1 files changed, 295 insertions, 0 deletions
diff --git a/libcaja-private/caja-users-groups-cache.c b/libcaja-private/caja-users-groups-cache.c
new file mode 100644
index 00000000..41682854
--- /dev/null
+++ b/libcaja-private/caja-users-groups-cache.c
@@ -0,0 +1,295 @@
+/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*-
+
+ caja-users-groups-cache.c: cache of users' and groups' names.
+
+ Copyright (C) 2006 Zbigniew Chyla
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public
+ License along with this program; if not, write to the
+ Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA.
+
+ Author: Zbigniew Chyla <[email protected]>
+*/
+
+#include <config.h>
+#include "caja-users-groups-cache.h"
+
+#include <glib.h>
+#include <grp.h>
+#include <pwd.h>
+
+
+typedef struct _ExpiringCache ExpiringCache;
+
+/* times in seconds */
+#define USERS_CACHE_EXPIRE_TIME 60
+#define GROUPS_CACHE_EXPIRE_TIME 60
+
+/* cache of users' names */
+static ExpiringCache *users_cache = NULL;
+
+/* cache of groups' names */
+static ExpiringCache *groups_cache = NULL;
+
+
+/**
+ * Generic implementation of cache with guint keys and values which expire
+ * after specified amount of time.
+ */
+
+typedef gpointer (*ExpiringCacheGetValFunc) (guint key);
+
+
+struct _ExpiringCache
+{
+ /* Expiration time of cached value */
+ time_t expire_time;
+
+ /* Called to obtain a value by a key */
+ ExpiringCacheGetValFunc get_value_func;
+
+ /* Called to destroy a value */
+ GDestroyNotify value_destroy_func;
+
+ /* Stores cached values */
+ GHashTable *cached_values;
+};
+
+
+typedef struct _ExpiringCacheEntry ExpiringCacheEntry;
+
+struct _ExpiringCacheEntry
+{
+ ExpiringCache *cache;
+ guint key;
+ gpointer value;
+};
+
+
+static ExpiringCache *
+expiring_cache_new (time_t expire_time, ExpiringCacheGetValFunc get_value_func,
+ GDestroyNotify value_destroy_func)
+{
+ ExpiringCache *cache;
+
+ g_assert (get_value_func != NULL);
+
+ cache = g_new (ExpiringCache, 1);
+ cache->expire_time = expire_time;
+ cache->get_value_func = get_value_func;
+ cache->value_destroy_func = value_destroy_func;
+ cache->cached_values = g_hash_table_new_full (g_direct_hash, g_direct_equal, NULL, NULL);
+
+ return cache;
+}
+
+static ExpiringCacheEntry *
+expiring_cache_entry_new (ExpiringCache *cache, guint key, gpointer value)
+{
+ ExpiringCacheEntry *entry;
+
+ entry = g_slice_new (ExpiringCacheEntry);
+ entry->cache = cache;
+ entry->key = key;
+ entry->value = value;
+
+ return entry;
+}
+
+static void
+expiring_cache_entry_destroy (ExpiringCacheEntry *entry)
+{
+ if (entry->cache->value_destroy_func != NULL)
+ {
+ entry->cache->value_destroy_func (entry->value);
+ }
+ g_slice_free (ExpiringCacheEntry, entry);
+}
+
+static gboolean
+cb_cache_entry_expired (ExpiringCacheEntry *entry)
+{
+ g_hash_table_remove (entry->cache->cached_values, GSIZE_TO_POINTER (entry->key));
+ expiring_cache_entry_destroy (entry);
+
+ return FALSE;
+}
+
+static gpointer
+expiring_cache_get_value (ExpiringCache *cache, guint key)
+{
+ ExpiringCacheEntry *entry;
+
+ g_assert (cache != NULL);
+
+ if (!g_hash_table_lookup_extended (cache->cached_values, GSIZE_TO_POINTER (key),
+ NULL, (gpointer) &entry))
+ {
+ entry = expiring_cache_entry_new (cache, key, cache->get_value_func (key));
+ g_hash_table_insert (cache->cached_values, GSIZE_TO_POINTER (key), entry);
+ g_timeout_add_seconds (cache->expire_time, (GSourceFunc) cb_cache_entry_expired, entry);
+ }
+
+ return entry->value;
+}
+
+
+/*
+ * Cache of users' names based on ExpiringCache.
+ */
+
+typedef struct _UserInfo UserInfo;
+
+struct _UserInfo
+{
+ char *name;
+ char *gecos;
+};
+
+
+static UserInfo *
+user_info_new (struct passwd *password_info)
+{
+ UserInfo *uinfo;
+
+ if (password_info != NULL)
+ {
+ uinfo = g_slice_new (UserInfo);
+ uinfo->name = g_strdup (password_info->pw_name);
+ uinfo->gecos = g_strdup (password_info->pw_gecos);
+ }
+ else
+ {
+ uinfo = NULL;
+ }
+
+ return uinfo;
+}
+
+static void
+user_info_free (UserInfo *uinfo)
+{
+ if (uinfo != NULL)
+ {
+ g_free (uinfo->name);
+ g_free (uinfo->gecos);
+ g_slice_free (UserInfo, uinfo);
+ }
+}
+
+static gpointer
+users_cache_get_value (guint key)
+{
+ return user_info_new (getpwuid (key));
+}
+
+static UserInfo *
+get_cached_user_info(guint uid)
+{
+ if (users_cache == NULL)
+ {
+ users_cache = expiring_cache_new (USERS_CACHE_EXPIRE_TIME, users_cache_get_value,
+ (GDestroyNotify) user_info_free);
+ }
+
+ return expiring_cache_get_value (users_cache, uid);
+}
+
+/**
+ * caja_users_cache_get_name:
+ *
+ * Returns name of user with given uid (using cached data if possible) or
+ * NULL in case a user with given uid can't be found.
+ *
+ * Returns: Newly allocated string or NULL.
+ */
+char *
+caja_users_cache_get_name (uid_t uid)
+{
+ UserInfo *uinfo;
+
+ uinfo = get_cached_user_info (uid);
+ if (uinfo != NULL)
+ {
+ return g_strdup (uinfo->name);
+ }
+ else
+ {
+ return NULL;
+ }
+}
+
+/**
+ * caja_users_cache_get_gecos:
+ *
+ * Returns gecos of user with given uid (using cached data if possible) or
+ * NULL in case a user with given uid can't be found.
+ *
+ * Returns: Newly allocated string or NULL.
+ */
+char *
+caja_users_cache_get_gecos (uid_t uid)
+{
+ UserInfo *uinfo;
+
+ uinfo = get_cached_user_info (uid);
+ if (uinfo != NULL)
+ {
+ return g_strdup (uinfo->gecos);
+ }
+ else
+ {
+ return NULL;
+ }
+}
+
+/*
+ * Cache of groups' names based on ExpiringCache.
+ */
+
+static gpointer
+groups_cache_get_value (guint key)
+{
+ struct group *group_info;
+
+ group_info = getgrgid (GPOINTER_TO_SIZE (key));
+ if (group_info != NULL)
+ {
+ return g_strdup (group_info->gr_name);
+ }
+ else
+ {
+ return NULL;
+ }
+}
+
+
+/**
+ * caja_groups_cache_get_name:
+ *
+ * Returns name of group with given gid (using cached data if possible) or
+ * NULL in case a group with given gid can't be found.
+ *
+ * Returns: Newly allocated string or NULL.
+ */
+char *
+caja_groups_cache_get_name (gid_t gid)
+{
+ if (groups_cache == NULL)
+ {
+ groups_cache = expiring_cache_new (GROUPS_CACHE_EXPIRE_TIME, groups_cache_get_value, g_free);
+ }
+
+ return g_strdup (expiring_cache_get_value (groups_cache, gid));
+}