Class: GraphQL::AnyCable::PostgreSQLStore::Store

Inherits:
Object
  • Object
show all
Defined in:
lib/graphql/anycable/postgresql_store/store.rb

Constant Summary collapse

SUBSCRIPTIONS_PREFIX = 
"subscriptions:"

Instance Method Summary collapse

Constructor Details

#initialize(config: PostgreSQLStore.config, graphql_config: GraphQL::AnyCable.config) ⇒ Store

Returns a new instance of Store.



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# File 'lib/graphql/anycable/postgresql_store/store.rb', line 11

def initialize(config: PostgreSQLStore.config, graphql_config: GraphQL::AnyCable.config)
  load_pg!

  @config = config
  @graphql_config = graphql_config
  @mutex = Mutex.new
  @subscriptions_table = quote_table_name(config.subscriptions_table)
  @events_table = quote_table_name(config.subscription_events_table)
  @channels_table = quote_table_name(config.channel_subscriptions_table)
end

Instance Method Details

#delete_channel_subscriptions(channel_id) ⇒ Object 



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# File 'lib/graphql/anycable/postgresql_store/store.rb', line 136

def delete_channel_subscriptions(channel_id)
  with_connection do |conn|
    transaction(conn) do
      conn.exec_params(<<~SQL, [channel_id])
        DELETE FROM #{subscriptions_table}
        WHERE id IN (
          SELECT subscription_id
          FROM #{channels_table}
          WHERE channel_id = $1
        )
      SQL
      conn.exec_params("DELETE FROM #{channels_table} WHERE channel_id = $1", [channel_id])
    end
  end
end

#delete_subscription(subscription_id) ⇒ Object 



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# File 'lib/graphql/anycable/postgresql_store/store.rb', line 152

def delete_subscription(subscription_id)
  with_connection do |conn|
    conn.exec_params("DELETE FROM #{subscriptions_table} WHERE id = $1", [subscription_id])
  end
end

#fingerprints_for_topic(topic) ⇒ Object 



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# File 'lib/graphql/anycable/postgresql_store/store.rb', line 26

def fingerprints_for_topic(topic)
  with_connection do |conn|
    conn.exec_params(<<~SQL, [topic]).map { |row| row.fetch("fingerprint") }
      SELECT events.fingerprint
      FROM #{events_table} events
      INNER JOIN #{subscriptions_table} subscriptions
        ON subscriptions.id = events.subscription_id
      WHERE events.topic = $1
        AND (subscriptions.expires_at IS NULL OR subscriptions.expires_at > CURRENT_TIMESTAMP)
      GROUP BY events.fingerprint
      ORDER BY COUNT(*) ASC, MIN(events.created_at) ASC
    SQL
  end
end

#read_subscription(subscription_id) ⇒ Object 



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# File 'lib/graphql/anycable/postgresql_store/store.rb', line 122

def read_subscription(subscription_id)
  with_connection do |conn|
    result = conn.exec_params(<<~SQL, [subscription_id])
      SELECT query_string, variables, context, operation_name
      FROM #{subscriptions_table}
      WHERE id = $1
        AND (expires_at IS NULL OR expires_at > CURRENT_TIMESTAMP)
    SQL
    return if result.ntuples.zero?

    result.first.transform_keys(&:to_sym)
  end
end

#stats(scan_count:, include_subscriptions: false) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/graphql/anycable/postgresql_store/store.rb', line 158

def stats(scan_count:, include_subscriptions: false)
  # PostgreSQL uses aggregate queries rather than key scans; scan_count
  # is accepted to match graphql-anycable's store stats interface.
  raise ArgumentError, "scan_count must be positive" if scan_count.to_i <= 0

  with_connection do |conn|
    result = {total: total_stats(conn)}
    result[:subscriptions] = subscription_stats(conn) if include_subscriptions
    result
  end
end

#stream_for(fingerprint) ⇒ Object 



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# File 'lib/graphql/anycable/postgresql_store/store.rb', line 22

def stream_for(fingerprint)
  "#{graphql_config.redis_prefix}-#{SUBSCRIPTIONS_PREFIX}#{fingerprint}"
end

#subscription_exists?(subscription_id) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/graphql/anycable/postgresql_store/store.rb', line 62

def subscription_exists?(subscription_id)
  with_connection do |conn|
    conn.exec_params(<<~SQL, [subscription_id]).getvalue(0, 0) == "t"
      SELECT EXISTS (
        SELECT 1
        FROM #{subscriptions_table}
        WHERE id = $1
          AND (expires_at IS NULL OR expires_at > CURRENT_TIMESTAMP)
      )
    SQL
  end
end

#subscription_ids_for_fingerprints(fingerprints) ⇒ Object 



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# File 'lib/graphql/anycable/postgresql_store/store.rb', line 41

def subscription_ids_for_fingerprints(fingerprints)
  result = fingerprints.to_h { |fingerprint| [fingerprint, []] }
  return result if fingerprints.empty?

  with_connection do |conn|
    conn.exec_params(<<~SQL, fingerprints).each do |row|
      SELECT events.fingerprint, events.subscription_id
      FROM #{events_table} events
      INNER JOIN #{subscriptions_table} subscriptions
        ON subscriptions.id = events.subscription_id
      WHERE events.fingerprint IN (#{placeholders(fingerprints.length)})
        AND (subscriptions.expires_at IS NULL OR subscriptions.expires_at > CURRENT_TIMESTAMP)
      ORDER BY events.fingerprint ASC, events.created_at ASC
    SQL
      result[row.fetch("fingerprint")] << row.fetch("subscription_id")
    end
  end

  result
end

#write_subscription(subscription_id, channel_id:, data:, events:, expiration_seconds:) ⇒ Object 



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# File 'lib/graphql/anycable/postgresql_store/store.rb', line 75

def write_subscription(subscription_id, channel_id:, data:, events:, expiration_seconds:)
  expires_at = expiration_seconds ? (Time.now.utc + expiration_seconds).iso8601(6) : nil
  subscription_params = [
    subscription_id,
    data.fetch(:query_string),
    data.fetch(:variables),
    data.fetch(:context),
    data.fetch(:operation_name),
    data.fetch(:events),
    expires_at
  ]

  with_connection do |conn|
    transaction(conn) do
      conn.exec_params(<<~SQL, subscription_params)
        INSERT INTO #{subscriptions_table}
          (id, query_string, variables, context, operation_name, events, expires_at, created_at, updated_at)
        VALUES ($1, $2, $3, $4, $5, $6, $7, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
        ON CONFLICT (id) DO UPDATE SET
          query_string = EXCLUDED.query_string,
          variables = EXCLUDED.variables,
          context = EXCLUDED.context,
          operation_name = EXCLUDED.operation_name,
          events = EXCLUDED.events,
          expires_at = EXCLUDED.expires_at,
          updated_at = CURRENT_TIMESTAMP
      SQL

      conn.exec_params("DELETE FROM #{events_table} WHERE subscription_id = $1", [subscription_id])
      conn.exec_params("DELETE FROM #{channels_table} WHERE subscription_id = $1", [subscription_id])
      conn.exec_params(<<~SQL, [channel_id, subscription_id])
        INSERT INTO #{channels_table} (channel_id, subscription_id, created_at)
        VALUES ($1, $2, CURRENT_TIMESTAMP)
        ON CONFLICT (channel_id, subscription_id) DO NOTHING
      SQL

      events.each do |event|
        conn.exec_params(<<~SQL, [subscription_id, event.topic, event.fingerprint])
          INSERT INTO #{events_table} (subscription_id, topic, fingerprint, created_at)
          VALUES ($1, $2, $3, CURRENT_TIMESTAMP)
          ON CONFLICT (subscription_id, topic, fingerprint) DO NOTHING
        SQL
      end
    end
  end
end