// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.
package kudu.tablet;

option java_package = "org.apache.kudu.tablet";

import "kudu/common/common.proto";
import "kudu/consensus/opid.proto";
import "kudu/fs/fs.proto";

// ============================================================================
//  Tablet Metadata
// ============================================================================

message ColumnDataPB {
  required BlockIdPB block = 2;
  // REMOVED: optional ColumnSchemaPB OBSOLETE_schema = 3;
  optional int32 column_id = 4;
}

message DeltaDataPB {
  required BlockIdPB block = 2;
}

message RowSetDataPB {
  required uint64 id = 1;
  required int64 last_durable_dms_id = 2;
  repeated ColumnDataPB columns = 3;
  repeated DeltaDataPB redo_deltas = 4;
  repeated DeltaDataPB undo_deltas = 5;
  optional BlockIdPB bloom_block = 6;
  optional BlockIdPB adhoc_index_block = 7;
}

// State flags indicating whether the tablet is in the middle of being copied
// and is therefore not possible to bring up, whether it has been deleted, or
// whether the data is in a usable state.
enum TabletDataState {
  TABLET_DATA_UNKNOWN = 999;

  // The tablet is set to TABLET_DATA_COPYING state when in the middle of
  // copying data files from a remote peer. If a tablet server crashes with
  // a tablet in this state, the tablet must be deleted and
  // the Tablet Copy process must be restarted for that tablet.
  TABLET_DATA_COPYING = 0;

  // Fresh empty tablets and successfully copied tablets are set to the
  // TABLET_DATA_READY state.
  TABLET_DATA_READY = 1;

  // This tablet is in the process of being deleted.
  // The tablet server should "roll forward" the deletion during boot,
  // rather than trying to load the tablet.
  TABLET_DATA_DELETED = 2;

  // The tablet has been deleted, and now just consists of a "tombstone".
  TABLET_DATA_TOMBSTONED = 3;
}

// The super-block keeps track of the tablet data blocks.
// A tablet contains one or more RowSets, which contain
// a set of blocks (one for each column), a set of delta blocks
// and optionally a block containing the bloom filter
// and a block containing the compound-keys.
message TabletSuperBlockPB {
  // Table ID of the table this tablet is part of.
  required bytes table_id = 1;

  // Tablet Id
  required bytes tablet_id = 2;

  // The latest durable MemRowSet id
  required int64 last_durable_mrs_id = 3;

  // DEPRECATED.
  optional bytes start_key = 4;

  // DEPRECATED.
  optional bytes end_key = 5;

  // The partition of the table.
  optional PartitionPB partition = 13;

  // Tablet RowSets
  repeated RowSetDataPB rowsets = 6;

  // The latest schema
  // TODO: maybe this should be TableSchemaPB? Need to actually put those attributes
  // into use throughout the code. Using the simpler one for now.
  required string table_name = 7;
  required SchemaPB schema = 8;
  required uint32 schema_version = 9;

  // The partition schema of the table.
  optional PartitionSchemaPB partition_schema = 14;

  // The current state of the tablet's data.
  optional TabletDataState tablet_data_state = 10 [ default = TABLET_DATA_UNKNOWN ];

  // Blocks that became orphans after flushing this superblock. In other
  // words, the set difference of the blocks belonging to the previous
  // superblock and this one.
  //
  // It's always safe to delete the blocks found here.
  repeated BlockIdPB orphaned_blocks = 11;

  // For tablets that have been tombstoned, stores the last OpId stored in the
  // WAL before tombstoning.
  // Only relevant for TOMBSTONED tablets.
  optional consensus.OpId tombstone_last_logged_opid = 12;
}

// The enum of tablet states.
// Tablet states are sent in TabletReports and kept in TabletPeer.
enum TabletStatePB {
  UNKNOWN = 999;

  // Tablet has not yet started.
  NOT_STARTED = 5;

  // Indicates the Tablet is bootstrapping, i.e. that the Tablet is not
  // available for RPC.
  BOOTSTRAPPING = 0;

  // Once the configuration phase is over Peers are in RUNNING state. In this
  // state Peers are available for client RPCs.
  RUNNING = 1;

  // The tablet failed to for some reason. TabletPeer::error() will return
  // the reason for the failure.
  FAILED = 2;

  // The Tablet is shutting down, and will not accept further requests.
  QUIESCING = 3;

  // The Tablet has been stopped.
  SHUTDOWN = 4;
}