Class: RubyEventStore::Specification

Inherits:
Object
  • Object
show all
Defined in:
lib/ruby_event_store/specification.rb

Overview

Used for building and executing the query specification.

Constant Summary collapse

DEFAULT_BATCH_SIZE =
100

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(reader, result = SpecificationResult.new) ⇒ Specification

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of Specification.


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# File 'lib/ruby_event_store/specification.rb', line 10

def initialize(reader, result = SpecificationResult.new)
  @reader = reader
  @result = result
end

Instance Attribute Details

#resultObject (readonly)

Returns the value of attribute result.


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# File 'lib/ruby_event_store/specification.rb', line 333

def result
  @result
end

Instance Method Details

#as_atSpecification

Sets the order of time sorting using transaction time / Find out more

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 127

def as_at
  Specification.new(reader, result.dup { |r| r.time_sort_by = :as_at})
end

#as_ofSpecification

Sets the order of time sorting using validity time / Find out more

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 135

def as_of
  Specification.new(reader, result.dup { |r| r.time_sort_by = :as_of })
end

#backwardSpecification

Sets the order of reading events to descending (backward from the start). / Find out more.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 151

def backward
  Specification.new(reader, result.dup { |r| r.direction = :backward })
end

#between(time_range) ⇒ Specification

Limits the query to events within given time range. / Find out more.

Parameters:

  • time_range (Range)

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 115

def between(time_range)
  if time_range.exclude_end?
    newer_than_or_equal(time_range.first).older_than(time_range.last)
  else
    newer_than_or_equal(time_range.first).older_than_or_equal(time_range.last)
  end
end

#countInteger

Calculates the size of result set based on the specification build up to this point. / Find out more.

Returns:

  • (Integer)

    Number of events to read


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# File 'lib/ruby_event_store/specification.rb', line 218

def count
  reader.count(result)
end

#each {|Event| ... } ⇒ Enumerator?

Executes the query based on the specification built up to this point. Yields events read from the store if block given. Otherwise, returns enumerable collection. / Find out more.

Yields:

Returns:

  • (Enumerator, nil)

    Enumerator is returned when block not given


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# File 'lib/ruby_event_store/specification.rb', line 185

def each
  return to_enum unless block_given?

  each_batch do |batch|
    batch.each { |event| yield event }
  end
end

#each_batch {|Array<Event>| ... } ⇒ Enumerator?

Executes the query based on the specification built up to this point. Yields each batch of records that was retrieved from the store. / Find out more.

Yields:

  • (Array<Event>)

    batch of events

Returns:

  • (Enumerator, nil)

    Enumerator is returned when block not given


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# File 'lib/ruby_event_store/specification.rb', line 171

def each_batch
  return to_enum(:each_batch) unless block_given?

  reader.each(in_batches(result.batch_size).result) do |batch|
    yield batch
  end
end

#event(event_id) ⇒ Event?

Reads single event from repository. Returns the event with specified id or nil if event is not found in specified collection of events. / Find out more.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 308

def event(event_id)
  reader.one(read_first.with_id([event_id]).result)
end

#event!(event_id) ⇒ Event

Reads single existing event from repository. Returns the event with specified id or raises [EventNotFound] error if event is not found in specified collection of events. / Find out more.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 318

def event!(event_id)
  event(event_id) or raise EventNotFound.new(event_id)
end

#events(event_ids) {|Event| ... } ⇒ Enumerator

Reads all events of given ids from repository. Yields each event (found by id in specified collection of events) read from the store if block given. Otherwise, returns enumerable collection. / Find out more.

Yields:

Returns:

  • (Enumerator)

    Enumerator is returned when block not given


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# File 'lib/ruby_event_store/specification.rb', line 329

def events(event_ids)
  with_id(event_ids).each
end

#firstEvent?

Executes the query based on the specification built up to this point. Returns the first event in specified collection of events. / Find out more.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 270

def first
  reader.one(read_first.result)
end

#forwardSpecification

Sets the order of reading events to ascending (forward from the start). / Find out more.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 143

def forward
  Specification.new(reader, result.dup { |r| r.direction = :forward })
end

#from(start) ⇒ Specification

Limits the query to events before or after another event. / Find out more.

Parameters:

  • start (String)

    id of event to start reading from.

Returns:

Raises:


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# File 'lib/ruby_event_store/specification.rb', line 29

def from(start)
  raise InvalidPageStart if start.nil? || start.empty?
  raise EventNotFound.new(start) unless reader.has_event?(start)
  Specification.new(reader, result.dup { |r| r.start = start })
end

#in_batches(batch_size = DEFAULT_BATCH_SIZE) ⇒ Specification Also known as: in_batches_of

Specifies that events should be obtained in batches. / Find out more.

Looping through a collection of events from the store can be inefficient since it will try to instantiate all the events at once.

In that case, batch processing methods allow you to work with the records in batches, thereby greatly reducing memory consumption.

Parameters:

  • batch_size (Integer) (defaults to: DEFAULT_BATCH_SIZE)

    number of events to read in a single batch

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 244

def in_batches(batch_size = DEFAULT_BATCH_SIZE)
  Specification.new(reader, result.dup { |r| r.read_as = :batch; r.batch_size = batch_size })
end

#lastEvent?

Executes the query based on the specification built up to this point. Returns the last event in specified collection of events. / Find out more.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 279

def last
  reader.one(read_last.result)
end

#limit(count) ⇒ Specification

Limits the query to specified number of events. / Find out more.

Parameters:

  • count (Integer)

    maximal number of events to retrieve

Returns:

Raises:


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# File 'lib/ruby_event_store/specification.rb', line 160

def limit(count)
  raise InvalidPageSize unless count && count > 0
  Specification.new(reader, result.dup { |r| r.count = count })
end

#map(&block) ⇒ Array

Executes the query based on the specification built up to this point and maps the result using provided block. / Find out more.

Returns:

  • (Array)

    of mapped result

Raises:

  • (ArgumentError)

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# File 'lib/ruby_event_store/specification.rb', line 198

def map(&block)
  raise ArgumentError.new("Block must be given") unless block_given?
  each.map(&block)
end

#newer_than(time) ⇒ Specification

Limits the query to events that occurred earlier than given time. / Find out more.

Parameters:

  • time (Time)

Returns:

Raises:

  • (ArgumentError)

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# File 'lib/ruby_event_store/specification.rb', line 83

def newer_than(time)
  raise ArgumentError unless time.respond_to?(:to_time)
  Specification.new(
    reader,
    result.dup do |r|
      r.newer_than_or_equal = nil
      r.newer_than          = time
    end
  )
end

#newer_than_or_equal(time) ⇒ Specification

Limits the query to events that occurred on given time or earlier. / Find out more.

Parameters:

  • time (Time)

Returns:

Raises:

  • (ArgumentError)

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# File 'lib/ruby_event_store/specification.rb', line 99

def newer_than_or_equal(time)
  raise ArgumentError unless time.respond_to?(:to_time)
  Specification.new(
    reader,
    result.dup do |r|
      r.newer_than_or_equal = time
      r.newer_than          = nil
    end
  )
end

#of_type(*types) ⇒ Specification Also known as: of_types

Limits the query to certain event type(s). / Find out more.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 288

def of_type(*types)
  Specification.new(reader, result.dup{ |r| r.with_types = types.flatten })
end

#older_than(time) ⇒ Specification

Limits the query to events that later than given time. / Find out more.

Parameters:

  • time (Time)

Returns:

Raises:

  • (ArgumentError)

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# File 'lib/ruby_event_store/specification.rb', line 51

def older_than(time)
  raise ArgumentError unless time.respond_to?(:to_time)
  Specification.new(
    reader,
    result.dup do |r|
      r.older_than          = time
      r.older_than_or_equal = nil
    end
  )
end

#older_than_or_equal(time) ⇒ Specification

Limits the query to events that occurred on given time or later. / Find out more.

Parameters:

  • time (Time)

Returns:

Raises:

  • (ArgumentError)

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# File 'lib/ruby_event_store/specification.rb', line 67

def older_than_or_equal(time)
  raise ArgumentError unless time.respond_to?(:to_time)
  Specification.new(
    reader,
    result.dup do |r|
      r.older_than          = nil
      r.older_than_or_equal = time
    end
  )
end

#read_firstSpecification

Specifies that only first event should be read. / Find out more.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 253

def read_first
  Specification.new(reader, result.dup { |r| r.read_as = :first })
end

#read_lastSpecification

Specifies that only last event should be read. / Find out more.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 261

def read_last
  Specification.new(reader, result.dup { |r| r.read_as = :last })
end

#reduce(accumulator = nil, &block) ⇒ Object

Reduces the results of the query based on the specification built up to this point result using provided block. / Find out more.

Parameters:

  • accumulator (defaults to: nil)

    starting state for reduce operation

Returns:

  • reduce result as defined by block given

Raises:

  • (ArgumentError)

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# File 'lib/ruby_event_store/specification.rb', line 209

def reduce(accumulator = nil, &block)
  raise ArgumentError.new("Block must be given") unless block_given?
  each.reduce(accumulator, &block)
end

#stream(stream_name) ⇒ Specification

Limits the query to certain stream. / Find out more.

Parameters:

  • stream_name (String)

    name of the stream to get events from

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 20

def stream(stream_name)
  Specification.new(reader, result.dup { |r| r.stream = Stream.new(stream_name) })
end

#to(stop) ⇒ Specification

Limits the query to events before or after another event. / Find out more.

Parameters:

  • stop (String)

    id of event to start reading from.

Returns:

Raises:


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# File 'lib/ruby_event_store/specification.rb', line 40

def to(stop)
  raise InvalidPageStop if stop.nil? || stop.empty?
  raise EventNotFound.new(stop) unless reader.has_event?(stop)
  Specification.new(reader, result.dup { |r| r.stop = stop })
end

#to_aArray<Event>

Executes the query based on the specification built up to this point. Returns array of domain events. / Find out more.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 227

def to_a
  each.to_a
end

#with_id(event_ids) ⇒ Specification

Limits the query to certain events by given even ids. / Find out more.

Parameters:

  • event_ids (Array(String))

    ids of event to look for.

Returns:


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# File 'lib/ruby_event_store/specification.rb', line 298

def with_id(event_ids)
  Specification.new(reader, result.dup{ |r| r.with_ids = event_ids })
end