[Add] Slice Operator

include/aidge/operator/Slice.hpp

+/********************************************************************************
+ * Copyright (c) 2023 CEA-List
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ ********************************************************************************/
+
+#ifndef AIDGE_CORE_OPERATOR_SLICE_H_
+#define AIDGE_CORE_OPERATOR_SLICE_H_
+
+#include <memory>
+#include <vector>
+
+#include "aidge/backend/OperatorImpl.hpp"
+#include "aidge/data/Data.hpp"
+#include "aidge/data/Tensor.hpp"
+#include "aidge/graph/Node.hpp"
+#include "aidge/operator/Operator.hpp"
+#include "aidge/utils/Registrar.hpp"
+#include "aidge/utils/StaticAttributes.hpp"
+#include "aidge/utils/Types.h"
+
+namespace Aidge {
+enum class SliceAttr { Beginning, SliceDims };
+
+template <DimIdx_t DIM>
+class Slice_Op
+    : public Operator,
+      public Registrable<Slice_Op<DIM>, std::string, std::unique_ptr<OperatorImpl>(const Slice_Op<DIM> &)>,
+      public StaticAttributes<SliceAttr, std::size_t, std::array<DimSize_t, DIM>> {
+public:
+    // FIXME: change accessibility
+    std::shared_ptr<Tensor> mInput = std::make_shared<Tensor>();
+    const std::shared_ptr<Tensor> mOutput = std::make_shared<Tensor>();
+
+public:
+    static constexpr const char *Type = "Slice";
+
+    Slice_Op() = delete;
+
+    using Attributes_ = StaticAttributes<SliceAttr, std::size_t, std::array<DimSize_t, DIM>>;
+    template <SliceAttr e>
+    using attr = typename Attributes_::template attr<e>;
+
+    Slice_Op(std::size_t beginningPos, std::array<DimSize_t, DIM> sliceDims)
+        : Operator(Type),
+          Attributes_(attr<SliceAttr::Beginning>(beginningPos),
+                      attr<SliceAttr::SliceDims>(sliceDims))
+    {
+        setDatatype(DataType::Float32);
+    }
+
+    /**
+     * @brief Copy-constructor. Copy the operator attributes and its output tensor(s), but not its
+     * input tensors (the new operator has no input associated).
+     * @param op Operator to copy.
+     */
+    Slice_Op(const Slice_Op &op)
+        : Operator(Type),
+          Attributes_(op),
+          mOutput(std::make_shared<Tensor>(*op.mOutput))
+    {
+        // cpy-ctor
+        setDatatype(op.mOutput->dataType());
+        mImpl = op.mImpl ? Registrar<Slice_Op<DIM>>::create(mOutput->getImpl()->backend())(*this)
+                         : nullptr;
+    }
+
+public:
+    /**
+     * @brief Clone the operator using its copy-constructor.
+     * @see Operator::Slice_Op
+     */
+    std::shared_ptr<Operator> clone() const override { return std::make_shared<Slice_Op>(*this); }
+
+    void associateInput(const IOIndex_t inputIdx, std::shared_ptr<Data> data) override final {
+        assert(inputIdx == 0 && "operator supports only 1 input");
+        (void)inputIdx;  // avoid unused warning
+        assert(strcmp(data->type(), Tensor::Type) == 0 && "input data must be of Tensor type");
+        mInput = std::dynamic_pointer_cast<Tensor>(data);
+    }
+
+    void computeOutputDims() override final {
+        if (!mInput->empty()) {
+            // Check input dimensions is compatible with slice dimensions
+            if (mInput->nbDims() != DIM) {
+                printf("Error: input and slice dimensions are not the same size.\n");
+                exit(-1);
+            }
+            std::array<DimSize_t, DIM> outputDims;
+
+            // Check that the sliced Tensor is actually part of the input Tensor
+            // For a 5*5 tensor ('x') and a 3*3 slice kernel ('o'):
+            // xxxxx               xxxxx
+            // xxxxx               xxxxx
+            // xxooo  --> ok       xxxoo --> out of bound
+            // xxooo               xxxoo
+            // xxooo               xxxoo
+            std::vector<std::size_t> beginningCoords = mInput->getCoord(this->template getAttr<SliceAttr::Beginning>());
+            for (std::size_t i = 0; i < DIM; ++i) {
+                if (beginningCoords[i] + this->template getAttr<SliceAttr::SliceDims>()[i] >= mInput->dims()[i]) {
+                    printf("ROI of Slice operator out of bounds");
+                    exit(-1);
+                } else {
+                    outputDims[i] = this->template getAttr<SliceAttr::SliceDims>()[i];
+                }
+            }
+
+            mOutput->resize(outputDims);
+        }
+    }
+
+    bool outputDimsForwarded() const override final { return !(mOutput->empty()); }
+
+    inline Tensor &input(const IOIndex_t /*inputIdx*/) const override final {
+        return *(mInput.get());
+    }
+    inline Tensor &output(const IOIndex_t /*outputIdx*/) const override final {
+        return *(mOutput.get());
+    }
+
+    inline std::shared_ptr<Tensor> getInput(const IOIndex_t inputIdx) const override final {
+        assert((inputIdx == 0) && "Slice Operator has only 1 input");
+        (void)inputIdx;  // avoid unused warning
+        return mInput;
+    }
+    inline std::shared_ptr<Tensor> getOutput(const IOIndex_t outputIdx) const override final {
+        assert((outputIdx == 0) && "Slice Operator has only 1 output");
+        (void)outputIdx;  // avoid unused warning
+        return mOutput;
+    }
+
+    std::shared_ptr<Data> getRawInput(const IOIndex_t inputIdx) const override final {
+        assert(inputIdx == 0 && "operator supports only 1 input");
+        (void)inputIdx;  // avoid unused warning
+        return std::static_pointer_cast<Data>(mInput);
+    }
+    std::shared_ptr<Data> getRawOutput(const IOIndex_t outputIdx) const override final {
+        assert(outputIdx == 0 && "operator supports only 1 output");
+        (void)outputIdx;  // avoid unused warning
+        return mOutput;
+    }
+
+    void setBackend(const std::string &name) {
+        mImpl = Registrar<Slice_Op>::create(name)(*this);
+        mOutput->setBackend(name);
+
+        // FIXME: temporary workaround
+        mInput->setBackend(name);
+    }
+    void setDatatype(const DataType &datatype) {
+        mOutput->setDatatype(datatype);
+
+        // FIXME: temporary workaround
+        mInput->setDatatype(datatype);
+    }
+
+    inline IOIndex_t nbInputs() const noexcept override final { return 1; }
+    inline IOIndex_t nbDataInputs() const noexcept override final { return 1; }
+    inline IOIndex_t nbOutputs() const noexcept override final { return 1; }
+};
+
+template <DimIdx_t DIM>
+inline std::shared_ptr<Node> Slice(std::size_t beginningPos, std::array<DimSize_t, DIM> sliceDims,
+                                   const std::string &name = "") {
+    // FIXME: properly handle default w&b initialization in every cases
+    return std::make_shared<Node>(std::make_shared<Slice_Op<DIM>>( beginningPos, sliceDims), name);
+}
+
+template <DimIdx_t DIM>
+inline std::shared_ptr<Node> Slice(std::size_t beginningPos, DimSize_t const (&sliceDims)[DIM], const std::string& name = "") {
+  return Slice(beginningPos, to_array(sliceDims), name);
+}
+}  // namespace Aidge
+
+namespace {
+template <>
+const char *const EnumStrings<Aidge::SliceAttr>::data[] = { "Beginning", "SliceDims" };
+}
+
+#endif /* AIDGE_CORE_OPERATOR_RELU_H_ */