defmodule Avrora.Utils.Registrar do
@moduledoc """
Memory store-aware schema registration with extended functionality
designed to be used in the intensive loops.
It gives you control over the name under which schema will be registered
(i.e subject in Schema Registry) and allows you to enforce registration
even if the schema exists.
## Examples
defmodule Sample do
alias Avrora.Utils.Registrar
def loop do
Enum.reduce_while(1..100, 0, fn x, acc ->
if x < 100, do: {:cont, register("io.confluent.Payment")}, else: {:halt, acc}
end)
end
defp register(schema_name), do: Registrar.register_schema_by_name(schema_name)
end
"""
require Logger
alias Avrora.Config
alias Avrora.Schema
@doc """
Register schema from local schema file in the Schema Registry.
Schema name conventions inherited from `Avrora.Storage.File.get/1`.
For extended documentation about registration process see `register_schema/2`.
## Options
* `:as` - the name which will be used to register schema (i.e subject).
* `:force` - the flag enforcing registration when schema was found
in the Memory store (`false` by default).
## Examples
...> {:ok, schema} = Avrora.Utils.Registrar.register_schema_by_name("io.confluent.Payment", as: "NewName", force: true)
...> schema.full_name
"io.confluent.Payment"
"""
@spec register_schema_by_name(String.t(), as: String.t(), force: boolean) :: {:ok, Schema.t()} | {:error, term()}
def register_schema_by_name(name, opts \\ []) do
if Keyword.get(opts, :force, false) do
with {:ok, schema} <- file_storage().get(name), do: register_schema(schema, opts)
else
with {:ok, nil} <- memory_storage().get(name),
{:ok, schema} <- file_storage().get(name) do
register_schema(schema, Keyword.put(opts, :force, true))
end
end
end
@doc """
Register schema in the Schema Registry.
This function relies on a Memory store before taking action.
The most complete schema name will be looked at the store, i.e if the schema
contains `version` then `full_name` + `version` will be used in prior just a `full_name`.
## Options
* `:as` - the name which will be used to register schema (i.e subject).
* `:force` - the flag enforcing registration when schema was found
in the Memory store (`false` by default).
## Examples
...> {:ok, schema} = Avrora.Resolver.resolve("io.confluent.Payment")
...> {:ok, schema} = Avrora.Utils.Registrar.register_schema(schema, as: "NewName", force: true)
...> schema.full_name
"io.confluent.Payment"
"""
@spec register_schema(Schema.t(), as: String.t(), force: boolean) :: {:ok, Schema.t()} | {:error, term()}
def register_schema(schema, opts \\ []) do
full_name =
if is_nil(schema.version),
do: schema.full_name,
else: "#{schema.full_name}:#{schema.version}"
subject = Keyword.get(opts, :as, full_name)
if Keyword.get(opts, :force, false) do
do_register(subject, schema)
else
with {:ok, nil} <- memory_storage().get(full_name), do: do_register(subject, schema)
end
end
defp do_register(subject, schema) do
with {:ok, schema} <- registry_storage().put(subject, schema.json),
{:ok, schema} <- memory_storage().put(schema.id, schema),
{:ok, schema} <- memory_storage().put(schema.full_name, schema),
{:ok, timestamp} <- memory_storage().expire(schema.full_name, names_ttl()) do
if timestamp == :infinity,
do: Logger.debug("schema `#{schema.full_name}` will be always resolved from memory")
if is_nil(schema.version),
do: {:ok, schema},
else: memory_storage().put("#{schema.full_name}:#{schema.version}", schema)
end
end
defp file_storage, do: Config.self().file_storage()
defp memory_storage, do: Config.self().memory_storage()
defp registry_storage, do: Config.self().registry_storage()
defp names_ttl, do: Config.self().names_cache_ttl()
end