Support for multipart requests, new ways of routing the request to MP graph (#3250)

CVS-163721

If request content-type is application-json - route based on model JSON field
If request content-type s multipart - route based on mode multipart field
In other cases try to deduce graph name from URI: /v3/GRAPH-NAME

- multipart field/file access for calculators
- unit tests

Author: dkalinowski

.gitignore

@@ -36,3 +36,4 @@ out
 *.errors.txt
 tmp/
 *.zip
+*.tar.gz

common_settings.bzl

@@ -123,8 +123,7 @@ def create_config_settings():
 ###############################
 # compilation settings
 ###############################
-COMMON_STATIC_LIBS_COPTS = select({
-                "//conditions:default": [
+LINUX_COMMON_STATIC_LIBS_COPTS = [
                     "-Wall",
                     # TODO: was in ovms bin "-Wconversion",
                     "-Wno-unknown-pragmas", 
@@ -133,8 +132,9 @@ COMMON_STATIC_LIBS_COPTS = select({
                     "-Werror", 
                     # ov::Tensor::data method call results in deprecated warning and we use it in multiple places
                     "-Wno-deprecated-declarations",
-                ],
-                "//src:windows" : [
+]
+
+WINDOWS_COMMON_STATIC_LIBS_COPTS = [
                         "/W4",
                         "/WX",
                         "/external:anglebrackets",
@@ -157,7 +157,11 @@ COMMON_STATIC_LIBS_COPTS = select({
                         "/wd4702",
                         "/wd4267",
                         "/wd4996",
-                    ],
+]
+
+COMMON_STATIC_LIBS_COPTS = select({
+                "//conditions:default": LINUX_COMMON_STATIC_LIBS_COPTS,
+                "//src:windows" : WINDOWS_COMMON_STATIC_LIBS_COPTS,
                 })
 
 COMMON_STATIC_TEST_COPTS = select({

src/BUILD

@@ -615,8 +615,14 @@ cc_library(
                 "//src/embeddings:embeddingscalculator",
                 "//src/rerank:rerankcalculator",],
         }) + select({
-            "//:enable_drogon": ["libdrogon_http_server"],
-            "//conditions:default" : ["libnet_http_server"],
+            "//:enable_drogon": [
+                "libdrogon_http_server",
+                "libmultipart_parser_drogon_impl",
+            ],
+            "//conditions:default" : [
+                "libnet_http_server",
+                # Add net-http implementation here if we ever want one
+            ],
         }) + [
             "cpp_headers",
             "ovms_header",
@@ -811,6 +817,7 @@ cc_library(
     deps = [
         "@com_github_tencent_rapidjson//:rapidjson",
         "libovmsclient_connection",
+        "libmultipart_parser",
     ],
     visibility = ["//visibility:public"],
     copts = COPTS_ADJUSTED,
@@ -829,6 +836,7 @@ cc_library(
     linkopts = LINKOPTS_ADJUSTED,
     alwayslink = 1,
 )
+
 cc_library(
     name = "libhttpclientconnection",
     hdrs = ["http_frontend/http_client_connection.hpp"],
@@ -843,6 +851,31 @@ cc_library(
     alwayslink = 1,
 )
 
+cc_library(
+    name = "libmultipart_parser",
+    hdrs = ["multi_part_parser.hpp"],
+    deps = [
+    ],
+    visibility = ["//visibility:public",],
+    local_defines = COMMON_LOCAL_DEFINES,
+    copts = COPTS_ADJUSTED,
+    linkopts = LINKOPTS_ADJUSTED,
+)
+
+cc_library(
+    name = "libmultipart_parser_drogon_impl",
+    hdrs = ["http_frontend/multi_part_parser_drogon_impl.hpp"],
+    srcs = ["http_frontend/multi_part_parser_drogon_impl.cpp"],
+    deps = [
+        "libmultipart_parser",
+        "@drogon//:drogon_cmake",
+    ],
+    visibility = ["//visibility:public",],
+    local_defines = COMMON_LOCAL_DEFINES,
+    copts = COPTS_ADJUSTED,
+    linkopts = LINKOPTS_ADJUSTED,
+)
+
 cc_library(
     name = "libovms_module",
     hdrs = ["module.hpp"],
@@ -2757,6 +2790,7 @@ cc_test(
                 "test/get_mediapipe_graph_metadata_response_test.cpp",
                 "test/mediapipe_framework_test.cpp",
                 "test/http_openai_handler_test.cpp",
+                "test/multipart_calculator_test.cpp",
             ],
             "//:disable_mediapipe" : [
                 "test/disabled_mediapipe_test.cpp",
@@ -2776,6 +2810,12 @@ cc_test(
                 "test/llm/visual_language_model/initialization_test.cpp",
             ],
             "//:disable_python" : [],
+        }) + select({
+            "//:enable_drogon": [
+                "test/multi_part_parser_drogon_test.cpp",
+            ],
+            "//conditions:default" : [
+            ],
         }),
     data = [
         "test/add_two_inputs_model/1/add.xml",
@@ -2827,6 +2867,7 @@ cc_test(
         "test/mediapipe/config_mediapipe_graph_with_side_packets.json",
         "test/mediapipe/config_mediapipe_two_inputs.json",
         "test/mediapipe/config_mediapipe_two_outputs_dag.json",
+        "test/mediapipe/config_mediapipe_multipart_mock.json",
         "test/mediapipe/config_mp_tf_passthrough.json",
         "test/mediapipe/config_standard_add.json",
         "test/mediapipe/config_standard_dummy.json",
@@ -2845,6 +2886,7 @@ cc_test(
         "test/mediapipe/graphdummyadapterfull_dummyinputnames.pbtxt",
         "test/mediapipe/graphadapterfull_two_outputs_dag.pbtxt",
         "test/mediapipe/graphdummyadapterfull_two_outputs.pbtxt",
+        "test/mediapipe/graph_multipart.pbtxt",
         "test/mediapipe/negative/config_exception_during_process.json",
         "test/mediapipe/negative/config_no_calc_output_stream.json",
         "test/mediapipe/negative/graph_exception_during_process.pbtxt",
@@ -2927,6 +2969,7 @@ cc_test(
             "//conditions:default": [
                 "//src/llm:genai_servables",
                 "//src/test/mediapipe/calculators:mediapipe_test_calculators",
+                "//src/test/mediapipe/calculators:dependency_free_http_test_calculators",
                 "@mediapipe//mediapipe/calculators/ovms:ovms_calculator",
                 "@mediapipe//mediapipe/framework:calculator_runner",
             ],

src/embeddings/BUILD

@@ -64,7 +64,8 @@ cc_library(
     name = "embeddings_api",
     hdrs = ["embeddings_api.hpp"],
     srcs = ["embeddings_api.cpp"],
-    deps = ["@mediapipe//mediapipe/framework:calculator_framework",
+    deps = ["//src:libovmslogging",
+            "@mediapipe//mediapipe/framework:calculator_framework",
             "//third_party:openvino",
             "@com_github_tencent_rapidjson//:rapidjson",],
     visibility = ["//visibility:public"],

src/embeddings/embeddings_api.cpp

@@ -20,6 +20,8 @@
 #include <utility>
 #include <variant>
 
+#include "../logging.hpp"
+
 #pragma warning(push)
 #pragma warning(disable : 4005 4309 6001 6386 6011 6246)
 #pragma GCC diagnostic push
@@ -128,6 +130,12 @@ std::variant<EmbeddingsRequest, std::string> EmbeddingsRequest::fromJson(rapidjs
 }
 
 absl::Status EmbeddingsHandler::parseRequest() {
+    // Parsed JSON is not guaranteed to be valid, we may reach this point via multipart content type request with no valid JSON parser
+    if (this->doc.HasParseError()) {
+        SPDLOG_LOGGER_DEBUG(embeddings_calculator_logger, "Non-json request received in embeddings calculator");
+        return absl::InvalidArgumentError("Non-json request received in embeddings calculator");
+    }
+
     auto parsed = EmbeddingsRequest::fromJson(&(this->doc));
 
     if (auto error = std::get_if<std::string>(&parsed)) {

src/http_frontend/multi_part_parser_drogon_impl.cpp

@@ -0,0 +1,43 @@
+//*****************************************************************************
+// Copyright 2025 Intel Corporation
+//
+// 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 "multi_part_parser_drogon_impl.hpp"
+
+namespace ovms {
+
+bool DrogonMultiPartParser::parse() {
+    this->hasParseError_ = this->parser->parse(request) != 0;
+    return !this->hasParseError_;
+}
+
+bool DrogonMultiPartParser::hasParseError() const {
+    return this->hasParseError_;
+}
+
+std::string DrogonMultiPartParser::getFieldByName(const std::string& name) const {
+    return this->parser->getParameter<std::string>(name);
+}
+
+std::string_view DrogonMultiPartParser::getFileContentByFieldName(const std::string& name) const {
+    auto fileMap = this->parser->getFilesMap();
+
+    auto it = fileMap.find(name);
+    if (it == fileMap.end()) {
+        return "";
+    }
+    return it->second.fileContent();
+}
+
+}  // namespace ovms

src/http_frontend/multi_part_parser_drogon_impl.hpp

@@ -0,0 +1,49 @@
+//*****************************************************************************
+// Copyright 2025 Intel Corporation
+//
+// 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.
+//*****************************************************************************
+#pragma once
+
+#include "../multi_part_parser.hpp"
+
+#pragma warning(push)
+#pragma warning(disable : 6326)
+#include <drogon/drogon.h>
+#pragma warning(pop)
+
+#include <string>
+#include <string_view>
+#include <memory>
+
+namespace ovms {
+
+class DrogonMultiPartParser : public MultiPartParser {
+    bool hasParseError_{true};
+    const drogon::HttpRequestPtr request{nullptr};
+    const std::shared_ptr<drogon::MultiPartParser> parser{nullptr};
+
+public:
+    DrogonMultiPartParser(const drogon::HttpRequestPtr& request) :
+        request(request),
+        parser(std::make_shared<drogon::MultiPartParser>()) {}
+
+    bool parse() override;
+
+    bool hasParseError() const override;
+
+    std::string getFieldByName(const std::string& name) const override;
+    std::string_view getFileContentByFieldName(const std::string& name) const override;
+};
+
+}  // namespace ovms

src/http_payload.hpp

@@ -17,6 +17,7 @@
 
 #include <memory>
 #include <string>
+#include <unordered_map>
 #include <utility>
 #include <vector>
 #pragma warning(push)
@@ -25,15 +26,17 @@
 #pragma warning(pop)
 
 #include "client_connection.hpp"
+#include "multi_part_parser.hpp"
 
 namespace ovms {
 
 struct HttpPayload {
     std::string uri;
-    std::vector<std::pair<std::string, std::string>> headers;
+    std::unordered_map<std::string, std::string> headers;
     std::string body;                                 // always
     std::shared_ptr<rapidjson::Document> parsedJson;  // pre-parsed body             = null
     std::shared_ptr<ClientConnection> client;
+    std::shared_ptr<MultiPartParser> multipartParser;
 };
 
 }  // namespace ovms