path: root/camel/providers/local/camel-mbox-store.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 *
 * Authors: Michael Zucchi <notzed@ximian.com>
 *
 * Copyright(C) 2000 Ximian, Inc.
 *
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of version 2 of the GNU General Public 
 * License as published by the Free Software Foundation.
 *
 * 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 <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>
#include <fcntl.h>
#include <errno.h>

#include "camel-mbox-store.h"
#include "camel-mbox-folder.h"
#include "camel-file-utils.h"
#include "camel-text-index.h"
#include "camel-exception.h"
#include "camel-url.h"
#include "camel-i18n.h"

#define d(x) 

static CamelLocalStoreClass *parent_class = NULL;

/* Returns the class for a CamelMboxStore */
#define CMBOXS_CLASS(so) CAMEL_MBOX_STORE_CLASS(CAMEL_OBJECT_GET_CLASS(so))
#define CF_CLASS(so) CAMEL_FOLDER_CLASS(CAMEL_OBJECT_GET_CLASS(so))
#define CMBOXF_CLASS(so) CAMEL_MBOX_FOLDER_CLASS(CAMEL_OBJECT_GET_CLASS(so))

static CamelFolder *get_folder(CamelStore *store, const char *folder_name, guint32 flags, CamelException *ex);
static void delete_folder(CamelStore *store, const char *folder_name, CamelException *ex);
static void rename_folder(CamelStore *store, const char *old, const char *new, CamelException *ex);
static CamelFolderInfo *create_folder(CamelStore *store, const char *parent_name, const char *folder_name, CamelException *ex);
static CamelFolderInfo *get_folder_info(CamelStore *store, const char *top, guint32 flags, CamelException *ex);

static void
camel_mbox_store_class_init(CamelMboxStoreClass *camel_mbox_store_class)
{
    CamelStoreClass *camel_store_class = CAMEL_STORE_CLASS(camel_mbox_store_class);

    parent_class =(CamelLocalStoreClass *)camel_type_get_global_classfuncs(camel_local_store_get_type());
    
    /* virtual method overload */
    camel_store_class->get_folder = get_folder;
    camel_store_class->delete_folder = delete_folder;
    camel_store_class->rename_folder = rename_folder;
    camel_store_class->create_folder = create_folder;
    
    camel_store_class->get_folder_info = get_folder_info;
    camel_store_class->free_folder_info = camel_store_free_folder_info_full;
}

CamelType
camel_mbox_store_get_type(void)
{
    static CamelType camel_mbox_store_type = CAMEL_INVALID_TYPE;
    
    if (camel_mbox_store_type == CAMEL_INVALID_TYPE)    {
        camel_mbox_store_type = camel_type_register(CAMEL_LOCAL_STORE_TYPE, "CamelMboxStore",
                                sizeof(CamelMboxStore),
                                sizeof(CamelMboxStoreClass),
                                (CamelObjectClassInitFunc) camel_mbox_store_class_init,
                                NULL,
                                NULL,
                                NULL);
    }
    
    return camel_mbox_store_type;
}

static char *
mbox_folder_name_to_path(CamelStore *store, const char *folder_name)
{
    const char *toplevel_dir = CAMEL_LOCAL_STORE(store)->toplevel_dir;
    
    return camel_mbox_folder_get_full_path(NULL, toplevel_dir, folder_name);
}

static char *
mbox_folder_name_to_meta_path(CamelStore *store, const char *folder_name, const char *ext)
{
    const char *toplevel_dir = CAMEL_LOCAL_STORE(store)->toplevel_dir;
    
    return camel_mbox_folder_get_meta_path(NULL, toplevel_dir, folder_name, ext);
}

static char *extensions[] = {
    ".msf", ".ev-summary", ".ibex.index", ".ibex.index.data", ".cmeta", ".lock"
};

static gboolean
ignore_file(const char *filename, gboolean sbd)
{
    int flen, len, i;
    
    /* TODO: Should probably just be 1 regex */
    flen = strlen(filename);
    if (flen > 0 && filename[flen-1] == '~')
        return TRUE;

    for (i = 0; i <(sizeof(extensions) / sizeof(extensions[0])); i++) {
        len = strlen(extensions[i]);
        if (len < flen && !strcmp(filename + flen - len, extensions[i]))
            return TRUE;
    }
    
    if (sbd && flen > 4 && !strcmp(filename + flen - 4, ".sbd"))
        return TRUE;
    
    return FALSE;
}

static CamelFolder *
get_folder(CamelStore *store, const char *folder_name, guint32 flags, CamelException *ex)
{
    struct stat st;
    char *name;
    
    if (!((CamelStoreClass *) parent_class)->get_folder(store, folder_name, flags, ex))
        return NULL;
    
    name = mbox_folder_name_to_path(store, folder_name);
    
    if (stat(name, &st) == -1) {
        const char *basename;
        char *dirname;
        int fd;
        
        if (errno != ENOENT) {
            camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                         _("Cannot get folder `%s': %s"),
                         folder_name, g_strerror (errno));
            g_free(name);
            return NULL;
        }
        
        if ((flags & CAMEL_STORE_FOLDER_CREATE) == 0) {
            camel_exception_setv(ex, CAMEL_EXCEPTION_STORE_NO_FOLDER,
                         _("Cannot get folder `%s': folder does not exist."),
                         folder_name);
            g_free(name);
            return NULL;
        }
        
        /* sanity check the folder name */
        if (!(basename = strrchr (folder_name, '/')))
            basename = folder_name;
        else
            basename++;
        
        if (basename[0] == '.' || ignore_file (basename, TRUE)) {
            camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                         _("Cannot create a folder by this name."));
            g_free (name);
            return NULL;
        }
        
        dirname = g_path_get_dirname(name);
        if (camel_mkdir(dirname, 0777) == -1 && errno != EEXIST) {
            camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                         _("Cannot create folder `%s': %s"),
                         folder_name, g_strerror (errno));
            g_free(dirname);
            g_free(name);
            return NULL;
        }
        
        g_free(dirname);
        
        fd = open(name, O_WRONLY | O_CREAT | O_APPEND, 0666);
        if (fd == -1) {
            camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                         _("Cannot create folder `%s': %s"),
                         folder_name, g_strerror (errno));
            g_free(name);
            return NULL;
        }
        
        g_free(name);
        close(fd);
    } else if (!S_ISREG(st.st_mode)) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Cannot get folder `%s': not a regular file."),
                     folder_name);
        g_free(name);
        return NULL;
    } else if (flags & CAMEL_STORE_FOLDER_EXCL) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Cannot create folder `%s': folder exists."),
                      folder_name);
        g_free (name);
        return NULL;
    } else
        g_free(name);
    
    return camel_mbox_folder_new(store, folder_name, flags, ex);
}

static void
delete_folder(CamelStore *store, const char *folder_name, CamelException *ex)
{
    CamelFolderInfo *fi;
    CamelException lex;
    CamelFolder *lf;
    char *name, *path;
    struct stat st;
    
    name = mbox_folder_name_to_path(store, folder_name);
    path = g_strdup_printf("%s.sbd", name);
    
    if (rmdir(path) == -1 && errno != ENOENT) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Could not delete folder `%s':\n%s"),
                     folder_name, g_strerror(errno));
        g_free(path);
        g_free(name);
        return;
    }
    
    g_free(path);
    
    if (stat(name, &st) == -1) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Could not delete folder `%s':\n%s"),
                     folder_name, g_strerror(errno));
        g_free(name);
        return;
    }
    
    if (!S_ISREG(st.st_mode)) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_STORE_NO_FOLDER,
                     _("`%s' is not a regular file."), name);
        g_free(name);
        return;
    }
    
    if (st.st_size != 0) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_FOLDER_NON_EMPTY,
                     _("Folder `%s' is not empty. Not deleted."),
                     folder_name);
        g_free(name);
        return;
    }
    
    if (unlink(name) == -1 && errno != ENOENT) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Could not delete folder `%s':\n%s"),
                     name, g_strerror(errno));
        g_free(name);
        return;
    }
    
    /* FIXME: we have to do our own meta cleanup here rather than
     * calling our parent class' delete_folder() method since our
     * naming convention is different. Need to find a way for
     * CamelLocalStore to be able to construct the folder & meta
     * paths itself */
    path = mbox_folder_name_to_meta_path(store, folder_name, ".ev-summary");
    if (unlink(path) == -1 && errno != ENOENT) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Could not delete folder summary file `%s': %s"),
                     path, g_strerror(errno));
        g_free(path);
        g_free(name);
        return;
    }
    
    g_free(path);
    
    path = mbox_folder_name_to_meta_path(store, folder_name, ".ibex");
    if (camel_text_index_remove(path) == -1 && errno != ENOENT) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Could not delete folder index file `%s': %s"),
                     path, g_strerror(errno));
        g_free(path);
        g_free(name);
        return;
    }
    
    g_free(path);

    path = NULL;
    camel_exception_init(&lex);
    if ((lf = camel_store_get_folder(store, folder_name, 0, &lex))) {
        camel_object_get(lf, NULL, CAMEL_OBJECT_STATE_FILE, &path, NULL);
        camel_object_set(lf, NULL, CAMEL_OBJECT_STATE_FILE, NULL, NULL);
        camel_object_unref(lf);
    } else {
        camel_exception_clear(&lex);
    }
    
    if (path == NULL)
        path = mbox_folder_name_to_meta_path(store, folder_name, ".cmeta");
    
    if (unlink(path) == -1 && errno != ENOENT) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Could not delete folder meta file `%s': %s"),
                     path, g_strerror(errno));
        
        g_free(path);
        g_free(name);
        return;
    }
    
    g_free(path);
    g_free(name);
    
    fi = g_new0(CamelFolderInfo, 1);
    fi->full_name = g_strdup(folder_name);
    fi->name = g_path_get_basename(folder_name);
    fi->uri = g_strdup_printf("mbox:%s#%s",((CamelService *) store)->url->path, folder_name);
    fi->unread = -1;
    
    camel_object_trigger_event(store, "folder_deleted", fi);
    
    camel_folder_info_free(fi);
}

static CamelFolderInfo *
create_folder(CamelStore *store, const char *parent_name, const char *folder_name, CamelException *ex)
{
    /* FIXME: this is almost an exact copy of CamelLocalStore::create_folder() except that we use
     * different path schemes... need to find a way to share parent's code? */
    const char *toplevel_dir =((CamelLocalStore *) store)->toplevel_dir;
    CamelFolderInfo *info = NULL;
    char *path, *name, *dir;
    CamelFolder *folder;
    struct stat st;
    
    if (toplevel_dir[0] != '/') {
        camel_exception_setv(ex, CAMEL_EXCEPTION_STORE_NO_FOLDER,
                     _("Store root %s is not an absolute path"), toplevel_dir);
        return NULL;
    }
    
    if (folder_name[0] == '.' || ignore_file(folder_name, TRUE)) {
        camel_exception_set(ex, CAMEL_EXCEPTION_SYSTEM,
                    _("Cannot create a folder by this name."));
        return NULL;
    }
    
    if (parent_name && *parent_name)
        name = g_strdup_printf("%s/%s", parent_name, folder_name);
    else
        name = g_strdup(folder_name);
    
    path = mbox_folder_name_to_path(store, name);
    
    dir = g_path_get_dirname(path);
    if (camel_mkdir(dir, 0777) == -1 && errno != EEXIST) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, _("Cannot create directory `%s': %s."),
                     dir, g_strerror(errno));
        
        g_free(path);
        g_free(name);
        g_free(dir);
        
        return NULL;
    }
    
    g_free(dir);
    
    if (stat(path, &st) == 0 || errno != ENOENT) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_STORE_NO_FOLDER,
                     _("Cannot create folder: %s: %s"),
                     path, errno ? g_strerror(errno) :
                     _("Folder already exists"));
        
        g_free(path);
        g_free(name);
        
        return NULL;
    }
    
    g_free(path);
    
    folder =((CamelStoreClass *)((CamelObject *) store)->klass)->get_folder(store, name, CAMEL_STORE_FOLDER_CREATE, ex);
    if (folder) {
        camel_object_unref(folder);
        info =((CamelStoreClass *)((CamelObject *) store)->klass)->get_folder_info(store, name, 0, ex);
    }
    
    g_free(name);
    
    return info;
}

static int
xrename(CamelStore *store, const char *old_name, const char *new_name, const char *ext, gboolean missingok)
{
    const char *toplevel_dir =((CamelLocalStore *) store)->toplevel_dir;
    char *oldpath, *newpath;
    struct stat st;
    int ret = -1;
    int err = 0;
    
    if (ext != NULL) {
        oldpath = camel_mbox_folder_get_meta_path(NULL, toplevel_dir, old_name, ext);
        newpath = camel_mbox_folder_get_meta_path(NULL, toplevel_dir, new_name, ext);
    } else {
        oldpath = camel_mbox_folder_get_full_path(NULL, toplevel_dir, old_name);
        newpath = camel_mbox_folder_get_full_path(NULL, toplevel_dir, new_name);
    }
    
    if (stat(oldpath, &st) == -1) {
        if (missingok && errno == ENOENT) {
            ret = 0;
        } else {
            err = errno;
            ret = -1;
        }
    } else if (S_ISDIR(st.st_mode)) {
        /* use rename for dirs */
        if (rename(oldpath, newpath) == 0 || stat(newpath, &st) == 0) {
            ret = 0;
        } else {
            err = errno;
            ret = -1;
        }
    } else if (link(oldpath, newpath) == 0 /* and link for files */
           ||(stat(newpath, &st) == 0 && st.st_nlink == 2)) {
        if (unlink(oldpath) == 0) {
            ret = 0;
        } else {
            err = errno;
            unlink(newpath);
            ret = -1;
        }
    } else {
        err = errno;
        ret = -1;
    }
    
    g_free(oldpath);
    g_free(newpath);
    
    return ret;
}

static void
rename_folder(CamelStore *store, const char *old, const char *new, CamelException *ex)
{
    CamelLocalFolder *folder = NULL;
    char *oldibex, *newibex, *newdir;
    int errnosav;
    
    if (new[0] == '.' || ignore_file(new, TRUE)) {
        camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                     _("The new folder name is illegal."));
        return;
    }
    
    /* try to rollback failures, has obvious races */
    
    oldibex = mbox_folder_name_to_meta_path(store, old, ".ibex");
    newibex = mbox_folder_name_to_meta_path(store, new, ".ibex");
    
    newdir = g_path_get_dirname(newibex);
    if (camel_mkdir(newdir, 0777) == -1) {
        if (errno != EEXIST) {
            camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                         _("Could not rename `%s': `%s': %s"),
                         old, new, g_strerror(errno));
            g_free(oldibex);
            g_free(newibex);
            g_free(newdir);
            
            return;
        }
        
        g_free(newdir);
        newdir = NULL;
    }
    
    folder = camel_object_bag_get(store->folders, old);
    if (folder && folder->index) {
        if (camel_index_rename(folder->index, newibex) == -1 && errno != ENOENT) {
            errnosav = errno;
            goto ibex_failed;
        }
    } else {
        /* TODO: camel_text_index_rename should find out if we have an active index itself? */
        if (camel_text_index_rename(oldibex, newibex) == -1 && errno != ENOENT) {
            errnosav = errno;
            goto ibex_failed;
        }
    }
    
    if (xrename(store, old, new, ".ev-summary", TRUE) == -1) {
        errnosav = errno;
        goto summary_failed;
    }

    if (xrename(store, old, new, ".cmeta", TRUE) == -1) {
        errnosav = errno;
        goto cmeta_failed;
    }
    
    if (xrename(store, old, new, ".sbd", TRUE) == -1) {
        errnosav = errno;
        goto subdir_failed;
    }
    
    if (xrename(store, old, new, NULL, FALSE) == -1) {
        errnosav = errno;
        goto base_failed;
    }
    
    g_free(oldibex);
    g_free(newibex);
    
    if (folder)
        camel_object_unref(folder);
    
    return;
    
base_failed:
    xrename(store, new, old, ".sbd", TRUE);
subdir_failed:
    xrename(store, new, old, ".cmeta", TRUE);
cmeta_failed:   
    xrename(store, new, old, ".ev-summary", TRUE);
summary_failed:
    if (folder) {
        if (folder->index)
            camel_index_rename(folder->index, oldibex);
    } else
        camel_text_index_rename(newibex, oldibex);
ibex_failed:
    if (newdir) {
        /* newdir is only non-NULL if we needed to mkdir */
        rmdir(newdir);
        g_free(newdir);
    }
    
    camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
                 _("Could not rename '%s' to %s: %s"),
                 old, new, g_strerror(errnosav));
    
    g_free(newibex);
    g_free(oldibex);
    
    if (folder)
        camel_object_unref(folder);
}

/* used to find out where we've visited already */
struct _inode {
    dev_t dnode;
    ino_t inode;
};

static guint
inode_hash(const void *d)
{
    const struct _inode *v = d;
    
    return v->inode ^ v->dnode;
}

static gboolean
inode_equal(const void *a, const void *b)
{
    const struct _inode *v1 = a, *v2 = b;
    
    return v1->inode == v2->inode && v1->dnode == v2->dnode;
}

static void
inode_free(void *k, void *v, void *d)
{
    g_free(k);
}

/* NB: duplicated in maildir store */
static void
fill_fi(CamelStore *store, CamelFolderInfo *fi, guint32 flags)
{
    CamelFolder *folder;

    fi->unread = -1;
    fi->total = -1;
    folder = camel_object_bag_get(store->folders, fi->full_name);
    if (folder) {
        if ((flags & CAMEL_STORE_FOLDER_INFO_FAST) == 0)
            camel_folder_refresh_info(folder, NULL);
        fi->unread = camel_folder_get_unread_message_count(folder);
        fi->total = camel_folder_get_message_count(folder);
        camel_object_unref(folder);
    } else {
        char *path, *folderpath;
        CamelMboxSummary *mbs;
        const char *root;

        /* This should be fast enough not to have to test for INFO_FAST */
        root = camel_local_store_get_toplevel_dir((CamelLocalStore *)store);
        path = camel_mbox_folder_get_meta_path(NULL, root, fi->full_name, ".ev-summary");
        folderpath = camel_mbox_folder_get_full_path(NULL, root, fi->full_name);
        
        mbs = (CamelMboxSummary *)camel_mbox_summary_new(NULL, path, folderpath, NULL);
        if (camel_folder_summary_header_load((CamelFolderSummary *)mbs) != -1) {
            fi->unread = ((CamelFolderSummary *)mbs)->unread_count;
            fi->total = ((CamelFolderSummary *)mbs)->saved_count;
        }

        camel_object_unref(mbs);
        g_free(folderpath);
        g_free(path);
    }
}

static CamelFolderInfo *
scan_dir(CamelStore *store, CamelURL *url, GHashTable *visited, CamelFolderInfo *parent, const char *root,
     const char *name, guint32 flags, CamelException *ex)
{
    CamelFolderInfo *folders, *tail, *fi;
    GHashTable *folder_hash;
    struct dirent *dent;
    DIR *dir;
    
    tail = folders = NULL;
    
    if (!(dir = opendir(root)))
        return NULL;
    
    folder_hash = g_hash_table_new(g_str_hash, g_str_equal);
    
    /* FIXME: it would be better if we queue'd up the recursive
     * scans till the end so that we can limit the number of
     * directory descriptors open at any given time... */
    
    while ((dent = readdir(dir))) {
        char *short_name, *full_name, *path, *ext;
        struct stat st;
        
        if (dent->d_name[0] == '.')
            continue;
        
        if (ignore_file(dent->d_name, FALSE))
            continue;
        
        path = g_strdup_printf("%s/%s", root, dent->d_name);
        if (stat(path, &st) == -1) {
            g_free(path);
            continue;
        }
        
        if (S_ISDIR(st.st_mode)) {
            struct _inode in = { st.st_dev, st.st_ino };
            
            if (g_hash_table_lookup(visited, &in)) {
                g_free(path);
                continue;
            }
        }
        
        short_name = g_strdup(dent->d_name);
        if ((ext = strrchr(short_name, '.')) && !strcmp(ext, ".sbd"))
            *ext = '\0';
        
        if (name != NULL)
            full_name = g_strdup_printf("%s/%s", name, short_name);
        else
            full_name = g_strdup(short_name);
                
        if ((fi = g_hash_table_lookup(folder_hash, short_name)) != NULL) {
            g_free(short_name);
            g_free(full_name);
            
            if (S_ISDIR(st.st_mode)) {
                fi->flags =(fi->flags & ~CAMEL_FOLDER_NOCHILDREN) | CAMEL_FOLDER_CHILDREN;
            } else {
                fi->flags &= ~CAMEL_FOLDER_NOSELECT;
            }
        } else {
            fi = g_new0(CamelFolderInfo, 1);
            fi->parent = parent;
            
            camel_url_set_fragment (url, full_name);
            
            fi->uri = camel_url_to_string (url, 0);
            fi->name = short_name;
            fi->full_name = full_name;
            fi->unread = -1;
            fi->total = -1;

            if (S_ISDIR(st.st_mode))
                fi->flags = CAMEL_FOLDER_NOSELECT;
            else
                fi->flags = CAMEL_FOLDER_NOCHILDREN;
            
            if (tail == NULL)
                folders = fi;
            else
                tail->next = fi;
            
            tail = fi;
            
            g_hash_table_insert(folder_hash, fi->name, fi);
        }
        
        if (!S_ISDIR(st.st_mode)) {
            fill_fi(store, fi, flags);
        } else if ((flags & CAMEL_STORE_FOLDER_INFO_RECURSIVE)) {
            struct _inode in = { st.st_dev, st.st_ino };
            
            if (g_hash_table_lookup(visited, &in) == NULL) {
                struct _inode *inew = g_new(struct _inode, 1);
                
                *inew = in;
                
                g_hash_table_insert(visited, inew, inew);
                
                if ((fi->child = scan_dir (store, url, visited, fi, path, fi->full_name, flags, ex)))
                    fi->flags |= CAMEL_FOLDER_CHILDREN;
                else
                    fi->flags =(fi->flags & ~CAMEL_FOLDER_CHILDREN) | CAMEL_FOLDER_NOCHILDREN;
            }
        }
        
        g_free(path);
    }
    
    closedir(dir);
    
    g_hash_table_destroy(folder_hash);
    
    return folders;
}

static CamelFolderInfo *
get_folder_info(CamelStore *store, const char *top, guint32 flags, CamelException *ex)
{
    GHashTable *visited;
    struct _inode *inode;
    char *path, *subdir;
    CamelFolderInfo *fi;
    const char *base;
    struct stat st;
    CamelURL *url;
    
    top = top ? top : "";
    path = mbox_folder_name_to_path(store, top);
    
    if (*top == '\0') {
        /* requesting root dir scan */
        if (stat(path, &st) == -1 || !S_ISDIR(st.st_mode)) {
            g_free(path);
            return NULL;
        }
        
        visited = g_hash_table_new(inode_hash, inode_equal);
        
        inode = g_malloc0(sizeof(*inode));
        inode->dnode = st.st_dev;
        inode->inode = st.st_ino;
        
        g_hash_table_insert(visited, inode, inode);
        
        url = camel_url_copy (((CamelService *) store)->url);
        fi = scan_dir (store, url, visited, NULL, path, NULL, flags, ex);
        g_hash_table_foreach(visited, inode_free, NULL);
        g_hash_table_destroy(visited);
        camel_url_free (url);
        g_free (path);
        
        return fi;
    }
    
    /* requesting scan of specific folder */
    if (stat(path, &st) == -1 || !S_ISREG(st.st_mode)) {
        g_free(path);
        return NULL;
    }
    
    visited = g_hash_table_new(inode_hash, inode_equal);
    
    if (!(base = strrchr(top, '/')))
        base = top;
    else
        base++;
    
    url = camel_url_copy (((CamelService *) store)->url);
    camel_url_set_fragment (url, top);
    
    fi = g_new0(CamelFolderInfo, 1);
    fi->parent = NULL;
    fi->uri = camel_url_to_string (url, 0);
    fi->name = g_strdup(base);
    fi->full_name = g_strdup(top);
    fi->unread = -1;
    fi->total = -1;
    
    subdir = g_strdup_printf("%s.sbd", path);
    if (stat(subdir, &st) == 0) {
        if  (S_ISDIR(st.st_mode))
            fi->child = scan_dir (store, url, visited, fi, subdir, top, flags, ex);
        else
            fill_fi(store, fi, flags);
    } else
        fill_fi(store, fi, flags);
    
    camel_url_free (url);
    
    if (fi->child)
        fi->flags |= CAMEL_FOLDER_CHILDREN;
    else
        fi->flags |= CAMEL_FOLDER_NOCHILDREN;
    
    g_free(subdir);
    
    g_hash_table_foreach(visited, inode_free, NULL);
    g_hash_table_destroy(visited);
    g_free(path);
    
    return fi;
}