// Copyright 2018 Google LLC
//
// 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 = "proto3";

package google.spanner.v1;

import "google/api/annotations.proto";
import "google/protobuf/struct.proto";

option csharp_namespace = "Google.Cloud.Spanner.V1";
option go_package = "google.golang.org/genproto/googleapis/spanner/v1;spanner";
option java_multiple_files = true;
option java_outer_classname = "KeysProto";
option java_package = "com.google.spanner.v1";
option php_namespace = "Google\\Cloud\\Spanner\\V1";

// KeyRange represents a range of rows in a table or index.
//
// A range has a start key and an end key. These keys can be open or
// closed, indicating if the range includes rows with that key.
//
// Keys are represented by lists, where the ith value in the list
// corresponds to the ith component of the table or index primary key.
// Individual values are encoded as described
// [here][google.spanner.v1.TypeCode].
//
// For example, consider the following table definition:
//
//     CREATE TABLE UserEvents (
//       UserName STRING(MAX),
//       EventDate STRING(10)
//     ) PRIMARY KEY(UserName, EventDate);
//
// The following keys name rows in this table:
//
//     ["Bob", "2014-09-23"]
//     ["Alfred", "2015-06-12"]
//
// Since the `UserEvents` table's `PRIMARY KEY` clause names two
// columns, each `UserEvents` key has two elements; the first is the
// `UserName`, and the second is the `EventDate`.
//
// Key ranges with multiple components are interpreted
// lexicographically by component using the table or index key's declared
// sort order. For example, the following range returns all events for
// user `"Bob"` that occurred in the year 2015:
//
//     "start_closed": ["Bob", "2015-01-01"]
//     "end_closed": ["Bob", "2015-12-31"]
//
// Start and end keys can omit trailing key components. This affects the
// inclusion and exclusion of rows that exactly match the provided key
// components: if the key is closed, then rows that exactly match the
// provided components are included; if the key is open, then rows
// that exactly match are not included.
//
// For example, the following range includes all events for `"Bob"` that
// occurred during and after the year 2000:
//
//     "start_closed": ["Bob", "2000-01-01"]
//     "end_closed": ["Bob"]
//
// The next example retrieves all events for `"Bob"`:
//
//     "start_closed": ["Bob"]
//     "end_closed": ["Bob"]
//
// To retrieve events before the year 2000:
//
//     "start_closed": ["Bob"]
//     "end_open": ["Bob", "2000-01-01"]
//
// The following range includes all rows in the table:
//
//     "start_closed": []
//     "end_closed": []
//
// This range returns all users whose `UserName` begins with any
// character from A to C:
//
//     "start_closed": ["A"]
//     "end_open": ["D"]
//
// This range returns all users whose `UserName` begins with B:
//
//     "start_closed": ["B"]
//     "end_open": ["C"]
//
// Key ranges honor column sort order. For example, suppose a table is
// defined as follows:
//
//     CREATE TABLE DescendingSortedTable {
//       Key INT64,
//       ...
//     ) PRIMARY KEY(Key DESC);
//
// The following range retrieves all rows with key values between 1
// and 100 inclusive:
//
//     "start_closed": ["100"]
//     "end_closed": ["1"]
//
// Note that 100 is passed as the start, and 1 is passed as the end,
// because `Key` is a descending column in the schema.
message KeyRange {
  // The start key must be provided. It can be either closed or open.
  oneof start_key_type {
    // If the start is closed, then the range includes all rows whose
    // first `len(start_closed)` key columns exactly match `start_closed`.
    google.protobuf.ListValue start_closed = 1;

    // If the start is open, then the range excludes rows whose first
    // `len(start_open)` key columns exactly match `start_open`.
    google.protobuf.ListValue start_open = 2;
  }

  // The end key must be provided. It can be either closed or open.
  oneof end_key_type {
    // If the end is closed, then the range includes all rows whose
    // first `len(end_closed)` key columns exactly match `end_closed`.
    google.protobuf.ListValue end_closed = 3;

    // If the end is open, then the range excludes rows whose first
    // `len(end_open)` key columns exactly match `end_open`.
    google.protobuf.ListValue end_open = 4;
  }
}

// `KeySet` defines a collection of Cloud Spanner keys and/or key ranges. All
// the keys are expected to be in the same table or index. The keys need
// not be sorted in any particular way.
//
// If the same key is specified multiple times in the set (for example
// if two ranges, two keys, or a key and a range overlap), Cloud Spanner
// behaves as if the key were only specified once.
message KeySet {
  // A list of specific keys. Entries in `keys` should have exactly as
  // many elements as there are columns in the primary or index key
  // with which this `KeySet` is used.  Individual key values are
  // encoded as described [here][google.spanner.v1.TypeCode].
  repeated google.protobuf.ListValue keys = 1;

  // A list of key ranges. See [KeyRange][google.spanner.v1.KeyRange] for more
  // information about key range specifications.
  repeated KeyRange ranges = 2;

  // For convenience `all` can be set to `true` to indicate that this
  // `KeySet` matches all keys in the table or index. Note that any keys
  // specified in `keys` or `ranges` are only yielded once.
  bool all = 3;
}
