Class: Mammoth::DeadLetterStore

Inherits:
Object
  • Object
show all
Defined in:
lib/mammoth/dead_letter_store.rb

Overview

Persists failed deliveries in Mammoth's SQLite dead letter queue.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sqlite_store) ⇒ DeadLetterStore

Returns a new instance of DeadLetterStore.

Parameters:



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# File 'lib/mammoth/dead_letter_store.rb', line 12

def initialize(sqlite_store)
  @sqlite_store = sqlite_store
end

Instance Attribute Details

#sqlite_store ⇒ Object (readonly)

Returns the value of attribute sqlite_store.



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# File 'lib/mammoth/dead_letter_store.rb', line 9

def sqlite_store
  @sqlite_store
end

Instance Method Details

#count(status: nil, destination: nil) ⇒ Integer

Count dead letters by status.

Parameters:

  • status (String, nil) (defaults to: nil) —

    optional status

Returns:

  • (Integer) —

    dead letter count



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# File 'lib/mammoth/dead_letter_store.rb', line 116

def count(status: nil, destination: nil)
  where, values = row_filters(status:, destination:)
  database.get_first_value("SELECT COUNT(*) FROM dead_letters#{where}", values)
end

#counts_by_destination(status: nil) ⇒ Array<Hash>

Count dead letters grouped by destination.

Parameters:

  • status (String, nil) (defaults to: nil) —

    optional status filter

Returns:

  • (Array<Hash>) —

    rows with destination_name and count



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# File 'lib/mammoth/dead_letter_store.rb', line 125

def counts_by_destination(status: nil)
  where, values = row_filters(status:)
  database.execute(
    "SELECT destination_name, COUNT(*) AS count FROM dead_letters#{where} GROUP BY destination_name",
    values
  )
end

#fetch(id) ⇒ Hash?

Fetch one dead letter by id.

Parameters:

  • id (Integer) —

    dead letter id

Returns:

  • (Hash, nil) —

    dead letter row



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# File 'lib/mammoth/dead_letter_store.rb', line 108

def fetch(id)
  database.get_first_row("SELECT * FROM dead_letters WHERE id = ?", [id])
end

#ignore(id) ⇒ void

This method returns an undefined value.

Mark a dead letter as ignored.

Parameters:

  • id (Integer) —

    dead letter id



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# File 'lib/mammoth/dead_letter_store.rb', line 145

def ignore(id)
  update_status(id, "ignored")
end

#pending(limit: 100, destination: nil, failed_after: nil, failed_before: nil) ⇒ Array<Hash>

Fetch pending dead letters.

Parameters:

  • limit (Integer) (defaults to: 100) —

    maximum number of rows

Returns:

  • (Array<Hash>) —

    pending dead letter rows



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# File 'lib/mammoth/dead_letter_store.rb', line 86

def pending(limit: 100, destination: nil, failed_after: nil, failed_before: nil)
  rows(status: "pending", limit: limit, destination: destination, failed_after: failed_after,
       failed_before: failed_before)
end

#resolve(id) ⇒ void

This method returns an undefined value.

Mark a dead letter as resolved.

Parameters:

  • id (Integer) —

    dead letter id



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# File 'lib/mammoth/dead_letter_store.rb', line 137

def resolve(id)
  update_status(id, "resolved")
end

#rows(status: nil, limit: 100, destination: nil, failed_after: nil, failed_before: nil) ⇒ Array<Hash>

Fetch dead letters, optionally filtered by status.

Parameters:

  • status (String, nil) (defaults to: nil) —

    optional dead-letter status filter

  • limit (Integer) (defaults to: 100) —

    maximum number of rows

Returns:

  • (Array<Hash>) —

    dead letter rows



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# File 'lib/mammoth/dead_letter_store.rb', line 96

def rows(status: nil, limit: 100, destination: nil, failed_after: nil, failed_before: nil)
  where, values = row_filters(status:, destination:, failed_after:, failed_before:)
  database.execute(
    "SELECT * FROM dead_letters#{where} ORDER BY failed_at ASC LIMIT ?",
    values + [limit]
  )
end

#write(event:, destination_name:, error: nil, retry_count: 0, serializer: EventSerializer) ⇒ Integer

Store a failed delivery.

Parameters:

  • event (CDC::Core::ChangeEvent, CDC::Core::TransactionEnvelope) —

    normalized core work item

  • destination_name (String) —

    destination name

  • error (Exception, nil) (defaults to: nil) —

    delivery failure

  • retry_count (Integer) (defaults to: 0) —

    number of delivery attempts

Returns:

  • (Integer) —

    inserted dead letter id



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# File 'lib/mammoth/dead_letter_store.rb', line 23

def write(event:, destination_name:, error: nil, retry_count: 0, serializer: EventSerializer)
  write_payload(
    payload: serializer.call(event),
    destination_name: destination_name,
    error: error,
    retry_count: retry_count
  )
end

#write_payload(payload:, destination_name:, error: nil, retry_count: 0) ⇒ Integer

Store the exact payload prepared for one destination.

Persisting the prepared payload prevents retries and replay from restoring fields removed by a destination payload policy.

Parameters:

  • payload (Hash) —

    prepared destination payload

  • destination_name (String) —

    destination name

  • error (Exception, nil) (defaults to: nil) —

    delivery failure

  • retry_count (Integer) (defaults to: 0) —

    number of delivery attempts

Returns:

  • (Integer) —

    inserted dead letter id



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# File 'lib/mammoth/dead_letter_store.rb', line 42

def write_payload(payload:, destination_name:, error: nil, retry_count: 0) # rubocop:disable Metrics/MethodLength
  now = Time.now.utc.iso8601
  database.execute(
    <<~SQL,
      INSERT INTO dead_letters(
        event_id,
        source_name,
        destination_name,
        operation,
        namespace,
        entity,
        source_position,
        payload_json,
        error_class,
        error_message,
        retry_count,
        status,
        failed_at,
        updated_at
      ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 'pending', ?, ?)
    SQL
    [
      payload.fetch("event_id"),
      payload.fetch("source"),
      destination_name,
      payload["operation"] || payload["type"],
      payload["namespace"],
      payload["entity"],
      payload["source_position"],
      JSON.generate(payload),
      error&.class&.name,
      error&.message,
      retry_count,
      now,
      now
    ]
  )
  database.last_insert_row_id
end