debian-mirror-gitlab/app/services/protected_branches/cache_service.rb
2023-01-12 18:35:48 +00:00

87 lines
2.7 KiB
Ruby

# frozen_string_literal: true
module ProtectedBranches
class CacheService < ProtectedBranches::BaseService
CACHE_ROOT_KEY = 'cache:gitlab:protected_branch'
TTL_UNSET = -1
CACHE_EXPIRE_IN = 1.day
CACHE_LIMIT = 1000
def fetch(ref_name, dry_run: false, &block)
record = OpenSSL::Digest::SHA256.hexdigest(ref_name)
with_redis do |redis|
cached_result = redis.hget(redis_key, record)
if cached_result.nil?
metrics.increment_cache_miss
else
metrics.increment_cache_hit
decoded_result = Gitlab::Redis::Boolean.decode(cached_result)
end
# If we're dry-running, don't break because we need to check against
# the real value to ensure the cache is working properly.
# If the result is nil we'll need to run the block, so don't break yet.
break decoded_result unless dry_run || decoded_result.nil?
calculated_value = metrics.observe_cache_generation(&block)
check_and_log_discrepancy(decoded_result, calculated_value, ref_name) if dry_run
redis.hset(redis_key, record, Gitlab::Redis::Boolean.encode(calculated_value))
# We don't want to extend cache expiration time
if redis.ttl(redis_key) == TTL_UNSET
redis.expire(redis_key, CACHE_EXPIRE_IN)
end
# If the cache record has too many elements, then something went wrong and
# it's better to drop the cache key.
if redis.hlen(redis_key) > CACHE_LIMIT
redis.unlink(redis_key)
end
calculated_value
end
end
def refresh
with_redis { |redis| redis.unlink(redis_key) }
end
private
def with_redis(&block)
Gitlab::Redis::Cache.with(&block) # rubocop:disable CodeReuse/ActiveRecord
end
def check_and_log_discrepancy(cached_value, real_value, ref_name)
return if cached_value.nil?
return if cached_value == real_value
encoded_ref_name = Gitlab::EncodingHelper.encode_utf8_with_replacement_character(ref_name)
log_error(
'class' => self.class.name,
'message' => "Cache mismatch '#{encoded_ref_name}': cached value: #{cached_value}, real value: #{real_value}",
'project_id' => @project.id,
'project_path' => @project.full_path
)
end
def redis_key
@redis_key ||= [CACHE_ROOT_KEY, @project.id].join(':')
end
def metrics
@metrics ||= Gitlab::Cache::Metrics.new(
caller_id: Gitlab::ApplicationContext.current_context_attribute(:caller_id),
cache_identifier: "#{self.class}#fetch",
feature_category: :source_code_management,
backing_resource: :cpu
)
end
end
end