Module: Lyra::Consistency::ReadYourWrites

Defined in:
lib/lyra/consistency/read_your_writes.rb

Overview

Read-Your-Writes consistency helper for event_sourcing mode.

When using async projections, there's a window where a record might exist in the event store but not yet in the database. This helper ensures that within a block, any writes are immediately projected before reads happen.

Usage:

Lyra::Consistency::ReadYourWrites.with_guaranteed_read do
@registration = Registration.create!(params)
redirect_to @registration  # Guaranteed to find it
end

Class Method Summary collapse

Class Method Details

.in_guaranteed_block? ⇒ Boolean

Check if we're in a guaranteed read block

Returns:

  • (Boolean) 


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# File 'lib/lyra/consistency/read_your_writes.rb', line 48

def in_guaranteed_block?
  !Thread.current[:lyra_pending_writes].nil?
end

.record_write(model_class, operation, result) ⇒ Object

Record a write that needs projection (called by interceptor)



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# File 'lib/lyra/consistency/read_your_writes.rb', line 40

def record_write(model_class, operation, result)
  pending = Thread.current[:lyra_pending_writes]
  return unless pending

  pending << { model_class: model_class, operation: operation, result: result }
end

.with_guaranteed_read ⇒ Object

Execute block with read-your-writes guarantee

Tracks any writes within the block and ensures they are projected before the block returns.



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# File 'lib/lyra/consistency/read_your_writes.rb', line 24

def with_guaranteed_read
  return yield unless Lyra.event_sourcing_mode?

  # Store pending writes in thread-local storage
  Thread.current[:lyra_pending_writes] = []

  begin
    result = yield
    ensure_projected
    result
  ensure
    Thread.current[:lyra_pending_writes] = nil
  end
end