executable_network.cpp

// Copyright (C) 2018-2023 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
//

// clang-format off
#include "ie_metric_helpers.hpp"
#include "executable_network.hpp"
#include "async_infer_request.hpp"
#include "itt.hpp"
#include "ie_precision.hpp"
#include "openvino/core/dimension.hpp"
#include "openvino/core/except.hpp"
#include "openvino/core/type.hpp"
#include "openvino/core/type/element_type.hpp"
#include "openvino/op/result.hpp"
#include "transformations/utils/utils.hpp"
#include "openvino/op/parameter.hpp"
#include "xml_parse_utils.h"
#include <caseless.hpp>

#include <vector>
#include <deque>
#include <map>
#include <utility>
#include <fstream>
#include <algorithm>
#include <string>
#include <memory>
#include <unordered_set>
#include <array>
#include <cstdint>

#include "openvino/pass/serialize.hpp"
#include "openvino/runtime/properties.hpp"
#include "ie_ngraph_utils.hpp"
#include "ie_plugin_config.hpp"
#include "ie_algorithm.hpp"
#include "cpp_interfaces/interface/ie_internal_plugin_config.hpp"
#include "plugin.hpp"
#include <ie_algorithm.hpp>

#include <ngraph/function.hpp>
#include <ngraph/variant.hpp>
#include <ngraph/graph_util.hpp>
#include <ngraph/op/result.hpp>
#include <ngraph/op/parameter.hpp>
#include <ngraph/op/util/op_types.hpp>
#include <ngraph/rt_info.hpp>
#include <ngraph/pass/visualize_tree.hpp>
// clang-format on

using namespace InferenceEngine;
using namespace details;
using namespace HeteroPlugin;
using namespace InferenceEngine::PluginConfigParams;
using namespace InferenceEngine::HeteroConfigParams;

template <typename T>
using NodeMap = std::unordered_map<ngraph::Node*, T>;

HeteroExecutableNetwork::HeteroExecutableNetwork(const InferenceEngine::CNNNetwork& network,
                                                 const Engine::Configs& config,
                                                 Engine* plugin)
    : InferenceEngine::ExecutableNetworkThreadSafeDefault(nullptr,
                                                          std::make_shared<InferenceEngine::ImmediateExecutor>()),
      _heteroPlugin{plugin},
      _name{network.getName()},
      _config{config} {
    auto function = network.getFunction();
    IE_ASSERT(function != nullptr);
    auto clonedFunction = ngraph::clone_function(*function);
    bool dumpDotFile = false;
    if (std::getenv("OPENVINO_HETERO_VISUALIZE")) {
        dumpDotFile = true;
    } else {
        auto itDumpDotFile = _config.find(HETERO_CONFIG_KEY(DUMP_GRAPH_DOT));
        dumpDotFile = itDumpDotFile != _config.end() ? (itDumpDotFile->second == YES) : false;
    }

    QueryNetworkResult queryNetworkResult;
    auto orderedOps = clonedFunction->get_ordered_ops();
    bool allEmpty = true;
    // Get user defined affinity
    for (auto&& node : orderedOps) {
        auto& nodeInfo = node->get_rt_info();
        auto itInfo = nodeInfo.find("affinity");
        if (itInfo != nodeInfo.end()) {
            IE_ASSERT(itInfo->second.is<std::string>());
            queryNetworkResult.supportedLayersMap.emplace(node->get_friendly_name(), itInfo->second.as<std::string>());
            allEmpty = false;
        }
    }

    if (queryNetworkResult.supportedLayersMap.empty()) {
        auto it = _config.find("TARGET_FALLBACK");
        if (it == _config.end()) {
            it = _config.find(ov::device::priorities.name());
        }
        if (it != _config.end()) {
            queryNetworkResult = _heteroPlugin->QueryNetwork(network, _config);
        } else {
            IE_THROW() << "The '" << ov::device::priorities.name()
                       << "' option was not defined for heterogeneous plugin";
        }
    }

    using Input = ngraph::Input<ngraph::Node>;
    using NodeSet = std::unordered_set<ngraph::Node*>;
    using InputSet = std::set<Input>;

    auto InputNode = [](const ngraph::Input<ngraph::Node>& input) {
        return input.get_source_output().get_node();
    };

    std::unordered_set<std::string> devices;
    NodeMap<std::string> affinities;
    // Check that all nodes has user or plugin defined affinities
    for (auto&& node : orderedOps) {
        auto itAffinity = queryNetworkResult.supportedLayersMap.find(node->get_friendly_name());
        if (itAffinity != queryNetworkResult.supportedLayersMap.end()) {
            affinities[node.get()] = itAffinity->second;
            devices.emplace(itAffinity->second);
        } else if (allEmpty) {
            IE_THROW() << "Hetero device used default fallback policy, but some layers eg: \n(Name:"
                       << node->get_friendly_name() << ", Type: " << node->get_type_name()
                       << ") were not able to be assigned on any pointed device.\n"
                       << "It happened because these layers are not supported in plugins by default.\n"
                       << "You need to implement custom layers to support them.";
        } else {
            IE_THROW() << "Network passed to LoadNetwork has affinity assigned, but some layers eg: \n(Name:"
                       << node->get_friendly_name() << ", Type: " << node->get_type_name()
                       << ") were not assigned to any device.\n"
                       << "It might happen if you assigned layers manually and missed some layers or\n"
                       << "if you used some automatic assigning mode which decided that these layers are not\n"
                       << "supported by any plugin";
        }
    }

    static const std::array<const char*, 14> colors = {
        "aliceblue",
        "antiquewhite4",
        "aquamarine4",
        "azure4",
        "bisque3",
        "blue1",
        "brown",
        "burlywood",
        "cadetblue",
        "chartreuse",
        "chocolate",
        "coral",
        "cornflowerblue",
        "cornsilk4",
    };

    if (dumpDotFile) {
        ngraph::pass::VisualizeTree{
            "hetero_affinity_" + _name + ".dot",
            [&](const ngraph::Node& node, std::vector<std::string>& attributes) {
                auto nodeDevice = queryNetworkResult.supportedLayersMap.at(node.get_friendly_name());
                int colorIndex = 0;
                for (auto&& device : devices) {
                    if (device == nodeDevice) {
                        attributes.push_back(std::string{"fillcolor="} + colors[colorIndex % colors.size()] +
                                             " style=filled");
                        auto itLabel =
                            std::find_if(std::begin(attributes), std::end(attributes), [](const std::string& str) {
                                return str.find("label") != std::string::npos;
                            });
                        auto label =
                            "\\ndevice=" + queryNetworkResult.supportedLayersMap.at(node.get_friendly_name()) + '\"';
                        IE_ASSERT(itLabel != attributes.end());
                        itLabel->pop_back();
                        (*itLabel) += label;
                        break;
                    }
                    colorIndex++;
                }
            }}
            .run_on_model(ngraph::clone_function(*function));
    }

    NodeMap<InputSet> nodeInputDependencies;
    NodeSet graphInputNodes;
    InputSet subgraphInputs;
    // Get all subgraph inputs using just node affinities. Also collect transitive closure
    for (auto&& node : orderedOps) {
        if (ngraph::op::is_parameter(node) || ngraph::op::is_constant(node)) {
            graphInputNodes.insert(node.get());
            subgraphInputs.insert(Input{node.get(), 0});
            nodeInputDependencies[node.get()].insert(Input{node.get(), 0});
        } else {
            auto inputs = node->inputs();
            auto& nodeInputDependency = nodeInputDependencies[node.get()];
            for (auto&& input : inputs) {
                nodeInputDependency.insert(input);
                auto& inputDependency = nodeInputDependencies[InputNode(input)];
                nodeInputDependency.insert(inputDependency.begin(), inputDependency.end());
                if (affinities[node.get()] != affinities[InputNode(input)]) {
                    subgraphInputs.insert(input);
                }
            }
        }
    }

    // Assign each node subgraph ID
    auto CollectSubgraphs = [&] {
        std::deque<int> subgraphIds;
        NodeMap<int*> subgraphIdPtrs;
        for (auto&& node : orderedOps) {
            auto allNodeInputs = node->inputs();
            std::vector<Input> inputs;
            for (auto&& input : allNodeInputs) {
                if (!contains(subgraphInputs, input)) {
                    inputs.emplace_back(std::move(input));
                }
            }
            if (inputs.empty()) {
                subgraphIds.push_back(static_cast<int>(subgraphIds.size()));
                subgraphIdPtrs.emplace(node.get(), &(subgraphIds.back()));
            } else {
                auto firstInputSubgraphIdPtr = subgraphIdPtrs[InputNode(inputs.front())];
                for (auto&& input : inputs) {
                    auto inputId = *subgraphIdPtrs[InputNode(input)];
                    for (auto& subgraphId : subgraphIds) {
                        if (subgraphId == inputId) {
                            subgraphId = *firstInputSubgraphIdPtr;
                        }
                    }
                }
                subgraphIdPtrs.emplace(node.get(), firstInputSubgraphIdPtr);
            }
        }
        NodeMap<int> result;
        for (auto&& subgraphIdPtr : subgraphIdPtrs) {
            result.emplace(subgraphIdPtr.first, *(subgraphIdPtr.second));
        }
        return result;
    };

    // Split cyclic dependencies.
    for (std::size_t prevSubgraphs = 0, cyclicSplitStep = 0; prevSubgraphs != subgraphInputs.size();
         ++cyclicSplitStep) {
        IE_ASSERT(cyclicSplitStep < orderedOps.size());
        prevSubgraphs = subgraphInputs.size();
        auto subgraphIds = CollectSubgraphs();
        // All inputs that belong to the same subgraph as node
        std::unordered_map<ngraph::Node*, InputSet> nodeSubgraphInputDependencies;
        // All inputs that depends on the same subgraph as node
        std::unordered_map<ngraph::Node*, InputSet> nodeSubgraphCyclicInputDependencies;
        for (auto&& node : orderedOps) {
            auto& nodeSubgraphInputDependency = nodeSubgraphInputDependencies[node.get()];
            auto allNodeSubgraphInputs = Intersection(nodeInputDependencies[node.get()], subgraphInputs);
            for (auto&& subgraphInput : allNodeSubgraphInputs) {
                if (subgraphIds[node.get()] == subgraphIds[subgraphInput.get_node()]) {
                    nodeSubgraphInputDependency.emplace(subgraphInput);
                }
            }
            auto& nodeSubgraphCyclicInputDependency = nodeSubgraphCyclicInputDependencies[node.get()];
            for (auto&& subgraphInput : allNodeSubgraphInputs) {
                if (!ngraph::op::is_parameter(subgraphInput.get_node()) &&
                    !ngraph::op::is_constant(subgraphInput.get_node()) &&
                    subgraphIds[node.get()] == subgraphIds[InputNode(subgraphInput)]) {
                    nodeSubgraphCyclicInputDependency.emplace(subgraphInput);
                }
            }
        }

        for (auto&& node : orderedOps) {
            auto& nodeSubgraphCyclicInputDependency = nodeSubgraphCyclicInputDependencies[node.get()];
            if (!nodeSubgraphCyclicInputDependency.empty()) {
                // Collect all subgraph inputs that cyclic subgraph output depends on
                InputSet cyclicInputsDependencies;
                for (auto&& cyclicInput : nodeSubgraphCyclicInputDependency) {
                    for (auto&& input : nodeSubgraphInputDependencies[InputNode(cyclicInput)]) {
                        cyclicInputsDependencies.emplace(input);
                    }
                }
                for (auto&& input : node->inputs()) {
                    auto& inputNodeSubgraphCyclicInputDependency =
                        nodeSubgraphCyclicInputDependencies[InputNode(input)];
                    auto& inputNodeSubgraphInputDependency = nodeSubgraphInputDependencies[InputNode(input)];
                    if (!Intersects(nodeSubgraphCyclicInputDependency, inputNodeSubgraphCyclicInputDependency) &&
                        Intersects(cyclicInputsDependencies, inputNodeSubgraphInputDependency)) {
                        subgraphInputs.insert(input);
                    }
                }
            }
        }
    }

    auto subgraphIds = CollectSubgraphs();

    if (dumpDotFile) {
        std::map<std::string, int> map_id;
        for (auto&& v : subgraphIds) {
            map_id.emplace(v.first->get_friendly_name(), v.second);
        }
        ngraph::pass::VisualizeTree{
            "hetero_subgraphs_" + _name + ".dot",
            [&](const ngraph::Node& node, std::vector<std::string>& attributes) {
                attributes.push_back(std::string{"fillcolor="} +
                                     colors[map_id.at(node.get_friendly_name()) % colors.size()] + " style=filled");
                auto itLabel = std::find_if(std::begin(attributes), std::end(attributes), [](const std::string& str) {
                    return str.find("label") != std::string::npos;
                });
                auto label = "\\nsubgraph=" + std::to_string(map_id.at(node.get_friendly_name())) + "\\n" +
                             "device=" + queryNetworkResult.supportedLayersMap.at(node.get_friendly_name()) + '\"';
                IE_ASSERT(itLabel != attributes.end());
                itLabel->pop_back();
                (*itLabel) += label;
            }}
            .run_on_model(std::const_pointer_cast<ov::Model>(function));
    }

    // Break graph using insertion of result parameter split
    NodeMap<ngraph::Node*> subgraphParameterToPrevResult;
    std::vector<std::shared_ptr<ngraph::op::Result>> results;
    {
        std::set<ngraph::Output<ngraph::Node>> subgraphOutputs;
        for (auto&& input : subgraphInputs) {
            if (!ngraph::op::is_parameter(input.get_node()) && !ngraph::op::is_constant(input.get_node())) {
                subgraphOutputs.insert(input.get_source_output());
            }
        }
        for (auto&& output : subgraphOutputs) {
            auto output_subgraph_id = subgraphIds.at(output.get_node());
            auto inputs = output.get_target_inputs();
            // Collect input subsets from other subgraphs. Each subset of inputs belongs to the same subgraph
            std::map<int, std::set<ngraph::Input<ngraph::Node>>> input_subsets;
            for (auto&& input : inputs) {
                auto input_subgraph_id = subgraphIds.at(input.get_node());
                if (output_subgraph_id != input_subgraph_id) {
                    input_subsets[input_subgraph_id].emplace(input);
                }
            }
            // for each subset of inputs create separate Result operation if subset belongs to other
            for (auto&& input_subset : input_subsets) {
                auto result = std::make_shared<ngraph::op::Result>(output);
                result->set_friendly_name(output.get_node()->get_friendly_name() + "_" +
                                          std::to_string(output.get_index()) + "_" +
                                          std::to_string(input_subset.first) + "_result");
                ngraph::copy_runtime_info(output.get_node_shared_ptr(), result);
                subgraphIds.emplace(result.get(), output_subgraph_id);
                results.push_back(result);
                for (auto&& input : input_subset.second) {
                    output.remove_target_input(input);
                    auto parameter =
                        std::make_shared<ngraph::op::Parameter>(output.get_element_type(), output.get_partial_shape());
                    parameter->set_friendly_name(input.get_node()->get_friendly_name() + "_" +
                                                 std::to_string(input.get_index()) + "_parameter");
                    ngraph::copy_runtime_info(input.get_node()->shared_from_this(), parameter);
                    input.replace_source_output(parameter->output(0));
                    subgraphIds.emplace(parameter.get(), input_subset.first);
                    subgraphParameterToPrevResult.emplace(parameter.get(), result.get());
                    _blobNameMap.emplace(
                        parameter->get_friendly_name(),
                        output.get_node()->get_friendly_name() + ((output.get_node()->get_output_size() != 1)
                                                                      ? ("." + std::to_string(output.get_index()))
                                                                      : std::string{}));
                }
            }
        }
    }

    struct Subgraph {
        ngraph::ResultVector _results;
        ngraph::ParameterVector _parameters;
        ngraph::SinkVector _sinks;
        std::string _affinity;
    };
    std::unordered_map<int, Subgraph> subgraphs;
    // Extracts subgraph parameters, results and affinities
    for (auto&& subgraphIdPtrValue : subgraphIds) {
        auto node = subgraphIdPtrValue.first;
        auto& subgraph = subgraphs[subgraphIdPtrValue.second];
        if (ngraph::op::is_output(node)) {
            subgraph._results.emplace_back(std::dynamic_pointer_cast<ngraph::op::v0::Result>(node->shared_from_this()));
        } else if (ngraph::op::is_parameter(node)) {
            subgraph._parameters.emplace_back(
                std::dynamic_pointer_cast<ngraph::op::v0::Parameter>(node->shared_from_this()));
        } else if (ngraph::op::is_sink(node)) {
            subgraph._sinks.emplace_back(std::dynamic_pointer_cast<ngraph::op::Sink>(node->shared_from_this()));
        }
        auto itAffinity = affinities.find(node);
        if (itAffinity != affinities.end()) {
            subgraph._affinity = itAffinity->second;
        }
    }
    results = {};

    // Subgraph topological sort
    std::vector<Subgraph> allSubgraphs;
    for (auto&& subgraph : subgraphs) {
        allSubgraphs.emplace_back(std::move(subgraph.second));
    }

    std::vector<Subgraph> orderedSubgraphs;
    NodeSet prevResults;
    size_t subgraphTopoSortsStep = 0;
    do {
        IE_ASSERT(subgraphTopoSortsStep < subgraphs.size());
        ++subgraphTopoSortsStep;
        std::vector<Subgraph> newOrderedSubgraphs;
        auto IsOrderedSubGraph = [&](const Subgraph& subgraph) {
            auto& parameters = subgraph._parameters;
            return std::all_of(parameters.begin(),
                               parameters.end(),
                               [&](const ngraph::ParameterVector::value_type& parameter) {
                                   return contains(graphInputNodes, parameter.get()) ||
                                          contains(prevResults, subgraphParameterToPrevResult[parameter.get()]);
                               });
        };
        std::remove_copy_if(std::begin(allSubgraphs),
                            std::end(allSubgraphs),
                            std::back_inserter(newOrderedSubgraphs),
                            [&](const Subgraph& subgraph) {
                                return !IsOrderedSubGraph(subgraph);
                            });
        allSubgraphs.erase(std::remove_if(std::begin(allSubgraphs), std::end(allSubgraphs), IsOrderedSubGraph),
                           std::end(allSubgraphs));
        for (auto&& subgraph : newOrderedSubgraphs) {
            for (auto&& result : subgraph._results) {
                prevResults.insert(result.get());
            }
        }
        std::move(std::begin(newOrderedSubgraphs), std::end(newOrderedSubgraphs), std::back_inserter(orderedSubgraphs));
    } while (!allSubgraphs.empty());

    InputsDataMap externalInputsData = network.getInputsInfo();
    OutputsDataMap externalOutputsData = network.getOutputsInfo();
    _networks.resize(orderedSubgraphs.size());
    std::vector<std::shared_ptr<ngraph::Function>> subFunctions(orderedSubgraphs.size());
    int id = 0;
    for (auto&& subgraph : orderedSubgraphs) {
        _networks[id]._device = subgraph._affinity;
        subFunctions[id] = std::make_shared<ngraph::Function>(subgraph._results,
                                                              subgraph._sinks,
                                                              subgraph._parameters,
                                                              _name + '_' + std::to_string(id));
        _networks[id]._clonedNetwork = CNNNetwork{subFunctions[id]};
        // update of pre-processing info
        auto clonedInputs = _networks[id]._clonedNetwork.getInputsInfo();
        for (auto&& externalInput : externalInputsData) {
            auto itClonedInput = clonedInputs.find(externalInput.first);
            if (itClonedInput != clonedInputs.end() && nullptr != itClonedInput->second) {
                itClonedInput->second->getPreProcess() = externalInput.second->getPreProcess();
                itClonedInput->second->setPrecision(externalInput.second->getPrecision());
                itClonedInput->second->setLayout(externalInput.second->getLayout());
            }
        }
        // update output info
        auto clonedOutputs = _networks[id]._clonedNetwork.getOutputsInfo();
        for (auto&& externalOutput : externalOutputsData) {
            auto itClonedOutput = clonedOutputs.find(externalOutput.first);
            if (itClonedOutput != clonedOutputs.end() && nullptr != itClonedOutput->second) {
                itClonedOutput->second->setPrecision(externalOutput.second->getPrecision());
                itClonedOutput->second->setLayout(externalOutput.second->getLayout());
            }
        }

        auto toLegacyType = [](const ngraph::element::Type& ngraph_type) {
            return (ngraph_type == ngraph::element::f16 || ngraph_type == ngraph::element::bf16) ? ngraph::element::f32
                                                                                                 : ngraph_type;
        };

        // CNNNetwork converts input and output types to preserve legacy behaviour
        // Here io types are reverted to ngraph types with some common plugin behaviour assumption
        // defined in `toLegacyType()`
        for (auto&& input : clonedInputs) {
            if (!InferenceEngine::details::contains(externalInputsData, input.first)) {
                for (auto&& parameter : subgraph._parameters) {
                    auto name = parameter->get_friendly_name();
                    if (parameter->get_friendly_name() == input.first) {
                        input.second->setPrecision(
                            InferenceEngine::details::convertPrecision(toLegacyType(parameter->get_element_type())));
                    }
                }
            }
        }
        for (auto&& output : clonedOutputs) {
            if (!InferenceEngine::details::contains(externalOutputsData, output.first)) {
                for (auto&& result : subgraph._results) {
                    auto source_output = result->input_value(0);
                    auto output_name = ov::op::util::create_ie_output_name(source_output);
                    if (output_name == output.first) {
                        output.second->setPrecision(
                            InferenceEngine::details::convertPrecision(toLegacyType(source_output.get_element_type())));
                    }
                }
            }
        }
        ++id;
    }
    for (auto&& network : _networks) {
        auto metaDevices = _heteroPlugin->GetDevicePlugins(network._device, _config);
        metaDevices[network._device].emplace(CONFIG_KEY_INTERNAL(FORCE_DISABLE_CACHE), "");
        network._network = _heteroPlugin->GetCore()->LoadNetwork(network._clonedNetwork,
                                                                 network._device,
                                                                 metaDevices[network._device]);
    }
}

HeteroExecutableNetwork::HeteroExecutableNetwork(std::istream& heteroModel,
                                                 const std::map<std::string, std::string>& configs,
                                                 Engine* heteroPlugin)
    : _heteroPlugin(heteroPlugin) {
    std::string heteroXmlStr;
    std::getline(heteroModel, heteroXmlStr);

    pugi::xml_document heteroXmlDoc;
    pugi::xml_parse_result res = heteroXmlDoc.load_string(heteroXmlStr.c_str());

    if (res.status != pugi::status_ok) {
        IE_THROW(NetworkNotRead) << "Error reading HETERO device xml header";
    }

    using namespace XMLParseUtils;

    pugi::xml_node heteroNode = heteroXmlDoc.document_element();
    _name = GetStrAttr(heteroNode, "name");

    std::unordered_set<std::string> networkInputs;
    pugi::xml_node inputsNode = heteroNode.child("inputs");
    FOREACH_CHILD (inputNode, inputsNode, "input") { networkInputs.insert(GetStrAttr(inputNode, "name")); }

    std::unordered_set<std::string> networkOutputs;
    pugi::xml_node outputsNode = heteroNode.child("outputs");
    FOREACH_CHILD (outputNode, outputsNode, "output") { networkOutputs.insert(GetStrAttr(outputNode, "name")); }

    Engine::Configs importedConfigs;
    auto configsNode = heteroNode.child("configs");
    FOREACH_CHILD (configNode, configsNode, "config") {
        importedConfigs.emplace(GetStrAttr(configNode, "key"), GetStrAttr(configNode, "value"));
    }

    auto blobNamesNode = heteroNode.child("blob_names_map");
    FOREACH_CHILD (blobNameNode, blobNamesNode, "blob_name_map") {
        _blobNameMap.emplace(GetStrAttr(blobNameNode, "key"), GetStrAttr(blobNameNode, "value"));
    }

    for (auto&& config : configs) {
        importedConfigs[config.first] = config.second;
    }

    std::vector<NetworkDesc> descs;
    pugi::xml_node subnetworksNode = heteroNode.child("subnetworks");
    FOREACH_CHILD (subnetworkNode, subnetworksNode, "subnetwork") {
        auto deviceName = GetStrAttr(subnetworkNode, "device");

        auto metaDevices = _heteroPlugin->GetDevicePlugins(deviceName, importedConfigs);
        assert(metaDevices.size() == 1);
        auto& loadConfig = metaDevices[deviceName];

        InferenceEngine::SoExecutableNetworkInternal executableNetwork;
        CNNNetwork cnnnetwork;
        bool loaded = false;
        if (_heteroPlugin->GetCore()->DeviceSupportsImportExport(deviceName)) {
            executableNetwork = _heteroPlugin->GetCore()->ImportNetwork(heteroModel, deviceName, loadConfig);
        } else {
            // read XML content
            std::string xmlString;
            std::uint64_t dataSize = 0;
            heteroModel.read(reinterpret_cast<char*>(&dataSize), sizeof(dataSize));
            xmlString.resize(dataSize);
            heteroModel.read(const_cast<char*>(xmlString.c_str()), dataSize);

            // read blob content
            InferenceEngine::Blob::Ptr dataBlob;
            heteroModel.read(reinterpret_cast<char*>(&dataSize), sizeof(dataSize));
            if (0 != dataSize) {
                dataBlob = InferenceEngine::make_shared_blob<std::uint8_t>(
                    InferenceEngine::TensorDesc(InferenceEngine::Precision::U8,
                                                {static_cast<std::size_t>(dataSize)},
                                                InferenceEngine::Layout::C));
                dataBlob->allocate();
                heteroModel.read(dataBlob->buffer(), dataSize);
            }

            cnnnetwork = _heteroPlugin->GetCore()->ReadNetwork(xmlString, std::move(dataBlob));
            auto inputs = cnnnetwork.getInputsInfo();
            auto inputsNode = subnetworkNode.child("inputs");
            FOREACH_CHILD (inputNode, inputsNode, "input") {
                auto inputName = GetStrAttr(inputNode, "name");
                inputs[inputName]->setPrecision(Precision::FromStr(GetStrAttr(inputNode, "precision")));
            }

            auto outputs = cnnnetwork.getOutputsInfo();
            auto outputsNode = subnetworkNode.child("outputs");
            FOREACH_CHILD (outputNode, outputsNode, "output") {
                auto outputName = GetStrAttr(outputNode, "name");
                outputs[outputName]->setPrecision(Precision::FromStr(GetStrAttr(outputNode, "precision")));
            }

            executableNetwork = _heteroPlugin->GetCore()->LoadNetwork(cnnnetwork, deviceName, loadConfig);
            loaded = true;
        }

        // restore network inputs and outputs
        for (auto&& input : executableNetwork->GetInputsInfo()) {
            if (networkInputs.end() != networkInputs.find(input.first)) {
                _networkInputs.emplace(input.first, std::make_shared<InputInfo>(*input.second));
            }
        }

        for (auto&& output : executableNetwork->GetOutputsInfo()) {
            if (networkOutputs.end() != networkOutputs.find(output.first)) {
                _networkOutputs.emplace(output.first, std::make_shared<Data>(*output.second));
            }
        }

        descs.emplace_back(NetworkDesc{
            deviceName,
            loaded ? cnnnetwork : CNNNetwork{},
            executableNetwork,
        });
    }
    const auto parseNode = [](const pugi::xml_node& xml_node, bool is_param) -> std::shared_ptr<const ov::Node> {
        const std::string operation_name = GetStrAttr(xml_node, "operation_name");
        const auto elementType = ov::EnumNames<ov::element::Type_t>::as_enum(GetStrAttr(xml_node, "element_type"));

        std::vector<ov::Dimension> partialShape;
        pugi::xml_node partialShapeNode = xml_node.child("partial_shape");
        FOREACH_CHILD (dimNode, partialShapeNode, "dim") {
            partialShape.emplace_back(ov::Dimension(GetInt64Attr(dimNode, "value")));
        }

        pugi::xml_node tensorNamesNode = xml_node.child("tensor_names");
        std::unordered_set<std::string> tensorNames;
        FOREACH_CHILD (tensorNameNode, tensorNamesNode, "tensor_name") {
            tensorNames.insert(GetStrAttr(tensorNameNode, "value"));
        }

        std::shared_ptr<ov::Node> node = std::make_shared<ov::op::v0::Parameter>(elementType, partialShape);
        if (!is_param)
            node = std::make_shared<ov::op::v0::Result>(node);
        node->set_friendly_name(operation_name);
        node->output(0).get_tensor().add_names(tensorNames);

        return node;
    };
    (void)parseNode;

    pugi::xml_node parametersNode = heteroNode.child("parameters");
    FOREACH_CHILD (parameterNode, parametersNode, "parameter") {
        _parameters.emplace_back(parseNode(parameterNode, true));
    }

    pugi::xml_node resultsNode = heteroNode.child("results");
    FOREACH_CHILD (resultNode, resultsNode, "result") { _results.emplace_back(parseNode(resultNode, false)); }

    // save state
    this->_config = importedConfigs;
    this->_networks = std::move(descs);
    this->SetPointerToPlugin(_heteroPlugin->shared_from_this());
}

void HeteroExecutableNetwork::Export(std::ostream& heteroModel) {
    pugi::xml_document doc;
    auto heteroNode = doc.append_child("hetero");
    heteroNode.append_attribute("name").set_value(_name.c_str());

    // CNNNetwork inputs and outputs information

    auto inputsNode = heteroNode.append_child("inputs");
    for (auto&& networkInput : _networkInputs) {
        inputsNode.append_child("input").append_attribute("name").set_value(networkInput.first.c_str());
    }

    auto outputsNode = heteroNode.append_child("outputs");
    for (auto&& networkInput : _networkOutputs) {
        outputsNode.append_child("output").append_attribute("name").set_value(networkInput.first.c_str());
    }

    const auto serializeNode = [&](const std::shared_ptr<const ov::Node>& node, pugi::xml_node& xml_node) {
        const bool is_result = ov::is_type<ov::op::v0::Result>(node);
        const std::string name =
            is_result ? ov::op::util::create_ie_output_name(node->input_value(0)) : node->get_friendly_name();
        xml_node.append_attribute("operation_name").set_value(name.c_str());
        xml_node.append_attribute("element_type").set_value(node->get_output_element_type(0).get_type_name().c_str());

        const auto& pShape = node->get_output_partial_shape(0);
        OPENVINO_ASSERT(pShape.rank().is_static(), "Serialization of shapes with dynamic rank is not supported");
        auto partialShapeNode = xml_node.append_child("partial_shape");
        for (auto&& dim : node->get_output_partial_shape(0)) {
            if (dim.is_dynamic())
                partialShapeNode.append_child("dim").append_attribute("value").set_value("-1");
            else
                partialShapeNode.append_child("dim").append_attribute("value").set_value(
                    std::to_string(dim.get_length()).c_str());
        }

        auto tensorNamesNode = xml_node.append_child("tensor_names");
        for (auto& tensorName : node->get_output_tensor(0).get_names()) {
            tensorNamesNode.append_child("tensor_name").append_attribute("value").set_value(tensorName.c_str());
        }
    };

    // ngraph parameters info
    auto subnetworkParamsNode = heteroNode.append_child("parameters");
    for (auto&& parameter : getInputs()) {
        auto parameterNode = subnetworkParamsNode.append_child("parameter");
        serializeNode(parameter, parameterNode);
    }

    // ngraph results info
    auto subnetworkResultsNode = heteroNode.append_child("results");
    for (auto&& result : getOutputs()) {
        auto parameterNode = subnetworkResultsNode.append_child("result");
        serializeNode(result, parameterNode);
    }

    auto subnetworksNode = heteroNode.append_child("subnetworks");
    for (auto&& subnetwork : _networks) {
        auto subnet = subnetwork._clonedNetwork;
        IE_ASSERT(subnet.getFunction() != nullptr);

        auto subnetworkNode = subnetworksNode.append_child("subnetwork");
        subnetworkNode.append_attribute("device").set_value(subnetwork._device.c_str());

        // inputs info
        auto subnetworkInputsNode = subnetworkNode.append_child("inputs");
        auto inputInfo = subnet.getInputsInfo();
        for (auto&& input : inputInfo) {
            auto inputNode = subnetworkInputsNode.append_child("input");
            inputNode.append_attribute("name").set_value(input.first.c_str());
            inputNode.append_attribute("precision").set_value(input.second->getPrecision().name());
        }

        // outputs info
        auto subnetworkOutputsNode = subnetworkNode.append_child("outputs");
        auto outputInfo = subnet.getOutputsInfo();
        for (auto&& output : outputInfo) {
            auto outputNode = subnetworkOutputsNode.append_child("output");
            outputNode.append_attribute("name").set_value(output.first.c_str());
            outputNode.append_attribute("precision").set_value(output.second->getPrecision().name());
        }
    }

    auto configsNode = heteroNode.append_child("configs");
    for (auto&& config : _config) {
        auto configNode = configsNode.append_child("config");
        configNode.append_attribute("key").set_value(config.first.c_str());
        configNode.append_attribute("value").set_value(config.second.c_str());
    }

    auto blobNamesNode = heteroNode.append_child("blob_names_map");
    for (auto&& kvp : _blobNameMap) {
        auto blobNameNode = blobNamesNode.append_child("blob_name_map");
        blobNameNode.append_attribute("key").set_value(kvp.first.c_str());
        blobNameNode.append_attribute("value").set_value(kvp.second.c_str());
    }

    doc.save(heteroModel, nullptr, pugi::format_raw);
    doc.reset();
    heteroModel << std::endl;

    for (auto&& subnetwork : _networks) {
        if (_heteroPlugin->GetCore()->DeviceSupportsImportExport(subnetwork._device)) {
            subnetwork._network->Export(heteroModel);
        } else {
            auto subnet = subnetwork._clonedNetwork;
            if (!subnet.getFunction()) {
                IE_THROW() << "Hetero device supports only ngraph function representation";
            }

            // Note: custom ngraph extensions are not supported
            std::stringstream xmlFile, binFile;
            ov::pass::Serialize serializer(xmlFile, binFile, ov::pass::Serialize::Version::IR_V10);
            serializer.run_on_model(subnet.getFunction());

            auto m_constants = binFile.str();
            auto m_model = xmlFile.str();

            auto dataSize = static_cast<std::uint64_t>(m_model.size());
            heteroModel.write(reinterpret_cast<char*>(&dataSize), sizeof(dataSize));
            heteroModel.write(m_model.c_str(), dataSize);

            dataSize = static_cast<std::uint64_t>(m_constants.size());
            heteroModel.write(reinterpret_cast<char*>(&dataSize), sizeof(dataSize));
            heteroModel.write(reinterpret_cast<char*>(&m_constants[0]), dataSize);
        }
    }
}

IInferRequestInternal::Ptr HeteroExecutableNetwork::CreateInferRequestImpl(
    const std::vector<std::shared_ptr<const ov::Node>>& inputs,
    const std::vector<std::shared_ptr<const ov::Node>>& outputs) {
    if (!this->_plugin || !_plugin->IsNewAPI())
        return nullptr;
    HeteroInferRequest::SubRequestsList inferRequests;
    int index = 0;
    for (auto&& subnetwork : _networks) {
        HeteroInferRequest::SubRequestDesc desc;
        desc._network = subnetwork._network;
        desc._profilingTask = openvino::itt::handle("Infer" + std::to_string(index++));
        inferRequests.push_back(desc);
    }
    return std::make_shared<HeteroInferRequest>(inputs, outputs, inferRequests, _blobNameMap);
}

IInferRequestInternal::Ptr HeteroExecutableNetwork::CreateInferRequestImpl(InputsDataMap networkInputs,
                                                                           OutputsDataMap networkOutputs) {
    HeteroInferRequest::SubRequestsList inferRequests;
    int index = 0;
    for (auto&& subnetwork : _networks) {
        HeteroInferRequest::SubRequestDesc desc;
        desc._network = subnetwork._network;
        desc._profilingTask = openvino::itt::handle("Infer" + std::to_string(index++));
        inferRequests.push_back(desc);
    }
    return std::make_shared<HeteroInferRequest>(networkInputs, networkOutputs, inferRequests, _blobNameMap);
}

IInferRequestInternal::Ptr HeteroExecutableNetwork::CreateInferRequest() {
    return CreateAsyncInferRequestFromSync<HeteroAsyncInferRequest>();
}

InferenceEngine::Parameter HeteroExecutableNetwork::GetConfig(const std::string& name) const {
    InferenceEngine::Parameter result;
    if (name == "TARGET_FALLBACK" || name == ov::device::priorities.name()) {
        auto it = _config.find("TARGET_FALLBACK");
        if (it == _config.end()) {
            it = _config.find(ov::device::priorities.name());
        }
        if (it != _config.end()) {
            result = it->second;
        } else {
            result = std::string{};
        }
    } else if (name == HETERO_CONFIG_KEY(DUMP_GRAPH_DOT) || name == CONFIG_KEY(EXCLUSIVE_ASYNC_REQUESTS)) {
        auto it = _config.find(name);
        IE_ASSERT(it != _config.end());
        result = it->second == YES ? true : false;
    } else {
        // find config key among plugin config keys
        for (auto&& desc : _networks) {
            auto execNetwork = desc._network;
            auto param = execNetwork->GetMetric(METRIC_KEY(SUPPORTED_CONFIG_KEYS));
            for (auto&& configKey : param.as<std::vector<std::string>>()) {
                if (configKey == name) {
                    return execNetwork->GetConfig(configKey);
                }
            }
        }

        IE_THROW() << "Unsupported ExecutableNetwork config key: " << name;
    }

    return result;
}

using Metrics = std::map<std::string, Parameter>;

namespace {

void collectPluginMetrics(std::vector<std::string>& baseMetrics, const std::vector<::Metrics> pluginMetrics) {
    // check whether the metric has unique name and value among all the plugins
    auto isMetricValueUnique = [&](const std::string& key, const Parameter& value) -> bool {
        if (std::find(baseMetrics.begin(), baseMetrics.end(), key) != baseMetrics.end())
            return false;

        for (auto&& metrics : pluginMetrics) {
            for (auto&& metric : metrics)
                if (key == metric.first && value != metric.second)
                    return false;
        }

        return true;
    };

    // collect only unique metrics
    std::vector<std::string> uniqueMetrics;
    for (auto&& metrics : pluginMetrics) {
        for (auto&& metric : metrics) {
            if (isMetricValueUnique(metric.first, metric.second)) {
                uniqueMetrics.push_back(metric.first);
            }
        }
    }

    // add plugin specific metrics which don't conflict with base ones
    std::copy(uniqueMetrics.begin(), uniqueMetrics.end(), std::back_inserter(baseMetrics));
}

}  // namespace

InferenceEngine::Parameter HeteroExecutableNetwork::GetMetric(const std::string& name) const {
    if (EXEC_NETWORK_METRIC_KEY(SUPPORTED_METRICS) == name) {
        std::vector<std::string> heteroMetrics = {ov::model_name.name(),
                                                  METRIC_KEY(SUPPORTED_METRICS),
                                                  METRIC_KEY(SUPPORTED_CONFIG_KEYS),
                                                  ov::optimal_number_of_infer_requests.name(),
                                                  ov::execution_devices.name()};

        {
            std::vector<::Metrics> pluginMetrics;
            for (auto&& desc : _networks) {
                auto execNetwork = desc._network;
                auto param = execNetwork->GetMetric(METRIC_KEY(SUPPORTED_METRICS));
                ::Metrics metrics;
                for (auto&& metricName : param.as<std::vector<std::string>>()) {
                    metrics[metricName] = execNetwork->GetMetric(metricName);
                }
                pluginMetrics.push_back(std::move(metrics));
            }

            collectPluginMetrics(heteroMetrics, pluginMetrics);
        }

        IE_SET_METRIC_RETURN(SUPPORTED_METRICS, heteroMetrics);
    } else if (EXEC_NETWORK_METRIC_KEY(SUPPORTED_CONFIG_KEYS) == name) {
        std::vector<std::string> heteroConfigKeys = {"TARGET_FALLBACK",
                                                     ov::device::priorities.name(),
                                                     HETERO_CONFIG_KEY(DUMP_GRAPH_DOT),
                                                     CONFIG_KEY(EXCLUSIVE_ASYNC_REQUESTS)};

        {
            std::vector<::Metrics> pluginConfigKeys;
            for (auto&& desc : _networks) {
                auto execNetwork = desc._network;
                auto param = execNetwork->GetMetric(METRIC_KEY(SUPPORTED_CONFIG_KEYS));
                ::Metrics configKeys;
                for (auto&& metricName : param.as<std::vector<std::string>>()) {
                    configKeys[metricName] = execNetwork->GetConfig(metricName);
                }
                pluginConfigKeys.push_back(std::move(configKeys));
            }

            collectPluginMetrics(heteroConfigKeys, pluginConfigKeys);
        }

        IE_SET_METRIC_RETURN(SUPPORTED_CONFIG_KEYS, heteroConfigKeys);
    } else if (ov::model_name == name) {
        return decltype(ov::model_name)::value_type{_name};
    } else if (ov::optimal_number_of_infer_requests == name) {
        unsigned int value = 0u;
        for (auto&& desc : _networks) {
            value = std::max(value,
                             desc._network->GetMetric(METRIC_KEY(OPTIMAL_NUMBER_OF_INFER_REQUESTS)).as<unsigned int>());
        }
        return decltype(ov::optimal_number_of_infer_requests)::value_type{value};
    } else if (name == ov::execution_devices) {
        std::vector<std::string> exeDevices;
        std::set<std::string> s;
        for (auto&& subnetwork : _networks) {
            if (s.count(subnetwork._device) != 0)
                continue;
            s.insert(subnetwork._device);
            exeDevices.push_back(subnetwork._device);
        }
        return decltype(ov::execution_devices)::value_type{exeDevices};
    } else {
        // find metric key among plugin metrics
        for (auto&& desc : _networks) {
            auto execNetwork = desc._network;
            auto param = execNetwork->GetMetric(METRIC_KEY(SUPPORTED_METRICS));
            for (auto&& metricKey : param.as<std::vector<std::string>>()) {
                if (metricKey == name) {
                    return execNetwork->GetMetric(metricKey);
                }
            }
        }

        IE_THROW() << "Unsupported ExecutableNetwork metric key: " << name;
    }
}