| /* |
| * Copyright (C) 2013, The Android Open Source Project |
| * |
| * 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 "dictionary/utils/sparse_table.h" |
| |
| namespace latinime { |
| |
| const int SparseTable::NOT_EXIST = -1; |
| const int SparseTable::INDEX_SIZE = 4; |
| |
| bool SparseTable::contains(const int id) const { |
| const int readingPos = getPosInIndexTable(id); |
| if (id < 0 || mIndexTableBuffer->getTailPosition() <= readingPos) { |
| return false; |
| } |
| const int index = mIndexTableBuffer->readUint(INDEX_SIZE, readingPos); |
| return index != NOT_EXIST; |
| } |
| |
| uint32_t SparseTable::get(const int id) const { |
| const int indexTableReadingPos = getPosInIndexTable(id); |
| const int index = mIndexTableBuffer->readUint(INDEX_SIZE, indexTableReadingPos); |
| const int contentTableReadingPos = getPosInContentTable(id, index); |
| if (contentTableReadingPos < 0 |
| || contentTableReadingPos >= mContentTableBuffer->getTailPosition()) { |
| AKLOGE("contentTableReadingPos(%d) is invalid. id: %d, index: %d", |
| contentTableReadingPos, id, index); |
| return NOT_A_DICT_POS; |
| } |
| const int contentValue = mContentTableBuffer->readUint(mDataSize, contentTableReadingPos); |
| return contentValue == NOT_EXIST ? NOT_A_DICT_POS : contentValue; |
| } |
| |
| bool SparseTable::set(const int id, const uint32_t value) { |
| const int posInIndexTable = getPosInIndexTable(id); |
| // Extends the index table if needed. |
| int tailPos = mIndexTableBuffer->getTailPosition(); |
| while (tailPos <= posInIndexTable) { |
| if (!mIndexTableBuffer->writeUintAndAdvancePosition(NOT_EXIST, INDEX_SIZE, &tailPos)) { |
| AKLOGE("cannot extend index table. tailPos: %d to: %d", tailPos, posInIndexTable); |
| return false; |
| } |
| } |
| if (contains(id)) { |
| // The entry is already in the content table. |
| const int index = mIndexTableBuffer->readUint(INDEX_SIZE, posInIndexTable); |
| if (!mContentTableBuffer->writeUint(value, mDataSize, getPosInContentTable(id, index))) { |
| AKLOGE("cannot update value %d. pos: %d, tailPos: %d, mDataSize: %d", value, |
| getPosInContentTable(id, index), mContentTableBuffer->getTailPosition(), |
| mDataSize); |
| return false; |
| } |
| return true; |
| } |
| // The entry is not in the content table. |
| // Create new entry in the content table. |
| const int index = getIndexFromContentTablePos(mContentTableBuffer->getTailPosition()); |
| if (!mIndexTableBuffer->writeUint(index, INDEX_SIZE, posInIndexTable)) { |
| AKLOGE("cannot write index %d. pos %d", index, posInIndexTable); |
| return false; |
| } |
| // Write a new block that containing the entry to be set. |
| int writingPos = getPosInContentTable(0 /* id */, index); |
| for (int i = 0; i < mBlockSize; ++i) { |
| if (!mContentTableBuffer->writeUintAndAdvancePosition(NOT_EXIST, mDataSize, |
| &writingPos)) { |
| AKLOGE("cannot write content table to extend. writingPos: %d, tailPos: %d, " |
| "mDataSize: %d", writingPos, mContentTableBuffer->getTailPosition(), mDataSize); |
| return false; |
| } |
| } |
| return mContentTableBuffer->writeUint(value, mDataSize, getPosInContentTable(id, index)); |
| } |
| |
| int SparseTable::getIndexFromContentTablePos(const int contentTablePos) const { |
| return contentTablePos / mDataSize / mBlockSize; |
| } |
| |
| int SparseTable::getPosInIndexTable(const int id) const { |
| return (id / mBlockSize) * INDEX_SIZE; |
| } |
| |
| int SparseTable::getPosInContentTable(const int id, const int index) const { |
| const int offset = id % mBlockSize; |
| return (index * mBlockSize + offset) * mDataSize; |
| } |
| |
| } // namespace latinime |