src/group_constraint.c

/* 
 * Copyright (C) 2005 Jukka Zitting <jz@yukatan.fi>
 *
 * 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) 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
 */

#include <config.h>
#include "group_constraint.h"

static void add_sql(MidgardQueryConstraint *constraint, GString *sql) {
        g_assert(constraint);
        g_assert(sql);

        MidgardGroupConstraint *group = MIDGARD_GROUP_CONSTRAINT(constraint);
        switch (g_queue_get_length(group->constraints)) {
        case 0:
                g_string_append(sql, "1 = 1");
                break;
        case 1:
                midgard_query_constraint_add_sql(
                        MIDGARD_QUERY_CONSTRAINT(g_queue_peek_head(group->constraints)), sql);
                break;
        default:
                g_string_append(sql, "(");
                GList *item = group->constraints->head;
                while (item != NULL) {
                        if (item != group->constraints->head) {
                                g_string_append(sql, " ");
                                g_string_append(sql, group->type);
                                g_string_append(sql, " ");
                        }
                        midgard_query_constraint_add_sql(
                                MIDGARD_QUERY_CONSTRAINT(item->data), sql);
                        item = g_list_next(item);
                }
                g_string_append(sql, ")");
                break;
        }
}

G_DEFINE_TYPE(MidgardGroupConstraint, midgard_group_constraint, MIDGARD_TYPE_QUERY_CONSTRAINT)

static void midgard_group_constraint_init(MidgardGroupConstraint *self) {
        g_assert(self);
        self->type = MIDGARD_GROUP_CONSTRAINT_TYPE_AND;
        self->constraints = g_queue_new();
}

static void midgard_group_constraint_dispose(MidgardGroupConstraint *group) {
        g_assert(group);

        GQueue *constraints = group->constraints;
        group->constraints = g_queue_new();
        while (!g_queue_is_empty(constraints)) {
                g_object_unref(G_OBJECT(g_queue_pop_head(constraints)));
        }
        g_queue_free(constraints);

        GObjectClass *parent =
                G_OBJECT_CLASS(midgard_group_constraint_parent_class);
        parent->dispose(G_OBJECT(group));
}

static void midgard_group_constraint_finalize(MidgardGroupConstraint *group) {
        g_assert(group);

        g_queue_free(group->constraints);

        GObjectClass *parent =
                G_OBJECT_CLASS(midgard_group_constraint_parent_class);
        parent->finalize(G_OBJECT(group));
}

static void midgard_group_constraint_class_init(
                MidgardGroupConstraintClass *klass) {
        g_assert(klass);
        MIDGARD_QUERY_CONSTRAINT_CLASS(klass)->add_sql = add_sql;
        G_OBJECT_CLASS(klass)->dispose = (void (*)(GObject *self))
                midgard_group_constraint_dispose;
        G_OBJECT_CLASS(klass)->finalize = (void (*)(GObject *self))
                midgard_group_constraint_finalize;
}

static const gchar *const types[] = {
        MIDGARD_GROUP_CONSTRAINT_TYPE_AND,
        MIDGARD_GROUP_CONSTRAINT_TYPE_OR,
        NULL
};

MidgardGroupConstraint *midgard_group_constraint_new(const gchar *type) {
        g_assert(type);
        guint i;
        for (i = 0; types[i] != NULL; i++) {
                if (g_ascii_strcasecmp(types[i], type) == 0) {
                        MidgardGroupConstraint *group =
                                MIDGARD_GROUP_CONSTRAINT(g_object_new(
                                        MIDGARD_TYPE_GROUP_CONSTRAINT, NULL));
                        group->type = types[i];
                        return group;
                }
        }
        return NULL;
}

void midgard_group_constraint_add_constraint(
                MidgardGroupConstraint *group,
                MidgardQueryConstraint *constraint) {
        g_assert(group);
        g_assert(constraint);
        g_object_ref(G_OBJECT(constraint));
        g_queue_push_tail(group->constraints, constraint);
}

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