Refactor metrics/cloudwatch (#1202)
* Refactor metrics/cloudwatch:
- Export `option` type for better documentation
- Add documentation for exported option functions
- Use `CloudWatch.apply` method and remove unused `Percentiles` type
* Remove the `apply` method
sina safari authored 2 years ago
GitHub committed 2 years ago
| 21 | 21 | maxConcurrentRequests = 20 |
| 22 | 22 | maxValuesInABatch = 150 |
| 23 | 23 | ) |
| 24 | ||
| 25 | type Percentiles []struct { | |
| 26 | s string | |
| 27 | f float64 | |
| 28 | } | |
| 29 | 24 | |
| 30 | 25 | // CloudWatch receives metrics observations and forwards them to CloudWatch. |
| 31 | 26 | // Create a CloudWatch object, use it to create metrics, and pass those metrics as |
| 45 | 40 | numConcurrentRequests int |
| 46 | 41 | } |
| 47 | 42 | |
| 48 | type option func(*CloudWatch) | |
| 49 | ||
| 50 | func (s *CloudWatch) apply(opt option) { | |
| 51 | if opt != nil { | |
| 52 | opt(s) | |
| 53 | } | |
| 54 | } | |
| 55 | ||
| 56 | func WithLogger(logger log.Logger) option { | |
| 43 | // Option is a function adapter to change config of the CloudWatch struct | |
| 44 | type Option func(*CloudWatch) | |
| 45 | ||
| 46 | // WithLogger sets the Logger that will receive error messages generated | |
| 47 | // during the WriteLoop. By default, fmt logger is used. | |
| 48 | func WithLogger(logger log.Logger) Option { | |
| 57 | 49 | return func(c *CloudWatch) { |
| 58 | 50 | c.logger = logger |
| 59 | 51 | } |
| 63 | 55 | // existing/default values. |
| 64 | 56 | // Reason is that Cloudwatch makes you pay per metric, so you can save half the money |
| 65 | 57 | // by only using 2 metrics instead of the default 4. |
| 66 | func WithPercentiles(percentiles ...float64) option { | |
| 58 | func WithPercentiles(percentiles ...float64) Option { | |
| 67 | 59 | return func(c *CloudWatch) { |
| 68 | 60 | c.percentiles = make([]float64, 0, len(percentiles)) |
| 69 | 61 | for _, p := range percentiles { |
| 75 | 67 | } |
| 76 | 68 | } |
| 77 | 69 | |
| 78 | func WithConcurrentRequests(n int) option { | |
| 70 | // WithConcurrentRequests sets the upper limit on how many | |
| 71 | // cloudwatch.PutMetricDataRequest may be under way at any | |
| 72 | // given time. If n is greater than 20, 20 is used. By default, | |
| 73 | // the max is set at 10 concurrent requests. | |
| 74 | func WithConcurrentRequests(n int) Option { | |
| 79 | 75 | return func(c *CloudWatch) { |
| 80 | 76 | if n > maxConcurrentRequests { |
| 81 | 77 | n = maxConcurrentRequests |
| 88 | 84 | // Namespace is applied to all created metrics and maps to the CloudWatch namespace. |
| 89 | 85 | // Callers must ensure that regular calls to Send are performed, either |
| 90 | 86 | // manually or with one of the helper methods. |
| 91 | func New(namespace string, svc cloudwatchiface.CloudWatchAPI, options ...option) *CloudWatch { | |
| 87 | func New(namespace string, svc cloudwatchiface.CloudWatchAPI, options ...Option) *CloudWatch { | |
| 92 | 88 | cw := &CloudWatch{ |
| 93 | 89 | sem: nil, // set below |
| 94 | 90 | namespace: namespace, |
| 101 | 97 | percentiles: []float64{0.50, 0.90, 0.95, 0.99}, |
| 102 | 98 | } |
| 103 | 99 | |
| 104 | for _, optFunc := range options { | |
| 105 | optFunc(cw) | |
| 100 | for _, opt := range options { | |
| 101 | opt(cw) | |
| 106 | 102 | } |
| 107 | 103 | |
| 108 | 104 | cw.sem = make(chan struct{}, cw.numConcurrentRequests) |