path: root/camel/camel-provider.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 * camel-provider.c: provider framework
 *
 * Authors:
 *  Bertrand Guiheneuf <bertrand@helixcode.com>
 *  Dan Winship <danw@ximian.com>
 *  Jeffrey Stedfast <fejj@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 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
 */

/* FIXME: Shouldn't we add a version number to providers ? */

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

#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>

#include <gmodule.h>

#include "camel-provider.h"
#include "camel-exception.h"
#include "camel-string-utils.h"
#include "camel-vee-store.h"
#include "libedataserver/e-msgport.h"
#include "camel-i18n.h"

/* table of CamelProviderModule's */
static GHashTable *module_table;
/* table of CamelProvider's */
static GHashTable *provider_table;
static EMutex *provider_lock;

#define LOCK() e_mutex_lock(provider_lock);
#define UNLOCK() e_mutex_unlock(provider_lock);

/* The vfolder provider is always available */
static CamelProvider vee_provider = {
    "vfolder",
    N_("Virtual folder email provider"),
    
    N_("For reading mail as a query of another set of folders"),
    
    "vfolder",
    
    CAMEL_PROVIDER_IS_STORAGE,
    CAMEL_URL_NEED_PATH | CAMEL_URL_PATH_IS_ABSOLUTE | CAMEL_URL_FRAGMENT_IS_PATH,
    
    /* ... */
};

static pthread_once_t setup_once = PTHREAD_ONCE_INIT;

static void
provider_setup(void)
{
    provider_lock = e_mutex_new(E_MUTEX_REC);
    module_table = g_hash_table_new(camel_strcase_hash, camel_strcase_equal);
    provider_table = g_hash_table_new(camel_strcase_hash, camel_strcase_equal);

    vee_provider.object_types[CAMEL_PROVIDER_STORE] = camel_vee_store_get_type ();
    vee_provider.url_hash = camel_url_hash;
    vee_provider.url_equal = camel_url_equal;
    camel_provider_register(&vee_provider);
}

/**
 * camel_provider_init:
 *
 * Initialize the Camel provider system by reading in the .urls
 * files in the provider directory and creating a hash table mapping
 * URLs to module names.
 *
 * A .urls file has the same initial prefix as the shared library it
 * correspond to, and consists of a series of lines containing the URL
 * protocols that that library handles.
 *
 * TODO: This should be pathed?
 * TODO: This should be plugin-d?
 **/
void
camel_provider_init (void)
{
    DIR *dir;
    struct dirent *d;
    char *p, *name, buf[80];
    CamelProviderModule *m;
    static int loaded = 0;

    pthread_once(&setup_once, provider_setup);

    if (loaded)
        return;

    loaded = 1;

    dir = opendir (CAMEL_PROVIDERDIR);
    if (!dir) {
        g_warning("Could not open camel provider directory (%s): %s",
              CAMEL_PROVIDERDIR, g_strerror (errno));
        return;
    }
    
    while ((d = readdir (dir))) {
        FILE *fp;
        
        p = strrchr (d->d_name, '.');
        if (!p || strcmp (p, ".urls") != 0)
            continue;
        
        name = g_strdup_printf ("%s/%s", CAMEL_PROVIDERDIR, d->d_name);
        fp = fopen (name, "r");
        if (!fp) {
            g_warning ("Could not read provider info file %s: %s",
                   name, g_strerror (errno));
            g_free (name);
            continue;
        }
        
        p = strrchr (name, '.');
        strcpy (p, ".so");

        m = g_malloc0(sizeof(*m));
        m->path = name;

        while ((fgets (buf, sizeof (buf), fp))) {
            buf[sizeof (buf) - 1] = '\0';
            p = strchr (buf, '\n');
            if (p)
                *p = '\0';
            
            if (*buf) {
                char *protocol = g_strdup(buf);

                m->types = g_slist_prepend(m->types, protocol);
                g_hash_table_insert(module_table, protocol, m);
            }
        }

        fclose (fp);
    }

    closedir (dir);
}

/**
 * camel_provider_load:
 * @session: the current session
 * @path: the path to a shared library
 * @ex: a CamelException
 *
 * Loads the provider at @path, and calls its initialization function,
 * passing @session as an argument. The provider should then register
 * itself with @session.
 **/ 
void
camel_provider_load(const char *path, CamelException *ex)
{
    GModule *module;
    CamelProvider *(*camel_provider_module_init) (void);

    pthread_once(&setup_once, provider_setup);

    if (!g_module_supported ()) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Could not load %s: Module loading "
                      "not supported on this system."),
                      path);
        return;
    }

    module = g_module_open (path, 0);
    if (!module) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Could not load %s: %s"),
                      path, g_module_error ());
        return;
    }

    if (!g_module_symbol (module, "camel_provider_module_init",
                  (gpointer *)&camel_provider_module_init)) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Could not load %s: No initialization "
                    "code in module."), path);
        g_module_close (module);
        return;
    }

    camel_provider_module_init ();
}

/**
 * camel_provider_register:
 * @provider: provider object
 *
 * Registers a provider.
 **/
void
camel_provider_register(CamelProvider *provider)
{
    int i;
    CamelProviderConfEntry *conf;
    GList *l;

    g_return_if_fail (provider != NULL);

    g_assert(provider_table);

    LOCK();

    if (g_hash_table_lookup(provider_table, provider->protocol) != NULL) {
        g_warning("Trying to re-register camel provider for protocol '%s'", provider->protocol);
        UNLOCK();
        return;
    }
    
    for (i = 0; i < CAMEL_NUM_PROVIDER_TYPES; i++) {
        if (provider->object_types[i])
            provider->service_cache[i] = camel_object_bag_new (provider->url_hash, provider->url_equal,
                                       (CamelCopyFunc)camel_url_copy, (GFreeFunc)camel_url_free);
    }

    /* Translate all strings here */
#define P_(string) dgettext (provider->translation_domain, string)

    provider->name = P_(provider->name);
    provider->description = P_(provider->description);
    conf = provider->extra_conf;
    if (conf) {
        for (i=0;conf[i].type != CAMEL_PROVIDER_CONF_END;i++) {
            if (conf[i].text)
                conf[i].text = P_(conf[i].text);
        }
    }

    l = provider->authtypes;
    while (l) {
        CamelServiceAuthType *auth = l->data;

        auth->name = P_(auth->name);
        auth->description = P_(auth->description);
        l = l->next;
    }

    g_hash_table_insert(provider_table, provider->protocol, provider);

    UNLOCK();
}

static gint
provider_compare (gconstpointer a, gconstpointer b)
{
    const CamelProvider *cpa = (const CamelProvider *)a;
    const CamelProvider *cpb = (const CamelProvider *)b;

    return strcmp (cpa->name, cpb->name);
}

static void
add_to_list (gpointer key, gpointer value, gpointer user_data)
{
    GList **list = user_data;

    *list = g_list_prepend(*list, value);
}

/**
 * camel_session_list_providers:
 * @session: the session
 * @load: whether or not to load in providers that are not already loaded
 *
 * This returns a list of available providers in this session. If @load
 * is %TRUE, it will first load in all available providers that haven't
 * yet been loaded.
 *
 * Return value: a GList of providers, which the caller must free.
 **/
GList *
camel_provider_list(gboolean load)
{
    GList *list = NULL;

    g_assert(provider_table);

    LOCK();

    if (load) {
        GList *w;

        g_hash_table_foreach(module_table, add_to_list, &list);
        for (w = list;w;w = w->next) {
            CamelProviderModule *m = w->data;

            if (!m->loaded) {
                camel_provider_load(m->path, NULL);
                m->loaded = 1;
            }
        }
        g_list_free(list);
        list = NULL;
    }

    g_hash_table_foreach(provider_table, add_to_list, &list);

    UNLOCK();

    list = g_list_sort(list, provider_compare);

    return list;
}

/**
 * camel_provider_get:
 * @url_string: the URL for the service whose provider you want
 * @ex: a CamelException
 *
 * This returns the CamelProvider that would be used to handle
 * @url_string, loading it in from disk if necessary.
 *
 * Return value: the provider, or %NULL, in which case @ex will be set.
 **/
CamelProvider *
camel_provider_get(const char *url_string, CamelException *ex)
{
    CamelProvider *provider = NULL;
    char *protocol;
    size_t len;

    g_return_val_if_fail(url_string != NULL, NULL);
    g_assert(provider_table);

    len = strcspn(url_string, ":");
    protocol = g_alloca(len+1);
    memcpy(protocol, url_string, len);
    protocol[len] = 0;

    LOCK();

    provider = g_hash_table_lookup(provider_table, protocol);
    if (!provider) {
        CamelProviderModule *m;

        m = g_hash_table_lookup(module_table, protocol);
        if (m && !m->loaded) {
            m->loaded = 1;
            camel_provider_load(m->path, ex);
            if (camel_exception_is_set (ex))
                goto fail;
        }
        provider = g_hash_table_lookup(provider_table, protocol);
    }

    if (provider == NULL)
        camel_exception_setv(ex, CAMEL_EXCEPTION_SERVICE_URL_INVALID,
                     _("No provider available for protocol `%s'"),
                     protocol);
fail:
    UNLOCK();

    return provider;
}


/**
 * camel_provider_auto_detect:
 * @provider: camel provider
 * @settings: currently set settings
 * @auto_detected: output hash table of auto-detected values
 * @ex: exception
 *
 * After filling in the standard Username/Hostname/Port/Path settings
 * (which must be set in @settings), if the provider supports it, you
 * may wish to have the provider auto-detect further settings based on
 * the aformentioned settings.
 *
 * If the provider does not support auto-detection, @auto_detected
 * will be set to %NULL. Otherwise the provider will attempt to
 * auto-detect whatever it can and file them into @auto_detected. If
 * for some reason it cannot auto-detect anything (not enough
 * information provided in @settings?) then @auto_deetected will be
 * set to %NULL and an exception may be set to explain why it failed.
 *
 * Returns 0 on success or -1 on fail.
 **/
int
camel_provider_auto_detect (CamelProvider *provider, CamelURL *url,
                GHashTable **auto_detected, CamelException *ex)
{
    g_return_val_if_fail (provider != NULL, -1);

    if (provider->auto_detect) {
        return provider->auto_detect (url, auto_detected, ex);
    } else {
        *auto_detected = NULL;
        return 0;
    }
}