use Vtc.Ecto.Postgres.Utils
defpgmodule Vtc.Ecto.Postgres.PgFramestamp.Migrations do
@moduledoc """
Migrations for adding framestamp types, functions and constraints to a
Postgres database.
"""
alias Ecto.Migration
alias Vtc.Ecto.Postgres
alias Vtc.Ecto.Postgres.PgFramerate
alias Vtc.Ecto.Postgres.PgRational
require Ecto.Migration
@typedoc """
Indicates returned string is am SQL command.
"""
@type raw_sql() :: String.t()
@typedoc """
SQL value that can be passed as an atom or a string.
"""
@type sql_value() :: String.t() | atom()
@doc section: :migrations_full
@doc """
Adds raw SQL queries to a migration for creating the database types, associated
functions, casts, operators, and operator families.
This migration included all migraitons under the
[Pg Types](Vtc.Ecto.Postgres.PgFramestamp.Migrations.html#pg-types),
[Pg Operators](Vtc.Ecto.Postgres.PgFramestamp.Migrations.html#pg-operators),
[Pg Operator Classes](Vtc.Ecto.Postgres.PgFramestamp.Migrations.html#pg-operator-classes),
[Pg Functions](Vtc.Ecto.Postgres.PgFramestamp.Migrations.html#pg-functions), and
[Pg Private Functions](Vtc.Ecto.Postgres.PgFramestamp.Migrations.html#pg-private-functions),
headings.
Safe to run multiple times when new functionality is added in updates to this library.
Existing values will be skipped.
Individual migration functions return raw sql commands in an
{up_command, down_command} tuple.
## Options
- `include`: A list of migration functions to inclide. If not set, all sub-migrations
will be included.
- `exclude`: A list of migration functions to exclude. If not set, no sub-migrations
will be excluded.
## Types Created
Calling this macro creates the following type definitions:
```sql
CREATE TYPE framestamp AS (
seconds rational,
rate framerate
);
```
## Schemas Created
Up to two schemas are created as detailed by the
[Configuring Database Objects](Vtc.Ecto.Postgres.PgFramestamp.Migrations.html#create_all/0-configuring-database-objects)
section below.
## Configuring Database Objects
To change where supporting functions are created, add the following to your
Repo confiugration:
```elixir
config :vtc, Vtc.Test.Support.Repo,
adapter: Ecto.Adapters.Postgres,
...
vtc: [
framestamp: [
functions_schema: :framestamp,
functions_prefix: "framestamp"
]
]
```
Option definitions are as follows:
- `functions_schema`: The postgres schema to store framestamp-related custom
functions.
- `functions_prefix`: A prefix to add before all functions. Defaults to "framestamp"
for any function created in the `:public` schema, and "" otherwise.
## Private Functions
Some custom function names are prefaced with `__private__`. These functions should
not be called by end-users, as they are not subject to *any* API staility guarantees.
## Examples
```elixir
defmodule MyMigration do
use Ecto.Migration
alias Vtc.Ecto.Postgres.PgFramestamp
require PgFramestamp.Migrations
def change do
PgFramestamp.Migrations.create_all()
end
end
```
"""
@spec create_all(include: Keyword.t(), exclude: Keyword.t()) :: :ok
def create_all(opts \\ []) do
migrations = [
&create_type_framestamp/0,
&create_function_schemas/0,
&create_func_with_seconds/0,
&create_func_with_frames/0,
&create_func_frames/0,
&create_func_eq/0,
&create_func_neq/0,
&create_func_strict_eq/0,
&create_func_strict_neq/0,
&create_func_lt/0,
&create_func_lte/0,
&create_func_gt/0,
&create_func_gte/0,
&create_func_cmp/0,
&create_func_add/0,
&create_func_sub/0,
&create_func_mult_rational/0,
&create_func_div_rational/0,
&create_func_floor_div_rational/0,
&create_func_modulo_rational/0,
&create_op_eq/0,
&create_op_neq/0,
&create_op_strict_eq/0,
&create_op_strict_neq/0,
&create_op_lt/0,
&create_op_lte/0,
&create_op_gt/0,
&create_op_gte/0,
&create_op_add/0,
&create_op_sub/0,
&create_op_mult_rational/0,
&create_op_div_rational/0,
&create_op_modulo_rational/0,
&create_op_class_btree/0
]
Postgres.Utils.run_migrations(migrations, opts)
end
@doc section: :migrations_types
@doc """
Adds `framestamp` composite type.
"""
@spec create_type_framestamp() :: {raw_sql(), raw_sql()}
def create_type_framestamp do
Postgres.Utils.create_type(:framestamp,
seconds: :rational,
rate: :framerate
)
end
@doc section: :migrations_types
@doc """
Creates function schema as described by the
[Configuring Database Objects](Vtc.Ecto.Postgres.PgFramestamp.Migrations.html#create_all/0-configuring-database-objects)
section above.
"""
@spec create_function_schemas() :: {raw_sql(), raw_sql()}
def create_function_schemas, do: Postgres.Utils.create_type_schema(:framestamp)
@doc section: :migrations_functions
@doc """
`framestamp.with_seconds(seconds, rate)`
Rounds `seconds` to the nearest whole frame based on `rate` and returns a constructed
`framestamp`.
"""
@spec create_func_with_seconds() :: {raw_sql(), raw_sql()}
def create_func_with_seconds do
Postgres.Utils.create_plpgsql_function(
function(:with_seconds, Migration.repo()),
args: [seconds: :rational, rate: :framerate],
declares: [rounded: :bigint],
returns: :framestamp,
body: """
rounded := ROUND((rate).playback * seconds);
RETURN (((rounded, 1)::rational / (rate).playback), rate);
"""
)
end
@doc section: :migrations_functions
@doc """
Creates `framestamp.with_frames(frames, rate)` that creates a framestamp for the
given frame count.
"""
@spec create_func_with_frames() :: {raw_sql(), raw_sql()}
def create_func_with_frames do
Postgres.Utils.create_plpgsql_function(
function(:with_frames, Migration.repo()),
args: [frames: :bigint, rate: :framerate],
declares: [seconds: {:rational, "(frames, 1)::rational / (rate).playback"}],
returns: :framestamp,
body: """
RETURN (seconds, rate);
"""
)
end
@doc section: :migrations_functions
@doc """
Converts `framestamp` to a frame number by the frame's index in the timecode
stream, with `0` as SMPTE midnight.
Equivalent to [Framestamp.frames/2](`Vtc.Framestamp.frames/2`) with `:round` set to
`trunc`.
"""
@spec create_func_frames() :: {raw_sql(), raw_sql()}
def create_func_frames do
Postgres.Utils.create_plpgsql_function(
function(:frames, Migration.repo()),
args: [value: :framestamp],
declares: [frames_rational: {:rational, "(value).seconds * (value).rate.playback"}],
returns: :bigint,
body: """
RETURN FLOOR(frames_rational);
"""
)
end
## COMPARISON BACKING FUNCTION
@doc section: :migrations_private_functions
@doc """
`framestamp.__private__eq(framestamp, framestamp)`
Backs the `=` operator.
"""
@spec create_func_eq() :: {raw_sql(), raw_sql()}
def create_func_eq do
Postgres.Utils.create_plpgsql_function(
private_function(:eq, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
returns: :boolean,
body: """
RETURN (a).seconds = (b).seconds;
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__strict_eq(a, b)` that backs the `===` operator.
"""
@spec create_func_strict_eq() :: {raw_sql(), raw_sql()}
def create_func_strict_eq do
Postgres.Utils.create_plpgsql_function(
private_function(:strict_eq, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
returns: :boolean,
body: """
RETURN (a).seconds = (b).seconds
AND (a).rate === (b).rate;
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__neq(a, b)` that backs the `<>` operator.
"""
@spec create_func_neq() :: {raw_sql(), raw_sql()}
def create_func_neq do
Postgres.Utils.create_plpgsql_function(
private_function(:neq, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
returns: :boolean,
body: """
RETURN (a).seconds <> (b).seconds;
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__strict_neq(a, b)` that backs the `!===` operator.
"""
@spec create_func_strict_neq() :: {raw_sql(), raw_sql()}
def create_func_strict_neq do
Postgres.Utils.create_plpgsql_function(
private_function(:strict_neq, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
returns: :boolean,
body: """
RETURN (a).seconds <> (b.seconds)
OR (a).rate !=== (b).rate;
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__lt(a, b)` that backs the `<` operator.
"""
@spec create_func_lt() :: {raw_sql(), raw_sql()}
def create_func_lt do
Postgres.Utils.create_plpgsql_function(
private_function(:lt, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
returns: :boolean,
body: """
RETURN (a).seconds < (b).seconds;
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__lte(a, b)` that backs the `<=` operator.
"""
@spec create_func_lte() :: {raw_sql(), raw_sql()}
def create_func_lte do
Postgres.Utils.create_plpgsql_function(
private_function(:lte, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
returns: :boolean,
body: """
RETURN (a).seconds <= (b).seconds;
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__gt(a, b)` that backs the `>` operator.
"""
@spec create_func_gt() :: {raw_sql(), raw_sql()}
def create_func_gt do
Postgres.Utils.create_plpgsql_function(
private_function(:gt, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
returns: :boolean,
body: """
RETURN (a).seconds > (b).seconds;
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__gte(a, b)` that backs the `>=` operator.
"""
@spec create_func_gte() :: {raw_sql(), raw_sql()}
def create_func_gte do
Postgres.Utils.create_plpgsql_function(
private_function(:gte, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
returns: :boolean,
body: """
RETURN (a).seconds >= (b).seconds;
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__cmp(a, b)` used in the PgTimecode b-tree operator class.
"""
@spec create_func_cmp() :: {raw_sql(), raw_sql()}
def create_func_cmp do
rational_cmp = PgRational.Migrations.private_function(:cmp, Migration.repo())
Postgres.Utils.create_plpgsql_function(
private_function(:cmp, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
returns: :integer,
body: """
RETURN #{rational_cmp}((a).seconds, (b).seconds);
"""
)
end
## ARITHMETIC FUNCTIONS
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__add(a, b)` that backs the `+` operator.
Just like [Framestamp.add/3](`Vtc.Framestamp.add/3`), if the `rate` of `a` and `b`
are not equal, the result will inheret `a`'s framerate, and the internal `seconds`
field will be rounded to the nearest whole-frame to ensure data integrity.
"""
@spec create_func_add() :: {raw_sql(), raw_sql()}
def create_func_add do
with_seconds = function(:with_seconds, Migration.repo())
Postgres.Utils.create_plpgsql_function(
private_function(:add, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
declares: [seconds: {:rational, "(a).seconds + (b).seconds"}],
returns: :framestamp,
body: """
IF (a).rate === (b).rate THEN
RETURN (seconds, (a).rate)::framestamp;
ELSE
RETURN #{with_seconds}(seconds, (a).rate);
END IF;
"""
)
end
@doc section: :migrations_private_functions
@doc """
`framestamp.__private__sub(a, b)`.
Backs the `-` operator.
Just like [Framestamp.sub/3](`Vtc.Framestamp.sub/3`), if the `rate` of `a` and `b`
are not equal, the result will inheret `a`'s framerate, and the internal `seconds`
field will be rounded to the nearest whole-frame to ensure data integrity.
"""
@spec create_func_sub() :: {raw_sql(), raw_sql()}
def create_func_sub do
with_seconds = function(:with_seconds, Migration.repo())
Postgres.Utils.create_plpgsql_function(
private_function(:sub, Migration.repo()),
args: [a: :framestamp, b: :framestamp],
declares: [seconds: {:rational, "(a).seconds - (b).seconds"}],
returns: :framestamp,
body: """
IF (a).rate === (b).rate THEN
RETURN (seconds, (a).rate)::framestamp;
ELSE
RETURN #{with_seconds}(seconds, (a).rate);
END IF;
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__mult(:framestamp, :rational)` that backs the `*` operator.
Just like [Framestamp.add/3](`Vtc.Framestamp.mult/3`), `a`'s the internal `seconds`
field will be rounded to the nearest whole-frame to ensure data integrity.
"""
@spec create_func_mult_rational() :: {raw_sql(), raw_sql()}
def create_func_mult_rational do
with_seconds = function(:with_seconds, Migration.repo())
Postgres.Utils.create_plpgsql_function(
private_function(:mult, Migration.repo()),
args: [a: :framestamp, b: :rational],
declares: [seconds: {:rational, "(a).seconds * (b)"}],
returns: :framestamp,
body: """
RETURN #{with_seconds}(seconds, (a).rate);
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__div(:framestamp, :rational)` that backs the `/` operator.
Just like [Framestamp.div/3](`Vtc.Framestamp.div/3`), `a`'s the internal `seconds`
field will be rounded to the nearest whole-frame to ensure data integrity.
Unlike [Framestamp.div/3](`Vtc.Framestamp.div/3`), the result is rounded to the
*closest* frame, rather than truncating ala integer division.
"""
@spec create_func_div_rational() :: {raw_sql(), raw_sql()}
def create_func_div_rational do
with_seconds = function(:with_seconds, Migration.repo())
Postgres.Utils.create_plpgsql_function(
private_function(:div, Migration.repo()),
args: [a: :framestamp, b: :rational],
declares: [seconds: {:rational, "(a).seconds / (b)"}],
returns: :framestamp,
body: """
RETURN #{with_seconds}(seconds, (a).rate);
"""
)
end
@doc section: :migrations_functions
@doc """
Creates `DIV(:framestamp, :rational)` that returns a floored :framestamp to match
Postgres' DIV(real, real) behavior.
Just like [Framestamp.div/3](`Vtc.Framestamp.div/3`), this operation is done on the
frame count representation of the Framestamp, which is then used as the basis of a new
framestamp.
"""
@spec create_func_floor_div_rational() :: {raw_sql(), raw_sql()}
def create_func_floor_div_rational do
framestamp_frames = function(:frames, Migration.repo())
simplify = PgRational.Migrations.private_function(:simplify, Migration.repo())
Postgres.Utils.create_plpgsql_function(
"DIV",
args: [a: :framestamp, b: :rational],
declares: [
frames: {:bigint, "#{framestamp_frames}(a)"},
seconds: :rational
],
returns: :framestamp,
body: """
frames := DIV(frames, b);
seconds := #{simplify}(frames / (a).rate.playback);
RETURN (seconds, (a).rate);
"""
)
end
@doc section: :migrations_private_functions
@doc """
Creates `framestamp.__private__modulo(:framestamp, :rational)` that backs the `%`
operator.
Just like [Framestamp.rem/3](`Vtc.Framestamp.rem/3`), this operation is done on the
frame count representation of the Framestamp, which is then used as the basis of a new
framestamp.
"""
@spec create_func_modulo_rational() :: {raw_sql(), raw_sql()}
def create_func_modulo_rational do
framestamp_frames = function(:frames, Migration.repo())
simplify = PgRational.Migrations.private_function(:simplify, Migration.repo())
Postgres.Utils.create_plpgsql_function(
private_function(:modulo, Migration.repo()),
args: [a: :framestamp, b: :rational],
declares: [
frames: {:bigint, "#{framestamp_frames}(a)"},
seconds: :rational
],
returns: :framestamp,
body: """
frames := ROUND(frames % b);
seconds := #{simplify}(frames / (a).rate.playback);
RETURN (seconds, (a).rate)::framestamp;
"""
)
end
### COMPARISON OPERATORS
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :framestamp `=` operator that returns true if the
real-world seconds values for both framestamps are equal.
"""
@spec create_op_eq() :: {raw_sql(), raw_sql()}
def create_op_eq do
Postgres.Utils.create_operator(
:=,
:framestamp,
:framestamp,
private_function(:eq, Migration.repo()),
commutator: :=,
negator: :<>
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :framestamp `===` operator that returns true if *both*
the real-world seconds values *and* the framerates for both framestamps are equal.
"""
@spec create_op_strict_eq() :: {raw_sql(), raw_sql()}
def create_op_strict_eq do
Postgres.Utils.create_operator(
:===,
:framestamp,
:framestamp,
private_function(:strict_eq, Migration.repo()),
commutator: :===,
negator: :"!==="
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :framestamp `<>` operator that returns true if the
real-world seconds values for both framestamps are not equal.
"""
@spec create_op_neq() :: {raw_sql(), raw_sql()}
def create_op_neq do
Postgres.Utils.create_operator(
:<>,
:framestamp,
:framestamp,
private_function(:neq, Migration.repo()),
commutator: :<>,
negator: :=
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :framestamp `!===` operator that returns true if `a` and
`b` do not have the same real-world-seconds, framerate playback, or framerate tags.
"""
@spec create_op_strict_neq() :: {raw_sql(), raw_sql()}
def create_op_strict_neq do
Postgres.Utils.create_operator(
:"!===",
:framestamp,
:framestamp,
private_function(:strict_neq, Migration.repo()),
commutator: :"!===",
negator: :===
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :framestamp `<` operator.
"""
@spec create_op_lt() :: {raw_sql(), raw_sql()}
def create_op_lt do
Postgres.Utils.create_operator(
:<,
:framestamp,
:framestamp,
private_function(:lt, Migration.repo()),
commutator: :>,
negator: :>=
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :framestamp `<=` operator.
"""
@spec create_op_lte() :: {raw_sql(), raw_sql()}
def create_op_lte do
Postgres.Utils.create_operator(
:<=,
:framestamp,
:framestamp,
private_function(:lte, Migration.repo()),
commutator: :>=,
negator: :>
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :framestamp `>` operator.
"""
@spec create_op_gt() :: {raw_sql(), raw_sql()}
def create_op_gt do
Postgres.Utils.create_operator(
:>,
:framestamp,
:framestamp,
private_function(:gt, Migration.repo()),
commutator: :<,
negator: :<=
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :framestamp `>=` operator.
"""
@spec create_op_gte() :: {raw_sql(), raw_sql()}
def create_op_gte do
Postgres.Utils.create_operator(
:>=,
:framestamp,
:framestamp,
private_function(:gte, Migration.repo()),
commutator: :<=,
negator: :<
)
end
## ARITHMETIC OPERATORS
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :framestamp `+` operator.
Just like [Framestamp.add/3](`Vtc.Framestamp.add/3`), if the `rate` of `a` and `b`
are not equal, the result will inheret `a`'s framerate, and the internal `seconds`
field will be rounded to the nearest whole-frame to ensure data integrity.
"""
@spec create_op_add() :: {raw_sql(), raw_sql()}
def create_op_add do
Postgres.Utils.create_operator(
:+,
:framestamp,
:framestamp,
private_function(:add, Migration.repo())
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :framestamp `-` operator.
Just like [Framestamp.add/3](`Vtc.Framestamp.sub/3`), if the `rate` of `a` and `b`
are not equal, the result will inheret `a`'s framerate, and the internal `seconds`
field will be rounded to the nearest whole-frame to ensure data integrity.
"""
@spec create_op_sub() :: {raw_sql(), raw_sql()}
def create_op_sub do
Postgres.Utils.create_operator(
:-,
:framestamp,
:framestamp,
private_function(:sub, Migration.repo())
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :rational `*` operator.
Just like [Framestamp.add/3](`Vtc.Framestamp.mult/3`), `a`'s the internal `seconds`
field will be rounded to the nearest whole-frame to ensure data integrity.
"""
@spec create_op_mult_rational() :: {raw_sql(), raw_sql()}
def create_op_mult_rational do
Postgres.Utils.create_operator(
:*,
:framestamp,
:rational,
private_function(:mult, Migration.repo())
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :rational `/` operator.
Just like [Framestamp.div/3](`Vtc.Framestamp.div/3`), `a`'s the internal `seconds`
field will be rounded to the nearest whole-frame to ensure data integrity.
Unlike [Framestamp.div/3](`Vtc.Framestamp.div/3`), the result is rounded to the
*closest* frame, rather than truncating ala integer division.
"""
@spec create_op_div_rational() :: {raw_sql(), raw_sql()}
def create_op_div_rational do
Postgres.Utils.create_operator(
:/,
:framestamp,
:rational,
private_function(:div, Migration.repo())
)
end
@doc section: :migrations_operators
@doc """
Creates a custom :framestamp, :rational `%` operator.
Just like [Framestamp.rem/3](`Vtc.Framestamp.rem/3`), this operation is done on the
frame count representation of the Framestamp, which is then used as the basis of a new
framestamp.
"""
@spec create_op_modulo_rational() :: {raw_sql(), raw_sql()}
def create_op_modulo_rational do
Postgres.Utils.create_operator(
:%,
:framestamp,
:rational,
private_function(:modulo, Migration.repo())
)
end
## OPERATOR CLASSES
@doc section: :migrations_operator_classes
@doc """
Creates a B-tree operator class to support indexing on comparison operations.
"""
@spec create_op_class_btree() :: {raw_sql(), raw_sql()}
def create_op_class_btree do
Postgres.Utils.create_operator_class(
:framestamp_ops_btree,
:framestamp,
:btree,
[
<: 1,
<=: 2,
=: 3,
>=: 4,
>: 5
],
[
{private_function(:cmp, Migration.repo()), 1}
]
)
end
@typedoc """
Option types for `create_constraints/2`.
"""
@type constraint_opt() ::
{:create_seconds_divisible_by_rate?, boolean()}
| {:framerate_opts, PgFramerate.Migrations.constraint_opt()}
@doc section: :migrations_constraints
@doc """
Creates basic constraints for a [PgFramestamp](`Vtc.Ecto.Postgres.PgFramestamp`) /
[Framestamp](`Vtc.Framestamp`) database field.
## Options
- `create_seconds_divisible_by_rate?`: If true, creates
`{field_name}_seconds_divisible_by_rate` constraint (see below). Default: `true`.
- `framerate_opts`: Opts for framerate constraints. See
[PgFramerate.Migrations.create_constraints/3](`Vtc.Ecto.Postgres.PgFramerate.Migrations.create_constraints/3`)
## Constraints created:
- `{field}_rate_positive`: Checks that the playback speed is positive.
- `{field}_rate_ntsc_tags`: Checks that both `drop` and `non_drop` are not set at the
same time.
- `{field}_rate_ntsc_valid`: Checks that NTSC framerates are mathematically sound,
i.e., that the rate is equal to `(round(rate.playback) * 1000) / 1001`.
- `{field}_rate_ntsc_drop_valid`: Checks that NTSC, drop-frame framerates are valid,
i.e, are cleanly divisible by `30_000/1001`.
- `{field_name}_seconds_divisible_by_rate`: Checks that the `seconds` value of the
framestamp is cleanly divisible by the `rate.playback` value.
## Examples
```elixir
create table("my_table", primary_key: false) do
add(:id, :uuid, primary_key: true, null: false)
add(:a, Framestamp.type())
add(:b, Framestamp.type())
end
PgRational.migration_add_field_constraints(:my_table, :a)
PgRational.migration_add_field_constraints(:my_table, :b)
```
"""
@spec create_constraints(atom(), atom(), [constraint_opt()]) :: :ok
def create_constraints(table, field, opts \\ []) do
table
|> build_constraint_list(field, opts)
|> Enum.each(&Migration.create(&1))
:ok
end
# Compiles the constraint structs to be created in the database.
@doc false
@spec build_constraint_list(sql_value(), sql_value(), [constraint_opt()]) :: [Migration.Constraint.t()]
def build_constraint_list(table, field, opts) do
sql_field = "#{table}.#{field}"
framerate_opts =
opts
|> Keyword.get(:framerate_opts, [])
|> Keyword.put(:check_value, "(#{sql_field}).rate")
framerate_list = PgFramerate.Migrations.build_constraint_list(table, field, framerate_opts)
if Keyword.get(opts, :create_seconds_divisible_by_rate?, true) do
seconds_divisible_by_rate =
Migration.constraint(
table,
"#{field}_seconds_divisible_by_rate",
check: """
((#{sql_field}).seconds * (#{sql_field}).rate.playback) % 1::bigint = 0::bigint
"""
)
framerate_list ++ [seconds_divisible_by_rate]
else
framerate_list
end
end
@doc """
Returns the config-qualified name of the function for this type.
"""
@spec function(atom(), Ecto.Repo.t()) :: String.t()
def function(name, repo) do
function_prefix = Postgres.Utils.type_function_prefix(repo, :framestamp)
"#{function_prefix}#{name}"
end
@spec private_function(atom(), Ecto.Repo.t()) :: String.t()
defp private_function(name, repo) do
function_prefix = Postgres.Utils.type_private_function_prefix(repo, :framestamp)
"#{function_prefix}#{name}"
end
end
