path: root/camel/camel-store.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-store.c : Abstract class for an email store */

/* 
 * Authors:
 *  Bertrand Guiheneuf <bertrand@helixcode.com>
 *  Dan Winship <danw@ximian.com>
 *
 * Copyright 1999, 2000 Ximian, Inc. (www.ximian.com)
 *
 * 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
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>

#include "camel-session.h"
#include "camel-store.h"
#include "camel-folder.h"
#include "camel-vtrash-folder.h"
#include "camel-exception.h"
#include "camel-private.h"

static CamelServiceClass *parent_class = NULL;

/* Returns the class for a CamelStore */
#define CS_CLASS(so) CAMEL_STORE_CLASS (CAMEL_OBJECT_GET_CLASS(so))

static CamelFolder *get_folder (CamelStore *store, const char *folder_name,
                guint32 flags, CamelException *ex);
static CamelFolder *get_inbox (CamelStore *store, CamelException *ex);

static void        init_trash (CamelStore *store);
static CamelFolder *get_trash (CamelStore *store, CamelException *ex);

static CamelFolderInfo *create_folder (CamelStore *store,
                       const char *parent_name,
                       const char *folder_name,
                       CamelException *ex);
static void delete_folder (CamelStore *store, const char *folder_name,
               CamelException *ex);
static void rename_folder (CamelStore *store, const char *old_name,
               const char *new_name, CamelException *ex);

static void store_sync (CamelStore *store, CamelException *ex);
static CamelFolderInfo *get_folder_info (CamelStore *store, const char *top,
                     guint32 flags, CamelException *ex);
static void free_folder_info (CamelStore *store, CamelFolderInfo *tree);

static gboolean folder_subscribed (CamelStore *store, const char *folder_name);
static void subscribe_folder (CamelStore *store, const char *folder_name, CamelException *ex);
static void unsubscribe_folder (CamelStore *store, const char *folder_name, CamelException *ex);

static void construct (CamelService *service, CamelSession *session,
               CamelProvider *provider, CamelURL *url,
               CamelException *ex);

static void
camel_store_class_init (CamelStoreClass *camel_store_class)
{
    CamelObjectClass *camel_object_class =
        CAMEL_OBJECT_CLASS (camel_store_class);
    CamelServiceClass *camel_service_class = CAMEL_SERVICE_CLASS(camel_store_class);

    parent_class = CAMEL_SERVICE_CLASS (camel_type_get_global_classfuncs (camel_service_get_type ()));
    
    /* virtual method definition */
    camel_store_class->hash_folder_name = g_str_hash;
    camel_store_class->compare_folder_name = g_str_equal;
    camel_store_class->get_folder = get_folder;
    camel_store_class->get_inbox = get_inbox;
    camel_store_class->init_trash = init_trash;
    camel_store_class->get_trash = get_trash;
    camel_store_class->create_folder = create_folder;
    camel_store_class->delete_folder = delete_folder;
    camel_store_class->rename_folder = rename_folder;
    camel_store_class->sync = store_sync;
    camel_store_class->get_folder_info = get_folder_info;
    camel_store_class->free_folder_info = free_folder_info;
    camel_store_class->folder_subscribed = folder_subscribed;
    camel_store_class->subscribe_folder = subscribe_folder;
    camel_store_class->unsubscribe_folder = unsubscribe_folder;
    
    /* virtual method overload */
    camel_service_class->construct = construct;

    camel_object_class_declare_event (camel_object_class,
                      "folder_created", NULL);
    camel_object_class_declare_event (camel_object_class,
                      "folder_deleted", NULL);
}

static void
camel_store_init (void *o)
{
    CamelStore *store = o;
    CamelStoreClass *store_class = (CamelStoreClass *)CAMEL_OBJECT_GET_CLASS (o);

    if (store_class->hash_folder_name) {
        store->folders = g_hash_table_new (store_class->hash_folder_name,
                           store_class->compare_folder_name);
    } else
        store->folders = NULL;
    
    /* set vtrash on by default */
    store->flags = CAMEL_STORE_VTRASH;
    
    store->priv = g_malloc0 (sizeof (*store->priv));
#ifdef ENABLE_THREADS
    store->priv->folder_lock = g_mutex_new ();
    store->priv->cache_lock = g_mutex_new ();
#endif
}

static void
camel_store_finalize (CamelObject *object)
{
    CamelStore *store = CAMEL_STORE (object);
    
    if (store->folders) {
        if (g_hash_table_size (store->folders) != 0) {
            g_warning ("Folder cache for store %p contains "
                   "%d folders at destruction.", store,
                   g_hash_table_size (store->folders));
        }
        g_hash_table_destroy (store->folders);
    }
    
#ifdef ENABLE_THREADS
    g_mutex_free (store->priv->folder_lock);
    g_mutex_free (store->priv->cache_lock);
#endif
    g_free (store->priv);
}


CamelType
camel_store_get_type (void)
{
    static CamelType camel_store_type = CAMEL_INVALID_TYPE;

    if (camel_store_type == CAMEL_INVALID_TYPE) {
        camel_store_type = camel_type_register (CAMEL_SERVICE_TYPE, "CamelStore",
                            sizeof (CamelStore),
                            sizeof (CamelStoreClass),
                            (CamelObjectClassInitFunc) camel_store_class_init,
                            NULL,
                            (CamelObjectInitFunc) camel_store_init,
                            (CamelObjectFinalizeFunc) camel_store_finalize );
    }

    return camel_store_type;
}


static gboolean
folder_matches (gpointer key, gpointer value, gpointer user_data)
{
    if (value == user_data) {
        g_free (key);
        return TRUE;
    } else
        return FALSE;
}

static void
folder_finalize (CamelObject *folder, gpointer event_data, gpointer user_data)
{
    CamelStore *store = CAMEL_STORE (user_data);

    if (store->folders) {
        CAMEL_STORE_LOCK(store, cache_lock);
        g_hash_table_foreach_remove (store->folders, folder_matches, folder);
        CAMEL_STORE_UNLOCK(store, cache_lock);
    }
}

static void
construct (CamelService *service, CamelSession *session,
       CamelProvider *provider, CamelURL *url,
       CamelException *ex)
{
    CamelStore *store = CAMEL_STORE(service);

    parent_class->construct(service, session, provider, url, ex);
    if (camel_exception_is_set (ex))
        return;

    if (camel_url_get_param(url, "filter"))
        store->flags |= CAMEL_STORE_FILTER_INBOX;
}

static CamelFolder *
get_folder (CamelStore *store, const char *folder_name, guint32 flags, CamelException *ex)
{
    g_warning ("CamelStore::get_folder not implemented for `%s'",
           camel_type_to_name(CAMEL_OBJECT_GET_TYPE(store)));
    return NULL;
}

/** 
 * camel_store_get_folder: Return the folder corresponding to a path.
 * @store: a CamelStore
 * @folder_name: name of the folder to get
 * @flags: folder flags (create, save body index, etc)
 * @ex: a CamelException
 * 
 * Return value: the folder corresponding to the path @folder_name.
 **/
CamelFolder *
camel_store_get_folder (CamelStore *store, const char *folder_name, guint32 flags, CamelException *ex)
{
    CamelFolder *folder = NULL;
    
    CAMEL_STORE_LOCK(store, folder_lock);
    
    if (store->folders) {
        /* Try cache first. */
        CAMEL_STORE_LOCK(store, cache_lock);
        folder = g_hash_table_lookup (store->folders, folder_name);
        if (folder)
            camel_object_ref (CAMEL_OBJECT (folder));
        CAMEL_STORE_UNLOCK(store, cache_lock);
    }
    
    if (!folder) {
        folder = CS_CLASS (store)->get_folder (store, folder_name, flags, ex);
        if (folder) {
            /* Add the folder to the vTrash folder if this store implements it */
            if (store->vtrash)
                camel_vee_folder_add_folder (CAMEL_VEE_FOLDER (store->vtrash), folder);
            
            if (store->folders) {
                CAMEL_STORE_LOCK(store, cache_lock);
                
                printf("adding folder '%s' to folders hashtable\n", folder_name);
                g_hash_table_insert (store->folders, g_strdup (folder_name), folder);
                
                printf("store folders size = %d\n", g_hash_table_size(store->folders));

                camel_object_hook_event (CAMEL_OBJECT (folder), "finalize", folder_finalize, store);
                CAMEL_STORE_UNLOCK(store, cache_lock);
            } else
                printf("not adding folder '%s' to folders hashtable\n", folder_name);
        }
    }
    
    CAMEL_STORE_UNLOCK(store, folder_lock);
    return folder;
}


static CamelFolderInfo *
create_folder (CamelStore *store, const char *parent_name,
           const char *folder_name, CamelException *ex)
{
    g_warning ("CamelStore::create_folder not implemented for `%s'",
           camel_type_to_name (CAMEL_OBJECT_GET_TYPE (store)));
    return NULL;
}

/** 
 * camel_store_create_folder:
 * @store: a CamelStore
 * @parent_name: name of the new folder's parent, or %NULL
 * @folder_name: name of the folder to create
 * @ex: a CamelException
 * 
 * Creates a new folder as a child of an existing folder.
 * @parent_name can be %NULL to create a new top-level folder.
 *
 * Return value: info about the created folder, which the caller must
 * free with camel_store_free_folder_info().
 **/
CamelFolderInfo *
camel_store_create_folder (CamelStore *store, const char *parent_name,
               const char *folder_name, CamelException *ex)
{
    CamelFolderInfo *fi;

    CAMEL_STORE_LOCK(store, folder_lock);
    fi = CS_CLASS (store)->create_folder (store, parent_name, folder_name, ex);
    CAMEL_STORE_UNLOCK(store, folder_lock);

    return fi;
}


static void
delete_folder (CamelStore *store, const char *folder_name, CamelException *ex)
{
    g_warning ("CamelStore::delete_folder not implemented for `%s'",
           camel_type_to_name (CAMEL_OBJECT_GET_TYPE (store)));
}

/** 
 * camel_store_delete_folder: Delete the folder corresponding to a path.
 * @store: a CamelStore
 * @folder_name: name of the folder to delete
 * @ex: a CamelException
 * 
 * Deletes the named folder. The folder must be empty.
 **/
void
camel_store_delete_folder (CamelStore *store, const char *folder_name, CamelException *ex)
{

    CAMEL_STORE_LOCK(store, folder_lock);

    CS_CLASS (store)->delete_folder (store, folder_name, ex);

    /* if we deleted a folder, force it out of the cache, and also out of the vtrash if setup */
    if (store->folders) {
        CamelFolder *folder;
        char *key;

        CAMEL_STORE_LOCK(store, cache_lock);
        if (g_hash_table_lookup_extended(store->folders, folder_name, (void **)&key, (void **)&folder)) {
            g_hash_table_remove(store->folders, key);
            g_free(key);
            CAMEL_STORE_UNLOCK(store, cache_lock);
            if (store->vtrash)
                camel_vee_folder_remove_folder((CamelVeeFolder *)store->vtrash, folder);
        } else {
            CAMEL_STORE_UNLOCK(store, cache_lock);
        }
    }

    CAMEL_STORE_UNLOCK(store, folder_lock);
}


static void
rename_folder (CamelStore *store, const char *old_name,
           const char *new_name, CamelException *ex)
{
    g_warning ("CamelStore::rename_folder not implemented for `%s'",
           camel_type_to_name (CAMEL_OBJECT_GET_TYPE (store)));
}

/**
 * camel_store_rename_folder:
 * @store: a CamelStore
 * @old_name: the current name of the folder
 * @new_name: the new name of the folder
 * @ex: a CamelException
 * 
 * Rename a named folder to a new name.
 **/
void
camel_store_rename_folder (CamelStore *store, const char *old_name, const char *new_name, CamelException *ex)
{
    char *key;
    CamelFolder *folder;

    if (strcmp(old_name, new_name) == 0)
        return;

    CAMEL_STORE_LOCK(store, folder_lock);
    CS_CLASS (store)->rename_folder (store, old_name, new_name, ex);

    /* remove the old name from the cache if it is there */
    CAMEL_STORE_LOCK(store, cache_lock);
    if (g_hash_table_lookup_extended(store->folders, old_name, (void **)&key, (void **)&folder)) {
        g_hash_table_remove(store->folders, key);
        g_free(key);
    }
    CAMEL_STORE_UNLOCK(store, cache_lock);

    CAMEL_STORE_UNLOCK(store, folder_lock);
}


static CamelFolder *
get_inbox (CamelStore *store, CamelException *ex)
{
    /* Default: assume the inbox's name is "inbox"
     * and open with default flags.
     */
    return CS_CLASS (store)->get_folder (store, "inbox", 0, ex);
}

/** 
 * camel_store_get_inbox:
 * @store: a CamelStore
 * @ex: a CamelException
 *
 * Return value: the folder in the store into which new mail is
 * delivered, or %NULL if no such folder exists.
 **/
CamelFolder *
camel_store_get_inbox (CamelStore *store, CamelException *ex)
{
    CamelFolder *folder;

    CAMEL_STORE_LOCK(store, folder_lock);
    folder = CS_CLASS (store)->get_inbox (store, ex);
    CAMEL_STORE_UNLOCK(store, folder_lock);

    return folder;
}


static void
trash_add_folder (gpointer key, gpointer value, gpointer data)
{
    CamelFolder *folder = CAMEL_FOLDER (value);
    CamelStore *store = CAMEL_STORE (data);
    
    camel_vee_folder_add_folder (CAMEL_VEE_FOLDER (store->vtrash), folder);
}

static void
trash_finalize (CamelObject *trash, gpointer event_data, gpointer user_data)
{
    CamelStore *store = CAMEL_STORE (user_data);
    
    store->vtrash = NULL;
}

static void
init_trash (CamelStore *store)
{
    if ((store->flags & CAMEL_STORE_VTRASH) == 0)
        return;

    store->vtrash = camel_vtrash_folder_new (store, CAMEL_VTRASH_NAME);
    
    if (store->vtrash) {
        /* attach to the finalise event of the vtrash */
        camel_object_hook_event (CAMEL_OBJECT (store->vtrash), "finalize",
                     trash_finalize, store);
        
        /* add all the pre-opened folders to the vtrash */
        if (store->folders) {
            CAMEL_STORE_LOCK(store, cache_lock);
            g_hash_table_foreach (store->folders, trash_add_folder, store);
            CAMEL_STORE_UNLOCK(store, cache_lock);
        }
    }
}


static CamelFolder *
get_trash (CamelStore *store, CamelException *ex)
{
    if (store->vtrash) {
        camel_object_ref (CAMEL_OBJECT (store->vtrash));
        return store->vtrash;
    } else {
        CS_CLASS (store)->init_trash (store);
        if (store->vtrash) {
            /* We don't ref here because we don't want the
                           store to own a ref on the trash folder */
            /*camel_object_ref (CAMEL_OBJECT (store->vtrash));*/
            return store->vtrash;
        } else {
            g_warning ("This store does not support vTrash.");
            return NULL;
        }
    }
}

/** 
 * camel_store_get_trash:
 * @store: a CamelStore
 * @ex: a CamelException
 *
 * Return value: the folder in the store into which trash is
 * delivered, or %NULL if no such folder exists.
 **/
CamelFolder *
camel_store_get_trash (CamelStore *store, CamelException *ex)
{
    CamelFolder *folder;

    if ((store->flags & CAMEL_STORE_VTRASH) == 0)
        return NULL;
    
    CAMEL_STORE_LOCK(store, folder_lock);
    folder = CS_CLASS (store)->get_trash (store, ex);
    CAMEL_STORE_UNLOCK(store, folder_lock);
    
    return folder;
}


static void
sync_folder (gpointer key, gpointer folder, gpointer ex)
{
    if (!camel_exception_is_set (ex))
        camel_folder_sync (folder, FALSE, ex);
    
    camel_object_unref (CAMEL_OBJECT (folder));
    g_free (key);
}

static void
copy_folder_cache (gpointer key, gpointer folder, gpointer hash)
{
    g_hash_table_insert ((GHashTable *) hash, g_strdup (key), folder);
    camel_object_ref (CAMEL_OBJECT (folder));
}

static void
store_sync (CamelStore *store, CamelException *ex)
{
    if (store->folders) {
        CamelException internal_ex;
        GHashTable *hash;
        
        hash = g_hash_table_new (CS_CLASS (store)->hash_folder_name,
                     CS_CLASS (store)->compare_folder_name);
        
        camel_exception_init (&internal_ex);
        CAMEL_STORE_LOCK(store, cache_lock);
        g_hash_table_foreach (store->folders, copy_folder_cache, hash);
        CAMEL_STORE_UNLOCK(store, cache_lock);
        camel_exception_xfer (ex, &internal_ex);
        
        g_hash_table_foreach (hash, sync_folder, &internal_ex);
        g_hash_table_destroy (hash);
    }
}

/**
 * camel_store_sync:
 * @store: a CamelStore
 * @ex: a CamelException
 *
 * Syncs any changes that have been made to the store object and its
 * folders with the real store.
 **/
void
camel_store_sync (CamelStore *store, CamelException *ex)
{
    g_return_if_fail (CAMEL_IS_STORE (store));

    CS_CLASS (store)->sync (store, ex);
}


static CamelFolderInfo *
get_folder_info (CamelStore *store, const char *top,
         guint32 flags, CamelException *ex)
{
    g_warning ("CamelStore::get_folder_info not implemented for `%s'",
           camel_type_to_name (CAMEL_OBJECT_GET_TYPE (store)));
    return NULL;
}

/**
 * camel_store_get_folder_info:
 * @store: a CamelStore
 * @top: the name of the folder to start from
 * @flags: various CAMEL_STORE_FOLDER_INFO_* flags to control behavior
 * @ex: a CamelException
 *
 * This fetches information about the folder structure of @store,
 * starting with @top, and returns a tree of CamelFolderInfo
 * structures. If @flags includes %CAMEL_STORE_FOLDER_INFO_SUBSCRIBED,
 * only subscribed folders will be listed. (This flag can only be used
 * for stores that support subscriptions.) If @flags includes
 * %CAMEL_STORE_FOLDER_INFO_RECURSIVE, the returned tree will include
 * all levels of hierarchy below @top. If not, it will only include
 * the immediate subfolders of @top. If @flags includes
 * %CAMEL_STORE_FOLDER_INFO_FAST, the unread_message_count fields of
 * some or all of the structures may be set to -1, if the store cannot
 * determine that information quickly.
 * 
 * Return value: a CamelFolderInfo tree, which must be freed with
 * camel_store_free_folder_info.
 **/
CamelFolderInfo *
camel_store_get_folder_info (CamelStore *store, const char *top,
                 guint32 flags, CamelException *ex)
{
    CamelFolderInfo *ret;

    g_return_val_if_fail (CAMEL_IS_STORE (store), NULL);
    g_return_val_if_fail ((store->flags & CAMEL_STORE_SUBSCRIPTIONS) ||
                  !(flags & CAMEL_STORE_FOLDER_INFO_SUBSCRIBED),
                  NULL);

    CAMEL_STORE_LOCK(store, folder_lock);
    ret = CS_CLASS (store)->get_folder_info (store, top, flags, ex);
    CAMEL_STORE_UNLOCK(store, folder_lock);

    return ret;
}


static void
free_folder_info (CamelStore *store, CamelFolderInfo *fi)
{
    g_warning ("CamelStore::free_folder_info not implemented for `%s'",
           camel_type_to_name (CAMEL_OBJECT_GET_TYPE (store)));
}

/**
 * camel_store_free_folder_info:
 * @store: a CamelStore
 * @tree: the tree returned by camel_store_get_folder_info()
 *
 * Frees the data returned by camel_store_get_folder_info().
 **/
void
camel_store_free_folder_info (CamelStore *store, CamelFolderInfo *fi)
{
    g_return_if_fail (CAMEL_IS_STORE (store));

    CS_CLASS (store)->free_folder_info (store, fi);
}

/**
 * camel_store_free_folder_info_full:
 * @store: a CamelStore
 * @tree: the tree returned by camel_store_get_folder_info()
 *
 * An implementation for CamelStore::free_folder_info. Frees all
 * of the data.
 **/
void
camel_store_free_folder_info_full (CamelStore *store, CamelFolderInfo *fi)
{
    camel_folder_info_free (fi);
}

/**
 * camel_store_free_folder_info_nop:
 * @store: a CamelStore
 * @tree: the tree returned by camel_store_get_folder_info()
 *
 * An implementation for CamelStore::free_folder_info. Does nothing.
 **/
void
camel_store_free_folder_info_nop (CamelStore *store, CamelFolderInfo *fi)
{
    ;
}


/**
 * camel_folder_info_free:
 * @fi: the CamelFolderInfo
 *
 * Frees @fi.
 **/
void
camel_folder_info_free (CamelFolderInfo *fi)
{
    if (fi) {
        camel_folder_info_free (fi->sibling);
        camel_folder_info_free (fi->child);
        g_free (fi->name);
        g_free (fi->full_name);
        g_free (fi->url);
        g_free (fi);
    }
}


/**
 * camel_folder_info_build:
 * @folders: an array of CamelFolderInfo
 * @namespace: an ignorable prefix on the folder names
 * @separator: the hieararchy separator character
 * @short_names: %TRUE if the (short) name of a folder is the part after
 * the last @separator in the full name. %FALSE if it is the full name.
 *
 * This takes an array of folders and attaches them together according
 * to the hierarchy described by their full_names and @separator. If
 * @namespace is non-%NULL, then it will be ignored as a full_name
 * prefix, for purposes of comparison. If necessary,
 * camel_folder_info_build will create additional CamelFolderInfo with
 * %NULL urls to fill in gaps in the tree. The value of @short_names
 * is used in constructing the names of these intermediate folders.
 *
 * Return value: the top level of the tree of linked folder info.
 **/
CamelFolderInfo *
camel_folder_info_build (GPtrArray *folders, const char *namespace,
             char separator, gboolean short_names)
{
    CamelFolderInfo *fi, *pfi, *top = NULL;
    GHashTable *hash;
    char *name, *p, *pname;
    int i, nlen;

    if (!namespace)
        namespace = "";
    nlen = strlen (namespace);

    /* Hash the folders. */
    hash = g_hash_table_new (g_str_hash, g_str_equal);
    for (i = 0; i < folders->len; i++) {
        fi = folders->pdata[i];
        if (!strncmp (namespace, fi->full_name, nlen))
            name = fi->full_name + nlen;
        else
            name = fi->full_name;
        if (*name == separator)
            name++;
        g_hash_table_insert (hash, name, fi);
    }

    /* Now find parents. */
    for (i = 0; i < folders->len; i++) {
        fi = folders->pdata[i];
        if (!strncmp (namespace, fi->full_name, nlen))
            name = fi->full_name + nlen;
        else
            name = fi->full_name;
        if (*name == separator)
            name++;
        p = strrchr (name, separator);
        if (p) {
            pname = g_strndup (name, p - name);
            pfi = g_hash_table_lookup (hash, pname);
            if (pfi) {
                g_free (pname);
            } else {
                CamelURL *url;
                char *sep;

                pfi = g_new0 (CamelFolderInfo, 1);
                pfi->full_name = pname;
                if (short_names) {
                    pfi->name = strrchr (pname, separator);
                    if (pfi->name)
                        pfi->name = g_strdup (pfi->name + 1);
                    else
                        pfi->name = g_strdup (pname);
                } else
                    pfi->name = g_strdup (pname);

                url = camel_url_new (fi->url, NULL);
                sep = strrchr (url->path, separator);
                if (sep)
                    *sep = '\0';
                else
                    g_warning ("huh, no \"%c\" in \"%s\"?", separator, fi->url);
                camel_url_set_param (url, "noselect", "yes");
                pfi->url = camel_url_to_string (url, 0);
                camel_url_free (url);

                g_hash_table_insert (hash, pname, pfi);
                g_ptr_array_add (folders, pfi);
            }
            fi->sibling = pfi->child;
            fi->parent = pfi;
            pfi->child = fi;
        } else if (!top)
            top = fi;
    }
    g_hash_table_destroy (hash);

    /* Link together the top-level folders */
    for (i = 0; i < folders->len; i++) {
        fi = folders->pdata[i];
        if (fi->parent || fi == top)
            continue;
        if (top)
            fi->sibling = top;
        top = fi;
    }

    return top;         
}

gboolean
camel_store_supports_subscriptions (CamelStore *store)
{
    return (store->flags & CAMEL_STORE_SUBSCRIPTIONS);
}


static gboolean
folder_subscribed (CamelStore *store, const char *folder_name)
{
    g_warning ("CamelStore::folder_subscribed not implemented for `%s'",
           camel_type_to_name (CAMEL_OBJECT_GET_TYPE (store)));
    return FALSE;
}

/**
 * camel_store_folder_subscribed: Tell whether or not a folder has been subscribed to.
 * @store: a CamelStore
 * @folder_name: the folder on which we're querying subscribed status.
 * Return value: TRUE if folder is subscribed, FALSE if not.
 **/
gboolean
camel_store_folder_subscribed (CamelStore *store,
                   const char *folder_name)
{
    gboolean ret;

    g_return_val_if_fail (CAMEL_IS_STORE (store), FALSE);
    g_return_val_if_fail (store->flags & CAMEL_STORE_SUBSCRIPTIONS, FALSE);

    CAMEL_STORE_LOCK(store, folder_lock);

    ret = CS_CLASS (store)->folder_subscribed (store, folder_name);

    CAMEL_STORE_UNLOCK(store, folder_lock);

    return ret;
}

static void
subscribe_folder (CamelStore *store, const char *folder_name, CamelException *ex)
{
    g_warning ("CamelStore::subscribe_folder not implemented for `%s'",
           camel_type_to_name (CAMEL_OBJECT_GET_TYPE (store)));
}

/**
 * camel_store_subscribe_folder: marks a folder as subscribed.
 * @store: a CamelStore
 * @folder_name: the folder to subscribe to.
 **/
void
camel_store_subscribe_folder (CamelStore *store,
                  const char *folder_name,
                  CamelException *ex)
{
    g_return_if_fail (CAMEL_IS_STORE (store));
    g_return_if_fail (store->flags & CAMEL_STORE_SUBSCRIPTIONS);

    CAMEL_STORE_LOCK(store, folder_lock);

    CS_CLASS (store)->subscribe_folder (store, folder_name, ex);

    CAMEL_STORE_UNLOCK(store, folder_lock);
}

static void
unsubscribe_folder (CamelStore *store, const char *folder_name, CamelException *ex)
{
    g_warning ("CamelStore::unsubscribe_folder not implemented for `%s'",
           camel_type_to_name (CAMEL_OBJECT_GET_TYPE (store)));
}


/**
 * camel_store_unsubscribe_folder: marks a folder as unsubscribed.
 * @store: a CamelStore
 * @folder_name: the folder to unsubscribe from.
 **/
void
camel_store_unsubscribe_folder (CamelStore *store,
                const char *folder_name,
                CamelException *ex)
{
    g_return_if_fail (CAMEL_IS_STORE (store));
    g_return_if_fail (store->flags & CAMEL_STORE_SUBSCRIPTIONS);

    CAMEL_STORE_LOCK(store, folder_lock);

    CS_CLASS (store)->unsubscribe_folder (store, folder_name, ex);

    CAMEL_STORE_UNLOCK(store, folder_lock);
}


int
camel_mkdir_hier (const char *path, mode_t mode)
{
    char *copy, *p;
    
    p = copy = g_strdup (path);
    do {
        p = strchr (p + 1, '/');
        if (p)
            *p = '\0';
        if (access (copy, F_OK) == -1) {
            if (mkdir (copy, mode) == -1) {
                g_free (copy);
                return -1;
            }
        }
        if (p)
            *p = '/';
    } while (p);
    
    g_free (copy);
    return 0;
}