text: /*
   * Open Chinese Convert
   *
   * Copyright 2010-2014 BYVoid <byvoid@byvoid.com>
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include "BinaryDict.hpp"
  #include "Lexicon.hpp"
  
  using namespace opencc;
  
  size_t BinaryDict::KeyMaxLength() const {
    size_t maxLength = 0;
    for (const DictEntry* entry : *lexicon) {
      maxLength = std::max(maxLength, entry->KeyLength());
    }
    return maxLength;
  }
  
  void BinaryDict::SerializeToFile(FILE* fp) const {
    string keyBuffer, valueBuffer;
    vector<size_t> keyOffsets, valueOffsets;
    size_t keyTotalLength = 0, valueTotalLength = 0;
    ConstructBuffer(keyBuffer, keyOffsets, keyTotalLength, valueBuffer,
                    valueOffsets, valueTotalLength);
    // Number of items
    size_t numItems = lexicon->Length();
    fwrite(&numItems, sizeof(size_t), 1, fp);
  
    // Data
    fwrite(&keyTotalLength, sizeof(size_t), 1, fp);
    fwrite(keyBuffer.c_str(), sizeof(char), keyTotalLength, fp);
    fwrite(&valueTotalLength, sizeof(size_t), 1, fp);
    fwrite(valueBuffer.c_str(), sizeof(char), valueTotalLength, fp);
  
    size_t keyCursor = 0, valueCursor = 0;
    for (const DictEntry* entry : *lexicon) {
      // Number of values
      size_t numValues = entry->NumValues();
      fwrite(&numValues, sizeof(size_t), 1, fp);
      // Key offset
      size_t keyOffset = keyOffsets[keyCursor++];
      fwrite(&keyOffset, sizeof(size_t), 1, fp);
      // Values offset
      for (size_t i = 0; i < numValues; i++) {
        size_t valueOffset = valueOffsets[valueCursor++];
        fwrite(&valueOffset, sizeof(size_t), 1, fp);
      }
    }
    assert(keyCursor == numItems);
  }
  
  BinaryDictPtr BinaryDict::NewFromFile(FILE* fp) {
    BinaryDictPtr dict(new BinaryDict(LexiconPtr(new Lexicon)));
  
    // Number of items
    size_t numItems;
    size_t unitsRead = fread(&numItems, sizeof(size_t), 1, fp);
    if (unitsRead != 1) {
      throw InvalidFormat("Invalid OpenCC binary dictionary (numItems)");
    }
  
    // Keys
    size_t keyTotalLength;
    unitsRead = fread(&keyTotalLength, sizeof(size_t), 1, fp);
    if (unitsRead != 1) {
      throw InvalidFormat("Invalid OpenCC binary dictionary (keyTotalLength)");
    }
    dict->keyBuffer.resize(keyTotalLength);
    unitsRead = fread(const_cast<char*>(dict->keyBuffer.c_str()), sizeof(char),
                      keyTotalLength, fp);
    if (unitsRead != keyTotalLength) {
      throw InvalidFormat("Invalid OpenCC binary dictionary (keyBuffer)");
    }
  
    // Values
    size_t valueTotalLength;
    unitsRead = fread(&valueTotalLength, sizeof(size_t), 1, fp);
    if (unitsRead != 1) {
      throw InvalidFormat("Invalid OpenCC binary dictionary (valueTotalLength)");
    }
    dict->valueBuffer.resize(valueTotalLength);
    unitsRead = fread(const_cast<char*>(dict->valueBuffer.c_str()), sizeof(char),
                      valueTotalLength, fp);
    if (unitsRead != valueTotalLength) {
      throw InvalidFormat("Invalid OpenCC binary dictionary (valueBuffer)");
    }
  
    // Offsets
    for (size_t i = 0; i < numItems; i++) {
      // Number of values
      size_t numValues;
      unitsRead = fread(&numValues, sizeof(size_t), 1, fp);
      if (unitsRead != 1) {
        throw InvalidFormat("Invalid OpenCC binary dictionary (numValues)");
      }
      // Key offset
      size_t keyOffset;
      unitsRead = fread(&keyOffset, sizeof(size_t), 1, fp);
      if (unitsRead != 1) {
        throw InvalidFormat("Invalid OpenCC binary dictionary (keyOffset)");
      }
      const char* key = dict->keyBuffer.c_str() + keyOffset;
      // Value offset
      vector<const char*> values;
      for (size_t j = 0; j < numValues; j++) {
        size_t valueOffset;
        unitsRead = fread(&valueOffset, sizeof(size_t), 1, fp);
        if (unitsRead != 1) {
          throw InvalidFormat("Invalid OpenCC binary dictionary (valueOffset)");
        }
        const char* value = dict->valueBuffer.c_str() + valueOffset;
        values.push_back(value);
      }
      PtrDictEntry* entry = new PtrDictEntry(key, values);
      dict->lexicon->Add(entry);
    }
  
    return dict;
  }
  
  void BinaryDict::ConstructBuffer(string& keyBuffer, vector<size_t>& keyOffset,
                                   size_t& keyTotalLength, string& valueBuffer,
                                   vector<size_t>& valueOffset,
                                   size_t& valueTotalLength) const {
    keyTotalLength = 0;
    valueTotalLength = 0;
    // Calculate total length
    for (const DictEntry* entry : *lexicon) {
      keyTotalLength += entry->KeyLength() + 1;
      assert(entry->NumValues() != 0);
      if (entry->NumValues() == 1) {
        const auto* svEntry = static_cast<const SingleValueDictEntry*>(entry);
        valueTotalLength += strlen(svEntry->Value()) + 1;
      } else {
        const auto* mvEntry = static_cast<const MultiValueDictEntry*>(entry);
        for (const auto& value : mvEntry->Values()) {
          valueTotalLength += strlen(value) + 1;
        }
      }
    }
    // Write keys and values to buffers
    keyBuffer.resize(keyTotalLength, '\0');
    valueBuffer.resize(valueTotalLength, '\0');
    char* pKeyBuffer = const_cast<char*>(keyBuffer.c_str());
    char* pValueBuffer = const_cast<char*>(valueBuffer.c_str());
    for (const DictEntry* entry : *lexicon) {
      strcpy(pKeyBuffer, entry->Key());
      keyOffset.push_back(pKeyBuffer - keyBuffer.c_str());
      pKeyBuffer += entry->KeyLength() + 1;
      if (entry->NumValues() == 1) {
        const auto* svEntry = static_cast<const SingleValueDictEntry*>(entry);
        strcpy(pValueBuffer, svEntry->Value());
        valueOffset.push_back(pValueBuffer - valueBuffer.c_str());
        pValueBuffer += strlen(svEntry->Value()) + 1;
      } else {
        const auto* mvEntry = static_cast<const MultiValueDictEntry*>(entry);
        for (const auto& value : mvEntry->Values()) {
          strcpy(pValueBuffer, value);
          valueOffset.push_back(pValueBuffer - valueBuffer.c_str());
          pValueBuffer += strlen(value) + 1;
        }
      }
    }
    assert(keyBuffer.c_str() + keyTotalLength == pKeyBuffer);
    assert(valueBuffer.c_str() + valueTotalLength == pValueBuffer);
  }
  