[gnome-software: 4/12] tools: Add a profiling tool for key color generation

[Phaedrus Leeds <mwleeds src gnome org>]

commit e31bab224ac9bcf9d70003f4d0dc724ed14c1b18
Author: Philip Withnall <pwithnall endlessos org>
Date:   Mon Feb 22 15:41:04 2021 +0000

    tools: Add a profiling tool for key color generation
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>

 lib/meson.build                |   2 +
 lib/tools/meson.build          |  24 ++++++
 lib/tools/profile-key-colors.c | 172 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 198 insertions(+)
---
diff --git a/lib/meson.build b/lib/meson.build
index 0c53797d3..44b41c272 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -157,3 +157,5 @@ if get_option('tests')
   )
   test('gs-self-test-lib', e, suite: ['lib'], env: test_env, timeout : 120)
 endif
+
+subdir('tools')
diff --git a/lib/tools/meson.build b/lib/tools/meson.build
new file mode 100644
index 000000000..0f19c10c1
--- /dev/null
+++ b/lib/tools/meson.build
@@ -0,0 +1,24 @@
+# Test program to profile performance of the key-colors functions
+executable(
+  'profile-key-colors',
+  sources : [
+    'profile-key-colors.c',
+    '../gs-key-colors.c',
+    '../gs-key-colors.h',
+  ],
+  include_directories : [
+    include_directories('..'),
+    include_directories('../..'),
+  ],
+  dependencies : [
+    glib,
+    dependency('gdk-3.0'),
+    gdk_pixbuf,
+    libm,
+  ],
+  c_args : [
+    '-Wall',
+    '-Wextra',
+  ],
+  install: false,
+)
diff --git a/lib/tools/profile-key-colors.c b/lib/tools/profile-key-colors.c
new file mode 100644
index 000000000..657eff885
--- /dev/null
+++ b/lib/tools/profile-key-colors.c
@@ -0,0 +1,172 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
+ * vi:set noexpandtab tabstop=8 shiftwidth=8:
+ *
+ * Copyright (C) 2021 Endless OS Foundation, Inc
+ *
+ * Authors:
+ *  - Philip Withnall <pwithnall endlessos org>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <glib.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+#include <gdk/gdk.h>
+#include <locale.h>
+#include <math.h>
+
+#include "gs-key-colors.h"
+
+/* Test program which can be used to check the output and performance of the
+ * gs_calculate_key_colors() function. It is linked against libgnomesoftware, so
+ * will use the function implementation from there. It outputs a HTML page which
+ * lists each icon from the flathub appstream data in your home directory, along
+ * with its extracted key colors and how long extraction took. */
+
+static void
+print_colours (GString *html_output,
+               GArray  *colours)
+{
+       g_string_append_printf (html_output, "<table class='colour-swatch'><tr>");
+       for (guint i = 0; i < colours->len; i++) {
+               GdkRGBA *rgba = &g_array_index (colours, GdkRGBA, i);
+
+               g_string_append_printf (html_output,
+                                       "<td style='background-color: rgb(%u, %u, %u)'></td>",
+                                       (guint) (rgba->red * 255),
+                                       (guint) (rgba->green * 255),
+                                       (guint) (rgba->blue * 255));
+
+               if (i % 3 == 2)
+                       g_string_append (html_output, "</tr><tr>");
+       }
+       g_string_append_printf (html_output, "</tr></table>");
+}
+
+static void
+print_summary_statistics (GString *html_output,
+                          GArray  *durations  /* (element-type gint64) */)
+{
+       gint64 sum = 0, min = G_MAXINT64, max = G_MININT64;
+       guint n_measurements = durations->len;
+       gint64 mean, stddev;
+       gint64 sum_of_square_deviations = 0;
+
+       for (guint i = 0; i < durations->len; i++) {
+               gint64 duration = g_array_index (durations, gint64, i);
+               sum += duration;
+               min = MIN (min, duration);
+               max = MAX (max, duration);
+       }
+
+       mean = sum / n_measurements;
+
+       for (guint i = 0; i < durations->len; i++) {
+               gint64 duration = g_array_index (durations, gint64, i);
+               gint64 diff = duration - mean;
+               sum_of_square_deviations += diff * diff;
+       }
+
+       stddev = sqrt (sum_of_square_deviations / n_measurements);
+
+       g_string_append_printf (html_output,
+                               "[%" G_GINT64_FORMAT ", %" G_GINT64_FORMAT "]μs, mean %" G_GINT64_FORMAT "±%" 
G_GINT64_FORMAT "μs, n = %u",
+                               min, max, mean, stddev, n_measurements);
+}
+
+int
+main (void)
+{
+       const gchar *icons_subdir = ".local/share/flatpak/appstream/flathub/x86_64/active/icons/128x128";
+       g_autofree gchar *icons_dir = g_build_filename (g_get_home_dir (), icons_subdir, NULL);
+       g_autoptr(GDir) dir = NULL;
+       const gchar *entry;
+       g_autoptr(GPtrArray) filenames = g_ptr_array_new_with_free_func (g_free);
+       g_autoptr(GPtrArray) pixbufs = g_ptr_array_new_with_free_func (g_object_unref);
+       g_autoptr(GString) html_output = g_string_new ("");
+       g_autoptr(GArray) durations = g_array_new (FALSE, FALSE, sizeof (gint64));
+
+       setlocale (LC_ALL, "");
+
+       /* Load pixbufs from the icons directory. */
+       dir = g_dir_open (icons_dir, 0, NULL);
+       if (dir == NULL)
+               return 1;
+
+       while ((entry = g_dir_read_name (dir)) != NULL) {
+               g_autofree gchar *filename = g_build_filename (icons_dir, entry, NULL);
+               g_autoptr(GdkPixbuf) pixbuf = gdk_pixbuf_new_from_file (filename, NULL);
+
+               if (pixbuf == NULL)
+                       continue;
+
+               g_ptr_array_add (filenames, g_steal_pointer (&filename));
+               g_ptr_array_add (pixbufs, g_steal_pointer (&pixbuf));
+       }
+
+       /* Set up an output page */
+       g_string_append (html_output,
+                        "<!DOCTYPE html>\n"
+                        "<html>\n"
+                        "  <head>\n"
+                        "    <meta charset='UTF-8'>\n"
+                        "    <style>\n"
+                        "      #main-table, #main-table th, #main-table td { border: 1px solid black; 
border-collapse: collapse }\n"
+                        "      #main-table th, #main-table td { padding: 4px }\n"
+                        "      td.number { text-align: right }\n"
+                        "      table.colour-swatch td { width: 30px; height: 30px }\n"
+                        "      .faster { background-color: rgb(190, 236, 57) }\n"
+                        "      .slower { background-color: red }\n"
+                        "    </style>\n"
+                        "  </head>\n"
+                        "  <body>\n"
+                        "    <table id='main-table'>\n"
+                        "      <thead>\n"
+                        "        <tr>\n"
+                        "          <td>Filename</td>\n"
+                        "          <td>Icon</td>\n"
+                        "          <td>Code duration (μs)</td>\n"
+                        "          <td>Code colours</td>\n"
+                        "        </tr>\n"
+                        "      </thead>\n");
+
+       /* For each pixbuf, run both algorithms. */
+       for (guint i = 0; i < pixbufs->len; i++) {
+               GdkPixbuf *pixbuf = pixbufs->pdata[i];
+               const gchar *filename = filenames->pdata[i];
+               g_autofree gchar *basename = g_path_get_basename (filename);
+               g_autoptr(GArray) colours = NULL;
+               gint64 start_time, duration;
+
+               g_message ("Processing %u of %u, %s", i + 1, pixbufs->len, filename);
+
+               start_time = g_get_real_time ();
+               colours = gs_calculate_key_colors (pixbuf);
+               duration = g_get_real_time () - start_time;
+
+               g_string_append_printf (html_output,
+                                       "<tr>\n"
+                                       "<th>%s</th>\n"
+                                       "<td><img src='file:%s'></td>\n"
+                                       "<td class='number'>%" G_GINT64_FORMAT "</td>\n"
+                                       "<td>",
+                                       basename, filename, duration);
+               print_colours (html_output, colours);
+               g_string_append (html_output,
+                                "</td>\n"
+                                "</tr>\n");
+
+               g_array_append_val (durations, duration);
+       }
+
+       /* Summary statistics for the timings. */
+       g_string_append (html_output, "<tfoot><tr><td></td><td></td><td>");
+       print_summary_statistics (html_output, durations);
+       g_string_append (html_output, "</td><td></td></tr></tfoot>");
+
+       g_string_append (html_output, "</table></body></html>");
+
+       g_print ("%s\n", html_output->str);
+
+       return 0;
+}