Merge branch 'develop' into 'cleanup/masto_fe-default_settings'

[akkoma] / lib / pleroma / repo.ex

diff --git a/lib/pleroma/repo.ex b/lib/pleroma/repo.ex
index 4af1bde566b4df98e299e87fbfb61a4b8613a426..f317e4d582e6cea6fee974190e30015797cffb8a 100644 (file)
--- a/lib/pleroma/repo.ex
+++ b/lib/pleroma/repo.ex
@@ -1,5 +1,5 @@
 # Pleroma: A lightweight social networking server
-# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Repo do
@@ -8,6 +8,11 @@ defmodule Pleroma.Repo do
     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.
@@ -15,4 +20,59 @@ defmodule Pleroma.Repo do
   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
+
+  def chunk_stream(query, chunk_size) 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
+              {records, last_id}
+          end
+      end,
+      fn _ -> :ok end
+    )
+  end
 end