Add spellcheck and word suggestion to the prediction service

services/prediction/dictionary_service.cc

Index: services/prediction/dictionary_service.cc
diff --git a/services/prediction/dictionary_service.cc b/services/prediction/dictionary_service.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2e0600de65f3f054936add288ee9d76c3179b138
--- /dev/null
+++ b/services/prediction/dictionary_service.cc
@@ -0,0 +1,199 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <algorithm>
+#include <deque>
+#include <fstream>
+#include <string>
+
+#include "base/base_paths.h"
+#include "base/files/file_path.h"
+#include "base/path_service.h"
+#include "base/strings/string16.h"
+#include "base/strings/utf_string_conversions.h"
+#include "mojo/services/prediction/public/interfaces/prediction.mojom.h"
+#include "mojo/tools/embed/data.h"
+#include "services/prediction/dictionary_service.h"
+#include "services/prediction/input_info.h"
+#include "services/prediction/kDictFile.h"
+#include "services/prediction/key_set.h"
+#include "services/prediction/proximity_info_factory.h"
+#include "third_party/android_prediction/suggest/core/dictionary/dictionary.h"
+#include "third_party/android_prediction/suggest/core/result/suggestion_results.h"
+#include "third_party/android_prediction/suggest/core/session/dic_traverse_session.h"
+#include "third_party/android_prediction/suggest/core/session/prev_words_info.h"
+#include "third_party/android_prediction/suggest/core/suggest_options.h"
+#include "third_party/android_prediction/suggest/policyimpl/dictionary/structure/dictionary_structure_with_buffer_policy_factory.h"
+
+namespace prediction {
+
+DictionaryService::DictionaryService() : max_suggestion_size_(50) {
+}
+
+DictionaryService::~DictionaryService() {
+}
+
+void DictionaryService::CreatDictFromEmbeddedDataIfNotExist(
+    const std::string path) {
+  if (std::ifstream(path.c_str()))
+    return;
+  std::ofstream dic_file(path.c_str(),
+                         std::ofstream::out | std::ofstream::binary);
+  dic_file.write(prediction::kDictFile.data, prediction::kDictFile.size);
+  dic_file.close();
+}
+
+latinime::Dictionary* const DictionaryService::OpenDictionary(
+    const std::string path,
+    const int start_offset,
+    const int size,
+    const bool is_updatable) {
+  latinime::DictionaryStructureWithBufferPolicy::StructurePolicyPtr
+      dictionary_structure_with_buffer_policy(
+          latinime::DictionaryStructureWithBufferPolicyFactory::
+              newPolicyForExistingDictFile(path.c_str(), start_offset, size,
+                                           is_updatable));
+  if (!dictionary_structure_with_buffer_policy) {
+    return nullptr;
+  }
+
+  latinime::Dictionary* const dictionary = new latinime::Dictionary(
+      std::move(dictionary_structure_with_buffer_policy));
+  return dictionary;
+}
+
+mojo::Array<mojo::String> DictionaryService::GetDictionarySuggestion(
+    PredictionInfoPtr prediction_info,
+    latinime::ProximityInfo* proximity_info) {
+  mojo::Array<mojo::String> suggestion_words =
+      mojo::Array<mojo::String>::New(0);
+
+  // dictionary
+  base::FilePath dir_temp;
+  PathService::Get(base::DIR_TEMP, &dir_temp);
+  std::string path = dir_temp.value() + "/main_en.dict";
+  if (!default_dictionary_) {
+    CreatDictFromEmbeddedDataIfNotExist(path);
+    default_dictionary_ = scoped_ptr<latinime::Dictionary>(
+        OpenDictionary(path, 0, prediction::kDictFile.size, false));
+    if (!default_dictionary_) {
+      return suggestion_words.Clone().Pass();
+    }
+  }
+
+  // dic_traverse_session
+  if (!default_session_) {
+    default_session_ = scoped_ptr<latinime::DicTraverseSession>(
+        reinterpret_cast<latinime::DicTraverseSession*>(
+            latinime::DicTraverseSession::getSessionInstance(
+                "en", prediction::kDictFile.size)));
+    latinime::PrevWordsInfo empty_prev_words;
+    default_session_->init(default_dictionary_.get(), &empty_prev_words, 0);
+  }
+
+  // current word
+  int input_size = std::min(
+      static_cast<int>(prediction_info->current_word.size()), MAX_WORD_LENGTH);
+  InputInfo input_info(prediction_info->current_word, input_size);
+  input_size = input_info.GetRealSize();
+
+  // previous words
+  latinime::PrevWordsInfo prev_words_info =
+      ProcessPrevWord(prediction_info->previous_words);
+
+  // suggestion options
+  // is_gesture, use_full_edit_distance,
+  // block_offensive_words, space_aware gesture_enabled
+  int options[] = {0, 0, 0, 0};
+  latinime::SuggestOptions suggest_options(options, arraysize(options));
+
+  latinime::SuggestionResults suggestion_results(max_suggestion_size_);
+  if (input_size > 0) {
+    default_dictionary_->getSuggestions(
+        proximity_info, default_session_.get(), input_info.GetXCoordinates(),
+        input_info.GetYCoordinates(), input_info.GetTimes(),
+        input_info.GetPointerIds(), input_info.GetCodepoints(), input_size,
+        &prev_words_info, &suggest_options, -1.0f, &suggestion_results);
+  } else {
+    default_dictionary_->getPredictions(&prev_words_info, &suggestion_results);
+  }
+
+  // process suggestion results
+  std::deque<std::string> suggestion_words_reverse;
+  char cur_beginning;
+  std::string lo_cur;
+  std::string up_cur;
+  if (input_size > 0) {
+    cur_beginning = prediction_info->current_word[0];
+    std::string cur_rest =
+        std::string(prediction_info->current_word.data())
+            .substr(1, prediction_info->current_word.size() - 1);
+    lo_cur = std::string(1, (char)tolower(cur_beginning)) + cur_rest;
+    up_cur = std::string(1, (char)toupper(cur_beginning)) + cur_rest;
+  }
+  while (!suggestion_results.mSuggestedWords.empty()) {
+    const latinime::SuggestedWord& suggested_word =
+        suggestion_results.mSuggestedWords.top();
+    base::string16 word;
+    for (int i = 0; i < suggested_word.getCodePointCount(); i++) {
+      base::char16 code_point = suggested_word.getCodePoint()[i];
+      word.push_back(code_point);
+    }
+    std::string word_string = base::UTF16ToUTF8(word);
+    if (word_string.compare(lo_cur) != 0 && word_string.compare(up_cur) != 0) {
+      if (input_size > 0 && isupper(cur_beginning)) {
+        word_string[0] = toupper(word_string[0]);
+      }
+      suggestion_words_reverse.push_front(word_string);
+    }
+    suggestion_results.mSuggestedWords.pop();
+  }
+
+  // remove dups within suggestion words
+  for (size_t i = 0; i < suggestion_words_reverse.size(); i++) {
+    for (size_t j = i + 1; j < suggestion_words_reverse.size(); j++) {
+      if (suggestion_words_reverse[i].compare(suggestion_words_reverse[j]) ==
+          0) {
+        suggestion_words_reverse.erase(suggestion_words_reverse.begin() + j);
+        j--;
+      }
+    }
+  }
+
+  for (std::deque<std::string>::iterator it = suggestion_words_reverse.begin();
+       it != suggestion_words_reverse.end(); ++it) {
+    suggestion_words.push_back(mojo::String(*it));
+  }
+
+  return suggestion_words.Clone().Pass();
+}
+
+// modified from Android JniDataUtils::constructPrevWordsInfo
+latinime::PrevWordsInfo DictionaryService::ProcessPrevWord(
+    mojo::Array<PrevWordInfoPtr>& prev_words) {
+  int prev_word_codepoints[MAX_PREV_WORD_COUNT_FOR_N_GRAM][MAX_WORD_LENGTH];
+  int prev_word_codepoint_count[MAX_PREV_WORD_COUNT_FOR_N_GRAM];
+  bool are_beginning_of_sentence[MAX_PREV_WORD_COUNT_FOR_N_GRAM];
+  int prevwords_count = std::min(
+      prev_words.size(), static_cast<size_t>(MAX_PREV_WORD_COUNT_FOR_N_GRAM));
+  for (int i = 0; i < prevwords_count; ++i) {
+    prev_word_codepoint_count[i] = 0;
+    are_beginning_of_sentence[i] = false;
+    int prev_word_size = prev_words[i]->word.size();
+    if (prev_word_size > MAX_WORD_LENGTH) {
+      continue;
+    }
+    for (int j = 0; j < prev_word_size; j++) {
+      prev_word_codepoints[i][j] = (int)((prev_words[i])->word)[j];
+    }
+    prev_word_codepoint_count[i] = prev_word_size;
+    are_beginning_of_sentence[i] = prev_words[i]->is_beginning_of_sentence;
+  }
+  latinime::PrevWordsInfo prev_words_info =
+      latinime::PrevWordsInfo(prev_word_codepoints, prev_word_codepoint_count,
+                              are_beginning_of_sentence, prevwords_count);
+  return prev_words_info;
+}
+
+}  // namespace prediction