Add tensor related data structures for the new API

Adds the following:
 - TensorDescriptor: which is responsible for holding the information
 needed to represent a tensor (e.g. shape, dimensions, etc)
 - Tensor: an aggreate object of a descriptor and a backing memory
 - TensorPack: A map of tensor that can be passed to operators as
 inputs/outputs

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: I02734ac6ad85700d91d6e73217b4637adbf5d177
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5260
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/c/AclTensorPack.cpp b/src/c/AclTensorPack.cpp
new file mode 100644
index 0000000..6700ef4
--- /dev/null
+++ b/src/c/AclTensorPack.cpp
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2021 Arm Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "arm_compute/AclEntrypoints.h"
+#include "src/common/ITensor.h"
+#include "src/common/TensorPack.h"
+#include "src/common/utils/Macros.h"
+
+namespace
+{
+using namespace arm_compute;
+StatusCode PackTensorInternal(TensorPack &pack, AclTensor external_tensor, int32_t slot_id)
+{
+    auto status = StatusCode::Success;
+    auto tensor = get_internal(external_tensor);
+
+    status = detail::validate_internal_tensor(tensor);
+
+    if(status != StatusCode::Success)
+    {
+        return status;
+    }
+
+    pack.add_tensor(tensor, slot_id);
+
+    return status;
+}
+} // namespace
+
+extern "C" AclStatus AclCreateTensorPack(AclTensorPack *external_pack, AclContext external_ctx)
+{
+    using namespace arm_compute;
+
+    IContext *ctx = get_internal(external_ctx);
+
+    const StatusCode status = detail::validate_internal_context(ctx);
+    ARM_COMPUTE_RETURN_CENUM_ON_FAILURE(status);
+
+    auto pack = new TensorPack(ctx);
+    if(pack == nullptr)
+    {
+        ARM_COMPUTE_LOG_ERROR_WITH_FUNCNAME_ACL("Couldn't allocate internal resources!");
+        return AclOutOfMemory;
+    }
+    *external_pack = pack;
+
+    return AclSuccess;
+}
+
+extern "C" AclStatus AclPackTensor(AclTensorPack external_pack, AclTensor external_tensor, int32_t slot_id)
+{
+    using namespace arm_compute;
+
+    auto pack = get_internal(external_pack);
+    ARM_COMPUTE_RETURN_CENUM_ON_FAILURE(detail::validate_internal_pack(pack));
+    ARM_COMPUTE_RETURN_CENUM_ON_FAILURE(PackTensorInternal(*pack, external_tensor, slot_id));
+    return AclStatus::AclSuccess;
+}
+
+extern "C" AclStatus AclPackTensors(AclTensorPack external_pack, AclTensor *external_tensors, int32_t *slot_ids, size_t num_tensors)
+{
+    using namespace arm_compute;
+
+    auto pack = get_internal(external_pack);
+    ARM_COMPUTE_RETURN_CENUM_ON_FAILURE(detail::validate_internal_pack(pack));
+
+    for(unsigned i = 0; i < num_tensors; ++i)
+    {
+        ARM_COMPUTE_RETURN_CENUM_ON_FAILURE(PackTensorInternal(*pack, external_tensors[i], slot_ids[i]));
+    }
+    return AclStatus::AclSuccess;
+}
+
+extern "C" AclStatus AclDestroyTensorPack(AclTensorPack external_pack)
+{
+    using namespace arm_compute;
+
+    auto       pack   = get_internal(external_pack);
+    StatusCode status = detail::validate_internal_pack(pack);
+    ARM_COMPUTE_RETURN_CENUM_ON_FAILURE(status);
+
+    delete pack;
+
+    return AclSuccess;
+}