..
   Copyright (c) 2021-2022, NVIDIA CORPORATION. All rights reserved.
   NVIDIA CORPORATION and its licensors retain all intellectual property
   and proprietary rights in and to this software, related documentation
   and any modifications thereto. Any use, reproduction, disclosure or
   distribution of this software and related documentation without an express
   license agreement from NVIDIA CORPORATION is strictly prohibited.

Graph Execution Engine
======================

Graph Execution Engine is used to execute AI application graphs. It accepts multiple graph files as input, and all graphs are executed in same process context. It also needs manifest files as input which includes list of extensions to load. It must list all extensions required for the graph. Registry `graph install` command can be used to download all required extensions and generate manifest file.


::

      /opt/nvidia/graph-composer/gxe --help
        Flags from gxf/gxe/gxe.cpp:
        -app (GXF app file to execute. Multiple files can be comma-separated)
          type: string default: ""
        -app_root (Root path for GXF app and subgraph files with relative path)
          type: string default: ""
        -graph_directory (Path to a directory for searching graph files.)
          type: string default: ""
        -log_file_path (Path to a file for logging.) type: string default: ""
        -manifest (GXF manifest file with extensions. Multiple files can be
          comma-separated) type: string default: ""
        -severity (Set log severity levels: 0=None, 1=Error, 2=Warning, 3=Info,
          4=Debug. Default: Info) type: int32 default: 3

Other options

1. How to override the parameters that are specified in the graph file using command line options?
--------------------------------------------------------------------------------------------------

1. Single graph file
^^^^^^^^^^^^^^^^^^^^
Command line option ``--param`` of gxe can be used to override the parameters specified
in the graph file. Complete path is delimited by ``/`` only exception being the last literal whose value has to be
overridden is delimited by ``=``

Below is the snippet of a graph file

.. code-block:: yaml

    ---
    name: Entity1
    components:
    - type: nvidia::gxf::PeriodicSchedulingTerm
      parameters:
        recess_period: 2000000
    - type: nvidia::gxf::CountSchedulingTerm
      parameters:
        count: 100
    - type: nvidia::gxf::test::StepCount
      parameters:
        expected_count: 100
    ---

To override the ``count`` of ``CountSchedulingTerm`` below command line option can be used.

:command:`--param=Entity1/nvidia::gxf::CountSchedulingTerm/count=101`

2. Multiple subgraph files
^^^^^^^^^^^^^^^^^^^^^^^^^^
When multiple subgraph files are used, then the entity names of various subgraphs are delimited by ``.`` until the
componet name is reached whose parameter has to be overriden. Hereafter the component type and the parameter will be
delimited by ``/``

Below is the snippet of multiple sub graph files

test_subgraph.yaml

.. code-block:: yaml

  ---
  name: gather_subgraph
  components:
  - type: nvidia::gxf::Subgraph
    name: gather_subgraph
    parameters:
      location: "gxf/test/apps/gather_subgraph.yaml"
      prerequisites:
        monitored_rx: rx/signal
  - name: output
    parameters:
      max_capacity: 2
  - name: forward1_buf_term
    parameters:
      min_size: 1
  ---

gather_subgraph.yaml

.. code-block:: yaml

  ---
  name: forward_subgraph_1
  components:
  - name: forward
    type: nvidia::gxf::Subgraph
    parameters:
      location: gxf/test/apps/forward_subgraph.yaml
      prerequisites:
        monitored_rx: prerequisites/monitored_rx
  ---

forward_subgraph.yaml

.. code-block:: yaml

  ---
  name: counter
  components:
  - name: step_counter
    type: nvidia::gxf::test::StepCount
    parameters:
      expected_count: 100
  ---

To override the ``expected_count`` of ``step_counter`` below command line option can be used.

:command:`--param=gather_subgraph.forward_subgraph_1.counter/nvidia::gxf::test::StepCount/expected_count=101`