpc_config") {
         "src/core/ext/filters/max_age/max_age_filter.h",
         "src/core/ext/filters/message_size/message_size_filter.cc",
         "src/core/ext/filters/message_size/message_size_filter.h",
+        "src/core/ext/filters/message_size/message_size_parser.cc",
+        "src/core/ext/filters/message_size/message_size_parser.h",
         "src/core/ext/filters/workarounds/workaround_cronet_compression_filter.cc",
         "src/core/ext/filters/workarounds/workaround_cronet_compression_filter.h",
         "src/core/ext/filters/workarounds/workaround_utils.cc",

CMakeLists.txt

@@ -1252,6 +1252,7 @@ add_library(grpc
   src/core/ext/filters/client_channel/service_config.cc
   src/core/ext/filters/client_channel/subchannel.cc
   src/core/ext/filters/client_channel/subchannel_pool_interface.cc
+  src/core/ext/filters/message_size/message_size_parser.cc
   src/core/ext/filters/deadline/deadline_filter.cc
   src/core/ext/filters/client_channel/health/health.pb.c
   src/core/tsi/fake_transport_security.cc
@@ -1608,6 +1609,7 @@ add_library(grpc_cronet
   src/core/ext/filters/client_channel/service_config.cc
   src/core/ext/filters/client_channel/subchannel.cc
   src/core/ext/filters/client_channel/subchannel_pool_interface.cc
+  src/core/ext/filters/message_size/message_size_parser.cc
   src/core/ext/filters/deadline/deadline_filter.cc
   src/core/ext/filters/client_channel/health/health.pb.c
   third_party/nanopb/pb_common.c
@@ -1989,6 +1991,7 @@ add_library(grpc_test_util
   src/core/ext/filters/client_channel/service_config.cc
   src/core/ext/filters/client_channel/subchannel.cc
   src/core/ext/filters/client_channel/subchannel_pool_interface.cc
+  src/core/ext/filters/message_size/message_size_parser.cc
   src/core/ext/filters/deadline/deadline_filter.cc
   src/core/ext/filters/client_channel/health/health.pb.c
   third_party/nanopb/pb_common.c
@@ -2315,6 +2318,7 @@ add_library(grpc_test_util_unsecure
   src/core/ext/filters/client_channel/service_config.cc
   src/core/ext/filters/client_channel/subchannel.cc
   src/core/ext/filters/client_channel/subchannel_pool_interface.cc
+  src/core/ext/filters/message_size/message_size_parser.cc
   src/core/ext/filters/deadline/deadline_filter.cc
   src/core/ext/filters/client_channel/health/health.pb.c
   third_party/nanopb/pb_common.c
@@ -2652,6 +2656,7 @@ add_library(grpc_unsecure
   src/core/ext/filters/client_channel/service_config.cc
   src/core/ext/filters/client_channel/subchannel.cc
   src/core/ext/filters/client_channel/subchannel_pool_interface.cc
+  src/core/ext/filters/message_size/message_size_parser.cc
   src/core/ext/filters/deadline/deadline_filter.cc
   src/core/ext/filters/client_channel/health/health.pb.c
   third_party/nanopb/pb_common.c
@@ -3523,6 +3528,7 @@ add_library(grpc++_cronet
   src/core/ext/filters/client_channel/service_config.cc
   src/core/ext/filters/client_channel/subchannel.cc
   src/core/ext/filters/client_channel/subchannel_pool_interface.cc
+  src/core/ext/filters/message_size/message_size_parser.cc
   src/core/ext/filters/deadline/deadline_filter.cc
   src/core/ext/transport/chttp2/server/insecure/server_chttp2.cc
   src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.cc

Makefile

@@ -3708,6 +3708,7 @@ LIBGRPC_SRC = \
     src/core/ext/filters/client_channel/service_config.cc \
     src/core/ext/filters/client_channel/subchannel.cc \
     src/core/ext/filters/client_channel/subchannel_pool_interface.cc \
+    src/core/ext/filters/message_size/message_size_parser.cc \
     src/core/ext/filters/deadline/deadline_filter.cc \
     src/core/ext/filters/client_channel/health/health.pb.c \
     src/core/tsi/fake_transport_security.cc \
@@ -4058,6 +4059,7 @@ LIBGRPC_CRONET_SRC = \
     src/core/ext/filters/client_channel/service_config.cc \
     src/core/ext/filters/client_channel/subchannel.cc \
     src/core/ext/filters/client_channel/subchannel_pool_interface.cc \
+    src/core/ext/filters/message_size/message_size_parser.cc \
     src/core/ext/filters/deadline/deadline_filter.cc \
     src/core/ext/filters/client_channel/health/health.pb.c \
     third_party/nanopb/pb_common.c \
@@ -4432,6 +4434,7 @@ LIBGRPC_TEST_UTIL_SRC = \
     src/core/ext/filters/client_channel/service_config.cc \
     src/core/ext/filters/client_channel/subchannel.cc \
     src/core/ext/filters/client_channel/subchannel_pool_interface.cc \
+    src/core/ext/filters/message_size/message_size_parser.cc \
     src/core/ext/filters/deadline/deadline_filter.cc \
     src/core/ext/filters/client_channel/health/health.pb.c \
     third_party/nanopb/pb_common.c \
@@ -4745,6 +4748,7 @@ LIBGRPC_TEST_UTIL_UNSECURE_SRC = \
     src/core/ext/filters/client_channel/service_config.cc \
     src/core/ext/filters/client_channel/subchannel.cc \
     src/core/ext/filters/client_channel/subchannel_pool_interface.cc \
+    src/core/ext/filters/message_size/message_size_parser.cc \
     src/core/ext/filters/deadline/deadline_filter.cc \
     src/core/ext/filters/client_channel/health/health.pb.c \
     third_party/nanopb/pb_common.c \
@@ -5056,6 +5060,7 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/ext/filters/client_channel/service_config.cc \
     src/core/ext/filters/client_channel/subchannel.cc \
     src/core/ext/filters/client_channel/subchannel_pool_interface.cc \
+    src/core/ext/filters/message_size/message_size_parser.cc \
     src/core/ext/filters/deadline/deadline_filter.cc \
     src/core/ext/filters/client_channel/health/health.pb.c \
     third_party/nanopb/pb_common.c \
@@ -5903,6 +5908,7 @@ LIBGRPC++_CRONET_SRC = \
     src/core/ext/filters/client_channel/service_config.cc \
     src/core/ext/filters/client_channel/subchannel.cc \
     src/core/ext/filters/client_channel/subchannel_pool_interface.cc \
+    src/core/ext/filters/message_size/message_size_parser.cc \
     src/core/ext/filters/deadline/deadline_filter.cc \
     src/core/ext/transport/chttp2/server/insecure/server_chttp2.cc \
     src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.cc \

build.yaml

@@ -596,6 +596,7 @@ filegroups:
   - src/core/ext/filters/client_channel/service_config.h
   - src/core/ext/filters/client_channel/subchannel.h
   - src/core/ext/filters/client_channel/subchannel_pool_interface.h
+  - src/core/ext/filters/message_size/message_size_parser.h
   src:
   - src/core/ext/filters/client_channel/backup_poller.cc
   - src/core/ext/filters/client_channel/channel_connectivity.cc
@@ -624,6 +625,7 @@ filegroups:
   - src/core/ext/filters/client_channel/service_config.cc
   - src/core/ext/filters/client_channel/subchannel.cc
   - src/core/ext/filters/client_channel/subchannel_pool_interface.cc
+  - src/core/ext/filters/message_size/message_size_parser.cc
   plugin: grpc_client_channel
   uses:
   - grpc_base

config.m4

@@ -366,6 +366,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/ext/filters/client_channel/service_config.cc \
     src/core/ext/filters/client_channel/subchannel.cc \
     src/core/ext/filters/client_channel/subchannel_pool_interface.cc \
+    src/core/ext/filters/message_size/message_size_parser.cc \
     src/core/ext/filters/deadline/deadline_filter.cc \
     src/core/ext/filters/client_channel/health/health.pb.c \
     src/core/tsi/fake_transport_security.cc \

config.w32

@@ -341,6 +341,7 @@ if (PHP_GRPC != "no") {
     "src\\core\\ext\\filters\\client_channel\\service_config.cc " +
     "src\\core\\ext\\filters\\client_channel\\subchannel.cc " +
     "src\\core\\ext\\filters\\client_channel\\subchannel_pool_interface.cc " +
+    "src\\core\\ext\\filters\\message_size\\message_size_parser.cc " +
     "src\\core\\ext\\filters\\deadline\\deadline_filter.cc " +
     "src\\core\\ext\\filters\\client_channel\\health\\health.pb.c " +
     "src\\core\\tsi\\fake_transport_security.cc " +

gRPC-C++.podspec

@@ -385,6 +385,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/service_config.h',
                       'src/core/ext/filters/client_channel/subchannel.h',
                       'src/core/ext/filters/client_channel/subchannel_pool_interface.h',
+                      'src/core/ext/filters/message_size/message_size_parser.h',
                       'src/core/ext/filters/deadline/deadline_filter.h',
                       'src/core/ext/filters/client_channel/health/health.pb.h',
                       'src/core/tsi/fake_transport_security.h',

gRPC-Core.podspec

@@ -367,6 +367,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/service_config.h',
                       'src/core/ext/filters/client_channel/subchannel.h',
                       'src/core/ext/filters/client_channel/subchannel_pool_interface.h',
+                      'src/core/ext/filters/message_size/message_size_parser.h',
                       'src/core/ext/filters/deadline/deadline_filter.h',
                       'src/core/ext/filters/client_channel/health/health.pb.h',
                       'src/core/tsi/fake_transport_security.h',
@@ -815,6 +816,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/service_config.cc',
                       'src/core/ext/filters/client_channel/subchannel.cc',
                       'src/core/ext/filters/client_channel/subchannel_pool_interface.cc',
+                      'src/core/ext/filters/message_size/message_size_parser.cc',
                       'src/core/ext/filters/deadline/deadline_filter.cc',
                       'src/core/ext/filters/client_channel/health/health.pb.c',
                       'src/core/tsi/fake_transport_security.cc',
@@ -1011,6 +1013,7 @@ Pod::Spec.new do |s|
                               'src/core/ext/filters/client_channel/service_config.h',
                               'src/core/ext/filters/client_channel/subchannel.h',
                               'src/core/ext/filters/client_channel/subchannel_pool_interface.h',
+                              'src/core/ext/filters/message_size/message_size_parser.h',
                               'src/core/ext/filters/deadline/deadline_filter.h',
                               'src/core/ext/filters/client_channel/health/health.pb.h',
                               'src/core/tsi/fake_transport_security.h',

grpc.gemspec

@@ -301,6 +301,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/client_channel/service_config.h )
   s.files += %w( src/core/ext/filters/client_channel/subchannel.h )
   s.files += %w( src/core/ext/filters/client_channel/subchannel_pool_interface.h )
+  s.files += %w( src/core/ext/filters/message_size/message_size_parser.h )
   s.files += %w( src/core/ext/filters/deadline/deadline_filter.h )
   s.files += %w( src/core/ext/filters/client_channel/health/health.pb.h )
   s.files += %w( src/core/tsi/fake_transport_security.h )
@@ -752,6 +753,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/client_channel/service_config.cc )
   s.files += %w( src/core/ext/filters/client_channel/subchannel.cc )
   s.files += %w( src/core/ext/filters/client_channel/subchannel_pool_interface.cc )
+  s.files += %w( src/core/ext/filters/message_size/message_size_parser.cc )
   s.files += %w( src/core/ext/filters/deadline/deadline_filter.cc )
   s.files += %w( src/core/ext/filters/client_channel/health/health.pb.c )
   s.files += %w( src/core/tsi/fake_transport_security.cc )

grpc.gyp

@@ -548,6 +548,7 @@
         'src/core/ext/filters/client_channel/service_config.cc',
         'src/core/ext/filters/client_channel/subchannel.cc',
         'src/core/ext/filters/client_channel/subchannel_pool_interface.cc',
+        'src/core/ext/filters/message_size/message_size_parser.cc',
         'src/core/ext/filters/deadline/deadline_filter.cc',
         'src/core/ext/filters/client_channel/health/health.pb.c',
         'src/core/tsi/fake_transport_security.cc',
@@ -813,6 +814,7 @@
         'src/core/ext/filters/client_channel/service_config.cc',
         'src/core/ext/filters/client_channel/subchannel.cc',
         'src/core/ext/filters/client_channel/subchannel_pool_interface.cc',
+        'src/core/ext/filters/message_size/message_size_parser.cc',
         'src/core/ext/filters/deadline/deadline_filter.cc',
         'src/core/ext/filters/client_channel/health/health.pb.c',
         'third_party/nanopb/pb_common.c',
@@ -1059,6 +1061,7 @@
         'src/core/ext/filters/client_channel/service_config.cc',
         'src/core/ext/filters/client_channel/subchannel.cc',
         'src/core/ext/filters/client_channel/subchannel_pool_interface.cc',
+        'src/core/ext/filters/message_size/message_size_parser.cc',
         'src/core/ext/filters/deadline/deadline_filter.cc',
         'src/core/ext/filters/client_channel/health/health.pb.c',
         'third_party/nanopb/pb_common.c',
@@ -1316,6 +1319,7 @@
         'src/core/ext/filters/client_channel/service_config.cc',
         'src/core/ext/filters/client_channel/subchannel.cc',
         'src/core/ext/filters/client_channel/subchannel_pool_interface.cc',
+        'src/core/ext/filters/message_size/message_size_parser.cc',
         'src/core/ext/filters/deadline/deadline_filter.cc',
         'src/core/ext/filters/client_channel/health/health.pb.c',
         'third_party/nanopb/pb_common.c',

package.xml

@@ -306,6 +306,7 @@
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/service_config.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/subchannel.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/subchannel_pool_interface.h" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/message_size/message_size_parser.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/deadline/deadline_filter.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/health/health.pb.h" role="src" />
     <file baseinstalldir="/" name="src/core/tsi/fake_transport_security.h" role="src" />
@@ -757,6 +758,7 @@
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/service_config.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/subchannel.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/subchannel_pool_interface.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/message_size/message_size_parser.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/deadline/deadline_filter.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/health/health.pb.c" role="src" />
     <file baseinstalldir="/" name="src/core/tsi/fake_transport_security.cc" role="src" />

src/core/ext/filters/client_channel/client_channel_plugin.cc

@@ -35,7 +35,7 @@
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/ext/filters/client_channel/resolver_result_parsing.h"
 #include "src/core/ext/filters/client_channel/retry_throttle.h"
-#include "src/core/ext/filters/message_size/message_size_filter.h"
+#include "src/core/ext/filters/message_size/message_size_parser.h"
 #include "src/core/lib/surface/channel_init.h"
 
 static bool append_filter(grpc_channel_stack_builder* builder, void* arg) {

src/core/ext/filters/message_size/message_size_filter.cc

@@ -26,7 +26,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/filters/client_channel/service_config.h"
+#include "src/core/ext/filters/message_size/message_size_parser.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/channel_stack_builder.h"
 #include "src/core/lib/gpr/string.h"
@@ -35,91 +35,10 @@
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel_init.h"
 
-namespace {
-size_t message_size_parser_index;
-
-// Consumes all the errors in the vector and forms a referencing error from
-// them. If the vector is empty, return GRPC_ERROR_NONE.
-template <size_t N>
-grpc_error* CreateErrorFromVector(
-    const char* desc, grpc_core::InlinedVector<grpc_error*, N>* error_list) {
-  grpc_error* error = GRPC_ERROR_NONE;
-  if (error_list->size() != 0) {
-    error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
-        desc, error_list->data(), error_list->size());
-    // Remove refs to all errors in error_list.
-    for (size_t i = 0; i < error_list->size(); i++) {
-      GRPC_ERROR_UNREF((*error_list)[i]);
-    }
-    error_list->clear();
-  }
-  return error;
-}
-}  // namespace
-
-namespace grpc_core {
-
-UniquePtr<ServiceConfigParsedObject> MessageSizeParser::ParsePerMethodParams(
-    const grpc_json* json, grpc_error** error) {
-  GPR_DEBUG_ASSERT(error != nullptr && *error == GRPC_ERROR_NONE);
-  int max_request_message_bytes = -1;
-  int max_response_message_bytes = -1;
-  InlinedVector<grpc_error*, 4> error_list;
-  for (grpc_json* field = json->child; field != nullptr; field = field->next) {
-    if (field->key == nullptr) continue;
-    if (strcmp(field->key, "maxRequestMessageBytes") == 0) {
-      if (max_request_message_bytes >= 0) {
-        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-            "field:maxRequestMessageBytes error:Duplicate entry"));
-      } else if (field->type != GRPC_JSON_STRING &&
-                 field->type != GRPC_JSON_NUMBER) {
-        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-            "field:maxRequestMessageBytes error:should be of type number"));
-      } else {
-        max_request_message_bytes = gpr_parse_nonnegative_int(field->value);
-        if (max_request_message_bytes == -1) {
-          error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-              "field:maxRequestMessageBytes error:should be non-negative"));
-        }
-      }
-    } else if (strcmp(field->key, "maxResponseMessageBytes") == 0) {
-      if (max_response_message_bytes >= 0) {
-        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-            "field:maxResponseMessageBytes error:Duplicate entry"));
-      } else if (field->type != GRPC_JSON_STRING &&
-                 field->type != GRPC_JSON_NUMBER) {
-        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-            "field:maxResponseMessageBytes error:should be of type number"));
-      } else {
-        max_response_message_bytes = gpr_parse_nonnegative_int(field->value);
-        if (max_response_message_bytes == -1) {
-          error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-              "field:maxResponseMessageBytes error:should be non-negative"));
-        }
-      }
-    }
-  }
-  if (!error_list.empty()) {
-    *error = CreateErrorFromVector("Message size parser", &error_list);
-    return nullptr;
-  }
-  return UniquePtr<ServiceConfigParsedObject>(New<MessageSizeParsedObject>(
-      max_request_message_bytes, max_response_message_bytes));
-}
-
-void MessageSizeParser::Register() {
-  message_size_parser_index = ServiceConfig::RegisterParser(
-      UniquePtr<ServiceConfigParser>(New<MessageSizeParser>()));
-}
-
-size_t MessageSizeParser::ParserIndex() { return message_size_parser_index; }
-}  // namespace grpc_core
-
 static void recv_message_ready(void* user_data, grpc_error* error);
 static void recv_trailing_metadata_ready(void* user_data, grpc_error* error);
 
 namespace {
-
 struct channel_data {
   grpc_core::MessageSizeParsedObject::message_size_limits limits;
   grpc_core::RefCountedPtr<grpc_core::ServiceConfig> svc_cfg;
@@ -140,18 +59,21 @@ struct call_data {
     // size to the receive limit.
     const grpc_core::MessageSizeParsedObject* limits = nullptr;
     const grpc_core::ServiceConfig::ServiceConfigObjectsVector* objs_vector =
-        static_cast<
-            const grpc_core::ServiceConfig::ServiceConfigObjectsVector*>(
-            args.context[GRPC_SERVICE_CONFIG_METHOD_PARAMS].value);
+        nullptr;
+    if (args.context != nullptr) {
+      objs_vector = static_cast<
+          const grpc_core::ServiceConfig::ServiceConfigObjectsVector*>(
+          args.context[GRPC_SERVICE_CONFIG_METHOD_PARAMS].value);
+    }
     if (objs_vector != nullptr) {
       limits = static_cast<const grpc_core::MessageSizeParsedObject*>(
-          (*objs_vector)[message_size_parser_index].get());
+          (*objs_vector)[grpc_core::MessageSizeParser::ParserIndex()].get());
     } else if (chand.svc_cfg != nullptr) {
       objs_vector =
           chand.svc_cfg->GetMethodServiceConfigObjectsVector(args.path);
       if (objs_vector != nullptr) {
         limits = static_cast<const grpc_core::MessageSizeParsedObject*>(
-            (*objs_vector)[message_size_parser_index].get());
+            (*objs_vector)[grpc_core::MessageSizeParser::ParserIndex()].get());
       }
     }
     if (limits != nullptr) {

src/core/ext/filters/message_size/message_size_filter.h

@@ -24,35 +24,4 @@
 
 extern const grpc_channel_filter grpc_message_size_filter;
 
-namespace grpc_core {
-
-class MessageSizeParsedObject : public ServiceConfigParsedObject {
- public:
-  struct message_size_limits {
-    int max_send_size;
-    int max_recv_size;
-  };
-
-  MessageSizeParsedObject(int max_send_size, int max_recv_size) {
-    limits_.max_send_size = max_send_size;
-    limits_.max_recv_size = max_recv_size;
-  }
-
-  const message_size_limits& limits() const { return limits_; }
-
- private:
-  message_size_limits limits_;
-};
-
-class MessageSizeParser : public ServiceConfigParser {
- public:
-  UniquePtr<ServiceConfigParsedObject> ParsePerMethodParams(
-      const grpc_json* json, grpc_error** error) override;
-
-  static void Register();
-
-  static size_t ParserIndex();
-};
-}  // namespace grpc_core
-
 #endif /* GRPC_CORE_EXT_FILTERS_MESSAGE_SIZE_MESSAGE_SIZE_FILTER_H */

src/core/ext/filters/message_size/message_size_parser.cc

@@ -0,0 +1,101 @@
+//
+// Copyright 2019 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/ext/filters/message_size/message_size_parser.h"
+
+#include "src/core/lib/gpr/string.h"
+
+namespace {
+size_t g_message_size_parser_index;
+
+// Consumes all the errors in the vector and forms a referencing error from
+// them. If the vector is empty, return GRPC_ERROR_NONE.
+template <size_t N>
+grpc_error* CreateErrorFromVector(
+    const char* desc, grpc_core::InlinedVector<grpc_error*, N>* error_list) {
+  grpc_error* error = GRPC_ERROR_NONE;
+  if (error_list->size() != 0) {
+    error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+        desc, error_list->data(), error_list->size());
+    // Remove refs to all errors in error_list.
+    for (size_t i = 0; i < error_list->size(); i++) {
+      GRPC_ERROR_UNREF((*error_list)[i]);
+    }
+    error_list->clear();
+  }
+  return error;
+}
+}  // namespace
+
+namespace grpc_core {
+
+UniquePtr<ServiceConfigParsedObject> MessageSizeParser::ParsePerMethodParams(
+    const grpc_json* json, grpc_error** error) {
+  GPR_DEBUG_ASSERT(error != nullptr && *error == GRPC_ERROR_NONE);
+  int max_request_message_bytes = -1;
+  int max_response_message_bytes = -1;
+  InlinedVector<grpc_error*, 4> error_list;
+  for (grpc_json* field = json->child; field != nullptr; field = field->next) {
+    if (field->key == nullptr) continue;
+    if (strcmp(field->key, "maxRequestMessageBytes") == 0) {
+      if (max_request_message_bytes >= 0) {
+        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+            "field:maxRequestMessageBytes error:Duplicate entry"));
+      } else if (field->type != GRPC_JSON_STRING &&
+                 field->type != GRPC_JSON_NUMBER) {
+        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+            "field:maxRequestMessageBytes error:should be of type number"));
+      } else {
+        max_request_message_bytes = gpr_parse_nonnegative_int(field->value);
+        if (max_request_message_bytes == -1) {
+          error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+              "field:maxRequestMessageBytes error:should be non-negative"));
+        }
+      }
+    } else if (strcmp(field->key, "maxResponseMessageBytes") == 0) {
+      if (max_response_message_bytes >= 0) {
+        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+            "field:maxResponseMessageBytes error:Duplicate entry"));
+      } else if (field->type != GRPC_JSON_STRING &&
+                 field->type != GRPC_JSON_NUMBER) {
+        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+            "field:maxResponseMessageBytes error:should be of type number"));
+      } else {
+        max_response_message_bytes = gpr_parse_nonnegative_int(field->value);
+        if (max_response_message_bytes == -1) {
+          error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+              "field:maxResponseMessageBytes error:should be non-negative"));
+        }
+      }
+    }
+  }
+  if (!error_list.empty()) {
+    *error = CreateErrorFromVector("Message size parser", &error_list);
+    return nullptr;
+  }
+  return UniquePtr<ServiceConfigParsedObject>(New<MessageSizeParsedObject>(
+      max_request_message_bytes, max_response_message_bytes));
+}
+
+void MessageSizeParser::Register() {
+  g_message_size_parser_index = ServiceConfig::RegisterParser(
+      UniquePtr<ServiceConfigParser>(New<MessageSizeParser>()));
+}
+
+size_t MessageSizeParser::ParserIndex() { return g_message_size_parser_index; }
+}  // namespace grpc_core

src/core/ext/filters/message_size/message_size_parser.h

@@ -0,0 +1,55 @@
+//
+// Copyright 2019 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef GRPC_CORE_EXT_FILTERS_MESSAGE_SIZE_MESSAGE_SIZE_PARSER_H
+#define GRPC_CORE_EXT_FILTERS_MESSAGE_SIZE_MESSAGE_SIZE_PARSER_H
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/ext/filters/client_channel/service_config.h"
+
+namespace grpc_core {
+
+class MessageSizeParsedObject : public ServiceConfigParsedObject {
+ public:
+  struct message_size_limits {
+    int max_send_size;
+    int max_recv_size;
+  };
+
+  MessageSizeParsedObject(int max_send_size, int max_recv_size) {
+    limits_.max_send_size = max_send_size;
+    limits_.max_recv_size = max_recv_size;
+  }
+
+  const message_size_limits& limits() const { return limits_; }
+
+ private:
+  message_size_limits limits_;
+};
+
+class MessageSizeParser : public ServiceConfigParser {
+ public:
+  UniquePtr<ServiceConfigParsedObject> ParsePerMethodParams(
+      const grpc_json* json, grpc_error** error) override;
+
+  static void Register();
+
+  static size_t ParserIndex();
+};
+}  // namespace grpc_core
+
+#endif /* GRPC_CORE_EXT_FILTERS_MESSAGE_SIZE_MESSAGE_SIZE_PARSER_H */

src/python/grpcio/grpc_core_dependencies.py

@@ -340,6 +340,7 @@ CORE_SOURCE_FILES = [
     'src/core/ext/filters/client_channel/service_config.cc',
     'src/core/ext/filters/client_channel/subchannel.cc',
     'src/core/ext/filters/client_channel/subchannel_pool_interface.cc',
+    'src/core/ext/filters/message_size/message_size_parser.cc',
     'src/core/ext/filters/deadline/deadline_filter.cc',
     'src/core/ext/filters/client_channel/health/health.pb.c',
     'src/core/tsi/fake_transport_security.cc',

tools/doxygen/Doxyfile.core.internal

@@ -989,6 +989,8 @@ src/core/ext/filters/max_age/max_age_filter.cc \
 src/core/ext/filters/max_age/max_age_filter.h \
 src/core/ext/filters/message_size/message_size_filter.cc \
 src/core/ext/filters/message_size/message_size_filter.h \
+src/core/ext/filters/message_size/message_size_parser.cc \
+src/core/ext/filters/message_size/message_size_parser.h \
 src/core/ext/filters/workarounds/workaround_cronet_compression_filter.cc \
 src/core/ext/filters/workarounds/workaround_cronet_compression_filter.h \
 src/core/ext/filters/workarounds/workaround_utils.cc \

tools/run_tests/generated/sources_and_headers.json

@@ -8733,7 +8733,8 @@
       "src/core/ext/filters/client_channel/server_address.h", 
       "src/core/ext/filters/client_channel/service_config.h", 
       "src/core/ext/filters/client_channel/subchannel.h", 
-      "src/core/ext/filters/client_channel/subchannel_pool_interface.h"
+      "src/core/ext/filters/client_channel/subchannel_pool_interface.h", 
+      "src/core/ext/filters/message_size/message_size_parser.h"
     ], 
     "is_filegroup": true, 
     "language": "c", 
@@ -8792,7 +8793,9 @@
       "src/core/ext/filters/client_channel/subchannel.cc", 
       "src/core/ext/filters/client_channel/subchannel.h", 
       "src/core/ext/filters/client_channel/subchannel_pool_interface.cc", 
-      "src/core/ext/filters/client_channel/subchannel_pool_interface.h"
+      "src/core/ext/filters/client_channel/subchannel_pool_interface.h", 
+      "src/core/ext/filters/message_size/message_size_parser.cc", 
+      "src/core/ext/filters/message_size/message_size_parser.h"
     ], 
     "third_party": false, 
     "type": "filegroup"