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authorKenneth Heafield <github@kheafield.com>2012-09-11 14:23:39 +0100
committerKenneth Heafield <github@kheafield.com>2012-09-11 14:27:52 +0100
commit8882e9ebe158aef382bb5544559ef7f2a553db62 (patch)
treef0ed595a45df16ddd1ca7ba61bc4ac0ee22d2dfb /klm/lm/partial.hh
parent104e23dd0b0795abab4565228537438481dc5a5b (diff)
Update kenlm and build system
Diffstat (limited to 'klm/lm/partial.hh')
-rw-r--r--klm/lm/partial.hh167
1 files changed, 167 insertions, 0 deletions
diff --git a/klm/lm/partial.hh b/klm/lm/partial.hh
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--- /dev/null
+++ b/klm/lm/partial.hh
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+#ifndef LM_PARTIAL__
+#define LM_PARTIAL__
+
+#include "lm/return.hh"
+#include "lm/state.hh"
+
+#include <algorithm>
+
+#include <assert.h>
+
+namespace lm {
+namespace ngram {
+
+struct ExtendReturn {
+ float adjust;
+ bool make_full;
+ unsigned char next_use;
+};
+
+template <class Model> ExtendReturn ExtendLoop(
+ const Model &model,
+ unsigned char seen, const WordIndex *add_rbegin, const WordIndex *add_rend, const float *backoff_start,
+ const uint64_t *pointers, const uint64_t *pointers_end,
+ uint64_t *&pointers_write,
+ float *backoff_write) {
+ unsigned char add_length = add_rend - add_rbegin;
+
+ float backoff_buf[2][KENLM_MAX_ORDER - 1];
+ float *backoff_in = backoff_buf[0], *backoff_out = backoff_buf[1];
+ std::copy(backoff_start, backoff_start + add_length, backoff_in);
+
+ ExtendReturn value;
+ value.make_full = false;
+ value.adjust = 0.0;
+ value.next_use = add_length;
+
+ unsigned char i = 0;
+ unsigned char length = pointers_end - pointers;
+ // pointers_write is NULL means that the existing left state is full, so we should use completed probabilities.
+ if (pointers_write) {
+ // Using full context, writing to new left state.
+ for (; i < length; ++i) {
+ FullScoreReturn ret(model.ExtendLeft(
+ add_rbegin, add_rbegin + value.next_use,
+ backoff_in,
+ pointers[i], i + seen + 1,
+ backoff_out,
+ value.next_use));
+ std::swap(backoff_in, backoff_out);
+ if (ret.independent_left) {
+ value.adjust += ret.prob;
+ value.make_full = true;
+ ++i;
+ break;
+ }
+ value.adjust += ret.rest;
+ *pointers_write++ = ret.extend_left;
+ if (value.next_use != add_length) {
+ value.make_full = true;
+ ++i;
+ break;
+ }
+ }
+ }
+ // Using some of the new context.
+ for (; i < length && value.next_use; ++i) {
+ FullScoreReturn ret(model.ExtendLeft(
+ add_rbegin, add_rbegin + value.next_use,
+ backoff_in,
+ pointers[i], i + seen + 1,
+ backoff_out,
+ value.next_use));
+ std::swap(backoff_in, backoff_out);
+ value.adjust += ret.prob;
+ }
+ float unrest = model.UnRest(pointers + i, pointers_end, i + seen + 1);
+ // Using none of the new context.
+ value.adjust += unrest;
+
+ std::copy(backoff_in, backoff_in + value.next_use, backoff_write);
+ return value;
+}
+
+template <class Model> float RevealBefore(const Model &model, const Right &reveal, const unsigned char seen, bool reveal_full, Left &left, Right &right) {
+ assert(seen < reveal.length || reveal_full);
+ uint64_t *pointers_write = reveal_full ? NULL : left.pointers;
+ float backoff_buffer[KENLM_MAX_ORDER - 1];
+ ExtendReturn value(ExtendLoop(
+ model,
+ seen, reveal.words + seen, reveal.words + reveal.length, reveal.backoff + seen,
+ left.pointers, left.pointers + left.length,
+ pointers_write,
+ left.full ? backoff_buffer : (right.backoff + right.length)));
+ if (reveal_full) {
+ left.length = 0;
+ value.make_full = true;
+ } else {
+ left.length = pointers_write - left.pointers;
+ value.make_full |= (left.length == model.Order() - 1);
+ }
+ if (left.full) {
+ for (unsigned char i = 0; i < value.next_use; ++i) value.adjust += backoff_buffer[i];
+ } else {
+ // If left wasn't full when it came in, put words into right state.
+ std::copy(reveal.words + seen, reveal.words + seen + value.next_use, right.words + right.length);
+ right.length += value.next_use;
+ left.full = value.make_full || (right.length == model.Order() - 1);
+ }
+ return value.adjust;
+}
+
+template <class Model> float RevealAfter(const Model &model, Left &left, Right &right, const Left &reveal, unsigned char seen) {
+ assert(seen < reveal.length || reveal.full);
+ uint64_t *pointers_write = left.full ? NULL : (left.pointers + left.length);
+ ExtendReturn value(ExtendLoop(
+ model,
+ seen, right.words, right.words + right.length, right.backoff,
+ reveal.pointers + seen, reveal.pointers + reveal.length,
+ pointers_write,
+ right.backoff));
+ if (reveal.full) {
+ for (unsigned char i = 0; i < value.next_use; ++i) value.adjust += right.backoff[i];
+ right.length = 0;
+ value.make_full = true;
+ } else {
+ right.length = value.next_use;
+ value.make_full |= (right.length == model.Order() - 1);
+ }
+ if (!left.full) {
+ left.length = pointers_write - left.pointers;
+ left.full = value.make_full || (left.length == model.Order() - 1);
+ }
+ return value.adjust;
+}
+
+template <class Model> float Subsume(const Model &model, Left &first_left, const Right &first_right, const Left &second_left, Right &second_right, const unsigned int between_length) {
+ assert(first_right.length < KENLM_MAX_ORDER);
+ assert(second_left.length < KENLM_MAX_ORDER);
+ assert(between_length < KENLM_MAX_ORDER - 1);
+ uint64_t *pointers_write = first_left.full ? NULL : (first_left.pointers + first_left.length);
+ float backoff_buffer[KENLM_MAX_ORDER - 1];
+ ExtendReturn value(ExtendLoop(
+ model,
+ between_length, first_right.words, first_right.words + first_right.length, first_right.backoff,
+ second_left.pointers, second_left.pointers + second_left.length,
+ pointers_write,
+ second_left.full ? backoff_buffer : (second_right.backoff + second_right.length)));
+ if (second_left.full) {
+ for (unsigned char i = 0; i < value.next_use; ++i) value.adjust += backoff_buffer[i];
+ } else {
+ std::copy(first_right.words, first_right.words + value.next_use, second_right.words + second_right.length);
+ second_right.length += value.next_use;
+ value.make_full |= (second_right.length == model.Order() - 1);
+ }
+ if (!first_left.full) {
+ first_left.length = pointers_write - first_left.pointers;
+ first_left.full = value.make_full || second_left.full || (first_left.length == model.Order() - 1);
+ }
+ assert(first_left.length < KENLM_MAX_ORDER);
+ assert(second_right.length < KENLM_MAX_ORDER);
+ return value.adjust;
+}
+
+} // namespace ngram
+} // namespace lm
+
+#endif // LM_PARTIAL__