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authorarmatthews <armatthe@cmu.edu>2014-10-13 14:59:23 -0400
committerarmatthews <armatthe@cmu.edu>2014-10-13 14:59:23 -0400
commit9a06ff1465eb3477ac3d1e92ab52e7eae40316a8 (patch)
tree808c266a3f510d00f37cd19c3f1da91d8fc683f7 /klm/lm/wrappers
parente51da099233df0a384b04fe5908b30e44040d13e (diff)
parentd3e2ec203a5cf550320caa8023ac3dd103b0be7d (diff)
Merge branch 'master' of github.com:redpony/cdec
Diffstat (limited to 'klm/lm/wrappers')
-rw-r--r--klm/lm/wrappers/README3
-rw-r--r--klm/lm/wrappers/nplm.cc90
-rw-r--r--klm/lm/wrappers/nplm.hh83
3 files changed, 176 insertions, 0 deletions
diff --git a/klm/lm/wrappers/README b/klm/lm/wrappers/README
new file mode 100644
index 00000000..56c34c23
--- /dev/null
+++ b/klm/lm/wrappers/README
@@ -0,0 +1,3 @@
+This directory is for wrappers around other people's LMs, presenting an interface similar to KenLM's. You will need to have their LM installed.
+
+NPLM is a work in progress.
diff --git a/klm/lm/wrappers/nplm.cc b/klm/lm/wrappers/nplm.cc
new file mode 100644
index 00000000..70622bd2
--- /dev/null
+++ b/klm/lm/wrappers/nplm.cc
@@ -0,0 +1,90 @@
+#include "lm/wrappers/nplm.hh"
+#include "util/exception.hh"
+#include "util/file.hh"
+
+#include <algorithm>
+
+#include <string.h>
+
+#include "neuralLM.h"
+
+namespace lm {
+namespace np {
+
+Vocabulary::Vocabulary(const nplm::vocabulary &vocab)
+ : base::Vocabulary(vocab.lookup_word("<s>"), vocab.lookup_word("</s>"), vocab.lookup_word("<unk>")),
+ vocab_(vocab), null_word_(vocab.lookup_word("<null>")) {}
+
+Vocabulary::~Vocabulary() {}
+
+WordIndex Vocabulary::Index(const std::string &str) const {
+ return vocab_.lookup_word(str);
+}
+
+bool Model::Recognize(const std::string &name) {
+ try {
+ util::scoped_fd file(util::OpenReadOrThrow(name.c_str()));
+ char magic_check[16];
+ util::ReadOrThrow(file.get(), magic_check, sizeof(magic_check));
+ const char nnlm_magic[] = "\\config\nversion ";
+ return !memcmp(magic_check, nnlm_magic, 16);
+ } catch (const util::Exception &) {
+ return false;
+ }
+}
+
+Model::Model(const std::string &file, std::size_t cache)
+ : base_instance_(new nplm::neuralLM(file)), vocab_(base_instance_->get_vocabulary()), cache_size_(cache) {
+ UTIL_THROW_IF(base_instance_->get_order() > NPLM_MAX_ORDER, util::Exception, "This NPLM has order " << (unsigned int)base_instance_->get_order() << " but the KenLM wrapper was compiled with " << NPLM_MAX_ORDER << ". Change the defintion of NPLM_MAX_ORDER and recompile.");
+ // log10 compatible with backoff models.
+ base_instance_->set_log_base(10.0);
+ State begin_sentence, null_context;
+ std::fill(begin_sentence.words, begin_sentence.words + NPLM_MAX_ORDER - 1, base_instance_->lookup_word("<s>"));
+ null_word_ = base_instance_->lookup_word("<null>");
+ std::fill(null_context.words, null_context.words + NPLM_MAX_ORDER - 1, null_word_);
+
+ Init(begin_sentence, null_context, vocab_, base_instance_->get_order());
+}
+
+Model::~Model() {}
+
+FullScoreReturn Model::FullScore(const State &from, const WordIndex new_word, State &out_state) const {
+ nplm::neuralLM *lm = backend_.get();
+ if (!lm) {
+ lm = new nplm::neuralLM(*base_instance_);
+ backend_.reset(lm);
+ lm->set_cache(cache_size_);
+ }
+ // State is in natural word order.
+ FullScoreReturn ret;
+ for (int i = 0; i < lm->get_order() - 1; ++i) {
+ lm->staging_ngram()(i) = from.words[i];
+ }
+ lm->staging_ngram()(lm->get_order() - 1) = new_word;
+ ret.prob = lm->lookup_from_staging();
+ // Always say full order.
+ ret.ngram_length = lm->get_order();
+ // Shift everything down by one.
+ memcpy(out_state.words, from.words + 1, sizeof(WordIndex) * (lm->get_order() - 2));
+ out_state.words[lm->get_order() - 2] = new_word;
+ // Fill in trailing words with zeros so state comparison works.
+ memset(out_state.words + lm->get_order() - 1, 0, sizeof(WordIndex) * (NPLM_MAX_ORDER - lm->get_order()));
+ return ret;
+}
+
+// TODO: optimize with direct call?
+FullScoreReturn Model::FullScoreForgotState(const WordIndex *context_rbegin, const WordIndex *context_rend, const WordIndex new_word, State &out_state) const {
+ // State is in natural word order. The API here specifies reverse order.
+ std::size_t state_length = std::min<std::size_t>(Order() - 1, context_rend - context_rbegin);
+ State state;
+ // Pad with null words.
+ for (lm::WordIndex *i = state.words; i < state.words + Order() - 1 - state_length; ++i) {
+ *i = null_word_;
+ }
+ // Put new words at the end.
+ std::reverse_copy(context_rbegin, context_rbegin + state_length, state.words + Order() - 1 - state_length);
+ return FullScore(state, new_word, out_state);
+}
+
+} // namespace np
+} // namespace lm
diff --git a/klm/lm/wrappers/nplm.hh b/klm/lm/wrappers/nplm.hh
new file mode 100644
index 00000000..b7dd4a21
--- /dev/null
+++ b/klm/lm/wrappers/nplm.hh
@@ -0,0 +1,83 @@
+#ifndef LM_WRAPPERS_NPLM_H
+#define LM_WRAPPERS_NPLM_H
+
+#include "lm/facade.hh"
+#include "lm/max_order.hh"
+#include "util/string_piece.hh"
+
+#include <boost/thread/tss.hpp>
+#include <boost/scoped_ptr.hpp>
+
+/* Wrapper to NPLM "by Ashish Vaswani, with contributions from David Chiang
+ * and Victoria Fossum."
+ * http://nlg.isi.edu/software/nplm/
+ */
+
+namespace nplm {
+class vocabulary;
+class neuralLM;
+} // namespace nplm
+
+namespace lm {
+namespace np {
+
+class Vocabulary : public base::Vocabulary {
+ public:
+ Vocabulary(const nplm::vocabulary &vocab);
+
+ ~Vocabulary();
+
+ WordIndex Index(const std::string &str) const;
+
+ // TODO: lobby them to support StringPiece
+ WordIndex Index(const StringPiece &str) const {
+ return Index(std::string(str.data(), str.size()));
+ }
+
+ lm::WordIndex NullWord() const { return null_word_; }
+
+ private:
+ const nplm::vocabulary &vocab_;
+
+ const lm::WordIndex null_word_;
+};
+
+// Sorry for imposing my limitations on your code.
+#define NPLM_MAX_ORDER 7
+
+struct State {
+ WordIndex words[NPLM_MAX_ORDER - 1];
+};
+
+class Model : public lm::base::ModelFacade<Model, State, Vocabulary> {
+ private:
+ typedef lm::base::ModelFacade<Model, State, Vocabulary> P;
+
+ public:
+ // Does this look like an NPLM?
+ static bool Recognize(const std::string &file);
+
+ explicit Model(const std::string &file, std::size_t cache_size = 1 << 20);
+
+ ~Model();
+
+ FullScoreReturn FullScore(const State &from, const WordIndex new_word, State &out_state) const;
+
+ FullScoreReturn FullScoreForgotState(const WordIndex *context_rbegin, const WordIndex *context_rend, const WordIndex new_word, State &out_state) const;
+
+ private:
+ boost::scoped_ptr<nplm::neuralLM> base_instance_;
+
+ mutable boost::thread_specific_ptr<nplm::neuralLM> backend_;
+
+ Vocabulary vocab_;
+
+ lm::WordIndex null_word_;
+
+ const std::size_t cache_size_;
+};
+
+} // namespace np
+} // namespace lm
+
+#endif // LM_WRAPPERS_NPLM_H