pdf_object.cpp

来自「ncbi源码」· C++ 代码 · 共 252 行

/*
 * ===========================================================================
 * PRODUCTION $Log: pdf_object.cpp,v $
 * PRODUCTION Revision 1000.1  2004/06/01 21:03:45  gouriano
 * PRODUCTION PRODUCTION: UPGRADED [GCC34_MSVC7] Dev-tree R1.10
 * PRODUCTION
 * ===========================================================================
 */

/*  $Id: pdf_object.cpp,v 1000.1 2004/06/01 21:03:45 gouriano Exp $
 * ===========================================================================
 *
 *                            PUBLIC DOMAIN NOTICE
 *               National Center for Biotechnology Information
 *
 *  This software / database is a "United States Government Work" under the
 *  terms of the United States Copyright Act.  It was written as part of
 *  the author's official duties as a United States Government employee and
 *  thus cannot be copyrighted.  This software / database is freely available
 *  to the public for use. The National Library of Medicine and the U.S.
 *  Government have not placed any restriction on its use or reproduction.
 *
 *  Although all reasonable efforts have been taken to ensure the accuracy
 *  and reliability of the software and data, the NLM and the U.S.
 *  Government do not and cannot warrant the performance or results that
 *  may be obtained by using this software or data. The NLM and the U.S.
 *  Government disclaim all warranties, express or implied, including
 *  warranties of performance, merchantability or fitness for any particular
 *  purpose.
 *
 *  Please cite the author in any work or product based on this material.
 *
 * ===========================================================================
 *
 * Authors:  Peter Meric
 *
 * File Description:
 *   CPdfObject - Stream for output of Adobe PDF objects
 */


#include <ncbi_pch.hpp>
#include "pdf_object.hpp"
#include "pdf_object_writer.hpp"
#include <util/compress/stream.hpp>
#include <util/compress/zlib.hpp>
#include <util/ascii85.hpp>


BEGIN_NCBI_SCOPE



CPdfObject::CPdfObject(unsigned int obj_num,
                       unsigned int generation,
                       bool allowCompression
                      )
    : m_ObjNum(obj_num),
      m_Generation(generation),
      m_Separator("\n"),
      m_AllowCompression(allowCompression)
{
}


CPdfObject::~CPdfObject()
{
    m_Buffer.freeze(false);
}


enum EPdfObjectFormat
{
    eUncompressed,
    eCompressed
};


unsigned int CPdfObject::GetObjNum(void) const
{
    return m_ObjNum;
}


unsigned int CPdfObject::GetGeneration(void) const
{
    return m_Generation;
}


void CPdfObject::PrintTo(CNcbiOstream& stream) const
{
    // start the page content object
    stream << m_ObjNum << ' ' << m_Generation << " obj" << endl;
    const_cast<CPdfObject*>(this)->x_PrintTo(stream);
    stream << "endobj" << endl;
}


void CPdfObject::x_PrintTo(CNcbiOstream& stream)
{
    string::size_type os_len = m_Buffer.pcount();
    const bool compress = m_AllowCompression && os_len > 4096;
    AutoPtr< char, ArrayDeleter<char> > strmbuf;

    if (os_len > 0) {
        // add the stream contents
        if (compress) {
            const size_t cbuflen = size_t(os_len * 1.03);
            AutoPtr< char, ArrayDeleter<char> > cbuf(new char[cbuflen]);
            const string str = m_Buffer.str();

            // compress the data
            CZipCompression c;
            unsigned int len;
            c.CompressBuffer(str.data(), os_len, cbuf.get(), cbuflen, &len);

            // encode the data using ASCII-85
            // ASCII-85 encoding produces five ASCII characters for
            // every four bytes of binary data
            const size_t buflen = size_t(len * 1.3);
            strmbuf.reset(new char[buflen]);
            os_len = CAscii85::s_Encode(cbuf.get(), len, strmbuf.get(), buflen);

            // add stream-related attributes to dictionary
            m_Dictionary["Length"] = new CPdfNumber(int(os_len));
            m_Dictionary["Filter"] = new CPdfObj("[/ASCII85Decode/FlateDecode]");
        }
        else {
            // add stream-related attributes to dictionary
            // don't count the last newline in the stream as part of the length
            m_Dictionary["Length"] = new CPdfNumber(int(os_len - 1));
        }
    }

    // write dictionary
    stream << m_Dictionary << endl;

    // write the stream
    if (os_len > 0) {
        stream << "stream" << endl;

        // add the stream contents
        if (compress && strmbuf.get()) {
            const unsigned int line_len = 72;
            const char* ptr = strmbuf.get();
            size_t l = os_len;
            for ( ; l > line_len; l -= line_len, ptr += line_len) {
                stream.write(ptr, line_len) << pdfeol;
            }
            stream.write(ptr, l) << pdfeol;
        }
        else {
            // write uncompressed stream
            stream << string(m_Buffer.str(), os_len);
        }
        stream << "endstream" << endl;
    }
}


CPdfDictionary& CPdfObject::GetDictionary(void)
{
    return m_Dictionary;
}


CPdfObject::TPdfObjRef& CPdfObject::operator[](const string& key)
{
    return m_Dictionary[key];
}


CPdfObject& CPdfObject::operator<<(CPdfObject& (*pf)(CPdfObject&))
{
    return (*pf)(*this);
}


CNcbiOstream& CPdfObject::GetWriteBuffer(void)
{
    return m_Buffer;
}


string CPdfObject::GetSeparator(void) const
{
    return m_Separator;
}


CPdfTrailer::CPdfTrailer() : CPdfObject(0)
{
}


CPdfTrailer::~CPdfTrailer()
{
}


void CPdfTrailer::PrintTo(CNcbiOstream& stream) const
{
    stream << "trailer" << endl;
    const_cast<CPdfTrailer*>(this)->x_PrintTo(stream);
}



END_NCBI_SCOPE


/*
 * ===========================================================================
 * $Log: pdf_object.cpp,v $
 * Revision 1000.1  2004/06/01 21:03:45  gouriano
 * PRODUCTION: UPGRADED [GCC34_MSVC7] Dev-tree R1.10
 *
 * Revision 1.10  2004/05/21 22:27:50  gorelenk
 * Added PCH ncbi_pch.hpp
 *
 * Revision 1.9  2003/07/16 20:04:17  meric
 * Added ASCII-85 encoding of compressed stream data
 *
 * Revision 1.8  2003/07/16 15:42:30  meric
 * Add flag to specify if object may be compressed
 *
 * Revision 1.7  2003/07/15 14:49:51  meric
 * Compress streams longer than 4KB
 *
 * Revision 1.6  2003/06/25 18:02:51  meric
 * Source rearrangement: move "private" headers into the src/ tree
 *
 * Revision 1.5  2003/06/24 15:54:43  meric
 * Fixed: Cast Length value to int before adding to object dictionary
 *
 * Revision 1.4  2003/06/18 17:25:39  meric
 * Final phase of print reorg: remove dependence on gui/opengl and OpenGL
 *
 * Revision 1.3  2003/06/16 19:19:36  meric
 * Fixed: CPdfTrailer c'tor passes 0 instead of -1 to avoid unsigned warning
 *
 * Revision 1.2  2003/06/16 12:44:52  dicuccio
 * Clean-up after initial commit
 *
 * Revision 1.1  2003 / 06 / 13 18:13:56  meric
 * Initial version
 *
 *
 * ===========================================================================
 */