static int32
lm3g_tg_score(NGRAM_MODEL_TYPE *model, int32 lw1,
int32 lw2, int32 lw3, int32 *n_used)
{
ngram_model_t *base = &model->base;
int32 i, n, score;
trigram_t *tg;
tginfo_t *tginfo, *prev_tginfo;
if ((base->n < 3) || (lw1 < 0) || (lw2 < 0))
return (lm3g_bg_score(model, lw2, lw3, n_used));
sbmtx_lock(model->lm3g.tginfo_mtx);
prev_tginfo = NULL;
for (tginfo = model->lm3g.tginfo[lw2]; tginfo; tginfo = tginfo->next) {
if (tginfo->w1 == lw1)
break;
prev_tginfo = tginfo;
}
if (!tginfo) {
load_tginfo(model, lw1, lw2);
tginfo = model->lm3g.tginfo[lw2];
}
else if (prev_tginfo) {
prev_tginfo->next = tginfo->next;
tginfo->next = model->lm3g.tginfo[lw2];
model->lm3g.tginfo[lw2] = tginfo;
}
tginfo->used = 1;
/* Trigrams for w1,w2 now pointed to by tginfo */
n = tginfo->n_tg;
tg = tginfo->tg;
if ((i = find_tg(tg, n, lw3)) >= 0) {
/* Access mode = trigram */
if (n_used) *n_used = 3;
score = model->lm3g.prob3[tg[i].prob3].l;
}
else {
score = tginfo->bowt + lm3g_bg_score(model, lw2, lw3, n_used);
}
sbmtx_unlock(model->lm3g.tginfo_mtx);
return (score);
}
static ngram_iter_t *
lm3g_template_iter(ngram_model_t *base, int32 wid,
int32 *history, int32 n_hist)
{
NGRAM_MODEL_TYPE *model = (NGRAM_MODEL_TYPE *)base;
lm3g_iter_t *itor = (lm3g_iter_t *)ckd_calloc(1, sizeof(*itor));
ngram_iter_init((ngram_iter_t *)itor, base, n_hist, FALSE);
if (n_hist == 0) {
/* Unigram is the easiest. */
itor->ug = model->lm3g.unigrams + wid;
return (ngram_iter_t *)itor;
}
else if (n_hist == 1) {
int32 i, n, b;
/* Find the bigram, as in bg_score above (duplicate code...) */
itor->ug = model->lm3g.unigrams + history[0];
b = FIRST_BG(model, history[0]);
n = FIRST_BG(model, history[0] + 1) - b;
itor->bg = model->lm3g.bigrams + b;
/* If no such bigram exists then fail. */
if ((i = find_bg(itor->bg, n, wid)) < 0) {
ngram_iter_free((ngram_iter_t *)itor);
return NULL;
}
itor->bg += i;
return (ngram_iter_t *)itor;
}
else if (n_hist == 2) {
int32 i, n;
tginfo_t *tginfo, *prev_tginfo;
/* Find the trigram, as in tg_score above (duplicate code...) */
itor->ug = model->lm3g.unigrams + history[1];
prev_tginfo = NULL;
for (tginfo = model->lm3g.tginfo[history[0]];
tginfo; tginfo = tginfo->next) {
if (tginfo->w1 == history[1])
break;
prev_tginfo = tginfo;
}
if (!tginfo) {
load_tginfo(model, history[1], history[0]);
tginfo = model->lm3g.tginfo[history[0]];
}
else if (prev_tginfo) {
prev_tginfo->next = tginfo->next;
tginfo->next = model->lm3g.tginfo[history[0]];
model->lm3g.tginfo[history[0]] = tginfo;
}
tginfo->used = 1;
/* Trigrams for w1,w2 now pointed to by tginfo */
n = tginfo->n_tg;
itor->tg = tginfo->tg;
if ((i = find_tg(itor->tg, n, wid)) >= 0) {
itor->tg += i;
/* Now advance the bigram pointer accordingly. FIXME:
* Note that we actually already found the relevant bigram
* in load_tginfo. */
itor->bg = model->lm3g.bigrams;
while (FIRST_TG(model, (itor->bg - model->lm3g.bigrams + 1))
<= (itor->tg - model->lm3g.trigrams))
++itor->bg;
return (ngram_iter_t *)itor;
}
else {
ngram_iter_free((ngram_iter_t *)itor);
return (ngram_iter_t *)NULL;
}
}
else {
/* Should not happen. */
assert(n_hist == 0); /* Guaranteed to fail. */
ngram_iter_free((ngram_iter_t *)itor);
return NULL;
}
}
