1// Copyright (C) MongoDB, Inc. 2017-present.
2//
3// Licensed under the Apache License, Version 2.0 (the "License"); you may
4// not use this file except in compliance with the License. You may obtain
5// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
6
7package readpref
8
9import (
10	"errors"
11	"time"
12
13	"go.mongodb.org/mongo-driver/tag"
14)
15
16// ErrInvalidTagSet indicates that an invalid set of tags was specified.
17var ErrInvalidTagSet = errors.New("an even number of tags must be specified")
18
19// Option configures a read preference
20type Option func(*ReadPref) error
21
22// WithMaxStaleness sets the maximum staleness a
23// server is allowed.
24func WithMaxStaleness(ms time.Duration) Option {
25	return func(rp *ReadPref) error {
26		rp.maxStaleness = ms
27		rp.maxStalenessSet = true
28		return nil
29	}
30}
31
32// WithTags sets a single tag set used to match
33// a server. The last call to WithTags or WithTagSets
34// overrides all previous calls to either method.
35func WithTags(tags ...string) Option {
36	return func(rp *ReadPref) error {
37		length := len(tags)
38		if length < 2 || length%2 != 0 {
39			return ErrInvalidTagSet
40		}
41
42		tagset := make(tag.Set, 0, length/2)
43
44		for i := 1; i < length; i += 2 {
45			tagset = append(tagset, tag.Tag{Name: tags[i-1], Value: tags[i]})
46		}
47
48		return WithTagSets(tagset)(rp)
49	}
50}
51
52// WithTagSets sets the tag sets used to match
53// a server. The last call to WithTags or WithTagSets
54// overrides all previous calls to either method.
55func WithTagSets(tagSets ...tag.Set) Option {
56	return func(rp *ReadPref) error {
57		rp.tagSets = tagSets
58		return nil
59	}
60}
61