schema/bundled_program_schema.fbs

// Copyright (c) Meta Platforms, Inc. and affiliates.

//
// See README.md before modifying this file.
//

include "scalar_type.fbs";

// TODO make this unique from the main schemas namespace
namespace executorch_flatbuffer;

// Identifier of a valid bundled program schema.
file_identifier "BP04";
// Extension of written files.
file_extension "bp";

// Reason for basic struct: union value type can only be table/struct/string
table BundledInt {
  int_val:long;
}

table BundledBool {
  bool_val:bool;
}

table BundledDouble {
  double_val:double;
}

// All information we need to bundle for a tensor EValue input.
table BundledTensor {
  // The scalar type of Tensor
  scalar_type: ScalarType;
  // The target sizes of the tensor.
  sizes: [int];
  // The contents of the corresponding input tensor.
  data: [ubyte] (force_align: 16);
  dim_order:[ubyte];
}

union BundledValueUnion {
  BundledTensor,
  BundledInt,
  BundledBool,
  BundledDouble,
}

// Abstraction for BundledIOSet values
table BundledValue {
  val: BundledValueUnion;
}

// All inputs and referenced outputs needs for single verification.
table BundledIOSet {
  // All inputs required by Program for execution. Its length should be
  // equal to the length of program inputs.
  inputs: [BundledValue];

  // The expected outputs generated while running the model in eager mode
  // using the inputs provided. Its length should be equal to the length
  // of program outputs.
  expected_outputs: [BundledValue];
}


table BundledString {
  string_value: string;
}

table BundledBytes {
  bytes_value: [ubyte];
}

union BundledAttachmentValueUnion {
  BundledBytes,
  BundledInt,
  BundledDouble,
  BundledBool,
  BundledString,
}

// Abstraction for BundledAttachment values
table BundledAttachmentValue {
  val: BundledAttachmentValueUnion;
}

// Extra data or files need to be recorded in BundledProgram
// for executing and verifying.
table BundledAttachment {
  key: string;
  val: BundledAttachmentValue;
}


// Context for testing and verifying an exceution plan.
table BundledExecutionPlanTest {

  // Sets of input/outputs to test with.
  test_sets: [BundledIOSet];

  // Optional extra data used for verification.
  metadata: [BundledAttachment];
}

// Executorch program bunlded with data for verification.
table BundledProgram {
  // Schema version.
  version:uint;

  // Extra files or other data attached by user for verification
  attachments: [BundledAttachment];

  // Test sets and other meta datas to verify the whole program.
  // Each BundledExecutionPlanTest should be used for the execution plan of program sharing same index.
  // Its length should be equal to the number of execution plans in program.
  execution_plan_tests: [BundledExecutionPlanTest];

  // The binary data of a serialized Executorch program.
  // The following `force_align` may sliently override any larger force_align
  // used in the program. Therefore, to keep the data (including constant
  // tensor, delegate data, etc, see schema.fbs for more info) in the
  // executorch program keeps the same alignment as original no matter how
  // the program schema changes, we need to make the force_align here the max
  // one around all kinds of force_align in the current and future program
  // schema, so we use the 16, the largest possible alignment of flatbuffer,
  // as the force_align here.
  // In the future, we may need to revisit that to enforce larger alignment
  // constraint. If needed, check against FLATBUFFERS_MAX_ALIGNMENT in the
  // flatbuffers/base.h, which is the given alignment ceiling of flatbuffer.
  program: [ubyte] (force_align: 16);
}

root_type BundledProgram;