6 files changed, 195 insertions, 215 deletions

diff --git a/lib/pleroma/http/adapter_helper.ex b/lib/pleroma/http/adapter_helper.ex
index 510722ff9..9ec3836b0 100644
--- a/lib/pleroma/http/adapter_helper.ex
+++ b/lib/pleroma/http/adapter_helper.ex
@@ -3,32 +3,30 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.HTTP.AdapterHelper do
-  alias Pleroma.HTTP.Connection
+  @moduledoc """
+  Configure Tesla.Client with default and customized adapter options.
+  """
+  @defaults [pool: :federation]
+
+  @type proxy_type() :: :socks4 | :socks5
+  @type host() :: charlist() | :inet.ip_address()
+
+  alias Pleroma.Config
+  alias Pleroma.HTTP.AdapterHelper
+  require Logger
 
   @type proxy ::
           {Connection.host(), pos_integer()}
           | {Connection.proxy_type(), Connection.host(), pos_integer()}
 
   @callback options(keyword(), URI.t()) :: keyword()
-  @callback after_request(keyword()) :: :ok
-
-  @spec options(keyword(), URI.t()) :: keyword()
-  def options(opts, _uri) do
-    proxy = Pleroma.Config.get([:http, :proxy_url], nil)
-    maybe_add_proxy(opts, format_proxy(proxy))
-  end
-
-  @spec maybe_get_conn(URI.t(), keyword()) :: keyword()
-  def maybe_get_conn(_uri, opts), do: opts
-
-  @spec after_request(keyword()) :: :ok
-  def after_request(_opts), do: :ok
+  @callback get_conn(URI.t(), keyword()) :: {:ok, term()} | {:error, term()}
 
   @spec format_proxy(String.t() | tuple() | nil) :: proxy() | nil
   def format_proxy(nil), do: nil
 
   def format_proxy(proxy_url) do
-    case Connection.parse_proxy(proxy_url) do
+    case parse_proxy(proxy_url) do
       {:ok, host, port} -> {host, port}
       {:ok, type, host, port} -> {type, host, port}
       _ -> nil
@@ -38,4 +36,105 @@ defmodule Pleroma.HTTP.AdapterHelper do
   @spec maybe_add_proxy(keyword(), proxy() | nil) :: keyword()
   def maybe_add_proxy(opts, nil), do: opts
   def maybe_add_proxy(opts, proxy), do: Keyword.put_new(opts, :proxy, proxy)
+
+  @doc """
+  Merge default connection & adapter options with received ones.
+  """
+
+  @spec options(URI.t(), keyword()) :: keyword()
+  def options(%URI{} = uri, opts \\ []) do
+    @defaults
+    |> put_timeout()
+    |> Keyword.merge(opts)
+    |> adapter_helper().options(uri)
+  end
+
+  # For Hackney, this is the time a connection can stay idle in the pool.
+  # For Gun, this is the timeout to receive a message from Gun.
+  defp put_timeout(opts) do
+    {config_key, default} =
+      if adapter() == Tesla.Adapter.Gun do
+        {:pools, Config.get([:pools, :default, :timeout], 5_000)}
+      else
+        {:hackney_pools, 10_000}
+      end
+
+    timeout = Config.get([config_key, opts[:pool], :timeout], default)
+
+    Keyword.merge(opts, timeout: timeout)
+  end
+
+  def get_conn(uri, opts), do: adapter_helper().get_conn(uri, opts)
+  defp adapter, do: Application.get_env(:tesla, :adapter)
+
+  defp adapter_helper do
+    case adapter() do
+      Tesla.Adapter.Gun -> AdapterHelper.Gun
+      Tesla.Adapter.Hackney -> AdapterHelper.Hackney
+      _ -> AdapterHelper.Default
+    end
+  end
+
+  @spec parse_proxy(String.t() | tuple() | nil) ::
+          {:ok, host(), pos_integer()}
+          | {:ok, proxy_type(), host(), pos_integer()}
+          | {:error, atom()}
+          | nil
+
+  def parse_proxy(nil), do: nil
+
+  def parse_proxy(proxy) when is_binary(proxy) do
+    with [host, port] <- String.split(proxy, ":"),
+         {port, ""} <- Integer.parse(port) do
+      {:ok, parse_host(host), port}
+    else
+      {_, _} ->
+        Logger.warn("Parsing port failed #{inspect(proxy)}")
+        {:error, :invalid_proxy_port}
+
+      :error ->
+        Logger.warn("Parsing port failed #{inspect(proxy)}")
+        {:error, :invalid_proxy_port}
+
+      _ ->
+        Logger.warn("Parsing proxy failed #{inspect(proxy)}")
+        {:error, :invalid_proxy}
+    end
+  end
+
+  def parse_proxy(proxy) when is_tuple(proxy) do
+    with {type, host, port} <- proxy do
+      {:ok, type, parse_host(host), port}
+    else
+      _ ->
+        Logger.warn("Parsing proxy failed #{inspect(proxy)}")
+        {:error, :invalid_proxy}
+    end
+  end
+
+  @spec parse_host(String.t() | atom() | charlist()) :: charlist() | :inet.ip_address()
+  def parse_host(host) when is_list(host), do: host
+  def parse_host(host) when is_atom(host), do: to_charlist(host)
+
+  def parse_host(host) when is_binary(host) do
+    host = to_charlist(host)
+
+    case :inet.parse_address(host) do
+      {:error, :einval} -> host
+      {:ok, ip} -> ip
+    end
+  end
+
+  @spec format_host(String.t()) :: charlist()
+  def format_host(host) do
+    host_charlist = to_charlist(host)
+
+    case :inet.parse_address(host_charlist) do
+      {:error, :einval} ->
+        :idna.encode(host_charlist)
+
+      {:ok, _ip} ->
+        host_charlist
+    end
+  end
 end
diff --git a/lib/pleroma/http/adapter_helper/default.ex b/lib/pleroma/http/adapter_helper/default.ex
new file mode 100644
index 000000000..e13441316
--- /dev/null
+++ b/lib/pleroma/http/adapter_helper/default.ex
@@ -0,0 +1,14 @@
+defmodule Pleroma.HTTP.AdapterHelper.Default do
+  alias Pleroma.HTTP.AdapterHelper
+
+  @behaviour Pleroma.HTTP.AdapterHelper
+
+  @spec options(keyword(), URI.t()) :: keyword()
+  def options(opts, _uri) do
+    proxy = Pleroma.Config.get([:http, :proxy_url], nil)
+    AdapterHelper.maybe_add_proxy(opts, AdapterHelper.format_proxy(proxy))
+  end
+
+  @spec get_conn(URI.t(), keyword()) :: {:ok, keyword()}
+  def get_conn(_uri, opts), do: {:ok, opts}
+end
diff --git a/lib/pleroma/http/adapter_helper/gun.ex b/lib/pleroma/http/adapter_helper/gun.ex
index ead7cdc6b..b4ff8306c 100644
--- a/lib/pleroma/http/adapter_helper/gun.ex
+++ b/lib/pleroma/http/adapter_helper/gun.ex
@@ -5,8 +5,8 @@
 defmodule Pleroma.HTTP.AdapterHelper.Gun do
   @behaviour Pleroma.HTTP.AdapterHelper
 
+  alias Pleroma.Gun.ConnectionPool
   alias Pleroma.HTTP.AdapterHelper
-  alias Pleroma.Pool.Connections
 
   require Logger
 
@@ -14,7 +14,7 @@ defmodule Pleroma.HTTP.AdapterHelper.Gun do
     connect_timeout: 5_000,
     domain_lookup_timeout: 5_000,
     tls_handshake_timeout: 5_000,
-    retry: 1,
+    retry: 0,
     retry_timeout: 1000,
     await_up_timeout: 5_000
   ]
@@ -31,16 +31,7 @@ defmodule Pleroma.HTTP.AdapterHelper.Gun do
     |> Keyword.merge(config_opts)
     |> add_scheme_opts(uri)
     |> AdapterHelper.maybe_add_proxy(proxy)
-    |> maybe_get_conn(uri, incoming_opts)
-  end
-
-  @spec after_request(keyword()) :: :ok
-  def after_request(opts) do
-    if opts[:conn] && opts[:body_as] != :chunks do
-      Connections.checkout(opts[:conn], self(), :gun_connections)
-    end
-
-    :ok
+    |> Keyword.merge(incoming_opts)
   end
 
   defp add_scheme_opts(opts, %{scheme: "http"}), do: opts
@@ -48,30 +39,40 @@ defmodule Pleroma.HTTP.AdapterHelper.Gun do
   defp add_scheme_opts(opts, %{scheme: "https"}) do
     opts
     |> Keyword.put(:certificates_verification, true)
-    |> Keyword.put(:tls_opts, log_level: :warning)
   end
 
-  defp maybe_get_conn(adapter_opts, uri, incoming_opts) do
-    {receive_conn?, opts} =
-      adapter_opts
-      |> Keyword.merge(incoming_opts)
-      |> Keyword.pop(:receive_conn, true)
-
-    if Connections.alive?(:gun_connections) and receive_conn? do
-      checkin_conn(uri, opts)
-    else
-      opts
+  @spec get_conn(URI.t(), keyword()) :: {:ok, keyword()} | {:error, atom()}
+  def get_conn(uri, opts) do
+    case ConnectionPool.get_conn(uri, opts) do
+      {:ok, conn_pid} -> {:ok, Keyword.merge(opts, conn: conn_pid, close_conn: false)}
+      err -> err
     end
   end
 
-  defp checkin_conn(uri, opts) do
-    case Connections.checkin(uri, :gun_connections) do
-      nil ->
-        Task.start(Pleroma.Gun.Conn, :open, [uri, :gun_connections, opts])
-        opts
+  @prefix Pleroma.Gun.ConnectionPool
+  def limiter_setup do
+    wait = Pleroma.Config.get([:connections_pool, :connection_acquisition_wait])
+    retries = Pleroma.Config.get([:connections_pool, :connection_acquisition_retries])
 
-      conn when is_pid(conn) ->
-        Keyword.merge(opts, conn: conn, close_conn: false)
-    end
+    :pools
+    |> Pleroma.Config.get([])
+    |> Enum.each(fn {name, opts} ->
+      max_running = Keyword.get(opts, :size, 50)
+      max_waiting = Keyword.get(opts, :max_waiting, 10)
+
+      result =
+        ConcurrentLimiter.new(:"#{@prefix}.#{name}", max_running, max_waiting,
+          wait: wait,
+          max_retries: retries
+        )
+
+      case result do
+        :ok -> :ok
+        {:error, :existing} -> :ok
+        e -> raise e
+      end
+    end)
+
+    :ok
   end
 end
diff --git a/lib/pleroma/http/adapter_helper/hackney.ex b/lib/pleroma/http/adapter_helper/hackney.ex
index 3972a03a9..cd569422b 100644
--- a/lib/pleroma/http/adapter_helper/hackney.ex
+++ b/lib/pleroma/http/adapter_helper/hackney.ex
@@ -24,5 +24,6 @@ defmodule Pleroma.HTTP.AdapterHelper.Hackney do
 
   defp add_scheme_opts(opts, _), do: opts
 
-  def after_request(_), do: :ok
+  @spec get_conn(URI.t(), keyword()) :: {:ok, keyword()}
+  def get_conn(_uri, opts), do: {:ok, opts}
 end
diff --git a/lib/pleroma/http/connection.ex b/lib/pleroma/http/connection.ex
deleted file mode 100644
index ebacf7902..000000000
--- a/lib/pleroma/http/connection.ex
+++ /dev/null
@@ -1,124 +0,0 @@
-# Pleroma: A lightweight social networking server
-# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
-# SPDX-License-Identifier: AGPL-3.0-only
-
-defmodule Pleroma.HTTP.Connection do
-  @moduledoc """
-  Configure Tesla.Client with default and customized adapter options.
-  """
-
-  alias Pleroma.Config
-  alias Pleroma.HTTP.AdapterHelper
-
-  require Logger
-
-  @defaults [pool: :federation]
-
-  @type ip_address :: ipv4_address() | ipv6_address()
-  @type ipv4_address :: {0..255, 0..255, 0..255, 0..255}
-  @type ipv6_address ::
-          {0..65_535, 0..65_535, 0..65_535, 0..65_535, 0..65_535, 0..65_535, 0..65_535, 0..65_535}
-  @type proxy_type() :: :socks4 | :socks5
-  @type host() :: charlist() | ip_address()
-
-  @doc """
-  Merge default connection & adapter options with received ones.
-  """
-
-  @spec options(URI.t(), keyword()) :: keyword()
-  def options(%URI{} = uri, opts \\ []) do
-    @defaults
-    |> pool_timeout()
-    |> Keyword.merge(opts)
-    |> adapter_helper().options(uri)
-  end
-
-  defp pool_timeout(opts) do
-    {config_key, default} =
-      if adapter() == Tesla.Adapter.Gun do
-        {:pools, Config.get([:pools, :default, :timeout])}
-      else
-        {:hackney_pools, 10_000}
-      end
-
-    timeout = Config.get([config_key, opts[:pool], :timeout], default)
-
-    Keyword.merge(opts, timeout: timeout)
-  end
-
-  @spec after_request(keyword()) :: :ok
-  def after_request(opts), do: adapter_helper().after_request(opts)
-
-  defp adapter, do: Application.get_env(:tesla, :adapter)
-
-  defp adapter_helper do
-    case adapter() do
-      Tesla.Adapter.Gun -> AdapterHelper.Gun
-      Tesla.Adapter.Hackney -> AdapterHelper.Hackney
-      _ -> AdapterHelper
-    end
-  end
-
-  @spec parse_proxy(String.t() | tuple() | nil) ::
-          {:ok, host(), pos_integer()}
-          | {:ok, proxy_type(), host(), pos_integer()}
-          | {:error, atom()}
-          | nil
-
-  def parse_proxy(nil), do: nil
-
-  def parse_proxy(proxy) when is_binary(proxy) do
-    with [host, port] <- String.split(proxy, ":"),
-         {port, ""} <- Integer.parse(port) do
-      {:ok, parse_host(host), port}
-    else
-      {_, _} ->
-        Logger.warn("Parsing port failed #{inspect(proxy)}")
-        {:error, :invalid_proxy_port}
-
-      :error ->
-        Logger.warn("Parsing port failed #{inspect(proxy)}")
-        {:error, :invalid_proxy_port}
-
-      _ ->
-        Logger.warn("Parsing proxy failed #{inspect(proxy)}")
-        {:error, :invalid_proxy}
-    end
-  end
-
-  def parse_proxy(proxy) when is_tuple(proxy) do
-    with {type, host, port} <- proxy do
-      {:ok, type, parse_host(host), port}
-    else
-      _ ->
-        Logger.warn("Parsing proxy failed #{inspect(proxy)}")
-        {:error, :invalid_proxy}
-    end
-  end
-
-  @spec parse_host(String.t() | atom() | charlist()) :: charlist() | ip_address()
-  def parse_host(host) when is_list(host), do: host
-  def parse_host(host) when is_atom(host), do: to_charlist(host)
-
-  def parse_host(host) when is_binary(host) do
-    host = to_charlist(host)
-
-    case :inet.parse_address(host) do
-      {:error, :einval} -> host
-      {:ok, ip} -> ip
-    end
-  end
-
-  @spec format_host(String.t()) :: charlist()
-  def format_host(host) do
-    host_charlist = to_charlist(host)
-
-    case :inet.parse_address(host_charlist) do
-      {:error, :einval} ->
-        :idna.encode(host_charlist)
-
-      {:ok, _ip} ->
-        host_charlist
-    end
-  end
-end
diff --git a/lib/pleroma/http/http.ex b/lib/pleroma/http/http.ex
index 66ca75367..6128bc4cf 100644
--- a/lib/pleroma/http/http.ex
+++ b/lib/pleroma/http/http.ex
@@ -7,7 +7,7 @@ defmodule Pleroma.HTTP do
     Wrapper for `Tesla.request/2`.
   """
 
-  alias Pleroma.HTTP.Connection
+  alias Pleroma.HTTP.AdapterHelper
   alias Pleroma.HTTP.Request
   alias Pleroma.HTTP.RequestBuilder, as: Builder
   alias Tesla.Client
@@ -60,49 +60,29 @@ defmodule Pleroma.HTTP do
           {:ok, Env.t()} | {:error, any()}
   def request(method, url, body, headers, options) when is_binary(url) do
     uri = URI.parse(url)
-    adapter_opts = Connection.options(uri, options[:adapter] || [])
-    options = put_in(options[:adapter], adapter_opts)
-    params = options[:params] || []
-    request = build_request(method, headers, options, url, body, params)
-
-    adapter = Application.get_env(:tesla, :adapter)
-    client = Tesla.client([Tesla.Middleware.FollowRedirects], adapter)
-
-    pid = Process.whereis(adapter_opts[:pool])
-
-    pool_alive? =
-      if adapter == Tesla.Adapter.Gun && pid do
-        Process.alive?(pid)
-      else
-        false
-      end
-
-    request_opts =
-      adapter_opts
-      |> Enum.into(%{})
-      |> Map.put(:env, Pleroma.Config.get([:env]))
-      |> Map.put(:pool_alive?, pool_alive?)
-
-    response = request(client, request, request_opts)
-
-    Connection.after_request(adapter_opts)
-
-    response
-  end
-
-  @spec request(Client.t(), keyword(), map()) :: {:ok, Env.t()} | {:error, any()}
-  def request(%Client{} = client, request, %{env: :test}), do: request(client, request)
-
-  def request(%Client{} = client, request, %{body_as: :chunks}), do: request(client, request)
-
-  def request(%Client{} = client, request, %{pool_alive?: false}), do: request(client, request)
-
-  def request(%Client{} = client, request, %{pool: pool, timeout: timeout}) do
-    :poolboy.transaction(
-      pool,
-      &Pleroma.Pool.Request.execute(&1, client, request, timeout),
-      timeout
-    )
+    adapter_opts = AdapterHelper.options(uri, options[:adapter] || [])
+
+    case AdapterHelper.get_conn(uri, adapter_opts) do
+      {:ok, adapter_opts} ->
+        options = put_in(options[:adapter], adapter_opts)
+        params = options[:params] || []
+        request = build_request(method, headers, options, url, body, params)
+
+        adapter = Application.get_env(:tesla, :adapter)
+        client = Tesla.client([Pleroma.HTTP.Middleware.FollowRedirects], adapter)
+
+        maybe_limit(
+          fn ->
+            request(client, request)
+          end,
+          adapter,
+          adapter_opts
+        )
+
+      # Connection release is handled in a custom FollowRedirects middleware
+      err ->
+        err
+    end
   end
 
   @spec request(Client.t(), keyword()) :: {:ok, Env.t()} | {:error, any()}
@@ -118,4 +98,13 @@ defmodule Pleroma.HTTP do
     |> Builder.add_param(:query, :query, params)
     |> Builder.convert_to_keyword()
   end
+
+  @prefix Pleroma.Gun.ConnectionPool
+  defp maybe_limit(fun, Tesla.Adapter.Gun, opts) do
+    ConcurrentLimiter.limit(:"#{@prefix}.#{opts[:pool] || :default}", fun)
+  end
+
+  defp maybe_limit(fun, _, _) do
+    fun.()
+  end
 end