path: root/lib/ephy-autocompletion.c

/*
 *  Copyright (C) 2002  Ricardo Fernández Pascual
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, 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 <string.h>
#include <stdlib.h>

#include "ephy-autocompletion.h"
#include "ephy-gobject-misc.h"
#include "ephy-marshal.h"
#include "ephy-debug.h"

/**
 * Private data
 */

typedef enum {
    GAS_NEEDS_REFINE,
    GAS_NEEDS_FULL_UPDATE,
    GAS_UPDATED
} EphyAutocompletionStatus;

typedef struct {
    EphyAutocompletionMatch *array;
    guint num_matches;
    guint num_action_matches;
    guint array_size;
} ACMatchArray;

#define ACMA_BASE_SIZE 10240

struct _EphyAutocompletionPrivate {
    GSList *sources;

    guint nkeys;
    gchar **keys;
    guint *key_lengths;
    gchar **prefixes;
    guint *prefix_lengths;

    gchar *common_prefix;
    ACMatchArray matches;
    EphyAutocompletionStatus status;
    gboolean sorted;
    gboolean changed;

    gboolean sort_alpha;
};

/**
 * Private functions, only availble from this file
 */
static void     ephy_autocompletion_class_init          (EphyAutocompletionClass *klass);
static void     ephy_autocompletion_init            (EphyAutocompletion *e);
static void     ephy_autocompletion_finalize_impl       (GObject *o);
static void     ephy_autocompletion_reset           (EphyAutocompletion *ac);
static void     ephy_autocompletion_update_matches      (EphyAutocompletion *ac);
static void     ephy_autocompletion_update_matches_full     (EphyAutocompletion *ac);
static gboolean     ephy_autocompletion_sort_by_score       (EphyAutocompletion *ac);
static void     ephy_autocompletion_data_changed_cb     (EphyAutocompletionSource *s,
                                     EphyAutocompletion *ac);

static void     acma_init                   (ACMatchArray *a);
static void     acma_destroy                    (ACMatchArray *a);
static inline void  acma_append                 (ACMatchArray *a,
                                     EphyAutocompletionMatch *m,
                                     gboolean action);
static void     acma_grow                   (ACMatchArray *a);


static gpointer g_object_class;

/**
 * Signals enums and ids
 */
enum EphyAutocompletionSignalsEnum {
    EPHY_AUTOCOMPLETION_SOURCES_CHANGED,
    EPHY_AUTOCOMPLETION_LAST_SIGNAL
};
static gint EphyAutocompletionSignals[EPHY_AUTOCOMPLETION_LAST_SIGNAL];

/**
 * Autocompletion object
 */

MAKE_GET_TYPE (ephy_autocompletion, "EphyAutocompletion", EphyAutocompletion,
       ephy_autocompletion_class_init, ephy_autocompletion_init, G_TYPE_OBJECT);

static void
ephy_autocompletion_class_init (EphyAutocompletionClass *klass)
{
    G_OBJECT_CLASS (klass)->finalize = ephy_autocompletion_finalize_impl;
    g_object_class = g_type_class_peek_parent (klass);

    EphyAutocompletionSignals[EPHY_AUTOCOMPLETION_SOURCES_CHANGED] = g_signal_new (
        "sources-changed", G_OBJECT_CLASS_TYPE (klass),
        G_SIGNAL_RUN_FIRST | G_SIGNAL_RUN_LAST | G_SIGNAL_RUN_CLEANUP,
                G_STRUCT_OFFSET (EphyAutocompletionClass, sources_changed),
        NULL, NULL,
        ephy_marshal_VOID__VOID,
        G_TYPE_NONE, 0);
}

static void
ephy_autocompletion_init (EphyAutocompletion *ac)
{
    EphyAutocompletionPrivate *p = g_new0 (EphyAutocompletionPrivate, 1);
    ac->priv = p;
    p->sources = NULL;
    p->common_prefix = NULL;
    acma_init (&p->matches);
    p->status = GAS_NEEDS_FULL_UPDATE;

    p->nkeys = 1;

    p->keys = g_new0 (gchar *, 2);
    p->keys[0] = g_strdup ("");
    p->key_lengths = g_new0 (guint, 2);
    p->key_lengths[0] = 0;

    p->prefixes = g_new0 (gchar *, 2);
    p->prefixes[0] = g_strdup ("");
    p->prefix_lengths = g_new0 (guint, 2);
    p->prefix_lengths[0] = 0;

    p->sort_alpha = TRUE;
}

static void
ephy_autocompletion_finalize_impl (GObject *o)
{
    EphyAutocompletion *ac = EPHY_AUTOCOMPLETION (o);
    EphyAutocompletionPrivate *p = ac->priv;
    GSList *li;

    ephy_autocompletion_reset (ac);

    for (li = p->sources; li; li = li->next)
    {
        g_signal_handlers_disconnect_by_func (li->data,
                              ephy_autocompletion_data_changed_cb, ac);
        g_object_unref (li->data);
    }

    g_slist_free (p->sources);

    g_strfreev (p->keys);
    g_free (p->key_lengths);
    g_strfreev (p->prefixes);
    g_free (p->prefix_lengths);

    G_OBJECT_CLASS (g_object_class)->finalize (o);

}

static void
ephy_autocompletion_reset (EphyAutocompletion *ac)
{
    EphyAutocompletionPrivate *p = ac->priv;

    START_PROFILER ("Resetting autocompletion")

    g_free (p->common_prefix);
    p->common_prefix = NULL;
    p->status = GAS_NEEDS_FULL_UPDATE;

    STOP_PROFILER ("Resetting autocompletion")
}

EphyAutocompletion *
ephy_autocompletion_new (void)
{
    EphyAutocompletion *ret = g_object_new (EPHY_TYPE_AUTOCOMPLETION, NULL);
    return ret;
}
void
ephy_autocompletion_add_source (EphyAutocompletion *ac,
                EphyAutocompletionSource *s)
{
    EphyAutocompletionPrivate *p = ac->priv;
    g_object_ref (G_OBJECT (s));
    p->sources = g_slist_prepend (p->sources, s);
    ephy_autocompletion_reset (ac);
    g_signal_connect (s, "data-changed", G_CALLBACK (ephy_autocompletion_data_changed_cb), ac);

    g_signal_emit (ac, EphyAutocompletionSignals[EPHY_AUTOCOMPLETION_SOURCES_CHANGED], 0);
}

void
ephy_autocompletion_set_key (EphyAutocompletion *ac,
                 const gchar *key)
{
    EphyAutocompletionPrivate *p = ac->priv;
    guint i;
    guint keylen = strlen (key);

    if (strcmp (key, p->keys[0]))
    {
        GSList *li;
        for (li = p->sources; li; li = li->next)
        {
            ephy_autocompletion_source_set_basic_key
                (EPHY_AUTOCOMPLETION_SOURCE (li->data), key);
        }
    }

    LOG ("Set key %s, old key %s", key, p->keys[0])

    if (keylen >= p->key_lengths[0]
        && !strncmp (p->keys[0], key, p->key_lengths[0]))
    {
        if (!strcmp (key, p->keys[0]))
        {
            return;
        }
        if (p->status != GAS_NEEDS_FULL_UPDATE)
        {
            p->status = GAS_NEEDS_REFINE;
        }
        if (p->common_prefix)
        {
            if (strncmp (p->common_prefix, key, keylen))
            {
                g_free (p->common_prefix);
                p->common_prefix = NULL;
            }
        }
    }
    else
    {
        p->status = GAS_NEEDS_FULL_UPDATE;
        g_free (p->common_prefix);
        p->common_prefix = NULL;
    }

    for (i = 0; p->prefixes[i]; ++i)
    {
        g_free (p->keys[i]);
        p->keys[i] = g_strconcat (p->prefixes[i], key, NULL);
        p->key_lengths[i] = keylen + p->prefix_lengths[i];
    }

}

gchar *
ephy_autocompletion_get_common_prefix (EphyAutocompletion *ac)
{
    EphyAutocompletionPrivate *p = ac->priv;
    ephy_autocompletion_update_matches (ac);
    if (!p->common_prefix)
    {
        guint common_length = 0;
        guint i;

        START_PROFILER ("Get Common Prefix")

        for (i = 0; i < p->matches.num_matches; i++)
        {
            EphyAutocompletionMatch *mi = &p->matches.array[i];
            const gchar *realmatch = mi->title + mi->offset;
            if (!p->common_prefix)
            {
                p->common_prefix = g_strdup (realmatch);
                common_length = strlen (p->common_prefix);
                continue;
            }
            else if (!strncmp (realmatch, p->common_prefix, common_length))
            {
                continue;
            }
            else
            {
                common_length = 0;
                while (realmatch[common_length]
                       && realmatch[common_length] == p->common_prefix[common_length])
                {
                    ++common_length;
                }
                g_free (p->common_prefix);
                p->common_prefix = g_strndup (realmatch, common_length);
            }
        }

        STOP_PROFILER ("Get Common Prefix")
    }
    return g_strdup (p->common_prefix);
}

const EphyAutocompletionMatch *
ephy_autocompletion_get_matches (EphyAutocompletion *ac)
{
    ephy_autocompletion_update_matches (ac);
    return ac->priv->matches.array;
}

const EphyAutocompletionMatch *
ephy_autocompletion_get_matches_sorted_by_score (EphyAutocompletion *ac,
                         gboolean *changed)
{
    *changed = ephy_autocompletion_sort_by_score (ac);
    return ac->priv->matches.array;
}

guint
ephy_autocompletion_get_num_matches (EphyAutocompletion *ac)
{
    ephy_autocompletion_update_matches (ac);

    return ac->priv->matches.num_matches;
}

guint
ephy_autocompletion_get_num_action_matches (EphyAutocompletion *ac)
{
    return ac->priv->matches.num_matches -
        ac->priv->matches.num_action_matches;
}

static void
ephy_autocompletion_refine_matches (EphyAutocompletion *ac)
{
    EphyAutocompletionPrivate *p = ac->priv;
    ACMatchArray oldmatches = p->matches;
    ACMatchArray newmatches;
    guint i;
    gchar *key0 = p->keys[0];
    guint key0l = p->key_lengths[0];

    START_PROFILER ("Refine matches")

    acma_init (&newmatches);

    p->changed = FALSE;

    for (i = 0; i < oldmatches.num_matches; i++)
    {
        EphyAutocompletionMatch *mi = &oldmatches.array[i];

        if (mi->is_action ||
            (mi->substring && g_strrstr (mi->match, p->keys[0])) ||
            (mi->substring && g_strrstr (mi->title, p->keys[0])) ||
            !strncmp (key0, mi->title + mi->offset, key0l))
        {
            acma_append (&newmatches, mi, mi->is_action);
        }
        else
        {
            p->changed = TRUE;
        }
    }

    acma_destroy (&oldmatches);
    p->matches = newmatches;

    STOP_PROFILER ("Refine matches")
}

static void
ephy_autocompletion_update_matches (EphyAutocompletion *ac)
{
    EphyAutocompletionPrivate *p = ac->priv;
    if (p->status == GAS_UPDATED)
    {
        return;
    }
    if (p->status == GAS_NEEDS_FULL_UPDATE)
    {
        ephy_autocompletion_update_matches_full (ac);
    }
    if (p->status == GAS_NEEDS_REFINE)
    {
        /* FIXME we do full update for now */
        ephy_autocompletion_refine_matches (ac);
    }

    g_free (p->common_prefix);
    p->common_prefix = NULL;
    p->status = GAS_UPDATED;
}

static void
ephy_autocompletion_update_matches_full_item (EphyAutocompletionSource *source,
                          const char *item,
                          const char *title,
                          const char *target,
                          gboolean is_action,
                          gboolean substring,
                          guint32 score,
                          EphyAutocompletionPrivate *p)
{
    if (is_action ||
        (substring && g_strrstr (item, p->keys[0])) ||
        (substring && g_strrstr (title, p->keys[0])))
    {
        EphyAutocompletionMatch m;
        m.match = item;
        m.title = title;
        m.target = target;
        m.is_action = is_action;
        m.substring = substring;
        m.offset = 0;
        m.score = score;
        acma_append (&p->matches, &m, is_action);
    }
    else
    {
        guint i;
        for (i = 0; p->keys[i]; ++i)
        {
            if (!strncmp (item, p->keys[i], p->key_lengths[i]))
            {
                EphyAutocompletionMatch m;
                m.match = item;
                m.title = title;
                m.target = target;
                m.is_action = is_action;
                m.substring = substring;
                m.offset = p->prefix_lengths[i];
                m.score = score;
                acma_append (&p->matches, &m, is_action);
            }
        }
    }
}

static void
ephy_autocompletion_update_matches_full (EphyAutocompletion *ac)
{
    EphyAutocompletionPrivate *p = ac->priv;
    GSList *li;

    START_PROFILER ("Update full")

    acma_destroy (&p->matches);

    for (li = p->sources; li; li = li->next)
    {
        EphyAutocompletionSource *s = EPHY_AUTOCOMPLETION_SOURCE (li->data);
        g_assert (s);
        ephy_autocompletion_source_foreach (s, p->keys[0],
                            (EphyAutocompletionSourceForeachFunc)
                            ephy_autocompletion_update_matches_full_item,
                            p);
    }

    STOP_PROFILER ("Update full")

    p->sorted = FALSE;
    p->changed = TRUE;

    LOG ("AC: %d matches, fully updated", p->matches.num_matches);
}

static gint
ephy_autocompletion_compare_scores (EphyAutocompletionMatch *a, EphyAutocompletionMatch *b)
{
    /* higher scores first */
    return b->score - a->score;
}

static gint
ephy_autocompletion_compare_scores_and_alpha (EphyAutocompletionMatch *a, EphyAutocompletionMatch *b)
{
    if (a->score == b->score)
    {
        return strcmp (a->title, b->title);
    }
    else
    {
        /* higher scores first */
        return b->score - a->score;
    }
}

static gboolean
ephy_autocompletion_sort_by_score (EphyAutocompletion *ac)
{
    EphyAutocompletionPrivate *p = ac->priv;

    gint (*comparer) (EphyAutocompletionMatch *m1, EphyAutocompletionMatch *m2);

    if (p->sort_alpha)
    {
        comparer = ephy_autocompletion_compare_scores_and_alpha;
    }
    else
    {
        comparer = ephy_autocompletion_compare_scores;
    }

    ephy_autocompletion_update_matches (ac);
    if (p->changed == FALSE) return FALSE;

    START_PROFILER ("Sorting")

    if (p->matches.num_matches > 0)
    {
        qsort (p->matches.array, p->matches.num_matches,
               sizeof (EphyAutocompletionMatch),
               (void *) comparer);
    }

    p->sorted = TRUE;

    STOP_PROFILER ("Sorting")

    return TRUE;
}

static void
ephy_autocompletion_data_changed_cb (EphyAutocompletionSource *s,
                     EphyAutocompletion *ac)
{
    LOG ("Data changed, resetting");
    ephy_autocompletion_reset (ac);

    g_signal_emit (ac, EphyAutocompletionSignals[EPHY_AUTOCOMPLETION_SOURCES_CHANGED], 0);
}

void
ephy_autocompletion_set_prefixes (EphyAutocompletion *ac,
                  const gchar **prefixes)
{
    EphyAutocompletionPrivate *p = ac->priv;
    guint nprefixes = 0;
    gchar *oldkey = g_strdup (p->keys[0]);
    guint i;

    /* count prefixes */
    while (prefixes[nprefixes])
    {
        ++nprefixes;
    }

    nprefixes--;

    g_strfreev (p->keys);
    g_free (p->key_lengths);
    g_strfreev (p->prefixes);
    g_free (p->prefix_lengths);

    p->prefixes = g_new0 (gchar *, nprefixes + 2);
    p->prefix_lengths = g_new0 (guint, nprefixes + 2);
    p->keys = g_new0 (gchar *, nprefixes + 2);
    p->key_lengths = g_new0 (guint, nprefixes + 2);

    p->prefixes[0] = g_strdup ("");
    p->prefix_lengths[0] = 0;
    p->keys[0] = oldkey;
    p->key_lengths[0] = strlen (p->keys[0]);

    for (i = 0; i < nprefixes; ++i)
    {
        p->prefixes[i + 1] = g_strdup (prefixes[i]);
        p->prefix_lengths[i + 1] = strlen (prefixes[i]);
        p->keys[i + 1] = g_strconcat (p->prefixes[i + 1], p->keys[0], NULL);
        p->key_lengths[i + 1] = p->prefix_lengths[i + 1] + p->key_lengths[0];
    }

    p->nkeys = nprefixes;
}


/* ACMatchArray */

static void
acma_init (ACMatchArray *a)
{
    a->array = NULL;
    a->array_size = 0;
    a->num_matches = 0;
}

/**
 * Does not free the struct itself, only its contents
 */
static void
acma_destroy (ACMatchArray *a)
{
    g_free (a->array);
    a->array = NULL;
    a->array_size = 0;
    a->num_matches = 0;
    a->num_action_matches = 0;
}

static inline void
acma_append (ACMatchArray *a,
         EphyAutocompletionMatch *m,
         gboolean action)
{
    if (a->array_size == a->num_matches)
    {
        acma_grow (a);
    }

    a->array[a->num_matches] = *m;
    a->num_matches++;
    if (action) a->num_action_matches++;
}

static void
acma_grow (ACMatchArray *a)
{
    gint new_size;
    EphyAutocompletionMatch *new_array;

    new_size = a->array_size + ACMA_BASE_SIZE;
    new_array = g_renew (EphyAutocompletionMatch, a->array, new_size);

    a->array_size = new_size;
    a->array = new_array;
}