cron

Documentation

Index

• type ConstantDelayCron
  • func Every(duration time.Duration) ConstantDelayCron
  • func (cron ConstantDelayCron) Next(t time.Time) time.Time
• type ConstantLastCron
  • func LastDay(duration time.Duration) ConstantLastCron
  • func (cron ConstantLastCron) Next(t time.Time) time.Time
• type Crontab
  • func Parse(spec string) (Crontab, error)
  • func ParseStandard(standardSpec string) (Crontab, error)
• type ParseOption
• type Parser
  • func NewParser(options ParseOption) Parser
  • func (p Parser) Parse(spec string) (Crontab, error)
• type SpecCron
  • func (s *SpecCron) Next(t time.Time) time.Time

Types

type ConstantDelayCron

type ConstantDelayCron struct {
	Delay time.Duration
}

ConstantDelaySchedule represents a simple recurring duty cycle, e.g. "Every 5 minutes". It does not support jobs more frequent than once a second.

func Every

func Every(duration time.Duration) ConstantDelayCron

Every returns a crontab Schedule that activates once every duration. Delays of less than a second are not supported (will round up to 1 second). Any fields less than a Second are truncated.

func (ConstantDelayCron) Next

func (cron ConstantDelayCron) Next(t time.Time) time.Time

Next returns the next time this should be run. This rounds so that the next activation time will be on the second.

type ConstantLastCron

type ConstantLastCron struct {
	Delay time.Duration
}

func LastDay

func LastDay(duration time.Duration) ConstantLastCron

func (ConstantLastCron) Next

func (cron ConstantLastCron) Next(t time.Time) time.Time

type Crontab

type Crontab interface {
	// Return the next activation time, later than the given time.
	// Next is invoked initially, and then each time the job is run.
	Next(time.Time) time.Time
}

func Parse

func Parse(spec string) (Crontab, error)

Parse returns a new crontab schedule representing the given spec. It returns a descriptive error if the spec is not valid.

It accepts

• Full crontab specs, e.g. "* * * * * ?"
• Descriptors, e.g. "@midnight", "@every 1h30m"

func ParseStandard

func ParseStandard(standardSpec string) (Crontab, error)

ParseStandard returns a new crontab schedule representing the given standardSpec (https://en.wikipedia.org/wiki/Cron). It differs from Parse requiring to always pass 5 entries representing: minute, hour, day of month, month and day of week, in that order. It returns a descriptive error if the spec is not valid.

It accepts

• Standard crontab specs, e.g. "* * * * * ?"
• Descriptors, e.g. "@midnight", "@every 1h30m"

type ParseOption

type ParseOption int

Configuration options for creating a parser. Most options specify which fields should be included, while others enable features. If a field is not included the parser will assume a default value. These options do not change the order fields are parse in.

const (
	Second      ParseOption = 1 << iota // Seconds field, default 0
	Minute                              // Minutes field, default 0
	Hour                                // Hours field, default 0
	Dom                                 // Day of month field, default *
	Month                               // Month field, default *
	Dow                                 // Day of week field, default *
	DowOptional                         // Optional day of week field, default *
	Descriptor                          // Allow descriptors such as @monthly, @weekly, etc.
)

type Parser

type Parser struct {
	// contains filtered or unexported fields
}

A custom Parser that can be configured.

func NewParser

func NewParser(options ParseOption) Parser

Creates a custom Parser with custom options.

// Standard parser without descriptors
specParser := NewParser(Minute | Hour | Dom | Month | Dow)
sched, err := specParser.Parse("0 0 15 */3 *")

// Same as above, just excludes time fields
subsParser := NewParser(Dom | Month | Dow)
sched, err := specParser.Parse("15 */3 *")

// Same as above, just makes Dow optional
subsParser := NewParser(Dom | Month | DowOptional)
sched, err := specParser.Parse("15 */3")

func (Parser) Parse

func (p Parser) Parse(spec string) (Crontab, error)

Parse returns a new crontab schedule representing the given spec. It returns a descriptive error if the spec is not valid. It accepts crontab specs and features configured by NewParser.

type SpecCron

type SpecCron struct {
	Second, Minute, Hour, Dom, Month, Dow uint64
}

SpecCron specifies a duty cycle (to the second granularity), based on a traditional crontab specification. It is computed initially and stored as bit sets.

func (*SpecCron) Next

func (s *SpecCron) Next(t time.Time) time.Time

Next returns the next time this schedule is activated, greater than the given time. If no time can be found to satisfy the schedule, return the zero time.