Class: DeltaCore::Context

Inherits:
Object
  • Object
show all
Defined in:
lib/delta_core/context.rb

Instance Method Summary collapse

Constructor Details

#initialize(config, adapter: nil) ⇒ Context

Returns a new instance of Context.



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# File 'lib/delta_core/context.rb', line 5

def initialize(config, adapter: nil)
  @config  = config
  @adapter = adapter || Adapters::ActiveRecord.new(config)
end

Instance Method Details

#build_state(model) ⇒ Object 



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# File 'lib/delta_core/context.rb', line 10

def build_state(model)
  StateBuilder.build(model, @config)
end

#calculate_delta(model) ⇒ Object 



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# File 'lib/delta_core/context.rb', line 14

def calculate_delta(model)
  snapshot      = @adapter.load_snapshot(model)
  current_state = build_state(model)
  Comparator.compare(snapshot.state, current_state, @config)
end

#reset_flags(_model) ⇒ Object 



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# File 'lib/delta_core/context.rb', line 55

def reset_flags(_model)
  # Extension point: clears any dirty-tracking metadata.
  # Default implementation is a no-op.
end

#update_snapshot(model) ⇒ Object

Raises:



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# File 'lib/delta_core/context.rb', line 20

def update_snapshot(model)
  delta = calculate_delta(model)
  raise EmptyDeltaError, "Cannot update snapshot: delta is empty" if delta.empty?

  @adapter.lock_record(model) do
    current_state  = build_state(model)
    serialized     = Snapshot.new.serialize(current_state)
    @adapter.persist(model, serialized)
  end
end

#with_delta_transaction(model) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/delta_core/context.rb', line 31

def with_delta_transaction(model)
  raise ArgumentError, "Block required" unless block_given?

  result = nil

  @adapter.lock_record(model) do
    current_state = build_state(model)
    delta         = Comparator.compare(
      @adapter.load_snapshot(model).state,
      current_state,
      @config
    )

    raise EmptyDeltaError, "Delta is empty — nothing to transmit" if delta.empty?

    result = yield delta

    serialized = Snapshot.new.serialize(current_state)
    @adapter.persist(model, serialized)
  end

  result
end