path: root/mail/mail-folder-cache.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 * 
 * Authors: Peter Williams <peterw@ximian.com>
 *      Michael Zucchi <notzed@ximian.com>
 *
 * Copyright 2000,2001 Ximian, Inc. (www.ximian.com)
 *
 * 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

#ifdef G_LOG_DOMAIN
#undef G_LOG_DOMAIN
#endif
#define G_LOG_DOMAIN "folder tree"

#include <pthread.h>

#include <bonobo/bonobo-exception.h>
#include <camel/camel-store.h>
#include <camel/camel-folder.h>
#include <camel/camel-vtrash-folder.h>
#include <camel/camel-vee-store.h>

#include "e-util/e-unicode-i18n.h"

#include "mail-mt.h"
#include "mail-folder-cache.h"
#include "mail-ops.h"
#include "mail-vfolder.h"

#define d(x) 

/* note that many things are effectively serialised by having them run in
   the main loop thread which they need to do because of corba/gtk calls */
#define LOCK(x) pthread_mutex_lock(&x)
#define UNLOCK(x) pthread_mutex_unlock(&x)

static pthread_mutex_t info_lock = PTHREAD_MUTEX_INITIALIZER;

struct _folder_info {
    struct _store_info *store_info; /* 'parent' link */

    char *path;     /* shell path */
    char *full_name;    /* full name of folder/folderinfo */
    char *uri;      /* uri of folder */

    CamelFolder *folder;    /* if known */
};

/* pending list of updates */
struct _folder_update {
    struct _folder_update *next;
    struct _folder_update *prev;

    unsigned int remove:1;  /* removing from vfolders */
    unsigned int delete:1;  /* deleting as well? */
    unsigned int add:1; /* add to vfolder */

    char *path;
    char *name;
    char *uri;
    char *oldpath;

    int unread;
    CamelStore *store;
};

struct _store_info {
    GHashTable *folders;    /* by full_name */
    GHashTable *folders_uri; /* by uri */

    CamelStore *store;  /* the store for these folders */

    /* only 1 should be set */
    EvolutionStorage *storage;
    GNOME_Evolution_Storage corba_storage;

    /* Outstanding folderinfo requests */
    EDList folderinfo_updates;
};

static void folder_changed(CamelObject *o, gpointer event_data, gpointer user_data);
static void folder_deleted(CamelObject *o, gpointer event_data, gpointer user_data);
static void folder_renamed(CamelObject *o, gpointer event_data, gpointer user_data);
static void folder_finalised(CamelObject *o, gpointer event_data, gpointer user_data);

/* Store to storeinfo table, active stores */
static GHashTable *stores;

/* List of folder changes to be executed in gui thread */
static EDList updates = E_DLIST_INITIALISER(updates);
static int update_id = -1;

/* hack for people who LIKE to have unsent count */
static int count_sent = FALSE;

static void
free_update(struct _folder_update *up)
{
    g_free(up->path);
    g_free(up->name);
    g_free(up->uri);
    if (up->store)
        camel_object_unref((CamelObject *)up->store);
    g_free(up);
}

static void
real_flush_updates(void *o, void *event_data, void *data)
{
    struct _folder_update *up;
    struct _store_info *si;
    EvolutionStorage *storage;
    GNOME_Evolution_Storage corba_storage;
    CORBA_Environment ev;

    LOCK(info_lock);
    while ((up = (struct _folder_update *)e_dlist_remhead(&updates))) {

        si = g_hash_table_lookup(stores, up->store);
        if (si) {
            storage = si->storage;
            if (storage)
                bonobo_object_ref((BonoboObject *)storage);
            corba_storage = si->corba_storage;
        } else {
            storage = NULL;
            corba_storage = CORBA_OBJECT_NIL;
        }

        UNLOCK(info_lock);

        if (up->remove) {
            if (up->delete)
                mail_vfolder_delete_uri(up->store, up->uri);
            else
                mail_vfolder_add_uri(up->store, up->uri, TRUE);
        } else {
            if (up->oldpath) {
                if (storage != NULL)
                    evolution_storage_removed_folder(storage, up->oldpath);
                /* ELSE? Shell supposed to handle the local snot case */
            }

            if (up->name == NULL) {
                if (storage != NULL) {
                    d(printf("Updating existing folder: %s (%d unread)\n", up->path, up->unread));
                    evolution_storage_update_folder(storage, up->path, up->unread);
                } else if (corba_storage != CORBA_OBJECT_NIL) {
                    d(printf("Updating existing (local) folder: %s (%d unread)\n", up->path, up->unread));
                    CORBA_exception_init(&ev);
                    GNOME_Evolution_Storage_updateFolder(corba_storage, up->path, up->unread, &ev);
                    CORBA_exception_free(&ev);
                }
            } else if (storage != NULL) {
                char *type = (strncmp(up->uri, "vtrash:", 7)==0)?"vtrash":"mail";
            
                d(printf("Adding new folder: %s\n", up->path));
                evolution_storage_new_folder(storage, up->path, up->name, type, up->uri, up->name, up->unread);
            }
            if (up->add)
                mail_vfolder_add_uri(up->store, up->uri, FALSE);
        }

        free_update(up);

        if (storage)
            bonobo_object_unref((BonoboObject *)storage);
        
        LOCK(info_lock);
    }
    update_id = -1;
    UNLOCK(info_lock);
}

static void
flush_updates(void)
{
    if (update_id == -1 && !e_dlist_empty(&updates))
        update_id = mail_async_event_emit(mail_async_event, MAIL_ASYNC_GUI, (MailAsyncFunc)real_flush_updates, 0, 0, 0);
}

static void
unset_folder_info(struct _folder_info *mfi, int delete)
{
    struct _folder_update *up;

    if (mfi->folder) {
        CamelFolder *folder = mfi->folder;

        camel_object_unhook_event((CamelObject *)folder, "folder_changed", folder_changed, mfi);
        camel_object_unhook_event((CamelObject *)folder, "message_changed", folder_changed, mfi);
        camel_object_unhook_event((CamelObject *)folder, "deleted", folder_deleted, mfi);
        camel_object_unhook_event((CamelObject *)folder, "renamed", folder_renamed, mfi);
        camel_object_unhook_event((CamelObject *)folder, "finalize", folder_finalised, mfi);
    }

    if (strstr(mfi->uri, ";noselect") == NULL) {
        up = g_malloc0(sizeof(*up));

        up->remove = TRUE;
        up->delete = delete;
        up->store = mfi->store_info->store;
        camel_object_ref((CamelObject *)up->store);
        up->uri = g_strdup(mfi->uri);

        e_dlist_addtail(&updates, (EDListNode *)up);
        flush_updates();
    }
}

static void
free_folder_info(struct _folder_info *mfi)
{
    g_free(mfi->path);
    g_free(mfi->full_name);
    g_free(mfi->uri);
    g_free(mfi);
}

/* This is how unread counts work (and don't work):
 *
 * camel_folder_unread_message_count() only gives a correct answer if
 * the store is paying attention to the folder. (Some stores always
 * pay attention to all folders, but IMAP can only pay attention to
 * one folder at a time.) But it doesn't have any way to know when
 * it's lying, so it's only safe to call it when you know for sure
 * that the store is paying attention to the folder, such as when it's
 * just been created, or you get a folder_changed or message_changed
 * signal on it.
 *
 * camel_store_get_folder_info() always gives correct answers for the
 * folders it checks, but it can also return -1 for a folder, meaning
 * it didn't check, and so you should stick with your previous answer.
 *
 * update_1folder is called from three places: with info != NULL when
 * the folder is created (or get_folder_info), with info == NULL when
 * a folder changed event is emitted.
 *
 * So if info is NULL, camel_folder_unread_message_count is correct,
 * and if it's not NULL and its unread_message_count isn't -1, then
 * it's correct.  */

static void
update_1folder(struct _folder_info *mfi, CamelFolderInfo *info)
{
    struct _store_info *si;
    struct _folder_update *up;
    CamelFolder *folder;
    int unread = -1;
    extern CamelFolder *outbox_folder, *sent_folder;

    si  = mfi->store_info;

    folder = mfi->folder;
    if (folder) {
        if (CAMEL_IS_VTRASH_FOLDER (folder) || folder == outbox_folder || (count_sent && folder == sent_folder)) {
            unread = camel_folder_get_message_count(folder);
        } else {
            if (info)
                unread = info->unread_message_count;
            else
                unread = camel_folder_get_unread_message_count (folder);
        }
    } else if (info)
        unread = info->unread_message_count;

    if (unread == -1)
        return;

    up = g_malloc0(sizeof(*up));
    up->path = g_strdup(mfi->path);
    up->unread = unread;
    up->store = mfi->store_info->store;
    camel_object_ref((CamelObject *)up->store);
    e_dlist_addtail(&updates, (EDListNode *)up);
    flush_updates();
}

static void
setup_folder(CamelFolderInfo *fi, struct _store_info *si)
{
    struct _folder_info *mfi;
    struct _folder_update *up;

    mfi = g_hash_table_lookup(si->folders, fi->full_name);
    if (mfi) {
        update_1folder(mfi, fi);
    } else {
        /* always 'add it', but only 'add it' to non-local stores */
        /*d(printf("Adding new folder: %s (%s) %d unread\n", fi->path, fi->url, fi->unread_message_count));*/
        mfi = g_malloc0(sizeof(*mfi));
        mfi->path = g_strdup(fi->path);
        mfi->full_name = g_strdup(fi->full_name);
        mfi->uri = g_strdup(fi->url);
        mfi->store_info = si;
        g_hash_table_insert(si->folders, mfi->full_name, mfi);
        g_hash_table_insert(si->folders_uri, mfi->uri, mfi);

        up = g_malloc0(sizeof(*up));
        up->path = g_strdup(mfi->path);
        if (si->storage != NULL) {
            up->name = g_strdup(fi->name);
        }
        up->uri = g_strdup(fi->url);
        up->unread = (fi->unread_message_count==-1)?0:fi->unread_message_count;
        up->store = si->store;
        camel_object_ref((CamelObject *)up->store);
        if (strstr(fi->url, ";noselect") == NULL)
            up->add = TRUE;

        e_dlist_addtail(&updates, (EDListNode *)up);
        flush_updates();
    }
}

static void
create_folders(CamelFolderInfo *fi, struct _store_info *si)
{
    d(printf("Setup new folder: %s\n", fi->url));

    setup_folder(fi, si);

    if (fi->child)
        create_folders(fi->child, si);
    if (fi->sibling)
        create_folders(fi->sibling, si);
}

static void
folder_changed(CamelObject *o, gpointer event_data, gpointer user_data)
{
    struct _folder_info *mfi = user_data;

    if (mfi->folder != CAMEL_FOLDER(o))
        return;

    LOCK(info_lock);
    update_1folder(mfi, NULL);
    UNLOCK(info_lock);
}

static void
folder_finalised(CamelObject *o, gpointer event_data, gpointer user_data)
{
    struct _folder_info *mfi = user_data;

    d(printf("Folder finalised '%s'!\n", ((CamelFolder *)o)->full_name));
    LOCK(info_lock);
    mfi->folder = NULL;
    UNLOCK(info_lock);
}

static void
folder_deleted(CamelObject *o, gpointer event_data, gpointer user_data)
{
    struct _folder_info *mfi = user_data;

    d(printf("Folder deleted '%s'!\n", ((CamelFolder *)o)->full_name));
    LOCK(info_lock);
    mfi->folder = NULL;
    UNLOCK(info_lock);
}

static void
folder_renamed(CamelObject *o, gpointer event_data, gpointer user_data)
{
    struct _folder_info *mfi = user_data;
    CamelFolder *folder = (CamelFolder *)o;
    char *old = event_data;

    printf("Folder renamed from '%s' to '%s'\n", old, folder->full_name);
    mfi = mfi;
    /* Dont do anything, do it from the store rename event? */
}

void mail_note_folder(CamelFolder *folder)
{
    CamelStore *store = folder->parent_store;
    struct _store_info *si;
    struct _folder_info *mfi;

    if (stores == NULL) {
        g_warning("Adding a folder `%s' to a store which hasn't been added yet?\n", folder->full_name);
        return;
    }

    LOCK(info_lock);
    si = g_hash_table_lookup(stores, store);
    if (si == NULL) {
        /*g_warning("Adding a folder `%s' to a store %p which hasn't been added yet?", folder->full_name, store);*/
        UNLOCK(info_lock);
        return;
    }

    mfi = g_hash_table_lookup(si->folders, folder->full_name);
    if (mfi == NULL) {
        g_warning("Adding a folder `%s' that I dont know about yet?", folder->full_name);
        UNLOCK(info_lock);
        return;
    }

    /* dont do anything if we already have this */
    if (mfi->folder == folder) {
        UNLOCK(info_lock);
        return;
    }

    mfi->folder = folder;

    camel_object_hook_event((CamelObject *)folder, "folder_changed", folder_changed, mfi);
    camel_object_hook_event((CamelObject *)folder, "message_changed", folder_changed, mfi);
    camel_object_hook_event((CamelObject *)folder, "deleted", folder_deleted, mfi);
    camel_object_hook_event((CamelObject *)folder, "renamed", folder_renamed, mfi);
    camel_object_hook_event((CamelObject *)folder, "finalize", folder_finalised, mfi);

    update_1folder(mfi, NULL);

    UNLOCK(info_lock);
}

static void
store_folder_subscribed(CamelObject *o, void *event_data, void *data)
{
    struct _store_info *si;
    CamelFolderInfo *fi = event_data;

    LOCK(info_lock);
    si = g_hash_table_lookup(stores, o);
    if (si)
        setup_folder(fi, si);
    UNLOCK(info_lock);
}

static void
store_folder_created(CamelObject *o, void *event_data, void *data)
{
    /* we only want created events to do more work if we dont support subscriptions */
    if (!camel_store_supports_subscriptions(CAMEL_STORE(o)))
        store_folder_subscribed(o, event_data, data);
}

static void
store_folder_unsubscribed(CamelObject *o, void *event_data, void *data)
{
    struct _store_info *si;
    CamelFolderInfo *fi = event_data;
    struct _folder_info *mfi;
    CamelStore *store = (CamelStore *)o;

    d(printf("Folder deleted: %s\n", fi->full_name));

    LOCK(info_lock);
    si = g_hash_table_lookup(stores, store);
    if (si) {
        mfi = g_hash_table_lookup(si->folders, fi->full_name);
        if (mfi) {
            g_hash_table_remove(si->folders, mfi->full_name);
            g_hash_table_remove(si->folders_uri, mfi->uri);
            unset_folder_info(mfi, TRUE);
            free_folder_info(mfi);
        }
    }
    UNLOCK(info_lock);
}

static void
store_folder_deleted(CamelObject *o, void *event_data, void *data)
{
    /* we only want deleted events to do more work if we dont support subscriptions */
    if (!camel_store_supports_subscriptions(CAMEL_STORE(o)))
        store_folder_unsubscribed(o, event_data, data);
}

static void
rename_folders(struct _store_info *si, const char *oldbase, const char *newbase, CamelFolderInfo *fi)
{
    char *old;
    struct _folder_info *mfi;
    struct _folder_update *up;

    up = g_malloc0(sizeof(*up));

    /* Form what was the old name, and try and look it up */
    old = g_strdup_printf("%s%s", oldbase, fi->full_name + strlen(newbase));
    mfi = g_hash_table_lookup(si->folders, old);
    if (mfi) {
        printf("Found old folder '%s' renaming to '%s'\n", mfi->full_name, fi->full_name);

        up->oldpath = mfi->path;

        /* Its a rename op */
        g_hash_table_remove(si->folders, mfi->full_name);
        g_hash_table_remove(si->folders, mfi->uri);
        g_free(mfi->full_name);
        g_free(mfi->uri);
        mfi->path = g_strdup(fi->path);
        mfi->full_name = g_strdup(fi->full_name);
        mfi->uri = g_strdup(fi->url);
        g_hash_table_insert(si->folders, mfi->full_name, mfi);
        g_hash_table_insert(si->folders_uri, mfi->uri, mfi);
    } else {
        printf("Rename found a new folder? old '%s' new '%s'\n", old, fi->full_name);
        /* Its a new op */
        mfi = g_malloc0(sizeof(*mfi));
        mfi->path = g_strdup(fi->path);
        mfi->full_name = g_strdup(fi->full_name);
        mfi->uri = g_strdup(fi->url);
        mfi->store_info = si;
        g_hash_table_insert(si->folders, mfi->full_name, mfi);
        g_hash_table_insert(si->folders_uri, mfi->uri, mfi);
    }

    g_free(old);

    up->path = g_strdup(mfi->path);
    if (si->storage)
        up->name = g_strdup(fi->name);
    up->uri = g_strdup(mfi->uri);
    up->unread = fi->unread_message_count==-1?0:fi->unread_message_count;
    up->store = si->store;
    camel_object_ref((CamelObject *)up->store);
    if (strstr(fi->url, ";noselect") == NULL)
        up->add = TRUE;

    e_dlist_addtail(&updates, (EDListNode *)up);
    flush_updates();

    if (fi->sibling)
        rename_folders(si, oldbase, newbase, fi->sibling);
    if (fi->child)
        rename_folders(si, oldbase, newbase, fi->child);
}

#if 0
/* This is if we want to get the folders individually and sort them and change them on
   the shell atomically (whcih of course, we can't) */
static void
get_folders(GPtrArray *folders, CamelFolderInfo *fi)
{
}

static int
folder_cmp(const void *ap, const void *bp)
{
    const struct _folder_update *a = ((struct _folder_update **)ap)[0];
    const struct _folder_update *b = ((struct _folder_update **)bp)[0];

    return strcmp(a->path, b->path);
}
#endif

static void
store_folder_renamed(CamelObject *o, void *event_data, void *data)
{
    CamelStore *store = (CamelStore *)o;
    CamelRenameInfo *info = event_data;
    struct _store_info *si;

    d(printf("Folder renamed?\n"));

    LOCK(info_lock);
    si = g_hash_table_lookup(stores, store);
    if (si) {
        GPtrArray *folders = g_ptr_array_new();
        struct _folder_update *up;

#if 0
        /* first, get an array of all folders */
        get_folders(folders, info->new);
#endif
        rename_folders(si, info->old_base, info->new->full_name, info->new);
#if 0
        qsort(folders->pdata, folders->len, sizeof(folders->pdata[0]), folder_cmp);
        up = g_malloc0(sizeof(*up));
        up->renamed = folders;

        e_dlist_addtail(&updates, (EDListNode *)up);
        flush_updates();
#endif
    }
    UNLOCK(info_lock);
}

struct _update_data {
    struct _update_data *next;
    struct _update_data *prev;

    int id;         /* id for cancellation */

    void (*done)(CamelStore *store, CamelFolderInfo *info, void *data);
    void *data;
};

static void
unset_folder_info_hash(char *path, struct _folder_info *mfi, void *data)
{
    unset_folder_info(mfi, FALSE);
}

static void
free_folder_info_hash(char *path, struct _folder_info *mfi, void *data)
{
    free_folder_info(mfi);
}

void
mail_note_store_remove(CamelStore *store)
{
    struct _update_data *ud;
    struct _store_info *si;

    g_assert(CAMEL_IS_STORE(store));

    if (stores == NULL)
        return;

    d(printf("store removed!!\n"));
    LOCK(info_lock);
    si = g_hash_table_lookup(stores, store);
    if (si) {
        g_hash_table_remove(stores, store);

        camel_object_unhook_event((CamelObject *)store, "folder_created", store_folder_created, NULL);
        camel_object_unhook_event((CamelObject *)store, "folder_deleted", store_folder_deleted, NULL);
        camel_object_unhook_event((CamelObject *)store, "folder_renamed", store_folder_renamed, NULL);
        camel_object_unhook_event((CamelObject *)store, "folder_subscribed", store_folder_subscribed, NULL);
        camel_object_unhook_event((CamelObject *)store, "folder_unsubscribed", store_folder_unsubscribed, NULL);
        g_hash_table_foreach(si->folders, (GHFunc)unset_folder_info_hash, NULL);

        ud = (struct _update_data *)si->folderinfo_updates.head;
        while (ud->next) {
            (printf("Cancelling outstanding folderinfo update %d\n", ud->id));
            mail_msg_cancel(ud->id);
            ud = ud->next;
        }

        /* This is the only gtk object we need to unref */
        mail_async_event_emit(mail_async_event, MAIL_ASYNC_GUI, (MailAsyncFunc)bonobo_object_unref, si->storage, 0, 0);

        camel_object_unref((CamelObject *)si->store);
        g_hash_table_foreach(si->folders, (GHFunc)free_folder_info_hash, NULL);
        g_hash_table_destroy(si->folders);
        g_hash_table_destroy(si->folders_uri);
        g_free(si);
    }
    UNLOCK(info_lock);
}

static void
update_folders(CamelStore *store, CamelFolderInfo *fi, void *data)
{
    struct _update_data *ud = data;
    struct _store_info *si;

    d(printf("Got folderinfo for store\n"));

    LOCK(info_lock);
    si = g_hash_table_lookup(stores, store);
    if (si) {
        /* the 'si' is still there, so we can remove ourselves from its list */
        /* otherwise its not, and we're on our own and free anyway */
        e_dlist_remove((EDListNode *)ud);

        if (fi) {
            if (si->storage)
                gtk_object_set_data (GTK_OBJECT (si->storage), "connected", GINT_TO_POINTER (TRUE));
            create_folders(fi, si);
        }
    }
    UNLOCK(info_lock);

    if (ud->done)
        ud->done(store, fi, ud->data);
    g_free(ud);
}

void
mail_note_store(CamelStore *store, EvolutionStorage *storage, GNOME_Evolution_Storage corba_storage,
        void (*done)(CamelStore *store, CamelFolderInfo *info, void *data), void *data)
{
    struct _store_info *si;
    struct _update_data *ud;

    g_assert(CAMEL_IS_STORE(store));
    g_assert(pthread_self() == mail_gui_thread);
    g_assert(storage != NULL || corba_storage != CORBA_OBJECT_NIL);

    LOCK(info_lock);

    if (stores == NULL) {
        stores = g_hash_table_new(NULL, NULL);
        count_sent = getenv("EVOLUTION_COUNT_SENT") != NULL;
    }

    si = g_hash_table_lookup(stores, store);
    if (si == NULL) {

        d(printf("Noting a new store: %p: %s\n", store, camel_url_to_string(((CamelService *)store)->url, 0)));

        /* FIXME: Need to ref the storages & store or something?? */

        si = g_malloc0(sizeof(*si));
        si->folders = g_hash_table_new(g_str_hash, g_str_equal);
        si->folders_uri = g_hash_table_new(CAMEL_STORE_CLASS(CAMEL_OBJECT_GET_CLASS(store))->hash_folder_name,
                           CAMEL_STORE_CLASS(CAMEL_OBJECT_GET_CLASS(store))->compare_folder_name);
        si->storage = storage;
        if (storage != NULL)
            bonobo_object_ref((BonoboObject *)storage);
        si->corba_storage = corba_storage;
        si->store = store;
        camel_object_ref((CamelObject *)store);
        g_hash_table_insert(stores, store, si);
        e_dlist_init(&si->folderinfo_updates);

        camel_object_hook_event((CamelObject *)store, "folder_created", store_folder_created, NULL);
        camel_object_hook_event((CamelObject *)store, "folder_deleted", store_folder_deleted, NULL);
        camel_object_hook_event((CamelObject *)store, "folder_renamed", store_folder_renamed, NULL);
        camel_object_hook_event((CamelObject *)store, "folder_subscribed", store_folder_subscribed, NULL);
        camel_object_hook_event((CamelObject *)store, "folder_unsubscribed", store_folder_unsubscribed, NULL);
    }

    ud = g_malloc(sizeof(*ud));
    ud->done = done;
    ud->data = data;
    ud->id = mail_get_folderinfo(store, update_folders, ud);

    e_dlist_addtail(&si->folderinfo_updates, (EDListNode *)ud);

    UNLOCK(info_lock);
}

struct _find_info {
    const char *uri;
    struct _folder_info *fi;
};

/* look up on each storeinfo using proper hash function for that stores uri's */
static void storeinfo_find_folder_info(CamelStore *store, struct _store_info *si, struct _find_info *fi)
{
    if (fi->fi == NULL)
        fi->fi = g_hash_table_lookup(si->folders_uri, fi->uri);
}

/* returns TRUE if the uri is available, folderp is set to a
   reffed folder if the folder has also already been opened */
int mail_note_get_folder_from_uri(const char *uri, CamelFolder **folderp)
{
    struct _find_info fi = { uri, NULL };

    if (stores == NULL)
        return FALSE;

    LOCK(info_lock);
    g_hash_table_foreach(stores, (GHFunc)storeinfo_find_folder_info, &fi);
    if (folderp) {
        if (fi.fi && fi.fi->folder) {
            *folderp = fi.fi->folder;
            camel_object_ref((CamelObject *)*folderp);
        } else {
            *folderp = NULL;
        }
    }
    UNLOCK(info_lock);

    return fi.fi != NULL;
}