Add libvips observablity functions

c_src/Makefile

@@ -66,6 +66,7 @@ calling_from_make:
 	cd .. && mix compile
 
 all: install
+	@echo > /dev/null
 
 install: $(PREFIX) $(VIX)
 

c_src/vips_operation.c

@@ -556,6 +556,37 @@ ERL_NIF_TERM nif_vips_cache_get_max_mem(ErlNifEnv *env, int argc,
   return enif_make_uint64(env, vips_cache_get_max_mem());
 }
 
+ERL_NIF_TERM nif_vips_leak_set(ErlNifEnv *env, int argc,
+                               const ERL_NIF_TERM argv[]) {
+  ASSERT_ARGC(argc, 1);
+
+  ErlNifUInt64 value = 0;
+
+  if (!enif_get_uint64(env, argv[0], &value)) {
+    return raise_badarg(env, "Failed to integer value");
+  }
+
+  if (value != 0) {
+    vips_leak_set(TRUE);
+  } else {
+    vips_leak_set(FALSE);
+  }
+
+  return ATOM_OK;
+}
+
+ERL_NIF_TERM nif_vips_tracked_get_mem(ErlNifEnv *env, int argc,
+                                      const ERL_NIF_TERM argv[]) {
+  ASSERT_ARGC(argc, 0);
+  return enif_make_uint64(env, vips_tracked_get_mem());
+}
+
+ERL_NIF_TERM nif_vips_tracked_get_mem_highwater(ErlNifEnv *env, int argc,
+                                                const ERL_NIF_TERM argv[]) {
+  ASSERT_ARGC(argc, 0);
+  return enif_make_uint64(env, vips_tracked_get_mem_highwater());
+}
+
 ERL_NIF_TERM nif_vips_shutdown(ErlNifEnv *env, int argc,
                                const ERL_NIF_TERM argv[]) {
   ASSERT_ARGC(argc, 0);

c_src/vips_operation.h

@@ -42,6 +42,15 @@ ERL_NIF_TERM nif_vips_cache_set_max_mem(ErlNifEnv *env, int argc,
 ERL_NIF_TERM nif_vips_cache_get_max_mem(ErlNifEnv *env, int argc,
                                         const ERL_NIF_TERM argv[]);
 
+ERL_NIF_TERM nif_vips_leak_set(ErlNifEnv *env, int argc,
+                               const ERL_NIF_TERM argv[]);
+
+ERL_NIF_TERM nif_vips_tracked_get_mem(ErlNifEnv *env, int argc,
+                                      const ERL_NIF_TERM argv[]);
+
+ERL_NIF_TERM nif_vips_tracked_get_mem_highwater(ErlNifEnv *env, int argc,
+                                                const ERL_NIF_TERM argv[]);
+
 ERL_NIF_TERM nif_vips_shutdown(ErlNifEnv *env, int argc,
                                const ERL_NIF_TERM argv[]);
 

c_src/vix.c

@@ -114,6 +114,9 @@ static ErlNifFunc nif_funcs[] = {
     {"nif_vips_cache_get_max_files", 0, nif_vips_cache_get_max_files, 0},
     {"nif_vips_cache_set_max_mem", 1, nif_vips_cache_set_max_mem, 0},
     {"nif_vips_cache_get_max_mem", 0, nif_vips_cache_get_max_mem, 0},
+    {"nif_vips_leak_set", 1, nif_vips_leak_set, 0},
+    {"nif_vips_tracked_get_mem", 0, nif_vips_tracked_get_mem, 0},
+    {"nif_vips_tracked_get_mem_highwater", 0, nif_vips_tracked_get_mem, 0},
     {"nif_vips_version", 0, nif_vips_version, 0},
     {"nif_vips_shutdown", 0, nif_vips_shutdown, 0},
     {"nif_vips_nickname_find", 1, nif_vips_nickname_find, 0},

lib/vix/nif.ex

@@ -121,6 +121,15 @@ defmodule Vix.Nif do
   def nif_vips_cache_get_max_mem,
     do: :erlang.nif_error(:nif_library_not_loaded)
 
+  def nif_vips_leak_set(_integer),
+    do: :erlang.nif_error(:nif_library_not_loaded)
+
+  def nif_vips_tracked_get_mem,
+    do: :erlang.nif_error(:nif_library_not_loaded)
+
+  def nif_vips_tracked_get_mem_highwater,
+    do: :erlang.nif_error(:nif_library_not_loaded)
+
   def nif_vips_version,
     do: :erlang.nif_error(:nif_library_not_loaded)
 

lib/vix/vips.ex

@@ -77,6 +77,34 @@ defmodule Vix.Vips do
     Nif.nif_vips_cache_get_max_mem()
   end
 
+  @doc """
+  Turn on or off vips leak checking
+  """
+  @spec set_vips_leak_checking(boolean()) :: :ok
+  def set_vips_leak_checking(bool) when is_boolean(bool) do
+    Nif.nif_vips_leak_set(if bool, do: 1, else: 0)
+  end
+
+  @doc """
+  Returns the number of bytes currently allocated by libvips.
+
+  Libvips uses this figure to decide when to start dropping cache.
+  """
+  @spec tracked_get_mem() :: integer()
+  def tracked_get_mem do
+    Nif.nif_vips_tracked_get_mem()
+  end
+
+  @doc """
+  Returns the largest number of bytes simultaneously allocated via libvips.
+
+  Handy for estimating max memory requirements for a program.
+  """
+  @spec tracked_get_mem_highwater() :: integer()
+  def tracked_get_mem_highwater do
+    Nif.nif_vips_tracked_get_mem_highwater()
+  end
+
   @doc """
   Get installed vips version
   """

test/vix/vips_test.exs

@@ -0,0 +1,24 @@
+defmodule Vix.VipsTest do
+  use ExUnit.Case, async: true
+
+  alias Vix.Vips
+  alias Vix.Vips.Image
+
+  import Vix.Support.Images
+
+  test "tracked_get_mem/0" do
+    {:ok, im} = Image.new_from_file(img_path("puppies.jpg"))
+    {:ok, _bin} = Image.write_to_buffer(im, ".png")
+
+    usage = Vips.tracked_get_mem()
+    assert is_integer(usage) && usage > 0
+  end
+
+  test "tracked_get_mem_highwater/0" do
+    {:ok, im} = Image.new_from_file(img_path("puppies.jpg"))
+    {:ok, _bin} = Image.write_to_buffer(im, ".png")
+
+    usage = Vips.tracked_get_mem_highwater()
+    assert is_integer(usage) && usage > 0
+  end
+end