// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// to you 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 "util/faststring.h"

#include <glog/logging.h>

#include <memory>

namespace doris {

void faststring::GrowToAtLeast(size_t newcapacity) {

    // Not enough space, need to reserve more.

    // Don't reserve exactly enough space for the new string -- that makes it

    // too easy to write perf bugs where you get O(n^2) append.

    // Instead, always expand by at least 50%.

    if (newcapacity < capacity_ * 3 / 2) {

        newcapacity = capacity_ * 3 / 2;

    }

    GrowArray(newcapacity);

}

void faststring::GrowArray(size_t newcapacity) {

    DCHECK_GE(newcapacity, capacity_);

    std::unique_ptr<uint8_t[]> newdata(reinterpret_cast<uint8_t*>(Allocator::alloc(newcapacity)));

    if (len_ > 0) {

        memcpy(&newdata[0], &data_[0], len_);

    }

    if (data_ != initial_data_) {

        Allocator::free(data_, capacity_);

    } else {

        ASAN_POISON_MEMORY_REGION(initial_data_, arraysize(initial_data_));

    }

    data_ = newdata.release();

    capacity_ = newcapacity;

    ASAN_POISON_MEMORY_REGION(data_ + len_, capacity_ - len_);

}

void faststring::ShrinkToFitInternal() {

    DCHECK_NE(data_, initial_data_);

    if (len_ <= kInitialCapacity) {

        ASAN_UNPOISON_MEMORY_REGION(initial_data_, len_);

        memcpy(initial_data_, &data_[0], len_);

        Allocator::free(data_, capacity_);

        data_ = initial_data_;

        capacity_ = kInitialCapacity;

    } else {

        std::unique_ptr<uint8_t[]> newdata(reinterpret_cast<uint8_t*>(Allocator::alloc(len_)));

        memcpy(&newdata[0], &data_[0], len_);

        Allocator::free(data_, capacity_);

        data_ = newdata.release();

        capacity_ = len_;

    }

}

} // namespace doris