2018-11-20 20:47:30 +05:30
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# frozen_string_literal: true
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2018-10-15 14:42:47 +05:30
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##
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# This module is for replacing `dependent: :destroy` and `before_destroy` hooks.
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#
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# In general, `destroy_all` is inefficient because it calls each callback with `DELETE` queries i.e. O(n), whereas,
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# `delete_all` is efficient as it deletes all rows with a single `DELETE` query.
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#
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# It's better to use `delete_all` as our best practice, however,
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2018-12-13 13:39:08 +05:30
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# if external data (e.g. ObjectStorage, FileStorage or Redis) are associated with database records,
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2018-10-15 14:42:47 +05:30
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# it is difficult to accomplish it.
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#
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# This module defines a format to use `delete_all` and delete associated external data.
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# Here is an exmaple
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#
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# Situation
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# - `Project` has many `Ci::BuildTraceChunk` through `Ci::Build`
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# - `Ci::BuildTraceChunk` stores associated data in Redis, so it relies on `dependent: :destroy` and `before_destroy` for the deletion
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#
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# How to use
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# - Define `use_fast_destroy :build_trace_chunks` in `Project` model.
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# - Define `begin_fast_destroy` and `finalize_fast_destroy(params)` in `Ci::BuildTraceChunk` model.
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# - Use `fast_destroy_all` instead of `destroy` and `destroy_all`
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# - Remove `dependent: :destroy` and `before_destroy` as it's no longer need
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#
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# Expectation
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# - When a project is `destroy`ed, the associated trace_chunks will be deleted by `delete_all`,
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# and the associated data will be removed, too.
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# - When `fast_destroy_all` is called, it also performns as same.
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module FastDestroyAll
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extend ActiveSupport::Concern
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ForbiddenActionError = Class.new(StandardError)
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included do
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before_destroy do
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2018-11-20 20:47:30 +05:30
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raise ForbiddenActionError, '`destroy` and `destroy_all` are forbidden. Please use `fast_destroy_all`'
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2018-10-15 14:42:47 +05:30
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end
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end
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class_methods do
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##
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# This method delete rows and associated external data efficiently
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#
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# This method can replace `destroy` and `destroy_all` without having `after_destroy` hook
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def fast_destroy_all
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params = begin_fast_destroy
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delete_all
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finalize_fast_destroy(params)
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end
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##
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# This method returns identifiers to delete associated external data (e.g. file paths, redis keys)
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#
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# This method must be defined in fast destroyable model
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def begin_fast_destroy
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raise NotImplementedError
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end
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##
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# This method deletes associated external data with the identifiers returned by `begin_fast_destroy`
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#
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# This method must be defined in fast destroyable model
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def finalize_fast_destroy(params)
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raise NotImplementedError
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end
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end
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module Helpers
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extend ActiveSupport::Concern
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2018-12-23 12:14:25 +05:30
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include AfterCommitQueue
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2018-10-15 14:42:47 +05:30
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class_methods do
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##
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# This method is to be defined on models which have fast destroyable models as children,
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# and let us avoid to use `dependent: :destroy` hook
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2018-12-23 12:14:25 +05:30
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def use_fast_destroy(relation, opts = {})
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set_callback :destroy, :before, opts.merge(prepend: true) do
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2018-10-15 14:42:47 +05:30
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perform_fast_destroy(public_send(relation)) # rubocop:disable GitlabSecurity/PublicSend
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end
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end
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end
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def perform_fast_destroy(subject)
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params = subject.begin_fast_destroy
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run_after_commit do
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subject.finalize_fast_destroy(params)
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end
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end
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end
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end
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