# frozen_string_literal: true

namespace :cache do
  namespace :clear do
    REDIS_CLEAR_BATCH_SIZE = 1000 # There seems to be no speedup when pushing beyond 1,000
    REDIS_SCAN_START_STOP = '0' # Magic value, see http://redis.io/commands/scan

    desc "GitLab | Cache | Clear redis cache"
    task redis: :environment do
      [Gitlab::Redis::Cache, Gitlab::Redis::RepositoryCache].each do |redis_instance|
        redis_instance.with do |redis|
          cache_key_pattern = %W[#{Gitlab::Redis::Cache::CACHE_NAMESPACE}*
                                 projects/*/pipeline_status]

          cache_key_pattern.each do |match|
            cursor = REDIS_SCAN_START_STOP
            loop do
              cursor, keys = redis.scan(
                cursor,
                match: match,
                count: REDIS_CLEAR_BATCH_SIZE
              )

              Gitlab::Instrumentation::RedisClusterValidator.allow_cross_slot_commands do
                Gitlab::Redis::ClusterUtil.batch_unlink(keys, redis) if keys.any?
              end

              break if cursor == REDIS_SCAN_START_STOP
            end
          end
        end
      end
    end

    task all: [:redis]
  end

  task clear: 'cache:clear:redis'
end