Module: Legion::Data::EventStore

Defined in:
lib/legion/data/event_store.rb,
lib/legion/data/event_store/projection.rb

Defined Under Namespace

Classes: ConsentState, GovernanceTimeline, Projection

Constant Summary collapse

GOVERNANCE_EVENT_TYPES = 
%w[
  consent.granted consent.revoked consent.modified
  extinction.triggered extinction.resolved
  worker.registered worker.retired worker.transferred
  scope.approved scope.violated scope.reconciled
  audit.retention_applied audit.exported
].freeze

Class Method Summary collapse

Class Method Details

.append(stream:, type:, data: {}, metadata: {}) ⇒ Object 



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# File 'lib/legion/data/event_store.rb', line 17

def append(stream:, type:, data: {}, metadata: {})
  return { error: 'db unavailable' } unless db_ready?

  conn = Legion::Data.connection
  conn.transaction do
    last = conn[:governance_events]
           .where(stream_id: stream)
           .order(Sequel.desc(:sequence_number))
           .first

    seq = (last&.[](:sequence_number) || 0) + 1
    prev_hash = last&.[](:event_hash) || ('0' * 64)

    data_json = Legion::JSON.dump(data)
    metadata_json = Legion::JSON.dump(metadata)
    event_hash = compute_hash(stream, seq, type, data_json, prev_hash)

    conn[:governance_events].insert(
      stream_id:       stream,
      event_type:      type,
      sequence_number: seq,
      data_json:       data_json,
      metadata_json:   metadata_json,
      event_hash:      event_hash,
      previous_hash:   prev_hash,
      created_at:      Time.now
    )

    { stream: stream, sequence: seq, hash: event_hash }
  end
end

.read_by_type(type, since: nil, limit: 100) ⇒ Object 



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# File 'lib/legion/data/event_store.rb', line 57

def read_by_type(type, since: nil, limit: 100)
  return [] unless db_ready?

  ds = Legion::Data.connection[:governance_events].where(event_type: type)
  ds = ds.where { created_at >= since } if since
  ds.order(Sequel.desc(:created_at)).limit(limit).all.map { |e| deserialize(e) }
end

.read_stream(stream, since: nil) ⇒ Object 



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# File 'lib/legion/data/event_store.rb', line 49

def read_stream(stream, since: nil)
  return [] unless db_ready?

  ds = Legion::Data.connection[:governance_events].where(stream_id: stream)
  ds = ds.where { created_at >= since } if since
  ds.order(:sequence_number).all.map { |e| deserialize(e) }
end

.verify_chain(stream) ⇒ Object 



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# File 'lib/legion/data/event_store.rb', line 65

def verify_chain(stream)
  return { valid: false, error: 'db unavailable' } unless db_ready?

  events = Legion::Data.connection[:governance_events]
                       .where(stream_id: stream)
                       .order(:sequence_number)
                       .all

  prev_hash = '0' * 64
  events.each do |e|
    expected = compute_hash(stream, e[:sequence_number], e[:event_type], e[:data_json], prev_hash)
    return { valid: false, broken_at: e[:sequence_number] } unless e[:event_hash] == expected
    return { valid: false, broken_at: e[:sequence_number] } unless e[:previous_hash] == prev_hash

    prev_hash = e[:event_hash]
  end

  { valid: true, length: events.size }
end