Extract StatusSafeReblogInsert concern from Status (#24821)
parent
830e6cefae
commit
0b249ebdb0
3 changed files with 79 additions and 65 deletions
@ -0,0 +1,72 @@ |
||||
# frozen_string_literal: true |
||||
|
||||
module StatusSafeReblogInsert |
||||
extend ActiveSupport::Concern |
||||
|
||||
class_methods do |
||||
# This is a hack to ensure that no reblogs of discarded statuses are created, |
||||
# as this cannot be enforced through database constraints the same way we do |
||||
# for reblogs of deleted statuses. |
||||
# |
||||
# To achieve this, we redefine the internal method responsible for issuing |
||||
# the "INSERT" statement and replace the "INSERT INTO ... VALUES ..." query |
||||
# with an "INSERT INTO ... SELECT ..." query with a "WHERE deleted_at IS NULL" |
||||
# clause on the reblogged status to ensure consistency at the database level. |
||||
# |
||||
# Otherwise, the code is kept as close as possible to ActiveRecord::Persistence |
||||
# code, and actually calls it if we are not handling a reblog. |
||||
def _insert_record(values) |
||||
return super unless values.is_a?(Hash) && values['reblog_of_id'].present? |
||||
|
||||
primary_key = self.primary_key |
||||
primary_key_value = nil |
||||
|
||||
if primary_key |
||||
primary_key_value = values[primary_key] |
||||
|
||||
if !primary_key_value && prefetch_primary_key? |
||||
primary_key_value = next_sequence_value |
||||
values[primary_key] = primary_key_value |
||||
end |
||||
end |
||||
|
||||
# The following line is where we differ from stock ActiveRecord implementation |
||||
im = _compile_reblog_insert(values) |
||||
|
||||
# Since we are using SELECT instead of VALUES, a non-error `nil` return is possible. |
||||
# For our purposes, it's equivalent to a foreign key constraint violation |
||||
result = connection.insert(im, "#{self} Create", primary_key || false, primary_key_value) |
||||
raise ActiveRecord::InvalidForeignKey, "(reblog_of_id)=(#{values['reblog_of_id']}) is not present in table \"statuses\"" if result.nil? |
||||
|
||||
result |
||||
end |
||||
|
||||
def _compile_reblog_insert(values) |
||||
# This is somewhat equivalent to the following code of ActiveRecord::Persistence: |
||||
# `arel_table.compile_insert(_substitute_values(values))` |
||||
# The main difference is that we use a `SELECT` instead of a `VALUES` clause, |
||||
# which means we have to build the `SELECT` clause ourselves and do a bit more |
||||
# manual work. |
||||
|
||||
# Instead of using Arel::InsertManager#values, we are going to use Arel::InsertManager#select |
||||
im = Arel::InsertManager.new |
||||
im.into(arel_table) |
||||
|
||||
binds = [] |
||||
reblog_bind = nil |
||||
values.each do |name, value| |
||||
attr = arel_table[name] |
||||
bind = predicate_builder.build_bind_attribute(attr.name, value) |
||||
|
||||
im.columns << attr |
||||
binds << bind |
||||
|
||||
reblog_bind = bind if name == 'reblog_of_id' |
||||
end |
||||
|
||||
im.select(arel_table.where(arel_table[:id].eq(reblog_bind)).where(arel_table[:deleted_at].eq(nil)).project(*binds)) |
||||
|
||||
im |
||||
end |
||||
end |
||||
end |
Loading…
Reference in new issue