AttachmentReader.h

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/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *     http://aws.amazon.com/apache2.0/
 *
 * or in the "license" file accompanying this file. This file 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 ALEXA_CLIENT_SDK_AVSCOMMON_AVS_INCLUDE_AVSCOMMON_AVS_ATTACHMENT_ATTACHMENTREADER_H_
#define ALEXA_CLIENT_SDK_AVSCOMMON_AVS_INCLUDE_AVSCOMMON_AVS_ATTACHMENT_ATTACHMENTREADER_H_

#include <chrono>
#include <cstddef>
#include <ostream>

#include "AVSCommon/Utils/SDS/ReaderPolicy.h"

namespace alexaClientSDK {
namespace avsCommon {
namespace avs {
namespace attachment {

class AttachmentReader {
public:
    enum class ReadStatus {
        OK,
        OK_WOULDBLOCK,
        OK_TIMEDOUT,
        OK_OVERRUN_RESET,
        CLOSED,
        ERROR_OVERRUN,
        ERROR_BYTES_LESS_THAN_WORD_SIZE,
        ERROR_INTERNAL
    };

    enum class ClosePoint {
        IMMEDIATELY,
        AFTER_DRAINING_CURRENT_BUFFER
    };

    /*
     * Destructor.
     */
    virtual ~AttachmentReader() = default;

    virtual std::size_t read(
        void* buf,
        std::size_t numBytes,
        ReadStatus* readStatus,
        std::chrono::milliseconds timeoutMs = std::chrono::milliseconds(0)) = 0;

    virtual bool seek(uint64_t offset) = 0;

    virtual uint64_t getNumUnreadBytes() = 0;

    virtual void close(ClosePoint closePoint = ClosePoint::AFTER_DRAINING_CURRENT_BUFFER) = 0;
};

inline std::ostream& operator<<(std::ostream& stream, const AttachmentReader::ReadStatus& status) {
    switch (status) {
        case AttachmentReader::ReadStatus::OK:
            stream << "OK";
            break;
        case AttachmentReader::ReadStatus::OK_WOULDBLOCK:
            stream << "OK_WOULDBLOCK";
            break;
        case AttachmentReader::ReadStatus::OK_TIMEDOUT:
            stream << "OK_TIMEDOUT";
            break;
        case AttachmentReader::ReadStatus::OK_OVERRUN_RESET:
            stream << "OK_OVERRUN_RESET";
            break;
        case AttachmentReader::ReadStatus::CLOSED:
            stream << "CLOSED";
            break;
        case AttachmentReader::ReadStatus::ERROR_BYTES_LESS_THAN_WORD_SIZE:
            stream << "ERROR_BYTES_LESS_THAN_WORD_SIZE";
            break;
        case AttachmentReader::ReadStatus::ERROR_OVERRUN:
            stream << "ERROR_OVERRUN";
            break;
        case AttachmentReader::ReadStatus::ERROR_INTERNAL:
            stream << "ERROR_INTERNAL";
            break;
    }
    return stream;
}

}  // namespace attachment
}  // namespace avs
}  // namespace avsCommon
}  // namespace alexaClientSDK

#endif  // ALEXA_CLIENT_SDK_AVSCOMMON_AVS_INCLUDE_AVSCOMMON_AVS_ATTACHMENT_ATTACHMENTREADER_H_