syntax = "proto3";

package tensorflow;
option cc_enable_arenas = true;
option java_outer_classname = "TensorBundleProtos";
option java_multiple_files = true;
option java_package = "org.tensorflow.util";

import "tensorflow/core/framework/tensor_shape.proto";
import "tensorflow/core/framework/tensor_slice.proto";
import "tensorflow/core/framework/types.proto";
import "tensorflow/core/framework/versions.proto";

// Protos used in the tensor bundle module (tf/core/util/tensor_bundle/).

// Special header that is associated with a bundle.
//
// TODO(zongheng,zhifengc): maybe in the future, we can add information about
// which binary produced this checkpoint, timestamp, etc. Sometime, these can be
// valuable debugging information. And if needed, these can be used as defensive
// information ensuring reader (binary version) of the checkpoint and the writer
// (binary version) must match within certain range, etc.
message BundleHeaderProto {
  // Number of data files in the bundle.
  int32 num_shards = 1;

  // An enum indicating the endianness of the platform that produced this
  // bundle.  A bundle can only be read by a platform with matching endianness.
  // Defaults to LITTLE, as most modern platforms are little-endian.
  //
  // Affects the binary tensor data bytes only, not the metadata in protobufs.
  enum Endianness {
    LITTLE = 0;
    BIG = 1;
  }
  Endianness endianness = 2;

  // Versioning of the tensor bundle format.
  VersionDef version = 3;
}

// Describes the metadata related to a checkpointed tensor.
message BundleEntryProto {
  // The tensor dtype and shape.
  DataType dtype = 1;
  TensorShapeProto shape = 2;
  // The binary content of the tensor lies in:
  //   File "shard_id": bytes [offset, offset + size).
  int32 shard_id = 3;
  int64 offset = 4;
  int64 size = 5;

  // The CRC32C checksum of the tensor bytes.
  fixed32 crc32c = 6;

  // Iff present, this entry represents a partitioned tensor.  The previous
  // fields are interpreted as follows:
  //
  //   "dtype", "shape": describe the full tensor.
  //   "shard_id", "offset", "size", "crc32c": all IGNORED.
  //      These information for each slice can be looked up in their own
  //      BundleEntryProto, keyed by each "slice_name".
  repeated TensorSliceProto slices = 7;
}
