# Pleroma: A lightweight social networking server # Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.Repo do use Ecto.Repo, otp_app: :pleroma, adapter: Ecto.Adapters.Postgres, migration_timestamps: [type: :naive_datetime_usec] import Ecto.Query require Logger defmodule Instrumenter, do: use(Prometheus.EctoInstrumenter) @doc """ Dynamically loads the repository url from the DATABASE_URL environment variable. """ def init(_, opts) do {:ok, Keyword.put(opts, :url, System.get_env("DATABASE_URL"))} end @doc "find resource based on prepared query" @spec find_resource(Ecto.Query.t()) :: {:ok, struct()} | {:error, :not_found} def find_resource(%Ecto.Query{} = query) do case __MODULE__.one(query) do nil -> {:error, :not_found} resource -> {:ok, resource} end end def find_resource(_query), do: {:error, :not_found} @doc """ Gets association from cache or loads if need ## Examples iex> Repo.get_assoc(token, :user) %User{} """ @spec get_assoc(struct(), atom()) :: {:ok, struct()} | {:error, :not_found} def get_assoc(resource, association) do case __MODULE__.preload(resource, association) do %{^association => assoc} when not is_nil(assoc) -> {:ok, assoc} _ -> {:error, :not_found} end end @doc """ Returns a lazy enumerable that emits all entries from the data store matching the given query. `returns_as` use to group records. use the `batches` option to fetch records in bulk. ## Examples # fetch records one-by-one iex> Pleroma.Repo.chunk_stream(Pleroma.Activity.Queries.by_actor(ap_id), 500) # fetch records in bulk iex> Pleroma.Repo.chunk_stream(Pleroma.Activity.Queries.by_actor(ap_id), 500, :batches) """ @spec chunk_stream(Ecto.Query.t(), integer(), atom()) :: Enumerable.t() def chunk_stream(query, chunk_size, returns_as \\ :one) do # We don't actually need start and end funcitons of resource streaming, # but it seems to be the only way to not fetch records one-by-one and # have individual records be the elements of the stream, instead of # lists of records Stream.resource( fn -> 0 end, fn last_id -> query |> order_by(asc: :id) |> where([r], r.id > ^last_id) |> limit(^chunk_size) |> all() |> case do [] -> {:halt, last_id} records -> last_id = List.last(records).id if returns_as == :one do {records, last_id} else {[records], last_id} end end end, fn _ -> :ok end ) end end