src/aosp/suggest/policyimpl/dictionary/shortcut/dynamic_shortcut_list_policy.h

/*
 * 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.
 */

#ifndef LATINIME_DYNAMIC_SHORTCUT_LIST_POLICY_H
#define LATINIME_DYNAMIC_SHORTCUT_LIST_POLICY_H

#include <stdint.h>

#include "defines.h"
#include "suggest/core/policy/dictionary_shortcuts_structure_policy.h"
#include "suggest/policyimpl/dictionary/shortcut/shortcut_list_reading_utils.h"
#include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"

namespace latinime {

/*
 * This is a dynamic version of ShortcutListPolicy and supports an additional buffer.
 */
class DynamicShortcutListPolicy : public DictionaryShortcutsStructurePolicy {
 public:
    explicit DynamicShortcutListPolicy(const BufferWithExtendableBuffer *const buffer)
            : mBuffer(buffer) {}

    ~DynamicShortcutListPolicy() {}

    int getStartPos(const int pos) const {
        if (pos == NOT_A_DICT_POS) {
            return NOT_A_DICT_POS;
        }
        return pos + ShortcutListReadingUtils::getShortcutListSizeFieldSize();
    }

    void getNextShortcut(const int maxCodePointCount, int *const outCodePoint,
            int *const outCodePointCount, bool *const outIsWhitelist, bool *const outHasNext,
            int *const pos) const {
        const bool usesAdditionalBuffer = mBuffer->isInAdditionalBuffer(*pos);
        const uint8_t *const buffer = mBuffer->getBuffer(usesAdditionalBuffer);
        if (usesAdditionalBuffer) {
            *pos -= mBuffer->getOriginalBufferSize();
        }
        const ShortcutListReadingUtils::ShortcutFlags flags =
                ShortcutListReadingUtils::getFlagsAndForwardPointer(buffer, pos);
        if (outHasNext) {
            *outHasNext = ShortcutListReadingUtils::hasNext(flags);
        }
        if (outIsWhitelist) {
            *outIsWhitelist = ShortcutListReadingUtils::isWhitelist(flags);
        }
        if (outCodePoint) {
            *outCodePointCount = ShortcutListReadingUtils::readShortcutTarget(
                    buffer, maxCodePointCount, outCodePoint, pos);
        }
        if (usesAdditionalBuffer) {
            *pos += mBuffer->getOriginalBufferSize();
        }
    }

    void skipAllShortcuts(int *const pos) const {
        const bool usesAdditionalBuffer = mBuffer->isInAdditionalBuffer(*pos);
        const uint8_t *const buffer = mBuffer->getBuffer(usesAdditionalBuffer);
        if (usesAdditionalBuffer) {
            *pos -= mBuffer->getOriginalBufferSize();
        }
        const int shortcutListSize = ShortcutListReadingUtils
                ::getShortcutListSizeAndForwardPointer(buffer, pos);
        *pos += shortcutListSize;
        if (usesAdditionalBuffer) {
            *pos += mBuffer->getOriginalBufferSize();
        }
    }

    // Copy shortcuts from the shortcut list that starts at fromPos in mBuffer to toPos in
    // bufferToWrite and advance these positions after the shortcut lists. This returns whether
    // the copy was succeeded or not.
    bool copyAllShortcutsAndReturnIfSucceededOrNot(BufferWithExtendableBuffer *const bufferToWrite,
            int *const fromPos, int *const toPos) const {
        const bool usesAdditionalBuffer = mBuffer->isInAdditionalBuffer(*fromPos);
        if (usesAdditionalBuffer) {
            *fromPos -= mBuffer->getOriginalBufferSize();
        }
        const int shortcutListSize = ShortcutListReadingUtils
                ::getShortcutListSizeAndForwardPointer(mBuffer->getBuffer(usesAdditionalBuffer),
                        fromPos);
        // Copy shortcut list size.
        if (!bufferToWrite->writeUintAndAdvancePosition(
                shortcutListSize + ShortcutListReadingUtils::getShortcutListSizeFieldSize(),
                ShortcutListReadingUtils::getShortcutListSizeFieldSize(), toPos)) {
            return false;
        }
        // Copy shortcut list.
        for (int i = 0; i < shortcutListSize; ++i) {
            const uint8_t data = ByteArrayUtils::readUint8AndAdvancePosition(
                    mBuffer->getBuffer(usesAdditionalBuffer), fromPos);
            if (!bufferToWrite->writeUintAndAdvancePosition(data, 1 /* size */, toPos)) {
                return false;
            }
        }
        if (usesAdditionalBuffer) {
            *fromPos += mBuffer->getOriginalBufferSize();
        }
        return true;
    }

 private:
    DISALLOW_IMPLICIT_CONSTRUCTORS(DynamicShortcutListPolicy);

    const BufferWithExtendableBuffer *const mBuffer;
};
} // namespace latinime
#endif // LATINIME_DYNAMIC_SHORTCUT_LIST_POLICY_H