Add clear-storage example

examples/clear-storage.c

@@ -0,0 +1,193 @@
+/*
+ * Example storage clearing program, which deletes all the
+ * fingers which have been previously enrolled to disk.
+ * Copyright (C) 2020 Marco Trevisan <marco.trevisan@canonical.com>
+ * Copyright (C) 2024 Abhinav Baid <abhinavbaid@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#define FP_COMPONENT "example-clear-storage"
+
+#include <stdio.h>
+#include <libfprint/fprint.h>
+#include <glib-unix.h>
+
+#include "storage.h"
+#include "utilities.h"
+
+typedef struct _ClearStorageData
+{
+  GMainLoop    *loop;
+  GCancellable *cancellable;
+  unsigned int  sigint_handler;
+  int           ret_value;
+} ClearStorageData;
+
+static void
+clear_storage_data_free (ClearStorageData *clear_storage_data)
+{
+  g_clear_handle_id (&clear_storage_data->sigint_handler, g_source_remove);
+  g_clear_object (&clear_storage_data->cancellable);
+  g_main_loop_unref (clear_storage_data->loop);
+  g_free (clear_storage_data);
+}
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (ClearStorageData, clear_storage_data_free)
+
+static void
+on_device_closed (FpDevice *dev, GAsyncResult *res, void *user_data)
+{
+  g_autoptr(GError) error = NULL;
+  ClearStorageData *clear_storage_data = user_data;
+
+  fp_device_close_finish (dev, res, &error);
+
+  if (error)
+    g_warning ("Failed closing device %s", error->message);
+
+  g_main_loop_quit (clear_storage_data->loop);
+}
+
+static void
+clear_storage_quit (FpDevice         *dev,
+                    ClearStorageData *clear_storage_data)
+{
+  if (!fp_device_is_open (dev))
+    {
+      g_main_loop_quit (clear_storage_data->loop);
+      return;
+    }
+
+  fp_device_close (dev, NULL, (GAsyncReadyCallback) on_device_closed,
+                   clear_storage_data);
+}
+
+static void
+on_clear_storage_completed (FpDevice *dev, GAsyncResult *res, void *user_data)
+{
+  g_autoptr(GError) error = NULL;
+  ClearStorageData *clear_storage_data = user_data;
+
+  if (!fp_device_clear_storage_finish (dev, res, &error))
+    {
+      g_warning ("Failed to clear storage: %s", error->message);
+      clear_storage_data->ret_value = EXIT_FAILURE;
+    }
+  else
+    {
+      int r = clear_saved_prints ();
+      if (r < 0)
+        {
+          g_warning ("Clear saved prints from local storage failed, code %d", r);
+          clear_storage_data->ret_value = EXIT_FAILURE;
+        }
+      else
+        {
+          g_print ("Clear storage successful!\n");
+          clear_storage_data->ret_value = EXIT_SUCCESS;
+        }
+    }
+
+  clear_storage_quit (dev, clear_storage_data);
+}
+
+static void
+start_clear_storage (FpDevice *dev, ClearStorageData *clear_storage_data)
+{
+  char buffer[20];
+
+  g_print ("Clear device storage? [Y/n]? ");
+  if (fgets (buffer, sizeof (buffer), stdin) &&
+      (buffer[0] == 'Y' || buffer[0] == 'y' || buffer[0] == '\n'))
+    {
+      fp_device_clear_storage (dev, clear_storage_data->cancellable, (GAsyncReadyCallback) on_clear_storage_completed, clear_storage_data);
+      return;
+    }
+
+  clear_storage_quit (dev, clear_storage_data);
+}
+
+static void
+on_device_opened (FpDevice *dev, GAsyncResult *res, void *user_data)
+{
+  g_autoptr(GError) error = NULL;
+  ClearStorageData *clear_storage_data = user_data;
+
+  if (!fp_device_open_finish (dev, res, &error))
+    {
+      g_warning ("Failed to open device: %s", error->message);
+      clear_storage_quit (dev, clear_storage_data);
+      return;
+    }
+
+  g_print ("Opened device. ");
+
+  start_clear_storage (dev, clear_storage_data);
+}
+
+static gboolean
+sigint_cb (void *user_data)
+{
+  ClearStorageData *clear_storage_data = user_data;
+
+  g_cancellable_cancel (clear_storage_data->cancellable);
+
+  return G_SOURCE_CONTINUE;
+}
+
+int
+main (void)
+{
+  g_autoptr(FpContext) ctx = NULL;
+  g_autoptr(ClearStorageData) clear_storage_data = NULL;
+  GPtrArray *devices;
+  FpDevice *dev;
+
+  setenv ("G_MESSAGES_DEBUG", "all", 0);
+  setenv ("LIBUSB_DEBUG", "3", 0);
+
+  ctx = fp_context_new ();
+
+  devices = fp_context_get_devices (ctx);
+  if (!devices)
+    {
+      g_warning ("Impossible to get devices");
+      return EXIT_FAILURE;
+    }
+
+  dev = discover_device (devices);
+  if (!dev)
+    {
+      g_warning ("No devices detected.");
+      return EXIT_FAILURE;
+    }
+
+  clear_storage_data = g_new0 (ClearStorageData, 1);
+  clear_storage_data->ret_value = EXIT_FAILURE;
+  clear_storage_data->loop = g_main_loop_new (NULL, FALSE);
+  clear_storage_data->cancellable = g_cancellable_new ();
+  clear_storage_data->sigint_handler = g_unix_signal_add_full (G_PRIORITY_HIGH,
+                                                               SIGINT,
+                                                               sigint_cb,
+                                                               clear_storage_data,
+                                                               NULL);
+  fp_device_open (dev, clear_storage_data->cancellable,
+                  (GAsyncReadyCallback) on_device_opened,
+                  clear_storage_data);
+
+  g_main_loop_run (clear_storage_data->loop);
+
+  return clear_storage_data->ret_value;
+}

examples/meson.build

@@ -5,6 +5,7 @@ examples = [
     'img-capture',
     'manage-prints',
     'verify',
+    'clear-storage',
 ]
 
 foreach example: examples

examples/storage.c

@@ -26,6 +26,7 @@
 #include "storage.h"
 
 #include <errno.h>
+#include <glib/gstdio.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -208,6 +209,12 @@ gallery_data_load (FpDevice *dev)
   return gallery;
 }
 
+int
+clear_saved_prints (void)
+{
+  return g_remove (STORAGE_FILE);
+}
+
 FpPrint *
 print_create_template (FpDevice *dev, FpFinger finger, gboolean load_existing)
 {

examples/storage.h

@@ -26,6 +26,7 @@ int print_data_save (FpPrint *print,
 FpPrint * print_data_load (FpDevice *dev,
                            FpFinger  finger);
 GPtrArray * gallery_data_load (FpDevice *dev);
+int clear_saved_prints (void);
 FpPrint * print_create_template (FpDevice      *dev,
                                  FpFinger       finger,
                                  const gboolean load_existing);