Class: FiberStream::Flow

Inherits:
Object
  • Object
show all
Defined in:
lib/fiber_stream/flow.rb,
sig/fiber_stream.rbs

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(&attach) ⇒ Flow

Returns a new instance of Flow.



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# File 'lib/fiber_stream/flow.rb', line 399

def initialize(&attach)
  @attach = attach
end

Class Method Details

.async ⇒ void

This method returns an undefined value.

Creates a scheduler-backed asynchronous boundary.

The boundary starts its producer on the first downstream demand and requires an installed Fiber.scheduler at that point. Upstream stages run in a non-blocking producer fiber, downstream stages remain in the caller's current fiber, and each downstream pull resumes at most one upstream pull. Closing the boundary closes upstream and requests producer cancellation. FiberStream does not depend on Async at runtime.



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# File 'lib/fiber_stream/flow.rb', line 243

def self.async
  new { |upstream| Pull.async(upstream) }
end

.buffer(count) ⇒ void

This method returns an undefined value.

Creates a bounded asynchronous buffer.

The buffer starts its producer on the first downstream demand and requires an installed Fiber.scheduler at that point. It preserves element order, stores at most count messages, and closes upstream while requesting producer cancellation when closed. count must be a positive Integer. FiberStream does not depend on Async at runtime.

Raises:

  • (TypeError) 


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# File 'lib/fiber_stream/flow.rb', line 254

def self.buffer(count)
  raise TypeError, "count must be an Integer" unless count.is_a?(Integer)
  raise ArgumentError, "count must be positive" unless count.positive?

  new { |upstream| Pull.buffer(upstream, count) }
end

.build(&attach) ⇒ Object

:nodoc:



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# File 'lib/fiber_stream/flow.rb', line 312

def self.build(&attach) # :nodoc:
  new(&attach)
end

.compact ⇒ void

This method returns an undefined value.

Creates a nil-dropping flow.

The flow drops nil elements and passes every non-nil element through unchanged, including false.



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# File 'lib/fiber_stream/flow.rb', line 32

def self.compact
  new { |upstream| Pull.compact(upstream) }
end

.drop(count) ⇒ void

This method returns an undefined value.

Creates a fixed-prefix dropping flow.

The flow discards the first count upstream elements, then passes later elements through unchanged. drop(0) behaves as pass-through. Negative counts raise ArgumentError; non-Integer counts raise TypeError.

Raises:

  • (TypeError) 


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# File 'lib/fiber_stream/flow.rb', line 178

def self.drop(count)
  raise TypeError, "count must be an Integer" unless count.is_a?(Integer)
  raise ArgumentError, "count must be non-negative" if count.negative?

  new { |upstream| Pull.drop(upstream, count) }
end

.drop_while(&block) ⇒ void

This method returns an undefined value.

Creates a predicate-based prefix-dropping flow.

The flow drops leading elements while the block result is truthy. The first false or nil result, and all later elements, pass through unchanged. After that boundary the block is not called again. Exceptions raised by the block fail the stream and are re-raised from Source#run_with.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 229

def self.drop_while(&block)
  raise ArgumentError, "missing block" unless block

  new { |upstream| Pull.drop_while(upstream, block) }
end

.filter_map(&block) ⇒ void

This method returns an undefined value.

Creates a transform-and-filter flow.

The block is called once for each upstream element observed by this stage. Truthy block results are emitted downstream as transformed values; false and nil results are dropped. Exceptions raised by the block fail the stream and are re-raised from Source#run_with.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 22

def self.filter_map(&block)
  raise ArgumentError, "missing block" unless block

  new { |upstream| Pull.filter_map(upstream, block) }
end

.grouped(count) ⇒ void

This method returns an undefined value.

Creates a fixed-size grouping flow.

The flow emits arrays containing up to count adjacent upstream elements. Full groups contain exactly count elements; normal upstream completion emits one final partial group when one exists. count must be a positive Integer.

Raises:

  • (TypeError) 


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# File 'lib/fiber_stream/flow.rb', line 191

def self.grouped(count)
  raise TypeError, "count must be an Integer" unless count.is_a?(Integer)
  raise ArgumentError, "count must be positive" unless count.positive?

  new { |upstream| Pull.grouped(upstream, count) }
end

.lines(chomp: true, max_length: nil) ⇒ Flow[String, String]

Creates a line-splitting flow.

The flow accepts String chunks and emits lines split on "\n". By default it chomps the trailing newline and one preceding "\r". max_length is an optional per-line bytesize limit. With max_length: nil, one unterminated line can buffer without bound. Set a positive max_length for untrusted, network-facing, or otherwise unbounded streams.

Parameters:

  • chomp: (Boolean) (defaults to: true)
  • max_length: (Integer, nil) (defaults to: nil)

Returns:

  • (Flow[String, String])

Raises:

  • (TypeError) 


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# File 'lib/fiber_stream/flow.rb', line 281

def self.lines(chomp: true, max_length: nil)
  raise TypeError, "chomp must be true or false" unless [true, false].include?(chomp)
  unless max_length.nil? || max_length.is_a?(Integer)
    raise TypeError, "max_length must be nil or an Integer"
  end
  raise ArgumentError, "max_length must be positive" if max_length&.<= 0

  new { |upstream| Pull.lines(upstream, chomp, max_length) }
end

.map(&block) ⇒ void

This method returns an undefined value.

Creates a mapping flow.

The block is called once for each element pulled through this flow. Exceptions raised by the block fail the stream and are re-raised from Source#run_with.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 10

def self.map(&block)
  raise ArgumentError, "missing block" unless block

  new { |upstream| Pull.map(upstream, block) }
end

.map_concat(&block) ⇒ void

This method returns an undefined value.

Creates a one-to-many mapping flow.

The block is called once for each upstream element whose expansion is needed. It must return an object that responds to #each; yielded values are emitted in order before the next upstream element is pulled. Exceptions raised by the block or by the returned object's #each fail the stream and are re-raised from Source#run_with.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 43

def self.map_concat(&block)
  raise ArgumentError, "missing block" unless block

  new { |upstream| Pull.map_concat(upstream, block) }
end

.parallel_map(concurrency:, &block) ⇒ void

This method returns an undefined value.

Creates an ordered scheduler-backed parallel mapping flow.

The stage starts internal scheduled fibers on first downstream demand and requires an installed Fiber.scheduler in a non-blocking fiber at that point. At most concurrency mapping blocks run at the same time, and at most concurrency upstream elements are pulled but not yet emitted downstream. Results are emitted in input order. Closing the boundary closes upstream and requests internal worker cancellation. FiberStream does not depend on Async at runtime.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 70

def self.parallel_map(concurrency:, &block)
  raise ArgumentError, "missing block" unless block
  raise TypeError, "concurrency must be an Integer" unless concurrency.is_a?(Integer)
  raise ArgumentError, "concurrency must be positive" unless concurrency.positive?

  new { |upstream| Pull.parallel_map(upstream, concurrency, block) }
end

.parallel_unordered_map(concurrency:, &block) ⇒ void

This method returns an undefined value.

Creates an unordered scheduler-backed parallel mapping flow.

The stage starts internal scheduled fibers on first downstream demand and requires an installed Fiber.scheduler in a non-blocking fiber at that point. At most concurrency mapping blocks run at the same time, and at most concurrency upstream elements are pulled but not yet emitted downstream. Results are emitted in completion order and input order is not preserved. Closing the boundary closes upstream and requests internal worker cancellation. FiberStream does not depend on Async at runtime.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 87

def self.parallel_unordered_map(concurrency:, &block)
  raise ArgumentError, "missing block" unless block
  raise TypeError, "concurrency must be an Integer" unless concurrency.is_a?(Integer)
  raise ArgumentError, "concurrency must be positive" unless concurrency.positive?

  new { |upstream| Pull.parallel_unordered_map(upstream, concurrency, block) }
end

.ractor_map(workers:, input_transfer: :copy, output_transfer: :copy, &block) ⇒ void

This method returns an undefined value.

Creates an ordered Ractor-backed mapping flow.

The mapper runs inside worker ractors and must be shareable, typically created with Ractor.shareable_proc. Results are emitted in input order, and at most workers upstream elements are pulled but not yet emitted. input_transfer and output_transfer must be :copy or :move and are passed to Ractor message sends for element and result transfer.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 102

def self.ractor_map(workers:, input_transfer: :copy, output_transfer: :copy, &block)
  raise ArgumentError, "missing block" unless block
  raise TypeError, "workers must be an Integer" unless workers.is_a?(Integer)
  raise ArgumentError, "workers must be positive" unless workers.positive?

  Internal::RactorTransferPolicy.validate!(:input_transfer, input_transfer)
  Internal::RactorTransferPolicy.validate!(:output_transfer, output_transfer)
  raise TypeError, "block must be shareable" unless Ractor.shareable?(block)

  new { |upstream| Pull.ractor_map(upstream, workers, input_transfer, output_transfer, block) }
end

.ractor_unordered_map(workers:, input_transfer: :copy, output_transfer: :copy, &block) ⇒ void

This method returns an undefined value.

Creates an unordered Ractor-backed mapping flow.

The mapper runs inside worker ractors and must be shareable, typically created with Ractor.shareable_proc. Results are emitted in worker completion order, and at most workers upstream elements are pulled but not yet emitted. input_transfer and output_transfer must be :copy or :move and are passed to Ractor message sends for element and result transfer.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 122

def self.ractor_unordered_map(workers:, input_transfer: :copy, output_transfer: :copy, &block)
  raise ArgumentError, "missing block" unless block
  raise TypeError, "workers must be an Integer" unless workers.is_a?(Integer)
  raise ArgumentError, "workers must be positive" unless workers.positive?

  Internal::RactorTransferPolicy.validate!(:input_transfer, input_transfer)
  Internal::RactorTransferPolicy.validate!(:output_transfer, output_transfer)
  raise TypeError, "block must be shareable" unless Ractor.shareable?(block)

  new { |upstream| Pull.ractor_unordered_map(upstream, workers, input_transfer, output_transfer, block) }
end

.reject(&block) ⇒ void

This method returns an undefined value.

Creates a complement filtering flow.

The block is called for upstream elements until it returns false or nil, or upstream completes. Truthy predicate results drop the original element; false and nil results pass the element through unchanged. Exceptions raised by the block fail the stream and are re-raised from Source#run_with.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 153

def self.reject(&block)
  raise ArgumentError, "missing block" unless block

  new { |upstream| Pull.reject(upstream, block) }
end

.scan(initial, &block) ⇒ void

This method returns an undefined value.

Creates a running-accumulator flow.

The block is called as block.call(accumulator, element) for each upstream element, matching Sink.fold. The block result becomes the new accumulator and is emitted downstream. The initial accumulator is not emitted before the first upstream element.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 204

def self.scan(initial, &block)
  raise ArgumentError, "missing block" unless block

  new { |upstream| Pull.scan(upstream, initial, block) }
end

.select(&block) ⇒ void

This method returns an undefined value.

Creates a filtering flow.

The block is called for upstream elements until it returns a truthy value or upstream completes. Matching elements pass through unchanged. Exceptions raised by the block fail the stream and are re-raised from Source#run_with.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 140

def self.select(&block)
  raise ArgumentError, "missing block" unless block

  new { |upstream| Pull.select(upstream, block) }
end

.split(separator, keep_separator: false, max_length: nil) ⇒ Flow[String, String]

Creates a delimiter-splitting flow.

The flow accepts String chunks and emits frames split on the non-empty String separator. Separator matching is byte-oriented. By default emitted frames exclude the separator; keep_separator: true preserves it on separator-terminated frames. max_length is an optional per-frame body bytesize limit. With max_length: nil, one unterminated frame can buffer without bound. Set a positive max_length for untrusted, network-facing, or otherwise unbounded streams.

Parameters:

  • separator (String)
  • keep_separator: (Boolean) (defaults to: false)
  • max_length: (Integer, nil) (defaults to: nil)

Returns:

  • (Flow[String, String])

Raises:

  • (TypeError) 


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# File 'lib/fiber_stream/flow.rb', line 300

def self.split(separator, keep_separator: false, max_length: nil)
  raise TypeError, "separator must be String" unless separator.is_a?(String)
  raise ArgumentError, "separator must not be empty" if separator.empty?
  raise TypeError, "keep_separator must be true or false" unless [true, false].include?(keep_separator)
  unless max_length.nil? || max_length.is_a?(Integer)
    raise TypeError, "max_length must be nil or an Integer"
  end
  raise ArgumentError, "max_length must be positive" if max_length&.<= 0

  new { |upstream| Pull.split(upstream, separator, keep_separator, max_length) }
end

.take(count) ⇒ void

This method returns an undefined value.

Creates a limiting flow.

The flow emits at most count elements. take(0) completes without pulling upstream and closes upstream on the first downstream demand. After the limit is reached, upstream is closed during the pull that forwards the final element. Negative counts raise ArgumentError; non-Integer counts raise TypeError.

Raises:

  • (TypeError) 


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# File 'lib/fiber_stream/flow.rb', line 166

def self.take(count)
  raise TypeError, "count must be an Integer" unless count.is_a?(Integer)
  raise ArgumentError, "count must be non-negative" if count.negative?

  new { |upstream| Pull.take(upstream, count) }
end

.take_while(&block) ⇒ void

This method returns an undefined value.

Creates a predicate-based limiting flow.

The flow emits leading elements while the block result is truthy. The first false or nil result completes the stream without emitting that element and closes upstream during the same downstream pull. Exceptions raised by the block fail the stream and are re-raised from Source#run_with.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 217

def self.take_while(&block)
  raise ArgumentError, "missing block" unless block

  new { |upstream| Pull.take_while(upstream, block) }
end

.tap(&block) ⇒ void

This method returns an undefined value.

Creates a pass-through observing flow.

The block is called once for each element before that element is emitted downstream. The block return value is ignored and the original element is passed through unchanged. Exceptions raised by the block fail the stream and are re-raised from Source#run_with.

Raises:

  • (ArgumentError) 


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# File 'lib/fiber_stream/flow.rb', line 55

def self.tap(&block)
  raise ArgumentError, "missing block" unless block

  new { |upstream| Pull.tap(upstream, block) }
end

.throttle(**options) ⇒ void

This method returns an undefined value.

Creates a scheduler-aware throttling flow.

The rate: form creates a fresh RateLimiter for each materialization. The limiter: form uses the supplied limiter object, which must respond to acquire(permits:) and return only after permits are acquired. When FiberStream-owned waiting is required, the current fiber must be non-blocking with an installed Fiber.scheduler.



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# File 'lib/fiber_stream/flow.rb', line 268

def self.throttle(**options)
  limiter = build_throttle_limiter(options)

  new { |upstream| Pull.throttle(upstream, limiter.call) }
end

Instance Method Details

#attach_to(upstream) ⇒ Object

:nodoc:



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# File 'lib/fiber_stream/flow.rb', line 405

def attach_to(upstream) # :nodoc:
  @attach.call(upstream)
end

#to(sink) ⇒ void

This method returns an undefined value.

Returns a sink that runs this flow before sink.

The composed sink accepts this flow's input elements and returns the wrapped sink's materialized value. It closes the attached flow chain after normal completion, failure, or early sink completion.

Raises:

  • (TypeError) 


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# File 'lib/fiber_stream/flow.rb', line 376

def to(sink)
  raise TypeError, "expected FiberStream::Sink" unless sink.is_a?(Sink)

  Sink.build do |stream|
    attached_stream = nil
    primary_error = nil

    begin
      attached_stream = attach_to(stream)
      sink.run_stream(attached_stream)
    rescue StandardError => error
      primary_error = error
      raise
    ensure
      begin
        attached_stream&.close
      rescue StandardError => close_error
        raise close_error unless primary_error
      end
    end
  end
end

#via(flow) ⇒ void

This method returns an undefined value.

Returns a reusable flow that applies this flow and then flow.

Construction is lazy. No upstream stream is attached and no elements are pulled until the composed flow is materialized by a source or sink.

Raises:

  • (TypeError) 


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# File 'lib/fiber_stream/flow.rb', line 352

def via(flow)
  raise TypeError, "expected FiberStream::Flow" unless flow.is_a?(Flow)

  self.class.build do |upstream|
    attached_stream = attach_to(upstream)

    begin
      flow.attach_to(attached_stream)
    rescue StandardError
      begin
        attached_stream.close
      rescue StandardError
        nil
      end
      raise
    end
  end
end