/*
** Copyright © 2018, Oracle and/or its affiliates. All rights reserved.
**
** Licensed under the Universal Permissive License v 1.0 as shown at
** http://oss.oracle.com/licenses/upl.
*/
namespace graphpipe;

/*
  Enumeration of supported types.
*/
enum Type:uint8 {
    Null,
    Uint8,
    Int8,
    Uint16,
    Int16,
    Uint32,
    Int32,
    Uint64,
    Int64,
    Float16,
    Float32,
    Float64,
    String,
}

/*
  Tensor definition.

  type: defines what type of data this Tensor holds
  shape: an array that describes the shape of the Tensor (like [10, 3, 224, 224])
  data: stores the actual tensor data for all types but String
  string_val: holds the data for tensors of type String
*/
table Tensor {
    type:Type;
    shape:[int64];
    data:[uint8];
    string_val:[string];
}

/*
  Req definition, which is a union of an InferRequest and a a MetadataRequest.
*/
union Req {InferRequest, MetadataRequest}

/*
  Request definition, which is a container for one of the two allowed request types.
  req: a union representing an InferRequest or a MetadataRequest.
*/
table Request {
    req:Req;
}

/*
  Infer Request definition, which is used to request data from a remote model.
  config: application-specific string used for request-specific model configuration.
  input_names: a list of input names
  input_tensors: a list of input tensors, associated with input_names
  output_names: a list of outputs to return in response to the provided inputs
*/
table InferRequest {
    config:string; // optional
    input_names:[string]; // optional
    input_tensors:[Tensor];
    output_names:[string]; // optional
}

/*
  Error definition
  code: integer representation of the error
  message: Human-readable message description
*/
table Error {
    code:int64;
    message:string;
}

/*
  InferResponse definition. Should contain either a list of tensors or a list
  of errors, but not both.
  output_tensors: a list of output_tensors, in the order requested by InferRequest.output_names
  errors: A list of errors that occurred during processing, if any
*/
table InferResponse {
    output_tensors:[Tensor];
    errors:[Error];
}

/*
  MetadatRequest.  Used to request metadata about a graphpipe model server.
*/
table MetadataRequest {}

/*
  IOMetadata definition.  Provides info about inputs and outputs of a model.
  name: name of the input/output
  description: description of the input/output
  shape: input or output shape
  type: Type of the input/output
*/
table IOMetadata {
    name:string; // required
    description:string; // optional
    shape:[int64]; // required
    type:Type; // required
}

/*
  MetadataResponse definition.  Describes characteristics of the server and the model being served.
  name: name of the model being served
  version: version of the server
  server: name of the server
  description: description of the model being served
  inputs: metadata about the model's inputs
  outputs: metadata about the model's outputs
*/
table MetadataResponse {
    name:string; // optional
    version:string; // optional
    server:string; // optional
    description:string; //optional
    inputs:[IOMetadata]; // required
    outputs:[IOMetadata]; // required
}

root_type Request;