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README
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Fork from https://github.com/robfig/cron
Documentation
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Index ¶
- Variables
- type Chain
- type ConstantDelaySchedule
- type Cron
- func (c *Cron) AddFunc(spec string, cmd func()) (EntryID, error)
- func (c *Cron) AddJob(spec string, cmd Job) (EntryID, error)
- func (c *Cron) Entries() []Entry
- func (c *Cron) Entry(id EntryID) Entry
- func (c *Cron) Location() *time.Location
- func (c *Cron) Remove(id EntryID)
- func (c *Cron) Run()
- func (c *Cron) Schedule(schedule Schedule, cmd Job) EntryID
- func (c *Cron) Start()
- func (c *Cron) Stop() context.Context
- type Entry
- type EntryID
- type FuncJob
- type Job
- type JobWrapper
- type Logger
- type Option
- type ParseOption
- type Parser
- type Schedule
- type ScheduleParser
- type SpecSchedule
Constants ¶
This section is empty.
Variables ¶
var DefaultLogger = PrintfLogger(log.New(os.Stdout, "cron: ", log.LstdFlags))
DefaultLogger is used by Cron if none is specified.
var DiscardLogger = PrintfLogger(log.New(io.Discard, "", 0))
DiscardLogger can be used by callers to discard all log messages.
Functions ¶
This section is empty.
Types ¶
type Chain ¶ added in v0.27.0
type Chain struct {
// contains filtered or unexported fields
}
Chain is a sequence of JobWrappers that decorates submitted jobs with cross-cutting behaviors like logging or synchronization.
func NewChain ¶ added in v0.27.0
func NewChain(c ...JobWrapper) Chain
NewChain returns a Chain consisting of the given JobWrappers.
type ConstantDelaySchedule ¶ added in v0.27.0
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 ¶ added in v0.27.0
func Every(duration time.Duration) ConstantDelaySchedule
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.
type Cron ¶
type Cron struct {
// contains filtered or unexported fields
}
Cron keeps track of any number of entries, invoking the associated func as specified by the schedule. It may be started, stopped, and the entries may be inspected while running.
func New ¶
New returns a new Cron job runner, modified by the given options.
Available Settings
Time Zone Description: The time zone in which schedules are interpreted Default: time.Local Parser Description: Parser converts cron spec strings into cron.Schedules. Default: Accepts this spec: https://en.wikipedia.org/wiki/Cron Chain Description: Wrap submitted jobs to customize behavior. Default: A chain that recovers panics and logs them to stderr.
See "cron.With*" to modify the default behavior.
func (*Cron) AddFunc ¶ added in v0.27.0
AddFunc adds a func to the Cron to be run on the given schedule. The spec is parsed using the time zone of this Cron instance as the default. An opaque ID is returned that can be used to later remove it.
func (*Cron) AddJob ¶ added in v0.27.0
AddJob adds a Job to the Cron to be run on the given schedule. The spec is parsed using the time zone of this Cron instance as the default. An opaque ID is returned that can be used to later remove it.
func (*Cron) Entry ¶ added in v0.27.0
Entry returns a snapshot of the given entry, or nil if it couldn't be found.
func (*Cron) Run ¶ added in v0.27.0
func (c *Cron) Run()
Run the cron scheduler, or no-op if already running.
func (*Cron) Schedule ¶ added in v0.27.0
Schedule adds a Job to the Cron to be run on the given schedule. The job is wrapped with the configured Chain.
type Entry ¶ added in v0.27.0
type Entry struct {
// ID is the cron-assigned ID of this entry, which may be used to look up a
// snapshot or remove it.
ID EntryID
// Schedule on which this job should be run.
Schedule Schedule
// Next time the job will run, or the zero time if Cron has not been
// started or this entry's schedule is unsatisfiable
Next time.Time
// Prev is the last time this job was run, or the zero time if never.
Prev time.Time
// WrappedJob is the thing to run when the Schedule is activated.
WrappedJob Job
// Job is the thing that was submitted to cron.
// It is kept around so that user code that needs to get at the job later,
// e.g. via Entries() can do so.
Job Job
}
Entry consists of a schedule and the func to execute on that schedule.
type EntryID ¶ added in v0.27.0
type EntryID int
EntryID identifies an entry within a Cron instance.
type FuncJob ¶ added in v0.27.0
type FuncJob func()
FuncJob is a wrapper that turns a func() into a cron.Job.
type Job ¶ added in v0.27.0
type Job interface {
Run()
}
Job is an interface for submitted cron jobs.
type JobWrapper ¶ added in v0.27.0
JobWrapper decorates the given Job with some behavior.
func DelayIfStillRunning ¶ added in v0.27.0
func DelayIfStillRunning(logger Logger) JobWrapper
DelayIfStillRunning serializes jobs, delaying subsequent runs until the previous one is complete. Jobs running after a delay of more than a minute have the delay logged at Info.
func Recover ¶ added in v0.27.0
func Recover(logger Logger) JobWrapper
Recover panics in wrapped jobs and log them with the provided logger.
func SkipIfStillRunning ¶ added in v0.27.0
func SkipIfStillRunning(logger Logger) JobWrapper
SkipIfStillRunning skips an invocation of the Job if a previous invocation is still running. It logs skips to the given logger at Info level.
type Logger ¶ added in v0.27.0
type Logger interface {
// Info logs routine messages about cron's operation.
Info(msg string, keysAndValues ...interface{})
// Error logs an error condition.
Error(err error, msg string, keysAndValues ...interface{})
}
Logger is the interface used in this package for logging, so that any backend can be plugged in. It is a subset of the github.com/go-logr/logr interface.
func PrintfLogger ¶ added in v0.27.0
PrintfLogger wraps a Printf-based logger (such as the standard library "log") into an implementation of the Logger interface which logs errors only.
func VerbosePrintfLogger ¶ added in v0.27.0
VerbosePrintfLogger wraps a Printf-based logger (such as the standard library "log") into an implementation of the Logger interface which logs everything.
type Option ¶ added in v0.27.0
type Option func(*Cron)
Option represents a modification to the default behavior of a Cron.
func WithChain ¶ added in v0.27.0
func WithChain(wrappers ...JobWrapper) Option
WithChain specifies Job wrappers to apply to all jobs added to this cron. Refer to the Chain* functions in this package for provided wrappers.
func WithLocation ¶ added in v0.27.0
WithLocation overrides the timezone of the cron instance.
func WithLogger ¶ added in v0.27.0
WithLogger uses the provided logger.
func WithParser ¶ added in v0.27.0
func WithParser(p ScheduleParser) Option
WithParser overrides the parser used for interpreting job schedules.
func WithSeconds ¶ added in v0.27.0
func WithSeconds() Option
WithSeconds overrides the parser used for interpreting job schedules to include a seconds field as the first one.
type ParseOption ¶ added in v0.27.0
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 parsed in.
const ( Second ParseOption = 1 << iota // Seconds field, default 0 SecondOptional // Optional 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 ¶ added in v0.27.0
type Parser struct {
// contains filtered or unexported fields
}
A custom Parser that can be configured.
func NewParser ¶ added in v0.27.0
func NewParser(options ParseOption) Parser
NewParser creates a Parser with custom options.
It panics if more than one Optional is given, since it would be impossible to correctly infer which optional is provided or missing in general.
Examples
// 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
specParser := NewParser(Dom | Month | Dow)
sched, err := specParser.Parse("15 */3 *")
// Same as above, just makes Dow optional
specParser := NewParser(Dom | Month | DowOptional)
sched, err := specParser.Parse("15 */3")
type Schedule ¶
type Schedule interface {
// Next returns 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
}
Schedule describes a job's duty cycle.
func ParseStandard ¶ added in v0.27.0
ParseStandard returns a new crontab schedule representing the given standardSpec (https://en.wikipedia.org/wiki/Cron). It requires 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 ScheduleParser ¶ added in v0.27.0
ScheduleParser is an interface for schedule spec parsers that return a Schedule.
type SpecSchedule ¶ added in v0.27.0
type SpecSchedule struct {
Second, Minute, Hour, Dom, Month, Dow uint64
// Override location for this schedule.
Location *time.Location
}
SpecSchedule specifies a duty cycle (to the second granularity), based on a traditional crontab specification. It is computed initially and stored as bit sets.
Source Files