include/armnn/backends/ITensorHandleFactory.hpp

//
// Copyright © 2017, 2019-2022 Arm Ltd and Contributors. All rights reserved.
// SPDX-License-Identifier: MIT
//

#pragma once

#include "ITensorHandle.hpp"
#include <armnn/MemorySources.hpp>
#include <armnn/Tensor.hpp>
#include <armnn/Types.hpp>
#include <armnn/utility/IgnoreUnused.hpp>

#include <memory>
#include <string>
#include <vector>

namespace armnn
{
class IConnectableLayer;

/// Capability class to calculate in the GetCapabilities function
/// so that only the capability in the scope can be choose to calculate
enum class CapabilityClass
{
    PaddingRequired = 1,
    FallbackImportDisabled = 2,

    // add new enum values here

    CapabilityClassMax = 254
};

/// Capability of the TensorHandleFactory
struct Capability
{
    Capability(CapabilityClass capabilityClass, bool value)
        : m_CapabilityClass(capabilityClass)
        , m_Value(value)
    {}

    CapabilityClass m_CapabilityClass;
    bool            m_Value;
};

class ITensorHandleFactory
{
public:
    using FactoryId = std::string;
    static const FactoryId LegacyFactoryId;   /// Use the workload factory to create the tensor handle
    static const FactoryId DeferredFactoryId; /// Some TensorHandleFactory decisions are deferred to run-time

    virtual ~ITensorHandleFactory() {}

    virtual std::unique_ptr<ITensorHandle> CreateSubTensorHandle(ITensorHandle& parent,
                                                                 TensorShape const& subTensorShape,
                                                                 unsigned int const* subTensorOrigin) const = 0;

    virtual std::unique_ptr<ITensorHandle> CreateTensorHandle(const TensorInfo& tensorInfo) const = 0;

    virtual std::unique_ptr<ITensorHandle> CreateTensorHandle(const TensorInfo& tensorInfo,
                                                              DataLayout dataLayout) const = 0;

    /// Utility Functions for backends which require TensorHandles to have unmanaged memory.
    /// These should be overloaded if required to facilitate direct import of input tensors
    /// and direct export of output tensors.
    virtual std::unique_ptr<ITensorHandle> CreateTensorHandle(const TensorInfo& tensorInfo,
                                                              const bool IsMemoryManaged) const
    {
        IgnoreUnused(IsMemoryManaged);
        return CreateTensorHandle(tensorInfo);
    }

    virtual std::unique_ptr<ITensorHandle> CreateTensorHandle(const TensorInfo& tensorInfo,
                                                              DataLayout dataLayout,
                                                              const bool IsMemoryManaged) const
    {
        IgnoreUnused(IsMemoryManaged);
        return CreateTensorHandle(tensorInfo, dataLayout);
    }

    virtual const FactoryId& GetId() const = 0;

    virtual bool SupportsInPlaceComputation() const { return false; }

    virtual bool SupportsSubTensors() const = 0;

    virtual bool SupportsMapUnmap() const { return true; }

    virtual MemorySourceFlags GetExportFlags() const { return 0; }
    virtual MemorySourceFlags GetImportFlags() const { return 0; }

    virtual std::vector<Capability> GetCapabilities(const IConnectableLayer* layer,
                                                    const IConnectableLayer* connectedLayer,
                                                    CapabilityClass capabilityClass)
    {
        IgnoreUnused(layer);
        IgnoreUnused(connectedLayer);
        IgnoreUnused(capabilityClass);
        return std::vector<Capability>();
    }
};

enum class EdgeStrategy
{
    Undefined,              /// No strategy has been defined. Used internally to verify integrity of optimizations.
    DirectCompatibility,    /// Destination backend can work directly with tensors on source backend.
    ExportToTarget,         /// Source backends tensor data can be exported to destination backend tensor without copy.
    CopyToTarget            /// Copy contents from source backend tensor to destination backend tensor.
};

} //namespace armnn