Class: Zizq::Crontab

Inherits:
Object
  • Object
show all
Defined in:
lib/zizq/crontab.rb

Overview

Represents a Crontab schedule defined on the Zizq server.

This requires a Pro license on the Zizq server.

The actual data is lazily fetched when first accessed.

Crontabs are used to define collections of recurring jobs that run on a specified schedule, such as at 2am on every Monday. Each entry on the Crontab is a single job enqueue, which the Zizq server automatically triggers at the correct point in time. Zizq uses standard Cron expression syntax (with support for seconds via 6-fields) to define entries.

Entire schedules, and individual entries on a schedule, can be paused and resumed.

By default schedules operate in the system time zone of the Zizq server but an explicit IANA timezone name can be specified when defining the Crontab.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name) ⇒ Crontab

Initialize the Crontab with the given group name.



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# File 'lib/zizq/crontab.rb', line 39

def initialize(name)
  @building = false #: bool
  @materialized = false #: bool
  @name = name #: String
  @entries = {} #: Hash[String, Zizq::CrontabEntry]
  @paused = false #: bool?
  @paused_at = nil #: Float?
  @resumed_at = nil #: Float?
end

Instance Attribute Details

#name ⇒ Object (readonly)

The name of the cron group that this schedule is backed by.



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# File 'lib/zizq/crontab.rb', line 28

def name
  @name
end

#paused ⇒ Object

Check if this schedule is currently paused.



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# File 'lib/zizq/crontab.rb', line 95

def paused #: () -> bool?
  materialize
  @paused
end

Instance Method Details

#clear ⇒ Object

Clear materialized data that was fetched from the Zizq server.

This triggers a refetch when the data is next accessed.



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# File 'lib/zizq/crontab.rb', line 64

def clear #: () -> self
  @entries = {}
  @paused = nil
  @paused_at = nil
  @resumed_at = nil
  @materialized = false

  self
end

#define_entry(name, expression, timezone: nil, paused: nil) ⇒ Object

Define (or redefine) an entry with this Crontab schedule.

Defining the same entry more than once is idempotent. If the entry does not exist, it is added to the schedule. If the entry already exists, it replaces the current entry.

The return value is a Zizq::CrontabEntryBuilder instance, on which the caller must call one of the enqueue methods (‘enqueue`, `enqueue_raw`, optionally chained onto `enqueue_with`, exactly the same as a regular job enqueue).

All enqueue options are supported except ‘delay` and `ready_at` which make no sense for recurring jobs.

Bulk enqueues are not supported.

crontab.define_entry(
  "refresh_data_warehose",
  "*/15 * * * *",
).enqueue(RefreshDataWarehoseJob, incremental: true)



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# File 'lib/zizq/crontab.rb', line 197

def define_entry(name, expression, timezone: nil, paused: nil)
  CrontabEntryBuilder.new(self, name, expression, timezone:, paused:) do |e|
    entry = materialize_entry_with(
      Zizq.client.replace_cron_group_entry(
        self.name,
        name,
        expression: e.expression,
        job: e.job.to_enqueue_params,
        timezone: e.timezone,
        paused: e.paused,
      ),
    )

    materialize # in case this was the first entry operation

    entry
  end
end

#delete! ⇒ Object

Delete this entire Crontab schedule and its entries.



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# File 'lib/zizq/crontab.rb', line 75

def delete! #: () -> void
  Zizq.client.delete_cron_group(name)
end

#entries ⇒ Object

Return a Hash of Zizq::CrontabEntry instances keyed by their names.

Each entry specifies the cron expression at which it executes, information about when it last/next enqueued a job, and details of the job that the entry enqueues.



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# File 'lib/zizq/crontab.rb', line 122

def entries #: () -> Hash[String, Zizq::CrontabEntry]
  materialize
  @entries
end

#entry(name) ⇒ Object

Return a handle for the specified Zizq::CrontabEntry.

The entry can be paused or resumed is isolation, can be deleted entirely or can be redefined (replaced) with another entry.



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# File 'lib/zizq/crontab.rb', line 161

def entry(name)
  materialize
  entries.fetch(name) do
    entry = materialize_entry_with(
      Zizq.client.get_cron_group_entry(self.name, name),
    )
    entries[name] = entry
  end
end

#materialize ⇒ Object

Fetch data from the Zizq server if not already fetched.

Once fetched, this method becomes a no-op, unless #clear is called to remove the fetched data.



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# File 'lib/zizq/crontab.rb', line 53

def materialize #: () -> self
  unless @building || @materialized
    materialize_with(Zizq.client.get_cron_group(name))
  end

  self
end

#pause! ⇒ Object

Pause this entire Crontab schedule.

All entries will stop enqueueing jobs, but the server continues to advance the schedule until it is resumed.



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# File 'lib/zizq/crontab.rb', line 83

def pause! #: () -> void
  materialize_with(Zizq.client.update_cron_group(name, paused: true))
end

#paused? ⇒ Boolean

Check if this schedule is currently paused.

Alias of #paused.

Returns:

  • (Boolean) 


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# File 'lib/zizq/crontab.rb', line 103

def paused? = paused #: () -> bool?

#paused_at ⇒ Object

Return the timestamp at which this Crontab schedule was last paused.



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# File 'lib/zizq/crontab.rb', line 106

def paused_at #: () -> Float?
  materialize
  @paused_at
end

#redefine(timezone: nil, paused: nil) {|CrontabBuilder.new(self, timezone:, paused:)| ... } ⇒ Object

Redefine (replace) this Crontab schedule with another.

This is equivalent to calling ‘Zizq.define_crontab` and is idempotent when given the same schedule more than once.

Yields:



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# File 'lib/zizq/crontab.rb', line 136

def redefine(timezone: nil, paused: nil, &block)
  @building = true

  yield CrontabBuilder.new(self, timezone:, paused:)

  materialize_with(
    Zizq.client.replace_cron_group(
      name,
      paused:,
      entries: entries.values.map(&:to_params),
    ),
  )

  @building = false

  self
end

#resume! ⇒ Object

Resume this Crontab schedule if it is currently paused.

Individual entries that are paused will remain paused.



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# File 'lib/zizq/crontab.rb', line 90

def resume! #: () -> void
  materialize_with(Zizq.client.update_cron_group(name, paused: false))
end

#resumed_at ⇒ Object

Return the timestamp at which this Crontab schedule was last resumed.



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# File 'lib/zizq/crontab.rb', line 112

def resumed_at #: () -> Float?
  materialize
  @resumed_at
end