File indexing completed on 2024-04-28 04:18:51

 // vim: set tabstop=4 shiftwidth=4 expandtab:
 /*
 Gwenview: an image viewer
 Copyright 2008 Aurélien Gâteau <agateau@kde.org>
 
 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Cambridge, MA 02110-1301, USA.
 
 */
 // Self
 #include "iodevicejpegsourcemanager.h"
 
 // Qt
 #include <QIODevice>
 
 // KF
 
 // libjpeg
 #include <cstdio>
 #define XMD_H
 extern "C" {
 #include <jpeglib.h>
 }
 
 // Local
 #include "gwenview_lib_debug.h"
 
 namespace Gwenview
 {
 namespace IODeviceJpegSourceManager
 {
 #define SOURCE_MANAGER_BUFFER_SIZE 4096
 struct IODeviceJpegSourceManager : public jpeg_source_mgr {
     QIODevice *mIODevice;
     JOCTET mBuffer[SOURCE_MANAGER_BUFFER_SIZE];
 };
 
 static boolean fill_input_buffer(j_decompress_ptr cinfo)
 {
     auto src = static_cast<IODeviceJpegSourceManager *>(cinfo->src);
     Q_ASSERT(src->mIODevice);
     int readSize = src->mIODevice->read((char *)src->mBuffer, SOURCE_MANAGER_BUFFER_SIZE);
     if (readSize > 0) {
         src->next_input_byte = src->mBuffer;
         src->bytes_in_buffer = readSize;
     } else {
         /**
          * JPEG file is broken. We feed the decoder with fake EOI, as specified
          * in the libjpeg documentation.
          */
         static JOCTET fakeEOI[2] = {JOCTET(0xFF), JOCTET(JPEG_EOI)};
         qCWarning(GWENVIEW_LIB_LOG) << "Image is incomplete";
         cinfo->src->next_input_byte = fakeEOI;
         cinfo->src->bytes_in_buffer = 2;
     }
     return true;
 }
 
 static void init_source(j_decompress_ptr cinfo)
 {
     fill_input_buffer(cinfo);
 }
 
 static void skip_input_data(j_decompress_ptr cinfo, long num_bytes)
 {
     if (num_bytes > 0) {
         while (num_bytes > (long)cinfo->src->bytes_in_buffer) {
             num_bytes -= (long)cinfo->src->bytes_in_buffer;
             fill_input_buffer(cinfo);
             /**
              * we assume that fill_input_buffer will never return FALSE, so
              * suspension need not be handled.
              */
         }
         cinfo->src->next_input_byte += (size_t)num_bytes;
         cinfo->src->bytes_in_buffer -= (size_t)num_bytes;
     }
 }
 
 static void term_source(j_decompress_ptr)
 {
 }
 
 void setup(j_decompress_ptr cinfo, QIODevice *ioDevice)
 {
     Q_ASSERT(!cinfo->src);
     auto src = (IODeviceJpegSourceManager *)(*cinfo->mem->alloc_small)((j_common_ptr)cinfo, JPOOL_PERMANENT, sizeof(IODeviceJpegSourceManager));
     cinfo->src = src;
 
     src->init_source = init_source;
     src->fill_input_buffer = fill_input_buffer;
     src->skip_input_data = skip_input_data;
     src->resync_to_restart = jpeg_resync_to_restart;
     src->term_source = term_source;
 
     src->mIODevice = ioDevice;
 }
 
 } // IODeviceJpegSourceManager namespace
 } // Gwenview namespace