state

Documentation

Overview

Package state provides the persistent storage layer for the metrics.

Index

• Constants
• func AvgSince(ctx context.Context, db *sql.DB, tableName string, name string, ...) (float64, error)
• func CreateTable(ctx context.Context, db *sql.DB, tableName string) error
• func EMASince(ctx context.Context, db *sql.DB, tableName string, name string, ...) (float64, error)
• func Insert(ctx context.Context, db *sql.DB, tableName string, metric Metric) error
• func Purge(ctx context.Context, db *sql.DB, tableName string, before time.Time) (int, error)
• type Metric
  • func ReadLast(ctx context.Context, db *sql.DB, tableName string, name string, ...) (*Metric, error)
• type Metrics
  • func ReadSince(ctx context.Context, db *sql.DB, tableName string, name string, ...) (Metrics, error)

Constants

const (
	ColumnUnixSeconds         = "unix_seconds"
	ColumnMetricName          = "metric_name"
	ColumnMetricSecondaryName = "metric_secondary_name"
	ColumnMetricValue         = "metric_value"
)

const DefaultTableName = "components_metrics"

Functions

func AvgSince

func AvgSince(ctx context.Context, db *sql.DB, tableName string, name string, secondaryName string, since time.Time) (float64, error)

Computes the average of the last metrics. If the since is zero, all metrics are used. Returns zero if no record is found ("database/sql.ErrNoRows").

func CreateTable

func CreateTable(ctx context.Context, db *sql.DB, tableName string) error

func EMASince

func EMASince(ctx context.Context, db *sql.DB, tableName string, name string, secondaryName string, period time.Duration, since time.Time) (float64, error)

EMASince calculates the Exponential Moving Average since a given time

func Insert

func Insert(ctx context.Context, db *sql.DB, tableName string, metric Metric) error

func Purge

func Purge(ctx context.Context, db *sql.DB, tableName string, before time.Time) (int, error)

Types

type Metric

type Metric struct {
	UnixSeconds         int64   `json:"unix_seconds"`
	MetricName          string  `json:"metric_name"`
	MetricSecondaryName string  `json:"metric_secondary_name,omitempty"`
	Value               float64 `json:"value"`
}

func ReadLast

func ReadLast(ctx context.Context, db *sql.DB, tableName string, name string, secondaryName string) (*Metric, error)

Reads the last metric. Returns nil if no record is found ("database/sql.ErrNoRows").

type Metrics

type Metrics []Metric

func ReadSince

func ReadSince(ctx context.Context, db *sql.DB, tableName string, name string, secondaryName string, since time.Time) (Metrics, error)

Returns nil if no record is found ("database/sql.ErrNoRows").