messagerenderer.h

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// Copyright (C) 2009-2024 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
#ifndef MESSAGERENDERER_H
#define MESSAGERENDERER_H
 
#include <util/buffer.h>
 
#include <boost/noncopyable.hpp>
 
#include <memory>
 
namespace isc {
namespace dns {
// forward declarations
class Name;
class LabelSequence;

class AbstractMessageRenderer {
public:
    enum CompressMode {
        CASE_INSENSITIVE,  
        CASE_SENSITIVE     
    };
protected:


    AbstractMessageRenderer();
 
public:
    virtual ~AbstractMessageRenderer() {}
protected:
    const isc::util::OutputBuffer& getBuffer() const { return (*buffer_); }
    isc::util::OutputBuffer& getBuffer() { return (*buffer_); }
private:
    isc::util::OutputBuffer local_buffer_;

    isc::util::OutputBuffer* buffer_;
public:


    const void* getData() const {
        return (buffer_->getData());
    }

    size_t getLength() const {
        return (buffer_->getLength());
    }

    virtual bool isTruncated() const = 0;

    virtual size_t getLengthLimit() const = 0;

    virtual CompressMode getCompressMode() const = 0;



    void setBuffer(isc::util::OutputBuffer* buffer);

    virtual void setTruncated() = 0;

    virtual void setLengthLimit(size_t len) = 0;

    virtual void setCompressMode(CompressMode mode) = 0;



    void skip(size_t len) {
        buffer_->skip(len);
    }

    void trim(size_t len) {
        buffer_->trim(len);
    }

    virtual void clear();

    void writeUint8(const uint8_t data) {
        buffer_->writeUint8(data);
    }

    void writeUint16(uint16_t data) {
        buffer_->writeUint16(data);
    }

    void writeUint16At(uint16_t data, size_t pos) {
        buffer_->writeUint16At(data, pos);
    }

    void writeUint32(uint32_t data) {
        buffer_->writeUint32(data);
    }

    void writeData(const void *data, size_t len) {
        buffer_->writeData(data, len);
    }

    virtual void writeName(const Name& name, bool compress = true) = 0;

    virtual void writeName(const LabelSequence& ls, bool compress = true) = 0;
};

class MessageRenderer : public AbstractMessageRenderer,
    public boost::noncopyable { // Can crash if copied
public:
    using AbstractMessageRenderer::CASE_INSENSITIVE;
    using AbstractMessageRenderer::CASE_SENSITIVE;
 
    MessageRenderer();
 
    virtual ~MessageRenderer();
    virtual bool isTruncated() const;
    virtual size_t getLengthLimit() const;
    virtual CompressMode getCompressMode() const;
    virtual void setTruncated();
    virtual void setLengthLimit(size_t len);

    virtual void setCompressMode(CompressMode mode);
 
    virtual void clear();
    virtual void writeName(const Name& name, bool compress = true);
    virtual void writeName(const LabelSequence& ls, bool compress = true);
 
private:
    struct MessageRendererImpl;
    std::unique_ptr<MessageRendererImpl> impl_;
};
}
}
#endif // MESSAGERENDERER_H