[evolution-data-server/account-mgmt: 41/42] Add 'cache-reaper' module.

[Matthew Barnes <mbarnes src gnome org>]

commit 33ec3b7398e7ab6a397eb90cf02e89c64b3e70bd
Author: Matthew Barnes <mbarnes redhat com>
Date:   Fri Apr 6 15:21:37 2012 -0400

    Add 'cache-reaper' module.

 configure.ac                                |    1 +
 modules/Makefile.am                         |    1 +
 modules/cache-reaper/Makefile.am            |   30 ++
 modules/cache-reaper/e-cache-reaper-utils.c |  196 ++++++++++
 modules/cache-reaper/e-cache-reaper-utils.h |   41 +++
 modules/cache-reaper/module-cache-reaper.c  |  513 +++++++++++++++++++++++++++
 6 files changed, 782 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 111b094..425482e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1651,6 +1651,7 @@ libedataserver/libedataserver.pc
 libedataserverui/Makefile
 libedataserverui/libedataserverui.pc
 modules/Makefile
+modules/cache-reaper/Makefile
 modules/google-backend/Makefile
 modules/online-accounts/Makefile
 modules/yahoo-backend/Makefile
diff --git a/modules/Makefile.am b/modules/Makefile.am
index 47a2e70..8023faf 100644
--- a/modules/Makefile.am
+++ b/modules/Makefile.am
@@ -5,6 +5,7 @@ ONLINE_ACCOUNTS_DIR = online-accounts
 endif
 
 SUBDIRS = \
+	cache-reaper \
 	google-backend \
 	yahoo-backend \
 	$(ONLINE_ACCOUNTS_DIR) \
diff --git a/modules/cache-reaper/Makefile.am b/modules/cache-reaper/Makefile.am
new file mode 100644
index 0000000..510a4a6
--- /dev/null
+++ b/modules/cache-reaper/Makefile.am
@@ -0,0 +1,30 @@
+NULL =
+
+module_LTLIBRARIES = module-cache-reaper.la
+
+module_cache_reaper_la_CPPFLAGS = \
+	$(AM_CPPFLAGS) \
+	-I$(top_srcdir) \
+	-DG_LOG_DOMAIN=\"module-cache-reaper\" \
+	$(E_BACKEND_CFLAGS) \
+	$(E_DATA_SERVER_CFLAGS) \
+	$(NULL)
+
+module_cache_reaper_la_SOURCES = \
+	module-cache-reaper.c \
+	e-cache-reaper-utils.c \
+	e-cache-reaper-utils.h \
+	$(NULL)
+
+module_cache_reaper_la_LIBADD = \
+	$(top_builddir)/libebackend/libebackend-1.2.la \
+	$(top_builddir)/libedataserver/libedataserver-1.2.la \
+	$(E_BACKEND_LIBS) \
+	$(E_DATA_SERVER_LIBS) \
+	$(NULL)
+
+module_cache_reaper_la_LDFLAGS = \
+	-module -avoid-version $(NO_UNDEFINED) \
+	$(NULL)
+
+-include $(top_srcdir)/git.mk
diff --git a/modules/cache-reaper/e-cache-reaper-utils.c b/modules/cache-reaper/e-cache-reaper-utils.c
new file mode 100644
index 0000000..4ba57c4
--- /dev/null
+++ b/modules/cache-reaper/e-cache-reaper-utils.c
@@ -0,0 +1,196 @@
+/*
+ * e-cache-reaper-utils.c
+ *
+ * This program 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 of the License, or (at your option) version 3.
+ *
+ * This program 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 the program; if not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+#include "e-cache-reaper-utils.h"
+
+#include <libedataserver/e-data-server-util.h>
+
+#define REAPING_DIRECTORY_NAME ".reaping"
+
+#define MINIMUM_DAYS_OLD_TO_REAP 5
+
+/* Helper for e_reap_trash_directory() */
+static void
+reap_trash_directory_thread (GSimpleAsyncResult *simple,
+                             GObject *object,
+                             GCancellable *cancellable)
+{
+	GError *error = NULL;
+
+	e_reap_trash_directory_sync (G_FILE (object), cancellable, &error);
+
+	if (error != NULL)
+		g_simple_async_result_take_error (simple, error);
+}
+
+gboolean
+e_reap_trash_directory_sync (GFile *trash_directory,
+                             GCancellable *cancellable,
+                             GError **error)
+{
+	GFileEnumerator *file_enumerator;
+	GQueue directories = G_QUEUE_INIT;
+	GFile *reaping_directory;
+	GFileInfo *file_info;
+	const gchar *attributes;
+	gboolean success = TRUE;
+	GError *local_error = NULL;
+
+	g_return_val_if_fail (G_IS_FILE (trash_directory), FALSE);
+
+	reaping_directory = g_file_get_child (
+		trash_directory, REAPING_DIRECTORY_NAME);
+
+	attributes =
+		G_FILE_ATTRIBUTE_STANDARD_NAME ","
+		G_FILE_ATTRIBUTE_STANDARD_TYPE ","
+		G_FILE_ATTRIBUTE_TIME_MODIFIED;
+
+	file_enumerator = g_file_enumerate_children (
+		trash_directory, attributes,
+		G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
+		cancellable, error);
+
+	if (file_enumerator == NULL)
+		return FALSE;
+
+	file_info = g_file_enumerator_next_file (
+		file_enumerator, cancellable, &local_error);
+
+	while (file_info != NULL) {
+		GFileType file_type;
+		GTimeVal mtime;
+		GDate *date_now;
+		GDate *date_mtime;
+		const gchar *name;
+		gboolean reap_it;
+		gint days_old;
+
+		name = g_file_info_get_name (file_info);
+		file_type = g_file_info_get_file_type (file_info);
+		g_file_info_get_modification_time (file_info, &mtime);
+
+		/* Calculate how many days ago the file was modified. */
+		date_now = g_date_new ();
+		g_date_set_time_t (date_now, time (NULL));
+		date_mtime = g_date_new ();
+		g_date_set_time_val (date_mtime, &mtime);
+		days_old = g_date_days_between (date_mtime, date_now);
+		g_date_free (date_mtime);
+		g_date_free (date_now);
+
+		reap_it =
+			(file_type == G_FILE_TYPE_DIRECTORY) &&
+			(days_old >= MINIMUM_DAYS_OLD_TO_REAP);
+
+		if (reap_it) {
+			GFile *child;
+
+			child = g_file_get_child (trash_directory, name);
+
+			/* If we find an unfinished reaping directory, put
+			 * it on the head of the queue so we reap it first. */
+			if (g_file_equal (child, reaping_directory))
+				g_queue_push_head (&directories, child);
+			else
+				g_queue_push_tail (&directories, child);
+		}
+
+		g_object_unref (file_info);
+
+		file_info = g_file_enumerator_next_file (
+			file_enumerator, cancellable, &local_error);
+	}
+
+	if (local_error != NULL) {
+		g_propagate_error (error, local_error);
+		success = FALSE;
+	}
+
+	g_object_unref (file_enumerator);
+
+	/* Now delete the directories we've queued up. */
+	while (success && !g_queue_is_empty (&directories)) {
+		GFile *directory;
+
+		directory = g_queue_pop_head (&directories);
+
+		/* First we rename the directory to prevent it
+		 * from being recovered while being deleted. */
+		if (!g_file_equal (directory, reaping_directory))
+			success = g_file_move (
+				directory, reaping_directory,
+				G_FILE_COPY_NONE, cancellable,
+				NULL, NULL, error);
+
+		if (success)
+			success = e_file_recursive_delete_sync (
+				reaping_directory, cancellable, error);
+
+		g_object_unref (directory);
+	}
+
+	/* Flush the queue in case we aborted on an error. */
+	while (!g_queue_is_empty (&directories))
+		g_object_unref (g_queue_pop_head (&directories));
+
+	g_object_unref (reaping_directory);
+
+	return success;
+}
+
+void
+e_reap_trash_directory (GFile *trash_directory,
+                        gint io_priority,
+                        GCancellable *cancellable,
+                        GAsyncReadyCallback callback,
+                        gpointer user_data)
+{
+	GSimpleAsyncResult *simple;
+
+	g_return_if_fail (G_IS_FILE (trash_directory));
+
+	simple = g_simple_async_result_new (
+		G_OBJECT (trash_directory), callback,
+		user_data, e_reap_trash_directory);
+
+	g_simple_async_result_run_in_thread (
+		simple, reap_trash_directory_thread,
+		io_priority, cancellable);
+
+	g_object_unref (simple);
+}
+
+gboolean
+e_reap_trash_directory_finish (GFile *trash_directory,
+                               GAsyncResult *result,
+                               GError **error)
+{
+	GSimpleAsyncResult *simple;
+
+	g_return_val_if_fail (
+		g_simple_async_result_is_valid (
+		result, G_OBJECT (trash_directory),
+		e_reap_trash_directory), FALSE);
+
+	simple = G_SIMPLE_ASYNC_RESULT (result);
+
+	/* Assume success unless a GError is set. */
+	return !g_simple_async_result_propagate_error (simple, error);
+}
+
diff --git a/modules/cache-reaper/e-cache-reaper-utils.h b/modules/cache-reaper/e-cache-reaper-utils.h
new file mode 100644
index 0000000..0b92801
--- /dev/null
+++ b/modules/cache-reaper/e-cache-reaper-utils.h
@@ -0,0 +1,41 @@
+/*
+ * e-cache-reaper-utils.h
+ *
+ * This program 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 of the License, or (at your option) version 3.
+ *
+ * This program 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 the program; if not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+#ifndef E_CACHE_REAPER_UTILS_H
+#define E_CACHE_REAPER_UTILS_H
+
+#include <gio/gio.h>
+
+G_BEGIN_DECLS
+
+gboolean	e_reap_trash_directory_sync	(GFile *trash_directory,
+						 GCancellable *cancellable,
+						 GError **error);
+void		e_reap_trash_directory		(GFile *trash_directory,
+						 gint io_priority,
+						 GCancellable *cancellable,
+						 GAsyncReadyCallback callback,
+						 gpointer user_data);
+gboolean	e_reap_trash_directory_finish	(GFile *trash_directory,
+						 GAsyncResult *result,
+						 GError **error);
+
+G_END_DECLS
+
+#endif /* E_CACHE_REAPER_UTILS_H */
+
diff --git a/modules/cache-reaper/module-cache-reaper.c b/modules/cache-reaper/module-cache-reaper.c
new file mode 100644
index 0000000..39c4142
--- /dev/null
+++ b/modules/cache-reaper/module-cache-reaper.c
@@ -0,0 +1,513 @@
+/*
+ * module-cache-reaper.c
+ *
+ * This program 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 of the License, or (at your option) version 3.
+ *
+ * This program 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 the program; if not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+#include <errno.h>
+#include <time.h>
+#include <glib/gstdio.h>
+
+#include <libedataserver/e-data-server-util.h>
+
+#include <libebackend/e-extension.h>
+#include <libebackend/e-source-registry-server.h>
+
+#include "e-cache-reaper-utils.h"
+
+/* Standard GObject macros */
+#define E_TYPE_CACHE_REAPER \
+	(e_cache_reaper_get_type ())
+#define E_CACHE_REAPER(obj) \
+	(G_TYPE_CHECK_INSTANCE_CAST \
+	((obj), E_TYPE_CACHE_REAPER, ECacheReaper))
+
+/* Where abandoned cache directories go to die. */
+#define TRASH_DIRECTORY_NAME "trash"
+
+/* XXX These intervals are rather arbitrary and prone to bikeshedding.
+ *     It's just what I decided on.  On startup we wait an hour to reap
+ *     abandoned cache directories, and thereafter repeat every 24 hours. */
+#define INITIAL_INTERVAL_SECONDS  ( 1 * (60 * 60))
+#define REGULAR_INTERVAL_SECONDS  (24 * (60 * 60))
+
+typedef struct _ECacheReaper ECacheReaper;
+typedef struct _ECacheReaperClass ECacheReaperClass;
+
+struct _ECacheReaper {
+	EExtension parent;
+
+	guint n_directories;
+	GFile **cache_directories;
+	GFile **trash_directories;
+
+	guint reaping_timeout_id;
+};
+
+struct _ECacheReaperClass {
+	EExtensionClass parent_class;
+};
+
+/* Module Entry Points */
+void e_module_load (GTypeModule *type_module);
+void e_module_unload (GTypeModule *type_module);
+
+/* Forward Declarations */
+GType e_cache_reaper_get_type (void);
+
+G_DEFINE_DYNAMIC_TYPE (
+	ECacheReaper,
+	e_cache_reaper,
+	E_TYPE_EXTENSION)
+
+static ESourceRegistryServer *
+cache_reaper_get_server (ECacheReaper *extension)
+{
+	EExtensible *extensible;
+
+	extensible = e_extension_get_extensible (E_EXTENSION (extension));
+
+	return E_SOURCE_REGISTRY_SERVER (extensible);
+}
+
+static void
+cache_reaper_trash_directory_reaped (GObject *source_object,
+                                     GAsyncResult *result,
+                                     gpointer unused)
+{
+	GFile *trash_directory;
+	GError *error = NULL;
+
+	trash_directory = G_FILE (source_object);
+
+	e_reap_trash_directory_finish (trash_directory, result, &error);
+
+	/* Ignore cancellations. */
+	if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
+		/* do nothing */
+
+	} else if (error != NULL) {
+		gchar *path;
+
+		path = g_file_get_path (trash_directory);
+		g_warning ("Failed to reap '%s': %s", path, error->message);
+		g_free (path);
+	}
+
+	g_clear_error (&error);
+}
+
+static gboolean
+cache_reaper_reap_trash_directories (gpointer user_data)
+{
+	ECacheReaper *extension = E_CACHE_REAPER (user_data);
+	guint ii;
+
+	g_message ("Reaping abandoned cache directories");
+
+	for (ii = 0; ii < extension->n_directories; ii++)
+		e_reap_trash_directory (
+			extension->trash_directories[ii],
+			G_PRIORITY_LOW, NULL,
+			cache_reaper_trash_directory_reaped,
+			NULL);
+
+	/* Always explicitly reschedule since the initial
+	 * interval is different than the regular interval. */
+	extension->reaping_timeout_id =
+		g_timeout_add_seconds (
+			REGULAR_INTERVAL_SECONDS,
+			cache_reaper_reap_trash_directories,
+			extension);
+
+	return FALSE;
+}
+
+static void
+cache_reaper_move_directory (GFile *source_directory,
+                             GFile *target_directory)
+{
+	GFileType file_type;
+	GError *error = NULL;
+
+	/* Make sure the source directory is really a directory. */
+
+	file_type = g_file_query_file_type (
+		source_directory,
+		G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS, NULL);
+
+	if (file_type == G_FILE_TYPE_DIRECTORY) {
+		g_file_move (
+			source_directory,
+			target_directory,
+			G_FILE_COPY_NOFOLLOW_SYMLINKS,
+			NULL, NULL, NULL, &error);
+
+		/* Update the target directory's modification time.
+		 * This step is not critical, do not set the GError. */
+		if (error == NULL) {
+			time_t now = time (NULL);
+
+			g_file_set_attribute (
+				target_directory,
+				G_FILE_ATTRIBUTE_TIME_MODIFIED,
+				G_FILE_ATTRIBUTE_TYPE_UINT64,
+				&now, G_FILE_QUERY_INFO_NONE,
+				NULL, NULL);
+		}
+	}
+
+	if (error != NULL) {
+		gchar *path;
+
+		path = g_file_get_path (source_directory);
+		g_warning ("Failed to move '%s': %s", path, error->message);
+		g_free (path);
+
+		g_error_free (error);
+	}
+}
+
+static void
+cache_reaper_scan_cache_directory (ECacheReaper *extension,
+                                   GFile *cache_directory,
+                                   GFile *trash_directory)
+{
+	GFileEnumerator *file_enumerator;
+	ESourceRegistryServer *server;
+	GFileInfo *file_info;
+	GError *error = NULL;
+
+	server = cache_reaper_get_server (extension);
+
+	file_enumerator = g_file_enumerate_children (
+		cache_directory,
+		G_FILE_ATTRIBUTE_STANDARD_NAME,
+		G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
+		NULL, &error);
+
+	if (error != NULL) {
+		g_warn_if_fail (file_enumerator == NULL);
+		goto exit;
+	}
+
+	g_return_if_fail (G_IS_FILE_ENUMERATOR (file_enumerator));
+
+	file_info = g_file_enumerator_next_file (
+		file_enumerator, NULL, &error);
+
+	while (file_info != NULL) {
+		ESource *source;
+		const gchar *name;
+
+		name = g_file_info_get_name (file_info);
+
+		/* Skip the trash directory, obviously. */
+		if (g_strcmp0 (name, TRASH_DIRECTORY_NAME) == 0)
+			goto next;
+
+		source = e_source_registry_server_ref_source (server, name);
+
+		if (source == NULL) {
+			GFile *source_directory;
+			GFile *target_directory;
+
+			source_directory = g_file_get_child (
+				cache_directory, name);
+			target_directory = g_file_get_child (
+				trash_directory, name);
+
+			cache_reaper_move_directory (
+				source_directory, target_directory);
+
+			g_object_unref (source_directory);
+			g_object_unref (target_directory);
+		} else {
+			g_object_unref (source);
+		}
+
+next:
+		g_object_unref (file_info);
+
+		file_info = g_file_enumerator_next_file (
+			file_enumerator, NULL, &error);
+	}
+
+	g_object_unref (file_enumerator);
+
+exit:
+	if (error != NULL) {
+		gchar *path;
+
+		path = g_file_get_path (cache_directory);
+		g_warning ("Failed to scan '%s': %s", path, error->message);
+		g_free (path);
+
+		g_error_free (error);
+	}
+}
+
+static void
+cache_reaper_scan_cache_directories (ECacheReaper *extension)
+{
+	guint ii;
+
+	/* Scan the base cache directories for unregnized subdirectories.
+	 * The subdirectories are named after data source UIDs, so compare
+	 * their names to registered data sources and move any unrecognized
+	 * subdirectories to the "trash" subdirectory to be reaped later. */
+
+	g_message ("Scanning cache directories");
+
+	for (ii = 0; ii < extension->n_directories; ii++)
+		cache_reaper_scan_cache_directory (
+			extension,
+			extension->cache_directories[ii],
+			extension->trash_directories[ii]);
+}
+
+static void
+cache_reaper_move_cache_to_trash (ECacheReaper *extension,
+                                  ESource *source,
+                                  GFile *cache_directory,
+                                  GFile *trash_directory)
+{
+	GFile *source_directory;
+	GFile *target_directory;
+	const gchar *uid;
+
+	uid = e_source_get_uid (source);
+
+	source_directory = g_file_get_child (cache_directory, uid);
+	target_directory = g_file_get_child (trash_directory, uid);
+
+	/* This is a no-op if the source directory does not exist. */
+	cache_reaper_move_directory (source_directory, target_directory);
+
+	g_object_unref (source_directory);
+	g_object_unref (target_directory);
+}
+
+static void
+cache_reaper_recover_cache_from_trash (ECacheReaper *extension,
+                                       ESource *source,
+                                       GFile *cache_directory,
+                                       GFile *trash_directory)
+{
+	GFile *source_directory;
+	GFile *target_directory;
+	const gchar *uid;
+
+	uid = e_source_get_uid (source);
+
+	source_directory = g_file_get_child (trash_directory, uid);
+	target_directory = g_file_get_child (cache_directory, uid);
+
+	/* This is a no-op if the source directory does not exist. */
+	cache_reaper_move_directory (source_directory, target_directory);
+
+	g_object_unref (source_directory);
+	g_object_unref (target_directory);
+}
+
+static void
+cache_reaper_files_loaded_cb (ESourceRegistryServer *server,
+                              ECacheReaper *extension)
+{
+	cache_reaper_scan_cache_directories (extension);
+
+	/* Schedule the initial reaping. */
+	if (extension->reaping_timeout_id == 0)
+		extension->reaping_timeout_id =
+			g_timeout_add_seconds (
+				INITIAL_INTERVAL_SECONDS,
+				cache_reaper_reap_trash_directories,
+				extension);
+}
+
+static void
+cache_reaper_source_added_cb (ESourceRegistryServer *server,
+                              ESource *source,
+                              ECacheReaper *extension)
+{
+	guint ii;
+
+	/* The Cache Reaper is not too proud to dig through the
+	 * trash on the off chance the newly-added source has a
+	 * recoverable cache directory. */
+	for (ii = 0; ii < extension->n_directories; ii++)
+		cache_reaper_recover_cache_from_trash (
+			extension, source,
+			extension->cache_directories[ii],
+			extension->trash_directories[ii]);
+}
+
+static void
+cache_reaper_source_removed_cb (ESourceRegistryServer *server,
+                                ESource *source,
+                                ECacheReaper *extension)
+{
+	guint ii;
+
+	/* Stage the removed source's cache directory for
+	 * reaping by moving it to the "trash" directory. */
+	for (ii = 0; ii < extension->n_directories; ii++)
+		cache_reaper_move_cache_to_trash (
+			extension, source,
+			extension->cache_directories[ii],
+			extension->trash_directories[ii]);
+}
+
+static void
+cache_reaper_finalize (GObject *object)
+{
+	ECacheReaper *extension;
+	guint ii;
+
+	extension = E_CACHE_REAPER (object);
+
+	for (ii = 0; ii < extension->n_directories; ii++) {
+		g_object_unref (extension->cache_directories[ii]);
+		g_object_unref (extension->trash_directories[ii]);
+	}
+
+	g_free (extension->cache_directories);
+	g_free (extension->trash_directories);
+
+	if (extension->reaping_timeout_id > 0)
+		g_source_remove (extension->reaping_timeout_id);
+
+	/* Chain up to parent's finalize() method. */
+	G_OBJECT_CLASS (e_cache_reaper_parent_class)->finalize (object);
+}
+
+static void
+cache_reaper_constructed (GObject *object)
+{
+	EExtension *extension;
+	EExtensible *extensible;
+
+	extension = E_EXTENSION (object);
+	extensible = e_extension_get_extensible (extension);
+
+	g_signal_connect (
+		extensible, "files-loaded",
+		G_CALLBACK (cache_reaper_files_loaded_cb), extension);
+
+	g_signal_connect (
+		extensible, "source-added",
+		G_CALLBACK (cache_reaper_source_added_cb), extension);
+
+	g_signal_connect (
+		extensible, "source-removed",
+		G_CALLBACK (cache_reaper_source_removed_cb), extension);
+
+	/* Chain up to parent's constructed() method. */
+	G_OBJECT_CLASS (e_cache_reaper_parent_class)->constructed (object);
+}
+
+static void
+e_cache_reaper_class_init (ECacheReaperClass *class)
+{
+	GObjectClass *object_class;
+	EExtensionClass *extension_class;
+
+	object_class = G_OBJECT_CLASS (class);
+	object_class->finalize = cache_reaper_finalize;
+	object_class->constructed = cache_reaper_constructed;
+
+	extension_class = E_EXTENSION_CLASS (class);
+	extension_class->extensible_type = E_TYPE_SOURCE_REGISTRY_SERVER;
+}
+
+static void
+e_cache_reaper_class_finalize (ECacheReaperClass *class)
+{
+}
+
+static void
+e_cache_reaper_init (ECacheReaper *extension)
+{
+	GFile *base_directory;
+	const gchar *user_cache_dir;
+	guint n_directories, ii;
+
+	/* These are component names from which
+	 * the cache directory arrays are built. */
+	const gchar *component_names[] = {
+		"addressbook",
+		"calendar",
+		"mail",
+		"memos",
+		"tasks"
+	};
+
+	n_directories = G_N_ELEMENTS (component_names);
+
+	extension->n_directories = n_directories;
+	extension->cache_directories = g_new0 (GFile *, n_directories);
+	extension->trash_directories = g_new0 (GFile *, n_directories);
+
+	user_cache_dir = e_get_user_cache_dir ();
+	base_directory = g_file_new_for_path (user_cache_dir);
+
+	for (ii = 0; ii < n_directories; ii++) {
+		GFile *cache_directory;
+		GFile *trash_directory;
+		GError *error = NULL;
+
+		cache_directory = g_file_get_child (
+			base_directory, component_names[ii]);
+		trash_directory = g_file_get_child (
+			cache_directory, TRASH_DIRECTORY_NAME);
+
+		/* Cache directory is a parent of the trash
+		 * directory so this is sufficient for both. */
+		g_file_make_directory_with_parents (
+			trash_directory, NULL, &error);
+
+		if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_EXISTS))
+			g_clear_error (&error);
+
+		if (error != NULL) {
+			gchar *path;
+
+			path = g_file_get_path (trash_directory);
+			g_warning (
+				"Failed to make directory '%s': %s",
+				path, error->message);
+			g_free (path);
+
+			g_error_free (error);
+		}
+
+		extension->cache_directories[ii] = cache_directory;
+		extension->trash_directories[ii] = trash_directory;
+	}
+
+	g_object_unref (base_directory);
+}
+
+G_MODULE_EXPORT void
+e_module_load (GTypeModule *type_module)
+{
+	e_cache_reaper_register_type (type_module);
+}
+
+G_MODULE_EXPORT void
+e_module_unload (GTypeModule *type_module)
+{
+}
+