67 lines
1.9 KiB
Ruby
67 lines
1.9 KiB
Ruby
module Gitlab
|
|
module EtagCaching
|
|
class Middleware
|
|
RESERVED_WORDS = ProjectPathValidator::RESERVED.map { |word| "/#{word}/" }.join('|')
|
|
ROUTE_REGEXP = Regexp.union(
|
|
%r(^(?!.*(#{RESERVED_WORDS})).*/noteable/issue/\d+/notes\z)
|
|
)
|
|
|
|
def initialize(app)
|
|
@app = app
|
|
end
|
|
|
|
def call(env)
|
|
return @app.call(env) unless enabled_for_current_route?(env)
|
|
Gitlab::Metrics.add_event(:etag_caching_middleware_used)
|
|
|
|
etag, cached_value_present = get_etag(env)
|
|
if_none_match = env['HTTP_IF_NONE_MATCH']
|
|
|
|
if if_none_match == etag
|
|
Gitlab::Metrics.add_event(:etag_caching_cache_hit)
|
|
[304, { 'ETag' => etag }, ['']]
|
|
else
|
|
track_cache_miss(if_none_match, cached_value_present)
|
|
|
|
status, headers, body = @app.call(env)
|
|
headers['ETag'] = etag
|
|
[status, headers, body]
|
|
end
|
|
end
|
|
|
|
private
|
|
|
|
def enabled_for_current_route?(env)
|
|
ROUTE_REGEXP.match(env['PATH_INFO'])
|
|
end
|
|
|
|
def get_etag(env)
|
|
cache_key = env['PATH_INFO']
|
|
store = Gitlab::EtagCaching::Store.new
|
|
current_value = store.get(cache_key)
|
|
cached_value_present = current_value.present?
|
|
|
|
unless cached_value_present
|
|
current_value = store.touch(cache_key, only_if_missing: true)
|
|
end
|
|
|
|
[weak_etag_format(current_value), cached_value_present]
|
|
end
|
|
|
|
def weak_etag_format(value)
|
|
%Q{W/"#{value}"}
|
|
end
|
|
|
|
def track_cache_miss(if_none_match, cached_value_present)
|
|
if if_none_match.blank?
|
|
Gitlab::Metrics.add_event(:etag_caching_header_missing)
|
|
elsif !cached_value_present
|
|
Gitlab::Metrics.add_event(:etag_caching_key_not_found)
|
|
else
|
|
Gitlab::Metrics.add_event(:etag_caching_resource_changed)
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|