xed/xed/xed-metadata-manager.c

564 lines
11 KiB
C

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
* xed-metadata-manager.c
* This file is part of xed
*
* Copyright (C) 2003-2007 Paolo Maggi
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/*
* Modified by the xed Team, 2003-2007. See the AUTHORS file for a
* list of people on the xed Team.
* See the ChangeLog files for a list of changes.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <time.h>
#include <stdlib.h>
#include <libxml/xmlreader.h>
#include "xed-metadata-manager.h"
#include "xed-debug.h"
#include "xed-dirs.h"
/*
#define XED_METADATA_VERBOSE_DEBUG 1
*/
#define METADATA_FILE "xed-metadata.xml"
#define MAX_ITEMS 50
typedef struct _XedMetadataManager XedMetadataManager;
typedef struct _Item Item;
struct _Item
{
time_t atime; /* time of last access */
GHashTable *values;
};
struct _XedMetadataManager
{
gboolean values_loaded; /* It is true if the file
has been read */
guint timeout_id;
GHashTable *items;
};
static gboolean xed_metadata_manager_save (gpointer data);
static XedMetadataManager *xed_metadata_manager = NULL;
static void
item_free (gpointer data)
{
Item *item;
g_return_if_fail (data != NULL);
#ifdef XED_METADATA_VERBOSE_DEBUG
xed_debug (DEBUG_METADATA);
#endif
item = (Item *)data;
if (item->values != NULL)
g_hash_table_destroy (item->values);
g_free (item);
}
static void
xed_metadata_manager_arm_timeout (void)
{
if (xed_metadata_manager->timeout_id == 0)
{
xed_metadata_manager->timeout_id =
g_timeout_add_seconds_full (G_PRIORITY_DEFAULT_IDLE,
2,
(GSourceFunc)xed_metadata_manager_save,
NULL,
NULL);
}
}
static gboolean
xed_metadata_manager_init (void)
{
xed_debug (DEBUG_METADATA);
if (xed_metadata_manager != NULL)
return TRUE;
xed_metadata_manager = g_new0 (XedMetadataManager, 1);
xed_metadata_manager->values_loaded = FALSE;
xed_metadata_manager->items =
g_hash_table_new_full (g_str_hash,
g_str_equal,
g_free,
item_free);
return TRUE;
}
/* This function must be called before exiting xed */
void
xed_metadata_manager_shutdown (void)
{
xed_debug (DEBUG_METADATA);
if (xed_metadata_manager == NULL)
return;
if (xed_metadata_manager->timeout_id)
{
g_source_remove (xed_metadata_manager->timeout_id);
xed_metadata_manager->timeout_id = 0;
xed_metadata_manager_save (NULL);
}
if (xed_metadata_manager->items != NULL)
g_hash_table_destroy (xed_metadata_manager->items);
g_free (xed_metadata_manager);
xed_metadata_manager = NULL;
}
static void
parseItem (xmlDocPtr doc, xmlNodePtr cur)
{
Item *item;
xmlChar *uri;
xmlChar *atime;
#ifdef XED_METADATA_VERBOSE_DEBUG
xed_debug (DEBUG_METADATA);
#endif
if (xmlStrcmp (cur->name, (const xmlChar *)"document") != 0)
return;
uri = xmlGetProp (cur, (const xmlChar *)"uri");
if (uri == NULL)
return;
atime = xmlGetProp (cur, (const xmlChar *)"atime");
if (atime == NULL)
{
xmlFree (uri);
return;
}
item = g_new0 (Item, 1);
item->atime = g_ascii_strtoull ((char *)atime, NULL, 0);
item->values = g_hash_table_new_full (g_str_hash,
g_str_equal,
g_free,
g_free);
cur = cur->xmlChildrenNode;
while (cur != NULL)
{
if (xmlStrcmp (cur->name, (const xmlChar *)"entry") == 0)
{
xmlChar *key;
xmlChar *value;
key = xmlGetProp (cur, (const xmlChar *)"key");
value = xmlGetProp (cur, (const xmlChar *)"value");
if ((key != NULL) && (value != NULL))
g_hash_table_insert (item->values,
g_strdup ((gchar *)key),
g_strdup ((gchar *)value));
if (key != NULL)
xmlFree (key);
if (value != NULL)
xmlFree (value);
}
cur = cur->next;
}
g_hash_table_insert (xed_metadata_manager->items,
g_strdup ((gchar *)uri),
item);
xmlFree (uri);
xmlFree (atime);
}
static gchar *
get_metadata_filename (void)
{
gchar *cache_dir;
gchar *metadata;
cache_dir = xed_dirs_get_user_cache_dir ();
metadata = g_build_filename (cache_dir,
METADATA_FILE,
NULL);
g_free (cache_dir);
return metadata;
}
static gboolean
load_values (void)
{
xmlDocPtr doc;
xmlNodePtr cur;
gchar *file_name;
xed_debug (DEBUG_METADATA);
g_return_val_if_fail (xed_metadata_manager != NULL, FALSE);
g_return_val_if_fail (xed_metadata_manager->values_loaded == FALSE, FALSE);
xed_metadata_manager->values_loaded = TRUE;
xmlKeepBlanksDefault (0);
/* FIXME: file locking - Paolo */
file_name = get_metadata_filename ();
if ((file_name == NULL) ||
(!g_file_test (file_name, G_FILE_TEST_EXISTS)))
{
g_free (file_name);
return FALSE;
}
doc = xmlParseFile (file_name);
g_free (file_name);
if (doc == NULL)
{
return FALSE;
}
cur = xmlDocGetRootElement (doc);
if (cur == NULL)
{
g_message ("The metadata file '%s' is empty", METADATA_FILE);
xmlFreeDoc (doc);
return FALSE;
}
if (xmlStrcmp (cur->name, (const xmlChar *) "metadata"))
{
g_message ("File '%s' is of the wrong type", METADATA_FILE);
xmlFreeDoc (doc);
return FALSE;
}
cur = xmlDocGetRootElement (doc);
cur = cur->xmlChildrenNode;
while (cur != NULL)
{
parseItem (doc, cur);
cur = cur->next;
}
xmlFreeDoc (doc);
return TRUE;
}
gchar *
xed_metadata_manager_get (const gchar *uri,
const gchar *key)
{
Item *item;
gchar *value;
g_return_val_if_fail (uri != NULL, NULL);
g_return_val_if_fail (key != NULL, NULL);
xed_debug_message (DEBUG_METADATA, "URI: %s --- key: %s", uri, key );
xed_metadata_manager_init ();
if (!xed_metadata_manager->values_loaded)
{
gboolean res;
res = load_values ();
if (!res)
return NULL;
}
item = (Item *)g_hash_table_lookup (xed_metadata_manager->items,
uri);
if (item == NULL)
return NULL;
item->atime = time (NULL);
if (item->values == NULL)
return NULL;
value = g_hash_table_lookup (item->values, key);
if (value == NULL)
return NULL;
else
return g_strdup (value);
}
void
xed_metadata_manager_set (const gchar *uri,
const gchar *key,
const gchar *value)
{
Item *item;
g_return_if_fail (uri != NULL);
g_return_if_fail (key != NULL);
xed_debug_message (DEBUG_METADATA, "URI: %s --- key: %s --- value: %s", uri, key, value);
xed_metadata_manager_init ();
if (!xed_metadata_manager->values_loaded)
{
gboolean res;
res = load_values ();
if (!res)
return;
}
item = (Item *)g_hash_table_lookup (xed_metadata_manager->items,
uri);
if (item == NULL)
{
item = g_new0 (Item, 1);
g_hash_table_insert (xed_metadata_manager->items,
g_strdup (uri),
item);
}
if (item->values == NULL)
item->values = g_hash_table_new_full (g_str_hash,
g_str_equal,
g_free,
g_free);
if (value != NULL)
g_hash_table_insert (item->values,
g_strdup (key),
g_strdup (value));
else
g_hash_table_remove (item->values,
key);
item->atime = time (NULL);
xed_metadata_manager_arm_timeout ();
}
static void
save_values (const gchar *key, const gchar *value, xmlNodePtr parent)
{
xmlNodePtr xml_node;
#ifdef XED_METADATA_VERBOSE_DEBUG
xed_debug (DEBUG_METADATA);
#endif
g_return_if_fail (key != NULL);
if (value == NULL)
return;
xml_node = xmlNewChild (parent,
NULL,
(const xmlChar *)"entry",
NULL);
xmlSetProp (xml_node,
(const xmlChar *)"key",
(const xmlChar *)key);
xmlSetProp (xml_node,
(const xmlChar *)"value",
(const xmlChar *)value);
#ifdef XED_METADATA_VERBOSE_DEBUG
xed_debug_message (DEBUG_METADATA, "entry: %s = %s", key, value);
#endif
}
static void
save_item (const gchar *key, const gpointer *data, xmlNodePtr parent)
{
xmlNodePtr xml_node;
const Item *item = (const Item *)data;
gchar *atime;
#ifdef XED_METADATA_VERBOSE_DEBUG
xed_debug (DEBUG_METADATA);
#endif
g_return_if_fail (key != NULL);
if (item == NULL)
return;
xml_node = xmlNewChild (parent, NULL, (const xmlChar *)"document", NULL);
xmlSetProp (xml_node, (const xmlChar *)"uri", (const xmlChar *)key);
#ifdef XED_METADATA_VERBOSE_DEBUG
xed_debug_message (DEBUG_METADATA, "uri: %s", key);
#endif
atime = g_strdup_printf ("%ld", item->atime);
xmlSetProp (xml_node, (const xmlChar *)"atime", (const xmlChar *)atime);
#ifdef XED_METADATA_VERBOSE_DEBUG
xed_debug_message (DEBUG_METADATA, "atime: %s", atime);
#endif
g_free (atime);
g_hash_table_foreach (item->values,
(GHFunc)save_values,
xml_node);
}
static void
get_oldest (const gchar *key, const gpointer value, const gchar ** key_to_remove)
{
const Item *item = (const Item *)value;
if (*key_to_remove == NULL)
{
*key_to_remove = key;
}
else
{
const Item *item_to_remove =
g_hash_table_lookup (xed_metadata_manager->items,
*key_to_remove);
g_return_if_fail (item_to_remove != NULL);
if (item->atime < item_to_remove->atime)
{
*key_to_remove = key;
}
}
}
static void
resize_items (void)
{
while (g_hash_table_size (xed_metadata_manager->items) > MAX_ITEMS)
{
gpointer key_to_remove = NULL;
g_hash_table_foreach (xed_metadata_manager->items,
(GHFunc)get_oldest,
&key_to_remove);
g_return_if_fail (key_to_remove != NULL);
g_hash_table_remove (xed_metadata_manager->items,
key_to_remove);
}
}
static gboolean
xed_metadata_manager_save (gpointer data)
{
xmlDocPtr doc;
xmlNodePtr root;
gchar *file_name;
xed_debug (DEBUG_METADATA);
xed_metadata_manager->timeout_id = 0;
resize_items ();
xmlIndentTreeOutput = TRUE;
doc = xmlNewDoc ((const xmlChar *)"1.0");
if (doc == NULL)
return TRUE;
/* Create metadata root */
root = xmlNewDocNode (doc, NULL, (const xmlChar *)"metadata", NULL);
xmlDocSetRootElement (doc, root);
g_hash_table_foreach (xed_metadata_manager->items,
(GHFunc)save_item,
root);
/* FIXME: lock file - Paolo */
file_name = get_metadata_filename ();
if (file_name != NULL)
{
gchar *cache_dir;
int res;
/* make sure the cache dir exists */
cache_dir = xed_dirs_get_user_cache_dir ();
res = g_mkdir_with_parents (cache_dir, 0755);
if (res != -1)
{
xmlSaveFormatFile (file_name, doc, 1);
}
g_free (cache_dir);
g_free (file_name);
}
xmlFreeDoc (doc);
xed_debug_message (DEBUG_METADATA, "DONE");
return FALSE;
}