path: root/em-format/e-mail-extension-registry.c

/*
 * e-mail-extension-registry.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 */

#include "e-mail-extension-registry.h"

#include <string.h>

#include <libebackend/libebackend.h>

#include "e-mail-formatter-extension.h"
#include "e-mail-parser-extension.h"

#define E_MAIL_EXTENSION_REGISTRY_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_MAIL_EXTENSION_REGISTRY, EMailExtensionRegistryPrivate))

struct _EMailExtensionRegistryPrivate {
    GHashTable *table;
};

G_DEFINE_ABSTRACT_TYPE (
    EMailExtensionRegistry,
    e_mail_extension_registry,
    G_TYPE_OBJECT)

/**
 * EMailExtensionRegistry:
 *
 * The #EMailExtensionRegistry is an abstract class representing a registry
 * for #EMailExtension<!-//>s.
 *
 * #EMailParser and #EMailFormatter both have internally a registry object
 * based on the #EMailExtensionRegistry.
 *
 * One extension can registry itself for more mime-types.
 */

static void
destroy_queue (GQueue *queue)
{
    g_queue_free_full (queue, g_object_unref);
}

static void
mail_extension_registry_add_extension (EMailExtensionRegistry *registry,
                                       const gchar **mime_types,
                                       GType extension_type,
                                       GCompareDataFunc compare_func)
{
    GObject *extension;
    gint ii;

    if (mime_types == NULL) {
        g_critical (
            "%s does not define any MIME types",
            g_type_name (extension_type));
        return;
    }

    extension = g_object_new (extension_type, NULL);

    for (ii = 0; mime_types[ii] != NULL; ii++) {
        GQueue *queue;

        queue = g_hash_table_lookup (
            registry->priv->table, mime_types[ii]);
        if (queue == NULL) {
            queue = g_queue_new ();
            g_hash_table_insert (
                registry->priv->table,
                (gpointer) mime_types[ii],
                queue);
        }

        g_queue_insert_sorted (
            queue, g_object_ref (extension),
            compare_func, NULL);

        if (camel_debug ("emformat:registry")) {
            printf (
                "Added extension '%s' for type '%s'\n",
                g_type_name (extension_type),
                mime_types[ii]);
        }
    }

    g_object_unref (extension);
}

static void
mail_extension_registry_finalize (GObject *object)
{
    EMailExtensionRegistryPrivate *priv;

    priv = E_MAIL_EXTENSION_REGISTRY_GET_PRIVATE (object);

    g_hash_table_destroy (priv->table);

    /* Chain up to parent's finalize() method. */
    G_OBJECT_CLASS (e_mail_extension_registry_parent_class)->
        finalize (object);
}

void
e_mail_extension_registry_class_init (EMailExtensionRegistryClass *class)
{
    GObjectClass *object_class;

    g_type_class_add_private (
        class, sizeof (EMailExtensionRegistryPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->finalize = mail_extension_registry_finalize;
}

void
e_mail_extension_registry_init (EMailExtensionRegistry *registry)
{
    registry->priv = E_MAIL_EXTENSION_REGISTRY_GET_PRIVATE (registry);

    registry->priv->table = g_hash_table_new_full (
        (GHashFunc) g_str_hash,
        (GEqualFunc) g_str_equal,
        (GDestroyNotify) NULL,
        (GDestroyNotify) destroy_queue);
}

/**
 * e_mail_extension_registry_get_for_mime_type:
 * @regstry: An #EMailExtensionRegistry
 * @mime_type: A string with mime-type to look up
 *
 * Tries to lookup list of #EMailExtension<!-//>s that has registryed themselves
 * as handlers for the @mime_type.
 *
 * Return value: Returns #GQueue of #EMailExtension<!-//>s or %NULL when there
 * are no extension registryed for given @mime_type.
 */
GQueue *
e_mail_extension_registry_get_for_mime_type (EMailExtensionRegistry *registry,
                                             const gchar *mime_type)
{
    g_return_val_if_fail (E_IS_MAIL_EXTENSION_REGISTRY (registry), NULL);
    g_return_val_if_fail (mime_type && *mime_type, NULL);

    return g_hash_table_lookup (registry->priv->table, mime_type);
}

/**
 * e_mail_extension_registry_get_fallback:
 * @registry: An #EMailExtensionRegistry
 * @mime_type: A string with mime-type whose fallback to look up
 *
 * Tries to lookup fallback parsers for given mime type. For instance, for
 * multipart/alternative, it will try to lookup multipart/ * parser.
 *
 * Return Value: Returns #QGueue of #EMailExtension<!-//>>s or %NULL when there
 * are no extensions registryed for the fallback type.
 */
GQueue *
e_mail_extension_registry_get_fallback (EMailExtensionRegistry *registry,
                                        const gchar *mime_type)
{
    gchar *s, *type;
    gsize len;
    GQueue *parsers;

    g_return_val_if_fail (E_IS_MAIL_EXTENSION_REGISTRY (registry), NULL);
    g_return_val_if_fail (mime_type && *mime_type, NULL);

    s = strchr (mime_type, '/');
    if (!s)
        return NULL;

    len = s - mime_type;

    s = g_alloca (len);
    strncpy (s, mime_type, len);
    type = g_ascii_strdown (s, len);
    s = g_strdup_printf ("%s/*", type);

    parsers = g_hash_table_lookup (registry->priv->table, s);

    g_free (type);
    g_free (s);

    return parsers;
}

/******************************************************************************/

G_DEFINE_TYPE_WITH_CODE (
    EMailParserExtensionRegistry,
    e_mail_parser_extension_registry,
    E_TYPE_MAIL_EXTENSION_REGISTRY,
    G_IMPLEMENT_INTERFACE (E_TYPE_EXTENSIBLE, NULL))

static void
e_mail_parser_extension_registry_class_init (EMailParserExtensionRegistryClass *class)
{
}

static void
e_mail_parser_extension_registry_init (EMailParserExtensionRegistry *registry)
{
}

static gint
mail_parser_extension_registry_compare (gconstpointer extension1,
                                        gconstpointer extension2,
                                        gpointer user_data)
{
    EMailParserExtensionClass *class1;
    EMailParserExtensionClass *class2;

    class1 = E_MAIL_PARSER_EXTENSION_GET_CLASS (extension1);
    class2 = E_MAIL_PARSER_EXTENSION_GET_CLASS (extension2);

    if (class1->priority == class2->priority)
        return 0;

    return (class1->priority < class2->priority) ? -1 : 1;
}

void
e_mail_parser_extension_registry_load (EMailParserExtensionRegistry *registry)
{
    GType *children;
    GType base_extension_type;
    guint ii, n_children;

    g_return_if_fail (E_IS_MAIL_PARSER_EXTENSION_REGISTRY (registry));

    base_extension_type = E_TYPE_MAIL_PARSER_EXTENSION;
    children = g_type_children (base_extension_type, &n_children);

    for (ii = 0; ii < n_children; ii++) {
        EMailParserExtensionClass *class;

        if (G_TYPE_IS_ABSTRACT (children[ii]))
            continue;

        class = g_type_class_ref (children[ii]);

        mail_extension_registry_add_extension (
            E_MAIL_EXTENSION_REGISTRY (registry),
            class->mime_types, children[ii],
            mail_parser_extension_registry_compare);

        g_type_class_unref (class);
    }

    g_free (children);
}

/******************************************************************************/

G_DEFINE_TYPE_WITH_CODE (
    EMailFormatterExtensionRegistry,
    e_mail_formatter_extension_registry,
    E_TYPE_MAIL_EXTENSION_REGISTRY,
    G_IMPLEMENT_INTERFACE (E_TYPE_EXTENSIBLE, NULL))

static void
e_mail_formatter_extension_registry_class_init (EMailFormatterExtensionRegistryClass *class)
{
}

static void
e_mail_formatter_extension_registry_init (EMailFormatterExtensionRegistry *registry)
{
}

static gint
mail_formatter_extension_registry_compare (gconstpointer extension1,
                                           gconstpointer extension2,
                                           gpointer user_data)
{
    EMailFormatterExtensionClass *class1;
    EMailFormatterExtensionClass *class2;

    class1 = E_MAIL_FORMATTER_EXTENSION_GET_CLASS (extension1);
    class2 = E_MAIL_FORMATTER_EXTENSION_GET_CLASS (extension2);

    if (class1->priority == class2->priority)
        return 0;

    return (class1->priority < class2->priority) ? -1 : 1;
}

void
e_mail_formatter_extension_registry_load (EMailFormatterExtensionRegistry *registry,
                                          GType base_extension_type)
{
    GType *children;
    guint ii, n_children;

    g_return_if_fail (E_IS_MAIL_FORMATTER_EXTENSION_REGISTRY (registry));

    children = g_type_children (base_extension_type, &n_children);

    for (ii = 0; ii < n_children; ii++) {
        EMailFormatterExtensionClass *class;

        if (G_TYPE_IS_ABSTRACT (children[ii]))
            continue;

        class = g_type_class_ref (children[ii]);

        mail_extension_registry_add_extension (
            E_MAIL_EXTENSION_REGISTRY (registry),
            class->mime_types, children[ii],
            mail_formatter_extension_registry_compare);

        g_type_class_unref (class);
    }

    g_free (children);
}