// Copyright 2015 The Cockroach Authors.
//
// Licensed 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.

syntax = "proto2";
package cockroach.config;
option go_package = "config";

import "gogoproto/gogo.proto";

// GCPolicy defines garbage collection policies which apply to MVCC
// values within a zone.
//
// TODO(spencer): flesh this out to include maximum number of values
//   as well as whether there's an intersection between max values
//   and TTL or a union.
message GCPolicy {
  option (gogoproto.equal) = true;
  option (gogoproto.populate) = true;

  // TTLSeconds specifies the maximum age of a value before it's
  // garbage collected. Only older versions of values are garbage
  // collected. Specifying <=0 mean older versions are never GC'd.
  optional int32 ttl_seconds = 1 [(gogoproto.nullable) = false, (gogoproto.customname) = "TTLSeconds"];
}

// Constraint constrains the stores a replica can be stored on.
message Constraint {
  option (gogoproto.equal) = true;
  option (gogoproto.goproto_stringer) = false;
  option (gogoproto.populate) = true;

  enum Type {
    // DEPRECATED_POSITIVE has no effect on a replica's placement.
    DEPRECATED_POSITIVE = 0;
    // REQUIRED ensures all replicas are placed on stores that match the
    // constraint. Replication will fail if there aren't any such stores.
    REQUIRED = 1;
    // PROHIBITED will prevent replicas from having this key, value.
    PROHIBITED = 2;
  }
  optional Type type = 1 [(gogoproto.nullable) = false];
  // Key is only set if this is a constraint on locality.
  optional string key = 2 [(gogoproto.nullable) = false];
  // Value to constrain to.
  optional string value = 3 [(gogoproto.nullable) = false];
}

// Constraints is a collection of constraints.
message Constraints {
  option (gogoproto.equal) = true;
  option (gogoproto.populate) = true;

  // The number of replicas that should abide by the constraints. If left
  // unspecified (i.e. set to 0), the constraints will be assumed to apply
  // to all replicas of the range.
  // As of v2.0, only REQUIRED constraints are allowed when num_replicas is
  // set to a non-zero value.
  optional int32 num_replicas = 7 [(gogoproto.nullable) = false];

  repeated Constraint constraints = 6 [(gogoproto.nullable) = false];
}

// LeasePreference specifies a preference about where range leases should be
// located.
message LeasePreference {
  option (gogoproto.equal) = true;
  option (gogoproto.populate) = true;

  repeated Constraint constraints = 1 [(gogoproto.nullable) = false, (gogoproto.moretags) = "yaml:\"constraints,flow\""];
}

// ZoneConfig holds configuration that applies to one or more ranges.
//
// Note: when adding.removing fields here, be sure to update
// supportedZoneConfigOptions in the sql package, to synchronize
// with the code for ALTER ... CONFIGURE ZONE.
message ZoneConfig {
  option (gogoproto.equal) = true;
  option (gogoproto.populate) = true;

  reserved 1;
  optional int64 range_min_bytes = 2 [(gogoproto.moretags) = "yaml:\"range_min_bytes\""];
  optional int64 range_max_bytes = 3 [(gogoproto.moretags) = "yaml:\"range_max_bytes\""];
  // If GC policy is not set, uses the next highest, non-null policy
  // in the zone config hierarchy, up to the default policy if necessary.
  optional GCPolicy gc = 4 [(gogoproto.customname) = "GC"];
  // NumReplicas specifies the desired number of replicas
  optional int32 num_replicas = 5 [(gogoproto.moretags) = "yaml:\"num_replicas\""];
  // Constraints constrains which stores the replicas can be stored on. The
  // order in which the constraints are stored is arbitrary and may change.
  // https://github.com/cockroachdb/cockroach/blob/master/docs/RFCS/20160706_expressive_zone_config.md#constraint-system
  //
  // NOTE: The sum of the num_replicas fields of the Constraints must add up to
  // ZoneConfig.num_replicas, or there must be no more than a single Constraints
  // field with num_replicas set to 0.
  repeated Constraints constraints = 6 [(gogoproto.nullable) = false, (gogoproto.moretags) = "yaml:\"constraints,flow\""];

  // InheritedContraints specifies if the value in the Constraints field was
  // inherited from the zone's parent or specified explicitly by the user.
  optional bool inherited_constraints = 10 [(gogoproto.nullable) = false];

  // LeasePreference stores information about where the user would prefer for
  // range leases to be placed. Leases are allowed to be placed elsewhere if
  // needed, but will follow the provided preference when possible.
  //
  // More than one lease preference is allowed, but they should be ordered from
  // most preferred to lease preferred. The first preference that an existing
  // replica of a range matches will take priority.
  repeated LeasePreference lease_preferences = 9 [(gogoproto.nullable) = false,
           (gogoproto.moretags) = "yaml:\"lease_preferences,flow\""];

  // InheritedLeasePreferences specifies if the value in the LeasePreferences field
  // was inherited from the zone's parent or specified explicitly by the user.
  optional bool inherited_lease_preferences = 11 [(gogoproto.nullable) = false];

  // Subzones stores config overrides for "subzones", each of which represents
  // either a SQL table index or a partition of a SQL table index. Subzones are
  // not applicable when the zone does not represent a SQL table (i.e., when the
  // zone represents a database, a special system range, or is itself a
  // subzone.)
  repeated Subzone subzones = 8 [(gogoproto.nullable) = false, (gogoproto.moretags) = "yaml:\"-\""];

  // SubzoneSpans maps each key span in a subzone to the slice index of an entry
  // in SubzoneConfig. Spans are non-overlapping and sorted by start key to
  // allow binary searching. SubzoneSpans can be easily derived from a
  // TableDescriptor, but are denormalized here to make GetZoneConfigForKey
  // lookups efficient.
  repeated SubzoneSpan subzone_spans = 7 [(gogoproto.nullable) = false, (gogoproto.moretags) = "yaml:\"-\""];
}

message Subzone {
  option (gogoproto.equal) = true;
  option (gogoproto.populate) = true;

  // IndexID is the ID of the SQL table index that the subzone represents. It
  // must always be set even though partition names are unique across all of a
  // table's indices.
  optional uint32 index_id = 1 [(gogoproto.nullable) = false, (gogoproto.customname) = "IndexID"];

  // PartitionName is the partition of the SQL table index that the subzone
  // represents. It is empty when the subzone represents the entire index.
  optional string partition_name = 2 [(gogoproto.nullable) = false];

  // Config stores the ZoneConfig that applies to this Subzone. It never
  // contains nested subzones.
  optional ZoneConfig config = 3 [(gogoproto.nullable) = false];
}

message SubzoneSpan {
  option (gogoproto.equal) = true;
  option (gogoproto.populate) = true;

  // Key stores a key suffix that represents the inclusive lower bound for this
  // span. The SQL table prefix, like /Table/51/, is omitted.
  //
  // Both Key and EndKey, below, are cast to roachpb.Key for convenience, but
  // there's no technical restriction that prevents switching them to []byte or
  // another type that communicates their missing prefix.
  optional bytes key = 1 [(gogoproto.casttype) = "github.com/cockroachdb/cockroach/pkg/roachpb.Key"];

  // EndKey stores a key suffix that represents the exclusive upper bound for
  // this span. Like with Key, the SQL table prefix is omitted. If EndKey is
  // empty, it is assumed to be Key.PrefixEnd().
  optional bytes end_key = 2 [(gogoproto.casttype) = "github.com/cockroachdb/cockroach/pkg/roachpb.Key"];

  // SubzoneIndex is the slice index of the Subzone this span belongs to in the
  // parent ZoneConfig's Subzones field.
  optional int32 subzone_index = 3 [(gogoproto.nullable) = false];
}