xref: /base/msdp/device_status/utils/ipc/src/circle_stream_buffer.cpp

/*
 * Copyright (c) 2022-2023 Huawei Device Co., Ltd.
 * 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 "circle_stream_buffer.h"

namespace OHOS {
namespace Msdp {
void CircleStreamBuffer::CopyDataToBegin()
{
    int32_t residualSize = ResidualSize();
    if (residualSize > 0 && rPos_ > 0) {
        int32_t pos = 0;
        for (int32_t i = rPos_; i <= wPos_;) {
            szBuff_[pos++] = szBuff_[i++];
        }
    }
    FI_HILOGD("ResidualSize:%{public}d rPos:%{public}d wPos:%{public}d", residualSize, rPos_, wPos_);
    rPos_ = 0;
    wPos_ = residualSize;
}

bool CircleStreamBuffer::CheckWrite(size_t size)
{
    int32_t bufferSize = static_cast<int32_t>(size);
    int32_t availableSize = GetAvailableBufSize();
    if (bufferSize > availableSize && rPos_ > 0) {
        CopyDataToBegin();
        availableSize = GetAvailableBufSize();
    }
    return (availableSize >= bufferSize);
}

bool CircleStreamBuffer::Write(const char *buf, size_t size)
{
    if (!CheckWrite(size)) {
        FI_HILOGE("Out of buffer memory, availableSize:%{public}d, size:%{public}zu,"
            "residualSize:%{public}d, rPos:%{public}d, wPos:%{public}d",
            GetAvailableBufSize(), size, ResidualSize(), rPos_, wPos_);
        return false;
    }
    return StreamBuffer::Write(buf, size);
}
} // namespace Msdp
} // namespace OHOS