cartodb-4.29/lib/carto/bolt.rb
2020-06-15 10:58:47 +08:00

95 lines
2.4 KiB
Ruby

module Carto
class Bolt
DEFAULT_REDIS_OBJECT = $users_metadata
DEFAULT_TTL_MS = 10000
DEFAULT_RETRY_ATTEMPTS = 1
DEFAULT_RETRY_TIMEOUT = 10000 # in_ms
def initialize(bolt_key, redis_object: DEFAULT_REDIS_OBJECT, ttl_ms: DEFAULT_TTL_MS)
@bolt_key = add_namespace_to_key(bolt_key)
@redis_object = redis_object
@ttl_ms = ttl_ms
end
def run_locked(attempts: DEFAULT_RETRY_ATTEMPTS,
timeout: DEFAULT_RETRY_TIMEOUT,
rerun_func: nil)
raise 'no code block given' unless block_given?
raise 'no proc/lambda passed as rerun_func' if rerun_func.present? && !proc?(rerun_func)
locked_acquired = acquire_lock(attempts, timeout)
begin
unless locked_acquired
set_rerun_after_finish
return !!locked_acquired
end
yield
try_to_rerun(rerun_func)
!!locked_acquired
ensure
unlock if locked_acquired
end
end
private
def acquire_lock(attempts, timeout)
attempts.times do |index|
lock_acquired = get_lock
# With only 1 attempt, the default value, we dont sleep
# even if false
if lock_acquired || (attempts == index + 1)
return lock_acquired
end
sleep((timeout / 1000.0).second)
end
CartoDB::Logger.warning(message: "Couldn't acquire bolt after #{attempts} attempts with #{timeout} timeout")
false
end
def try_to_rerun(rerun_func)
return unless rerun_func.present?
while retry?
refresh_lock_timeout
rerun_func.call
end
end
def proc?(proc)
proc.respond_to?(:call)
end
def unlock
removed_keys = @redis_object.del(@bolt_key)
# This may happen due to Redis failure. Highly unlikely, still nice to know.
if removed_keys > 1
CartoDB.notify_error('Removed bolt key was duplicated', bolt_key: @bolt_key, amount: removed_keys)
end
removed_keys > 0
end
def get_lock
@redis_object.set(@bolt_key, true, px: @ttl_ms, nx: true)
end
def set_rerun_after_finish
@redis_object.set("#{@bolt_key}:retry", true, px: @ttl_ms, nx: true)
end
def refresh_lock_timeout
@redis_object.pexpire(@bolt_key, @ttl_ms)
end
def retry?
@redis_object.del("#{@bolt_key}:retry") > 0
end
def add_namespace_to_key(key)
"rails:bolt:#{key}"
end
end
end