debian-mirror-gitlab/doc/development/creating_enums.md

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

155 lines
4.1 KiB
Markdown
Raw Normal View History

2021-01-29 00:20:46 +05:30
---
stage: Enablement
group: Database
2021-02-22 17:27:13 +05:30
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
2021-01-29 00:20:46 +05:30
---
2019-12-26 22:10:19 +05:30
# Creating enums
When creating a new enum, it should use the database type `SMALLINT`.
The `SMALLINT` type size is 2 bytes, which is sufficient for an enum.
This would help to save space in the database.
To use this type, add `limit: 2` to the migration that creates the column.
Example:
2020-04-08 14:13:33 +05:30
```ruby
2019-12-26 22:10:19 +05:30
def change
add_column :ci_job_artifacts, :file_format, :integer, limit: 2
end
```
2020-05-24 23:13:21 +05:30
## All of the key/value pairs should be defined in FOSS
**Summary:** All enums needs to be defined in FOSS, if a model is also part of the FOSS.
```ruby
class Model < ApplicationRecord
enum platform: {
aws: 0,
gcp: 1 # EE-only
}
end
```
When you add a new key/value pair to a `enum` and if it's EE-specific, you might be
tempted to organize the `enum` as the following:
```ruby
# Define `failure_reason` enum in `Pipeline` model:
class Pipeline < ApplicationRecord
2020-11-24 15:15:51 +05:30
enum failure_reason: Enums::Pipeline.failure_reasons
2020-05-24 23:13:21 +05:30
end
```
```ruby
# Define key/value pairs that used in FOSS and EE:
2020-11-24 15:15:51 +05:30
module Enums
module Pipeline
def self.failure_reasons
{ unknown_failure: 0, config_error: 1 }
end
2020-05-24 23:13:21 +05:30
end
end
2021-06-08 01:23:25 +05:30
Enums::Pipeline.prepend_mod_with('Enums::Pipeline')
2020-05-24 23:13:21 +05:30
```
```ruby
# Define key/value pairs that used in EE only:
module EE
2020-11-24 15:15:51 +05:30
module Enums
module Pipeline
override :failure_reasons
def failure_reasons
super.merge(activity_limit_exceeded: 2)
end
2020-05-24 23:13:21 +05:30
end
end
end
```
This works as-is, however, it has a couple of downside that:
- Someone could define a key/value pair in EE that is **conflicted** with a value defined in FOSS.
2021-10-27 15:23:28 +05:30
For example, define `activity_limit_exceeded: 1` in `EE::Enums::Pipeline`.
2020-05-24 23:13:21 +05:30
- When it happens, the feature works totally different.
2021-10-27 15:23:28 +05:30
For example, we cannot figure out `failure_reason` is either `config_error` or `activity_limit_exceeded`.
2020-05-24 23:13:21 +05:30
- When it happens, we have to ship a database migration to fix the data integrity,
which might be impossible if you cannot recover the original value.
Also, you might observe a workaround for this concern by setting an offset in EE's values.
For example, this example sets `1000` as the offset:
```ruby
module EE
2020-11-24 15:15:51 +05:30
module Enums
module Pipeline
override :failure_reasons
def failure_reasons
super.merge(activity_limit_exceeded: 1_000, size_limit_exceeded: 1_001)
end
2020-05-24 23:13:21 +05:30
end
end
end
```
2020-06-23 00:09:42 +05:30
This looks working as a workaround, however, this approach has some downsides that:
2020-05-24 23:13:21 +05:30
- Features could move from EE to FOSS or vice versa. Therefore, the offset might be mixed between FOSS and EE in the future.
2021-10-27 15:23:28 +05:30
For example, when you move `activity_limit_exceeded` to FOSS, you'll see `{ unknown_failure: 0, config_error: 1, activity_limit_exceeded: 1_000 }`.
2020-05-24 23:13:21 +05:30
- The integer column for the `enum` is likely created [as `SMALLINT`](#creating-enums).
Therefore, you need to be careful of that the offset doesn't exceed the maximum value of 2 bytes integer.
As a conclusion, you should define all of the key/value pairs in FOSS.
For example, you can simply write the following code in the above case:
```ruby
class Pipeline < ApplicationRecord
enum failure_reason: {
unknown_failure: 0,
config_error: 1,
activity_limit_exceeded: 2
}
end
```
2021-04-29 21:17:54 +05:30
## Add new values in the gap
After merging some EE and FOSS enums, there might be a gap between the two groups of values:
```ruby
module Enums
module Ci
module CommitStatus
def self.failure_reasons
{
# ...
data_integrity_failure: 12,
forward_deployment_failure: 13,
insufficient_bridge_permissions: 1_001,
downstream_bridge_project_not_found: 1_002,
# ...
}
end
end
end
end
```
To add new values, you should fill the gap first.
In the example above add `14` instead of `1_003`:
```ruby
{
# ...
data_integrity_failure: 12,
forward_deployment_failure: 13,
a_new_value: 14,
insufficient_bridge_permissions: 1_001,
downstream_bridge_project_not_found: 1_002,
# ...
}
```