gitlab-org--gitlab-foss/app/models/concerns/routable.rb
Toon Claes d13669716a Create idea of read-only database
In GitLab EE, a GitLab instance can be read-only (e.g. when it's a Geo
secondary node). But in GitLab CE it also might be useful to have the
"read-only" idea around. So port it back to GitLab CE.

Also having the principle of read-only in GitLab CE would hopefully
lead to less errors introduced, doing write operations when there
aren't allowed for read-only calls.

Closes gitlab-org/gitlab-ce#37534.
2017-10-06 22:37:40 +02:00

172 lines
4.5 KiB
Ruby

# Store object full path in separate table for easy lookup and uniq validation
# Object must have name and path db fields and respond to parent and parent_changed? methods.
module Routable
extend ActiveSupport::Concern
included do
has_one :route, as: :source, autosave: true, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
has_many :redirect_routes, as: :source, autosave: true, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
validates_associated :route
validates :route, presence: true
scope :with_route, -> { includes(:route) }
before_validation do
if full_path_changed? || full_name_changed?
prepare_route
end
end
end
class_methods do
# Finds a single object by full path match in routes table.
#
# Usage:
#
# Klass.find_by_full_path('gitlab-org/gitlab-ce')
#
# Returns a single object, or nil.
def find_by_full_path(path, follow_redirects: false)
# On MySQL we want to ensure the ORDER BY uses a case-sensitive match so
# any literal matches come first, for this we have to use "BINARY".
# Without this there's still no guarantee in what order MySQL will return
# rows.
#
# Why do we do this?
#
# Even though we have Rails validation on Route for unique paths
# (case-insensitive), there are old projects in our DB (and possibly
# clients' DBs) that have the same path with different cases.
# See https://gitlab.com/gitlab-org/gitlab-ce/issues/18603. Also note that
# our unique index is case-sensitive in Postgres.
binary = Gitlab::Database.mysql? ? 'BINARY' : ''
order_sql = "(CASE WHEN #{binary} routes.path = #{connection.quote(path)} THEN 0 ELSE 1 END)"
found = where_full_path_in([path]).reorder(order_sql).take
return found if found
if follow_redirects
if Gitlab::Database.postgresql?
joins(:redirect_routes).find_by("LOWER(redirect_routes.path) = LOWER(?)", path)
else
joins(:redirect_routes).find_by(redirect_routes: { path: path })
end
end
end
# Builds a relation to find multiple objects by their full paths.
#
# Usage:
#
# Klass.where_full_path_in(%w{gitlab-org/gitlab-ce gitlab-org/gitlab-ee})
#
# Returns an ActiveRecord::Relation.
def where_full_path_in(paths)
wheres = []
cast_lower = Gitlab::Database.postgresql?
paths.each do |path|
path = connection.quote(path)
where =
if cast_lower
"(LOWER(routes.path) = LOWER(#{path}))"
else
"(routes.path = #{path})"
end
wheres << where
end
if wheres.empty?
none
else
joins(:route).where(wheres.join(' OR '))
end
end
end
def full_name
if route && route.name.present?
@full_name ||= route.name
else
update_route if persisted?
build_full_name
end
end
# Every time `project.namespace.becomes(Namespace)` is called for polymorphic_path,
# a new instance is instantiated, and we end up duplicating the same query to retrieve
# the route. Caching this per request ensures that even if we have multiple instances,
# we will not have to duplicate work, avoiding N+1 queries in some cases.
def full_path
return uncached_full_path unless RequestStore.active?
RequestStore[full_path_key] ||= uncached_full_path
end
def full_path_components
full_path.split('/')
end
def expires_full_path_cache
RequestStore.delete(full_path_key) if RequestStore.active?
@full_path = nil
end
def build_full_path
if parent && path
parent.full_path + '/' + path
else
path
end
end
private
def uncached_full_path
if route && route.path.present?
@full_path ||= route.path
else
update_route if persisted?
build_full_path
end
end
def full_name_changed?
name_changed? || parent_changed?
end
def full_path_changed?
path_changed? || parent_changed?
end
def full_path_key
@full_path_key ||= "routable/full_path/#{self.class.name}/#{self.id}"
end
def build_full_name
if parent && name
parent.human_name + ' / ' + name
else
name
end
end
def update_route
return if Gitlab::Database.read_only?
prepare_route
route.save
end
def prepare_route
route || build_route(source: self)
route.path = build_full_path
route.name = build_full_name
@full_path = nil
@full_name = nil
end
end