1 files changed, 45 insertions, 0 deletions
diff --git a/nixpkgs/nixos/modules/services/x11/gdk-pixbuf.nix b/nixpkgs/nixos/modules/services/x11/gdk-pixbuf.nix
new file mode 100644
index 000000000000..58faa8e2f9df
--- /dev/null
+++ b/nixpkgs/nixos/modules/services/x11/gdk-pixbuf.nix
@@ -0,0 +1,45 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.xserver.gdk-pixbuf;
+
+  # Get packages to generate the cache for. We always include gdk_pixbuf.
+  effectivePackages = unique ([pkgs.gdk_pixbuf] ++ cfg.modulePackages);
+
+  # Generate the cache file by running gdk-pixbuf-query-loaders for each
+  # package and concatenating the results.
+  loadersCache = pkgs.runCommand "gdk-pixbuf-loaders.cache" {} ''
+    (
+      for package in ${concatStringsSep " " effectivePackages}; do
+        module_dir="$package/${pkgs.gdk_pixbuf.moduleDir}"
+        if [[ ! -d $module_dir ]]; then
+          echo "Warning (services.xserver.gdk-pixbuf): missing module directory $module_dir" 1>&2
+          continue
+        fi
+        GDK_PIXBUF_MODULEDIR="$module_dir" \
+          ${pkgs.gdk_pixbuf.dev}/bin/gdk-pixbuf-query-loaders
+      done
+    ) > "$out"
+  '';
+in
+
+{
+  options = {
+    services.xserver.gdk-pixbuf.modulePackages = mkOption {
+      type = types.listOf types.package;
+      default = [ ];
+      description = "Packages providing GDK-Pixbuf modules, for cache generation.";
+    };
+  };
+
+  # If there is any package configured in modulePackages, we generate the
+  # loaders.cache based on that and set the environment variable
+  # GDK_PIXBUF_MODULE_FILE to point to it.
+  config = mkIf (cfg.modulePackages != []) {
+    environment.variables = {
+      GDK_PIXBUF_MODULE_FILE = "${loadersCache}";
+    };
+  };
+}